Version 1 of the Hubble Source Catalog

Science.gov (United States)

Whitmore, Bradley C.; Allam, Sahar S.; Budavári, Tamás; Casertano, Stefano; Downes, Ronald A.; Donaldson, Thomas; Fall, S. Michael; Lubow, Stephen H.; Quick, Lee; Strolger, Louis-Gregory; Wallace, Geoff; White, Richard L.

2016-06-01

The Hubble Source Catalog is designed to help optimize science from the Hubble Space Telescope (HST) by combining the tens of thousands of visit-based source lists in the Hubble Legacy Archive (HLA) into a single master catalog. Version 1 of the Hubble Source Catalog includes WFPC2, ACS/WFC, WFC3/UVIS, and WFC3/IR photometric data generated using SExtractor software to produce the individual source lists. The catalog includes roughly 80 million detections of 30 million objects involving 112 different detector/filter combinations, and about 160,000 HST exposures. Source lists from Data Release 8 of the HLA are matched using an algorithm developed by Budavári & Lubow. The mean photometric accuracy for the catalog as a whole is better than 0.10 mag, with relative accuracy as good as 0.02 mag in certain circumstances (e.g., bright isolated stars). The relative astrometric residuals are typically within 10 mas, with a value for the mode (I.e., most common value) of 2.3 mas. The absolute astrometric accuracy is better than 0''\\hspace{-0.5em}. 1 for most sources, but can be much larger for a fraction of fields that could not be matched to the PanSTARRS, SDSS, or 2MASS reference systems. In this paper we describe the database design with emphasis on those aspects that enable the users to fully exploit the catalog while avoiding common misunderstandings and potential pitfalls. We provide usage examples to illustrate some of the science capabilities and data quality characteristics, and briefly discuss plans for future improvements to the Hubble Source Catalog.

BEAUTY IN THE EYE OF HUBBLE

Science.gov (United States)

2002-01-01

A dying star, IC 4406, dubbed the 'Retina Nebula' is revealed in this month's Hubble Heritage image. Like many other so-called planetary nebulae, IC 4406 exhibits a high degree of symmetry; the left and right halves of the Hubble image are nearly mirror images of the other. If we could fly around IC4406 in a starship, we would see that the gas and dust form a vast donut of material streaming outward from the dying star. From Earth, we are viewing the donut from the side. This side view allows us to see the intricate tendrils of dust that have been compared to the eye's retina. In other planetary nebulae, like the Ring Nebula (NGC 6720), we view the donut from the top. The donut of material confines the intense radiation coming from the remnant of the dying star. Gas on the inside of the donut is ionized by light from the central star and glows. Light from oxygen atoms is rendered blue in this image; hydrogen is shown as green, and nitrogen as red. The range of color in the final image shows the differences in concentration of these three gases in the nebula. Unseen in the Hubble image is a larger zone of neutral gas that is not emitting visible light, but which can be seen by radio telescopes. One of the most interesting features of IC 4406 is the irregular lattice of dark lanes that criss-cross the center of the nebula. These lanes are about 160 astronomical units wide (1 astronomical unit is the distance between the Earth and Sun). They are located right at the boundary between the hot glowing gas that produces the visual light imaged here and the neutral gas seen with radio telescopes. We see the lanes in silhouette because they have a density of dust and gas that is a thousand times higher than the rest of the nebula. The dust lanes are like a rather open mesh veil that has been wrapped around the bright donut. The fate of these dense knots of material is unknown. Will they survive the nebula's expansion and become dark denizens of the space between the stars

Hubble induced mass after inflation in spectator field models

Energy Technology Data Exchange (ETDEWEB)

Fujita, Tomohiro [Stanford Institute for Theoretical Physics and Department of Physics, Stanford University, Stanford, CA 94306 (United States); Harigaya, Keisuke, E-mail: tomofuji@stanford.edu, E-mail: keisukeh@icrr.u-tokyo.ac.jp [Department of Physics, University of California, Berkeley, CA 94720 (United States)

2016-12-01

Spectator field models such as the curvaton scenario and the modulated reheating are attractive scenarios for the generation of the cosmic curvature perturbation, as the constraints on inflation models are relaxed. In this paper, we discuss the effect of Hubble induced masses on the dynamics of spectator fields after inflation. We pay particular attention to the Hubble induced mass by the kinetic energy of an oscillating inflaton, which is generically unsuppressed but often overlooked. In the curvaton scenario, the Hubble induced mass relaxes the constraint on the property of the inflaton and the curvaton, such as the reheating temperature and the inflation scale. We comment on the implication of our discussion for baryogenesis in the curvaton scenario. In the modulated reheating, the predictions of models e.g. the non-gaussianity can be considerably altered. Furthermore, we propose a new model of the modulated reheating utilizing the Hubble induced mass which realizes a wide range of the local non-gaussianity parameter.

Testing the isotropy of the Hubble expansion

OpenAIRE

Migkas, K.; Plionis, M.

2016-01-01

Abstract: We have used the Union2.1 SNIa compilation to search for possible Hubble expansion anisotropies, dividing the sky in 9 solid angles containing roughly the same number of SNIa, as well as in two Galactic hemispheres. We identified only one sky region, containing 82 SNIa (~15% of total sample with z > 0.02), that indeed appears to share a Hubble expansion significantly different from the rest of the sample. However, this behaviour can be attributed to the joint "erratic" behaviour of ...

The muleskinner and the stars the life and times of Milton la Salle Humason, astronomer

CERN Document Server

Voller, Ronald L

2016-01-01

Milt Humason’s unlikely story began on the shores of the Mississippi River in Winona, Minnesota, in 1891 and led to the foot of Mount Wilson outside Los Angeles, California, twelve years later. Captivated by his surroundings, the mountain would become the backdrop for his life and career over the next six decades as he first helped build George Ellery Hale’s observatory on the summit and then rose to become one of that institution’s leading figures through the first half of the twentieth century.   The story chronicles Humason’s life on Mount Wilson, from his first trip to the mountain to his days as a muleskinner, leading teams of mules hauling supplies to the summit during the construction of the observatory, and follows him through his extraordinary career in spectroscopy, working beside Edwin Hubble as the two helped to reconstruct our concept of the universe, despite having no formal education beyond the eighth grade. His work, which included assisting in the formulation of Hubble’s Law of red...

Hubble 2020: Outer Planet Atmospheres Legacy (OPAL) Program

Science.gov (United States)

Simon, Amy

2017-08-01

Long time base observations of the outer planets are critical in understanding the atmospheric dynamics and evolution of the gas giants. We propose yearly monitoring of each giant planet for the remainder of Hubble's lifetime to provide a lasting legacy of increasingly valuable data for time-domain studies. The Hubble Space Telescope is a unique asset to planetary science, allowing high spatial resolution data with absolute photometric knowledge. For the outer planets, gas/ice giant planets Jupiter, Saturn, Uranus and Neptune, many phenomena happen on timescales of years to decades, and the data we propose are beyond the scope of a typical GO program. Hubble is the only platform that can provide high spatial resolution global studies of cloud coloration, activity, and motion on a consistent time basis to help constrain the underlying mechanics.

Carnegie Hubble Program: A Mid-Infrared Calibration of the Hubble Constant

Science.gov (United States)

Freedman, Wendy L.; Madore, Barry F.; Scowcroft, Victoria; Burns, Chris; Monson, Andy; Persson, S. Eric; Seibert, Mark; Rigby, Jane

2012-01-01

Using a mid-infrared calibration of the Cepheid distance scale based on recent observations at 3.6 micrometers with the Spitzer Space Telescope, we have obtained a new, high-accuracy calibration of the Hubble constant. We have established the mid-IR zero point of the Leavitt law (the Cepheid period-luminosity relation) using time-averaged 3.6 micrometers data for 10 high-metallicity, MilkyWay Cepheids having independently measured trigonometric parallaxes. We have adopted the slope of the PL relation using time-averaged 3.6micrometers data for 80 long-period Large Magellanic Cloud (LMC) Cepheids falling in the period range 0.8 < log(P) < 1.8.We find a new reddening-corrected distance to the LMC of 18.477 +/- 0.033 (systematic) mag. We re-examine the systematic uncertainties in H(sub 0), also taking into account new data over the past decade. In combination with the new Spitzer calibration, the systematic uncertainty in H(sub 0) over that obtained by the Hubble Space Telescope Key Project has decreased by over a factor of three. Applying the Spitzer calibration to the Key Project sample, we find a value of H(sub 0) = 74.3 with a systematic uncertainty of +/-2.1 (systematic) kilometers per second Mpc(sup -1), corresponding to a 2.8% systematic uncertainty in the Hubble constant. This result, in combination with WMAP7measurements of the cosmic microwave background anisotropies and assuming a flat universe, yields a value of the equation of state for dark energy, w(sub 0) = -1.09 +/- 0.10. Alternatively, relaxing the constraints on flatness and the numbers of relativistic species, and combining our results with those of WMAP7, Type Ia supernovae and baryon acoustic oscillations yield w(sub 0) = -1.08 +/- 0.10 and a value of N(sub eff) = 4.13 +/- 0.67, mildly consistent with the existence of a fourth neutrino species.

HUBBLE SPIES MOST DISTANT SUPERNOVA EVER SEEN

Science.gov (United States)

2002-01-01

Using NASA's Hubble Space Telescope, astronomers pinpointed a blaze of light from the farthest supernova ever seen, a dying star that exploded 10 billion years ago. The detection and analysis of this supernova, called 1997ff, is greatly bolstering the case for the existence of a mysterious form of dark energy pervading the cosmos, making galaxies hurl ever faster away from each other. The supernova also offers the first glimpse of the universe slowing down soon after the Big Bang, before it began speeding up. This panel of images, taken with the Wide Field and Planetary Camera 2, shows the supernova's cosmic neighborhood; its home galaxy; and the dying star itself. Astronomers found this supernova in 1997 during a second look at the northern Hubble Deep Field [top panel], a tiny region of sky first explored by the Hubble telescope in 1995. The image shows the myriad of galaxies Hubble spied when it peered across more than 10 billion years of time and space. The white box marks the area where the supernova dwells. The photo at bottom left is a close-up view of that region. The white arrow points to the exploding star's home galaxy, a faint elliptical. Its redness is due to the billions of old stars residing there. The picture at bottom right shows the supernova itself, distinguished by the white dot in the center. Although this stellar explosion is among the brightest beacons in the universe, it could not be seen directly in the Hubble images. The stellar blast is so distant from Earth that its light is buried in the glow of its host galaxy. To find the supernova, astronomers compared two pictures of the 'deep field' taken two years apart. One image was of the original Hubble Deep Field; the other, the follow-up deep-field picture taken in 1997. Using special computer software, astronomers then measured the light from the galaxies in both images. Noting any changes in light output between the two pictures, the computer identified a blob of light in the 1997 picture

Dismantling Hubble's Legacy?

OpenAIRE

Way, Michael J.

2013-01-01

Edwin Hubble is famous for a number of discoveries that are well known to amateur and professional astronomers, students and the general public. The origins of these discoveries are examined and it is demonstrated that, in each case, a great deal of supporting evidence was already in place. In some cases the discoveries had either already been made, or competing versions were not adopted for complex scientific and sociological reasons.

New Hubble Servicing Mission to upgrade instruments

Science.gov (United States)

2006-10-01

The history of the NASA/ESA Hubble Space Telescope is dominated by the familiar sharp images and amazing discoveries that have had an unprecedented scientific impact on our view of the world and our understanding of the universe. Nevertheless, such important contributions to science and humankind have only been possible as result of regular upgrades and enhancements to Hubble’s instrumentation. Using the Space Shuttle for this fifth Servicing Mission underlines the important role that astronauts have played and continue to play in increasing the Space Telescope’s lifespan and scientific power. Since the loss of Columbia in 2003, the Shuttle has been successfully launched on three missions, confirming that improvements made to it have established the required high level of safety for the spacecraft and its crew. “There is never going to be an end to the science that we can do with a machine like Hubble”, says David Southwood, ESA’s Director of Science. “Hubble is our way of exploring our origins. Everyone should be proud that there is a European element to it and that we all are part of its success at some level.” This Servicing Mission will not just ensure that Hubble can function for perhaps as much as another ten years; it will also increase its capabilities significantly in key areas. This highly visible mission is expected to take place in 2008 and will feature several space walks. As part of the upgrade, two new scientific instruments will be installed: the Cosmic Origins Spectrograph and Wide Field Camera 3. Each has advanced technology sensors that will dramatically improve Hubble’s potential for discovery and enable it to observe faint light from the youngest stars and galaxies in the universe. With such an astounding increase in its science capabilities, this orbital observatory will continue to penetrate the most distant regions of outer space and reveal breathtaking phenomena. “Today, Hubble is producing more science than ever before in

Finding our Origins with the Hubble and James Webb Space Telescopes

Science.gov (United States)

Gardner, Jonathan P.

2009-01-01

NASA is planning a successor to the Hubble Space Telescope designed to study the origins of galaxies, stars, planets and life in the universe. In this talk, Dr. Gardner will discuss the origin and evolution of galaxies, beginning with the Big Bang and tracing what we have learned with Hubble through to the present day. He will show that results from studies with Hubble have led to plans for its successor, the James Webb Space Telescope. Webb is scheduled to launch in 2014, and is designed to find the first galaxies that formed in the distant past and to penetrate the dusty clouds of gas where stars are still forming today. He will compare Webb to Hubble, and discuss recent progress in the construction of the observatory.

Replacement vs. Renovation: The Reincarnation of Hubble Middle School

Science.gov (United States)

Ogurek, Douglas J.

2010-01-01

At the original Hubble Middle School, neither the views (a congested Roosevelt Road and glimpses of downtown Wheaton) nor the century-old facility that offered them was very inspiring. Built at the start of the 20th century, the 250,000-square-foot building was converted from Wheaton Central High School to Hubble Middle School in the early 1980s.…

A Hubble Diagram for Quasars

Directory of Open Access Journals (Sweden)

Susanna Bisogni

2018-01-01

Full Text Available The cosmological model is at present not tested between the redshift of the farthest observed supernovae (z ~ 1.4 and that of the Cosmic Microwave Background (z ~ 1,100. Here we introduce a new method to measure the cosmological parameters: we show that quasars can be used as “standard candles” by employing the non-linear relation between their intrinsic UV and X-ray emission as an absolute distance indicator. We built a sample of ~1,900 quasars with available UV and X-ray observations, and produced a Hubble Diagram up to z ~ 5. The analysis of the quasar Hubble Diagram, when used in combination with supernovae, provides robust constraints on the matter and energy content in the cosmos. The application of this method to forthcoming, larger quasar samples, will also provide tight constraints on the dark energy equation of state and its possible evolution with time.

Delivering Hubble Discoveries to the Classroom

Science.gov (United States)

Eisenhamer, B.; Villard, R.; Weaver, D.; Cordes, K.; Knisely, L.

2013-04-01

Today's classrooms are significantly influenced by current news events, delivered instantly into the classroom via the Internet. Educators are challenged daily to transform these events into student learning opportunities. In the case of space science, current news events may be the only chance for educators and students to explore the marvels of the Universe. Inspired by these circumstances, the education and news teams developed the Star Witness News science content reading series. These online news stories (also available in downloadable PDF format) mirror the content of Hubble press releases and are designed for upper elementary and middle school level readers to enjoy. Educators can use Star Witness News stories to reinforce students' reading skills while exposing students to the latest Hubble discoveries.

Cataclysmic variables, Hubble-Sandage variables and eta Carinae

International Nuclear Information System (INIS)

Bath, G.T.

1980-01-01

The Hubble-Sandage variables are the most luminous stars in external galaxies. They were first investigated by Hubble and Sandage (1953) for use as distance indicators. Their main characteristics are high luminosity, blue colour indices, and irregular variability. Spectroscopically they show hydrogen and helium in emission with occasionally weaker FeII and [FeII], and no Balmer jump (Humphreys 1975, 1978). In this respect they closely resemble cataclysmic variables, particularly dwarf novae. In the quiescent state dwarf novae show broad H and HeI, together with a strong UV continuum. In contrast to the spectroscopic similarities, the luminosities could hardly differ more. Rather than being the brightest stars known, quiescent dwarf novae are as faint or fainter than the sun. It is suggested that the close correspondence between the spectral appearance of the two classes combined with the difference in luminosity is well accounted for by a model of Hubble-Sandage variables in which the same physical processes are occurring, but on a larger scale. (Auth.)

Cosmic Collisions The Hubble Atlas of Merging Galaxies

CERN Document Server

Christensen, Lars Lindberg; Martin, Davide

2009-01-01

Lars Lindberg Christensen, Raquel Yumi Shida & Davide De Martin Cosmic Collisions: The Hubble Atlas of Merging Galaxies Like majestic ships in the grandest night, galaxies can slip ever closer until their mutual gravitational interaction begins to mold them into intricate figures that are finally, and irreversibly, woven together. It is an immense cosmic dance, choreographed by gravity. Cosmic Collisions contains a hundred new, many thus far unpublished, images of colliding galaxies from the NASA/ESA Hubble Space Telescope. It is believed that many present-day galaxies, including the Milky Way, were assembled from such a coalescence of smaller galaxies, occurring over billions of years. Triggered by the colossal and violent interaction between the galaxies, stars form from large clouds of gas in firework bursts, creating brilliant blue star clusters. The importance of these cosmic encounters reaches far beyond the stunning Hubble images. They may, in fact, be among the most important processes that shape ...

Hubble expansion in static spacetime

International Nuclear Information System (INIS)

Rossler, Otto E.; Froehlich, Dieter; Movassagh, Ramis; Moore, Anthony

2007-01-01

A recently proposed mechanism for light-path expansion in a static spacetime is based on the moving-lenses paradigm. Since the latter is valid independently of whether space expands or not, a static universe can be used to better see the implications. The moving-lenses paradigm is related to the paradigm of dynamical friction. If this is correct, a Hubble-like law is implicit. It is described quantitatively. A bent in the Hubble-like line is predictably implied. The main underlying assumption is Price's Principle (PI 3 ). If the theory is sound, the greatest remaining problem in cosmology becomes the origin of hydrogen. Since Blandford's jet production mechanism for quasars is too weak, a generalized Hawking radiation hidden in the walls of cosmic voids is invoked. A second prediction is empirical: slow pattern changes in the cosmic microwave background. A third is ultra-high redshifts for Giacconi quasars. Bruno's eternal universe in the spirit of Augustine becomes a bit less outlandish

The Carnegie Hubble Program

Science.gov (United States)

Freedman, Wendy L.; Madore, Barry F.; Scowcroft, Vicky; Mnso, Andy; Persson, S. E.; Rigby, Jane; Sturch, Laura; Stetson, Peter

2011-01-01

We present an overview of and preliminary results from an ongoing comprehensive program that has a goal of determining the Hubble constant to a systematic accuracy of 2%. As part of this program, we are currently obtaining 3.6 micron data using the Infrared Array Camera (IRAC) on Spitzer, and the program is designed to include JWST in the future. We demonstrate that the mid-infrared period-luminosity relation for Cepheids at 3.6 microns is the most accurate means of measuring Cepheid distances to date. At 3.6 microns, it is possible to minimize the known remaining systematic uncertainties in the Cepheid extragalactic distance scale. We discuss the advantages of 3.6 micron observations in minimizing systematic effects in the Cepheid calibration of the Hubble constant including the absolute zero point, extinction corrections, and the effects of metallicity on the colors and magnitudes of Cepheids. We are undertaking three independent tests of the sensitivity of the mid-IR Cepheid Leavitt Law to metallicity, which when combined will allow a robust constraint on the effect. Finally, we are providing a new mid-IR Tully-Fisher relation for spiral galaxies.

Hubble Space Telescope: a Vision to 2020 and Beyond: The Hubble Source Catalog

Science.gov (United States)

Strolger, Louis-Gregory

2016-01-01

The Hubble Source Catalog (HSC) is an initiative centered on what science would be enabled by a master catalog of all the sources HST has imaged over its lifetime. The first version of this catalog was released in early 2015, and included approximately 30 million sources from archived direct imaging with WFPC2, ACS (through 2011), and WFC3 (to 2014). Version 2, scheduled for release in early 2016, will feed off the Hubble Legacy Archive DR9 release, updating the ACS sources with more detections, and more direct imaging, through to mid-2015. This talk will overview the properties and goals of the HSC in terms of its source detection, object resolution, confusion limits, and overall astrometric and photometric precision. I will also discuss the connections to other MAST activities (e.g., the Discovery Portal interface), to STScI and user products (e.g., the Spectroscopic Catalog and High-Level Science Products), and to community resources (e.g., Pan-STARRS, SDSS, and eventually GAIA). The HSC successfully amalgamates the diverse observations with HST, and despite the limitations in uniformity on the sky, will be an important reference for JWST, LSST, and other future telescopes.

HUBBLE provides multiple views of how to feed a black hole

Science.gov (United States)

1998-05-01

Although the cause-and-effect relationships are not yet clear, the views provided by complementary images from two instruments aboard the Hubble Space Telescope are giving astronomers new insights into the powerful forces being exerted in this complex maelstrom. Researchers believe these forces may even have shifted the axis of the massive black hole from its expected orientation. The Hubble wide-field camera visible image of the merged Centaurus A galaxy, also called NGC 5128, shows in sharp clarity a dramatic dark lane of dust girdling the galaxy. Blue clusters of newborn stars are clearly resolved, and silhouettes of dust filaments are interspersed with blazing orange-glowing gas. Located only 10 million light-years away, this peculiar-looking galaxy contains the closest active galactic nucleus to Earth and has long been considered an example of an elliptical galaxy disrupted by a recent collision with a smaller companion spiral galaxy. Using the infrared vision of Hubble, astronomers have penetrated this wall of dust for the first time to see a twisted disk of hot gas swept up in the black hole's gravitational whirlpool. The suspected black hole is so dense it contains the mass of perhaps a billion stars, compacted into a small region of space not much larger than our Solar System. Resolving features as small as seven light-years across, Hubble has shown astronomers that the hot gas disk is tilted in a different direction from the black hole's axis -- like a wobbly wheel around an axle. The black hole's axis is identified by the orientation of a high-speed jet of material, glowing in X-rays and radio frequencies, blasted from the black hole at 1/100th the speed of light. This gas disk presumably fueling the black hole may have formed so recently it is not yet aligned to the black hole's spin axis, or it may simply be influenced more by the galaxy's gravitational tug than by the black hole's. "This black hole is doing its own thing. Aside from receiving fresh

Gravity waves as a probe of the Hubble expansion rate during an electroweak scale phase transition

International Nuclear Information System (INIS)

Chung, Daniel J. H.; Zhou Peng

2010-01-01

Just as big bang nucleosynthesis allows us to probe the expansion rate when the temperature of the Universe was around 1 MeV, the measurement of gravity waves from electroweak scale first order phase transitions may allow us to probe the expansion rate when the temperature of the Universe was at the electroweak scale. We compute the simple transformation rule for the gravity wave spectrum under the scaling transformation of the Hubble expansion rate. We then apply this directly to the scenario of quintessence kination domination and show how gravity wave spectra would shift relative to Laser Interferometer Space Antenna and Big Bang Observer projected sensitivities.

Observational constraint on spherical inhomogeneity with CMB and local Hubble parameter

Science.gov (United States)

Tokutake, Masato; Ichiki, Kiyotomo; Yoo, Chul-Moon

2018-03-01

We derive an observational constraint on a spherical inhomogeneity of the void centered at our position from the angular power spectrum of the cosmic microwave background (CMB) and local measurements of the Hubble parameter. The late time behaviour of the void is assumed to be well described by the so-called Λ-Lemaȋtre-Tolman-Bondi (ΛLTB) solution. Then, we restrict the models to the asymptotically homogeneous models each of which is approximated by a flat Friedmann-Lemaȋtre-Robertson-Walker model. The late time ΛLTB models are parametrized by four parameters including the value of the cosmological constant and the local Hubble parameter. The other two parameters are used to parametrize the observed distance-redshift relation. Then, the ΛLTB models are constructed so that they are compatible with the given distance-redshift relation. Including conventional parameters for the CMB analysis, we characterize our models by seven parameters in total. The local Hubble measurements are reflected in the prior distribution of the local Hubble parameter. As a result of a Markov-Chains-Monte-Carlo analysis for the CMB temperature and polarization anisotropies, we found that the inhomogeneous universe models with vanishing cosmological constant are ruled out as is expected. However, a significant under-density around us is still compatible with the angular power spectrum of CMB and the local Hubble parameter.

A Toy Cosmology Using a Hubble-Scale Casimir Effect

Directory of Open Access Journals (Sweden)

Michael E. McCulloch

2014-02-01

Full Text Available The visible mass of the observable universe agrees with that needed for a flat cosmos, and the reason for this is not known. It is shown that this can be explained by modelling the Hubble volume as a black hole that emits Hawking radiation inwards, disallowing wavelengths that do not fit exactly into the Hubble diameter, since partial waves would allow an inference of what lies outside the horizon. This model of “horizon wave censorship” is equivalent to a Hubble-scale Casimir effect. This incomplete toy model is presented to stimulate discussion. It predicts a minimum mass and acceleration for the observable universe which are in agreement with the observed mass and acceleration, and predicts that the observable universe gains mass as it expands and was hotter in the past. It also predicts a suppression of variation on the largest cosmic scales that agrees with the low-l cosmic microwave background anomaly seen by the Planck satellite.

Building the Hubble Space Telescope

International Nuclear Information System (INIS)

O'dell, C.R.

1989-01-01

The development of the design for the Hubble Space Telescope (HST) is discussed. The HST optical system is described and illustrated. The financial and policy issues related to the development of the HST are considered. The actual construction of the HST optical telescope is examined. Also, consideration is given to the plans for the HST launch

Apparatus for measuring speed through the Doppler frequency shift of sound

Science.gov (United States)

Schier, Walter

2011-04-01

The Doppler frequency shift of sound apparatus is based on a one meter diameter rotary table with a "button" speaker at its outer edge. A semicircular waveguide encloses half the periphery and has a microphone pickup on its wall at the midpoint. The tangential speed of the button speaker can be determined two ways for comparison. One method calculates speed from the frequency shift of sound, the other uses the repeat sound pattern. Agreement to one percent is possible at speeds of about 25 mph. In the lab the microphone output is fed successively to pairs of students at ten computer stations. Students must also perform an exercise in their lab report that introduces them to the red shifted wavelengths of receding galaxies at determined distances from the earth thus introducing them to Hubble's law, the concept of the "Big Bang", and their estimate of the age of the universe.

Hubble peers inside a celestial geode

Science.gov (United States)

2004-08-01

celestial geode hi-res Size hi-res: 148 Kb Credits: ESA/NASA, Yäel Nazé (University of Liège, Belgium) and You-Hua Chu (University of Illinois, Urbana, USA) Hubble peers inside a celestial geode In this unusual image, the NASA/ESA Hubble Space Telescope captures a rare view of the celestial equivalent of a geode - a gas cavity carved by the stellar wind and intense ultraviolet radiation from a young hot star. Real geodes are handball-sized, hollow rocks that start out as bubbles in volcanic or sedimentary rock. Only when these inconspicuous round rocks are split in half by a geologist, do we get a chance to appreciate the inside of the rock cavity that is lined with crystals. In the case of Hubble's 35 light-year diameter ‘celestial geode’ the transparency of its bubble-like cavity of interstellar gas and dust reveals the treasures of its interior. Low resolution version (JPG format) 148 Kb High resolution version (TIFF format) 1929 Kb Acknowledgment: This image was created with the help of the ESA/ESO/NASA Photoshop FITS Liberator. Real geodes are handball-sized, hollow rocks that start out as bubbles in volcanic or sedimentary rock. Only when these inconspicuous round rocks are split in half by a geologist, do we get a chance to appreciate the inside of the rock cavity that is lined with crystals. In the case of Hubble's 35 light-year diameter ‘celestial geode’ the transparency of its bubble-like cavity of interstellar gas and dust reveals the treasures of its interior. The object, called N44F, is being inflated by a torrent of fast-moving particles (what astronomers call a 'stellar wind') from an exceptionally hot star (the bright star just below the centre of the bubble) once buried inside a cold dense cloud. Compared with our Sun (which is losing mass through the so-called 'solar wind'), the central star in N44F is ejecting more than a 100 million times more mass per second and the hurricane of particles moves much faster at 7 million km per hour

European astronaut selected for the third Hubble Space Telescope

Science.gov (United States)

1998-08-01

The STS-104 crew will rendezvous with the orbiting Hubble Space Telescope, which is the size of a city bus, capture it using the Shuttle's Canadian robot arm and secure it in Columbia's payload bay. Then, working in teams of two, the four astronauts will leave the Shuttle's pressurised cabin and venture into the payload bay, performing a variety of tasks that will improve the productivity and reliability of the telescope. The four astronauts will perform a series of six "extravehicular" activities in the open space environment. Such activities are commonly called spacewalks, but this term does little justice to the considerable physical and mental efforts that astronauts need to make in doing the very demanding work involved. The Shuttle commander and pilot for this flight have not yet been appointed, but the four designated mission specialists begin training for the STS-104 mission immediately. "The ambitious nature of this mission, with its six spacewalks, made it important for the payload crew to begin training as early as possible," said David C. Leestma, NASA Director of Flight Crew Operations at the Johnson Space Center in Houston, to which Claude Nicollier is on resident assignment from ESA's European Astronaut Centre in Cologne, Germany, the home base of the European astronaut corps. The Hubble Space Telescope was launched into orbit in April 1990. It is one of the most capable optical telescopes available to astronomers today, producing images and spectral observations at the forefront of astronomy. The European Space Agency contributed a 15 share to the development of Hubble. One of the five scientific instruments on board, the Faint Object Camera, was built by a European industrial consortium made up of British Aerospace, Dornier and Matra under a contract with the European Space Agency. The solar arrays which provide Hubble with electrical power were manufactured by British Aerospace and Dornier. In its eight years of operation, the telescope has not

Hubble Source Catalog

Science.gov (United States)

Lubow, S.; Budavári, T.

2013-10-01

We have created an initial catalog of objects observed by the WFPC2 and ACS instruments on the Hubble Space Telescope (HST). The catalog is based on observations taken on more than 6000 visits (telescope pointings) of ACS/WFC and more than 25000 visits of WFPC2. The catalog is obtained by cross matching by position in the sky all Hubble Legacy Archive (HLA) Source Extractor source lists for these instruments. The source lists describe properties of source detections within a visit. The calculations are performed on a SQL Server database system. First we collect overlapping images into groups, e.g., Eta Car, and determine nearby (approximately matching) pairs of sources from different images within each group. We then apply a novel algorithm for improving the cross matching of pairs of sources by adjusting the astrometry of the images. Next, we combine pairwise matches into maximal sets of possible multi-source matches. We apply a greedy Bayesian method to split the maximal matches into more reliable matches. We test the accuracy of the matches by comparing the fluxes of the matched sources. The result is a set of information that ties together multiple observations of the same object. A byproduct of the catalog is greatly improved relative astrometry for many of the HST images. We also provide information on nondetections that can be used to determine dropouts. With the catalog, for the first time, one can carry out time domain, multi-wavelength studies across a large set of HST data. The catalog is publicly available. Much more can be done to expand the catalog capabilities.

A guide to hubble space telescope objects their selection, location, and significance

CERN Document Server

Chen, James L

2015-01-01

From the authors of "How to Find the Apollo Landing Sites," this is a guide to connecting the view above with the history of recent scientific discoveries from the Hubble Space Telescope. Each selected HST photo is shown with a sky map and a photograph or drawing to illustrate where to find it and how it should appear from a backyard telescope. Here is the casual observer's chance to locate the deep space objects visually, and appreciate the historic Hubble photos in comparison to what is visible from a backyard telescope. HST objects of all types are addressed, from Messier objects, Caldwell objects, and NGC objects, and are arranged in terms of what can be seen during the seasons. Additionally, the reader is given an historical perspective on the work of Edwin Hubble, while locating and viewing the deep space objects that changed astronomy forever.  Countless people have seen the amazing photographs taken by the Hubble Space Telescope. But how many people can actually point out where in the sky ...

Observations of the Hubble Deep Field with the Infrared Space Observatory .4. Association of sources with Hubble Deep Field galaxies

DEFF Research Database (Denmark)

Mann, R.G.; Oliver, S.J.; Serjeant, S.B.G.

1997-01-01

We discuss the identification of sources detected by the Infrared Space Observatory (ISO) at 6.7 and 15 mu m in the Hubble Deep Field (HDF) region. We conservatively associate ISO sources with objects in existing optical and near-infrared HDF catalogues using the likelihood ratio method, confirming...... these results (and, in one case, clarifying them) with independent visual searches, We find 15 ISO sources to be reliably associated with bright [I-814(AB) HDF, and one with an I-814(AB)=19.9 star, while a further 11 are associated with objects in the Hubble Flanking Fields (10 galaxies...... and one star), Amongst optically bright HDF galaxies, ISO tends to detect luminous, star-forming galaxies at fairly high redshift and with disturbed morphologies, in preference to nearby ellipticals....

Type Ia supernova Hubble residuals and host-galaxy properties

International Nuclear Information System (INIS)

Kim, A. G.; Aldering, G.; Aragon, C.; Bailey, S.; Fakhouri, H. K.; Antilogus, P.; Bongard, S.; Canto, A.; Cellier-Holzem, F.; Fleury, M.; Guy, J.; Baltay, C.; Buton, C.; Feindt, U.; Greskovic, P.; Kowalski, M.; Childress, M.; Chotard, N.; Copin, Y.; Gangler, E.

2014-01-01

Kim et al. introduced a new methodology for determining peak-brightness absolute magnitudes of type Ia supernovae from multi-band light curves. We examine the relation between their parameterization of light curves and Hubble residuals, based on photometry synthesized from the Nearby Supernova Factory spectrophotometric time series, with global host-galaxy properties. The K13 Hubble residual step with host mass is 0.013 ± 0.031 mag for a supernova subsample with data coverage corresponding to the K13 training; at <<1σ, the step is not significant and lower than previous measurements. Relaxing the data coverage requirement of the Hubble residual step with the host mass is 0.045 ± 0.026 mag for the larger sample; a calculation using the modes of the distributions, less sensitive to outliers, yields a step of 0.019 mag. The analysis of this article uses K13 inferred luminosities, as distinguished from previous works that use magnitude corrections as a function of SALT2 color and stretch parameters: steps at >2σ significance are found in SALT2 Hubble residuals in samples split by the values of their K13 x(1) and x(2) light-curve parameters. x(1) affects the light-curve width and color around peak (similar to the Δm 15 and stretch parameters), and x(2) affects colors, the near-UV light-curve width, and the light-curve decline 20-30 days after peak brightness. The novel light-curve analysis, increased parameter set, and magnitude corrections of K13 may be capturing features of SN Ia diversity arising from progenitor stellar evolution.

The Hubble Legacy Archive: Data Processing in the Era of AstroDrizzle

Science.gov (United States)

Strolger, Louis-Gregory; Hubble Legacy Archive Team, The Hubble Source Catalog Team

2015-01-01

The Hubble Legacy Archive (HLA) expands the utility of Hubble Space Telescope wide-field imaging data by providing high-level composite images and source lists, perusable and immediately available online. The latest HLA data release (DR8.0) marks a fundamental change in how these image combinations are produced, using DrizzlePac tools and Astrodrizzle to reduce geometric distortion and provide improved source catalogs for all publicly available data. We detail the HLA data processing and source list schemas, what products are newly updated and available for WFC3 and ACS, and how these data products are further utilized in the production of the Hubble Source Catalog. We also discuss plans for future development, including updates to WFPC2 products and field mosaics.

A nuclear data approach for the Hubble constant measurements

Directory of Open Access Journals (Sweden)

Pritychenko Boris

2017-01-01

Full Text Available An extraordinary number of Hubble constant measurements challenges physicists with selection of the best numerical value. The standard U.S. Nuclear Data Program (USNDP codes and procedures have been applied to resolve this issue. The nuclear data approach has produced the most probable or recommended Hubble constant value of 67.2(69 (km/sec/Mpc. This recommended value is based on the last 20 years of experimental research and includes contributions from different types of measurements. The present result implies (14.55 ± 1.51 × 109 years as a rough estimate for the age of the Universe. The complete list of recommended results is given and possible implications are discussed.

The Speed of Light and the Hubble parameter: The Mass-Boom Effect

International Nuclear Information System (INIS)

Alfonso-Faus, Antonio

2008-01-01

We prove here that Newton's universal gravitation and momentum conservation laws together reproduce Weinberg's relation. It is shown that the Hubble parameter H must be built in this relation, or equivalently the age of the Universe t. Using a wave-to-particle interaction technique we then prove that the speed of light c decreases with cosmological time, and that c is proportional to the Hubble parameter H. We see the expansion of the Universe as a local effect due to the LAB value of the speed of light co taken as constant. We present a generalized red shift law and find a predicted acceleration for photons that agrees well with the result from Pioneer 10/11 anomalous acceleration. We finally present a cosmological model coherent with the above results that we call the Mass-Boom. It has a linear increase of mass m with time as a result of the speed of light c linear decrease with time, and the conservation of momentum mc. We obtain the baryonic mass parameter equal to the curvature parameter, Ω m Ω k , so that the model is of the type of the Einstein static, closed, finite, spherical, unlimited, with zero cosmological constant. This model is the cosmological view as seen by photons, neutrinos, tachyons etc. in contrast with the local view, the LAB reference. Neither dark matter nor dark energy is required by this model. With an initial constant speed of light during a short time we get inflation (an exponential expansion). This converts, during the inflation time, the Planck's fluctuation length of 10 -33 cm to the present size of the Universe (about 10 28 cm, constant from then on). Thereafter the Mass-Boom takes care to bring the initial values of the Universe (about 10 15 gr) to the value at the present time of about 10 55 gr

HUBBLE'S ULTRAVIOLET VIEWS OF NEARBY GALAXIES YIELD CLUES TO EARLY UNIVERSE

Science.gov (United States)

2002-01-01

Astronomers are using these three NASA Hubble Space Telescope images to help tackle the question of why distant galaxies have such odd shapes, appearing markedly different from the typical elliptical and spiral galaxies seen in the nearby universe. Do faraway galaxies look weird because they are truly weird? Or, are they actually normal galaxies that look like oddballs, because astronomers are getting an incomplete picture of them, seeing only the brightest pieces? Light from these galaxies travels great distances (billions of light-years) to reach Earth. During its journey, the light is 'stretched' due to the expansion of space. As a result, the light is no longer visible, but has been shifted to the infrared where present instruments are less sensitive. About the only light astronomers can see comes from regions where hot, young stars reside. These stars emit mostly ultraviolet light. But this light is stretched, appearing as visible light by the time it reaches Earth. Studying these distant galaxies is like trying to put together a puzzle with some of the pieces missing. What, then, do distant galaxies really look like? Astronomers studied 37 nearby galaxies to find out. By viewing these galaxies in ultraviolet light, astronomers can compare their shapes with those of their distant relatives. These three Hubble telescope pictures, taken with the Wide Field and Planetary Camera 2, represent a sampling from that survey. Astronomers observed the galaxies in ultraviolet and visible light to study all the stars that make up these 'cities of stars.' The results of their survey support the idea that astronomers are detecting the 'tip of the iceberg' of very distant galaxies. Based on these Hubble ultraviolet images, not all the faraway galaxies necessarily possess intrinsically odd shapes. The results are being presented today at the 197th meeting of the American Astronomical Society in San Diego, CA. The central region of the 'star-burst' spiral galaxy at far left

Measurement of Hubble constant: non-Gaussian errors in HST Key Project data

Energy Technology Data Exchange (ETDEWEB)

Singh, Meghendra [Dr. A.P.J. Abdul Kalam Technical University, Uttar Pradesh, Lucknow, 226021 India (India); Gupta, Shashikant; Pandey, Ashwini [Amity University Haryana, Gurgaon, Haryana, 122413 India (India); Sharma, Satendra, E-mail: meghendrasingh_db@yahoo.co.in, E-mail: shashikantgupta.astro@gmail.com, E-mail: satyamkashwini@gmail.com, E-mail: ssharma_phy@yahoo.co.uk [Yobe State University, Damaturu, Yobe State (Nigeria)

2016-08-01

Assuming the Central Limit Theorem, experimental uncertainties in any data set are expected to follow the Gaussian distribution with zero mean. We propose an elegant method based on Kolmogorov-Smirnov statistic to test the above; and apply it on the measurement of Hubble constant which determines the expansion rate of the Universe. The measurements were made using Hubble Space Telescope. Our analysis shows that the uncertainties in the above measurement are non-Gaussian.

On the determination of the Hubble constant

International Nuclear Information System (INIS)

Gurzadyan, V.G.; Harutyunyan, V.V.; Kocharyan, A.A.

1990-10-01

The possibility of an alternative determination of the distance scale of the Universe and the Hubble constant based on the numerical analysis of the hierarchical nature of the large scale Universe (galaxies, clusters and superclusters) is proposed. The results of computer experiments performed by means of special numerical algorithms are represented. (author). 9 refs, 7 figs

Hubble Captures Volcanic Eruption Plume From Io

Science.gov (United States)

1997-01-01

The Hubble Space Telescope has snapped a picture of a 400-km-high (250-mile-high) plume of gas and dust from a volcanic eruption on Io, Jupiter's large innermost moon.Io was passing in front of Jupiter when this image was taken by the Wide Field and Planetary Camera 2 in July 1996. The plume appears as an orange patch just off the edge of Io in the eight o'clock position, against the blue background of Jupiter's clouds. Io's volcanic eruptions blasts material hundreds of kilometers into space in giant plumes of gas and dust. In this image, material must have been blown out of the volcano at more than 2,000 mph to form a plume of this size, which is the largest yet seen on Io.Until now, these plumes have only been seen by spacecraft near Jupiter, and their detection from the Earth-orbiting Hubble Space Telescope opens up new opportunities for long-term studies of these remarkable phenomena.The plume seen here is from Pele, one of Io's most powerful volcanos. Pele's eruptions have been seen before. In March 1979, the Voyager 1 spacecraft recorded a 300-km-high eruption cloud from Pele. But the volcano was inactive when the Voyager 2 spacecraft flew by Jupiter in July 1979. This Hubble observation is the first glimpse of a Pele eruption plume since the Voyager expeditions.Io's volcanic plumes are much taller than those produced by terrestrial volcanos because of a combination of factors. The moon's thin atmosphere offers no resistance to the expanding volcanic gases; its weak gravity (one-sixth that of Earth) allows material to climb higher before falling; and its biggest volcanos are more powerful than most of Earth's volcanos.This image is a contrast-enhanced composite of an ultraviolet image (2600 Angstrom wavelength), shown in blue, and a violet image (4100 Angstrom wavelength), shown in orange. The orange color probably occurs because of the absorption and/or scattering of ultraviolet light in the plume. This light from Jupiter passes through the plume and is

Enhancing Hubble's vision service missions that expanded our view of the universe

CERN Document Server

Shayler, David J

2016-01-01

After a 20-year struggle to place a large, sophisticated optical telescope in orbit the Hubble Space Telescope was finally launched in 1990, though its primary mirror was soon found to be flawed. A dramatic mission in 1993 installed corrective optics so that the intended science program could finally begin. Those events are related in a companion to this book, The Hubble Space Telescope: From Concept to Success.   Enhancing Hubble’s Vision: Service Missions That Expanded Our View of the Universe tells the story of the four missions between 1997 and 2009 that repaired, serviced and upgraded the instruments on the telescope to maintain its state-of-the-art capabilities. It draws on first hand interviews with those closely involved in the project. The spacewalking skills and experiences gained from maintaining and upgrading Hubble had direct application to the construction of the International Space Station and help with its maintenance. These skills can be applied to future human and robotic satellite servic...

Construcción de un diagrama de Hubble: Una herramienta para la Enseñanza de la Astronomía

Directory of Open Access Journals (Sweden)

Giovanni Cardona Rodriguez

2016-06-01

Full Text Available Se presenta una actividad que puede apoyar el trabajo de los docentes que dirigen  clubes de Astronomía y quieren abordar el tema de evolución del Universo, ya que   se  reconstruye  la ley de Hubble  a partir de la construcción de un Diagrama de Hubble con  datos  tomados del Sloan Digital Sky Survey   (SDSS ,  del  cual se obtiene el valor del parámetro de Hubble y se infiere la expansión del Universo. Esta actividad  didáctica permite a los profesores orientar a sus estudiantes por el camino que siguió Hubble  para determinar su ley, en este sentido se exponen algunas implicaciones de aplicación de la misma en el contexto de la formación de profesores de física y de los clubes de Astronomía.  Construction of a Hubble Diagram: A tool for teaching astronomy This article presents the construction and analysis of an activity that can support the work of teachers who run Astronomy clubs and want to address the issue of evolution of the Universe. Here Hubble's law is reconstructed by reproducing a Hubble diagram with Sloan Digital Sky Survey's (SDSS data, from which the Hubble parameter value is obtained and the expansion of the Universe is inferred. This educational activity allows teachers to guide their students along the path followed by Hubble to determine his law. In this sense some implications of applying the latter are discussed in the context of teacher's training in Physics and Astronomy clubs. Construção de um diagrama de Hubble: Uma ferramenta para ensino de astronomía Se apresenta uma actividade que pode apoiar o trabalho dos professores que dirigem clubes de Astronomia e querem abordar a questão da evolução do Universo, como a lei de Hubble é reconstruída a partir da reprodução de um diagrama de Hubble com os dados tomados do Sloan digital Sky Survey (SDSS, é achado o parâmetro de Hubble e inferida a expansão do universo. Esta actividade educativa permite aos professores orientar seus alunos ao

HUBBLE CAPTURES MERGER BETWEEN QUASAR AND GALAXY

Science.gov (United States)

2002-01-01

This NASA Hubble Space Telescope image shows evidence fo r a merger between a quasar and a companion galaxy. This surprising result might require theorists to rethink their explanations for the nature of quasars, the most energetic objects in the universe. The bright central object is the quasar itself, located several billion light-years away. The two wisps on the (left) of the bright central object are remnants of a bright galaxy that have been disrupted by the mutual gravitational attraction between the quasar and the companion galaxy. This provides clear evidence for a merger between the two objects. Since their discovery in 1963, quasars (quasi-stellar objects) have been enigmatic because they emit prodigious amounts of energy from a very compact source. The most widely accepted model is that a quasar is powered by a supermassive black hole in the core of a galaxy. These new observations proved a challenge for theorists as no current models predict the complex quasar interactions unveiled by Hubble. The image was taken with the Wide Field Planetary Camera-2. Credit: John Bahcall, Institute for Advanced Study, NASA.

Hubble Space Telescope: Should NASA Proceed with a Servicing Mission?

National Research Council Canada - National Science Library

Morgan, Daniel

2006-01-01

The National Aeronautics and Space Administration (NASA) estimates that without a servicing mission to replace key components, the Hubble Space Telescope will cease scientific operations in 2008 instead of 2010...

The Prevalence of Tobacco, Hubble-Bubble, Alcoholic Drinks, Drugs, and Stimulants among High-School Students

Directory of Open Access Journals (Sweden)

Roghayeh Alaee

2011-08-01

Full Text Available Introduction: The purpose of the present study was to investigate the prevalence of tobacco, hubble-bubble, alcoholic drinks, and other drugs among Karaj high-school students in 2011. Methods: The research method was a descriptive-sectional study. Participants of this study were 447 girl and boy high-school students of Karaj that were selected by clustering random sampling. For data gathering, drug abuse questionnaire, and risk and protective factors inventory were administered among selected sample. Results: According to the results, 57% of students in this study said that they have had experiences with a kind of drug including tobacco, hubble-bubble, alcoholic drinks, and other drugs at least once in their lives. The study showed the prevalence for soft drugs: hubble-bubble, tobacco, and alcoholic drinks, and for hard drugs ecstasy, opium, hashish, meth, crack, and heroin respectively. Conclusion: Soft drugs including hubble-bubble, tobacco, and alcoholic drinks, are the most common among Karaj high-school students. The prevalence of hard drugs among them is rather low.

Hubble Space Telescope nickel hydrogen battery system briefing

Science.gov (United States)

Nawrocki, David; Saldana, David; Rao, Gopal

1993-01-01

The topics covered are presented in viewgraph form and include the following: the Hubble Space Telescope (HST) Mission; system constraints; battery specification; battery module; simplified block diagram; cell design summary; present status; voltage decay; system depth of discharge; pressure since launch; system capacity; eclipse time vs. trickle charge; capacity test objectives; and capacity during tests.

European astronomers' successes with the Hubble Space Telescope*

Science.gov (United States)

1997-02-01

[Figure: Laguna Nebula] Their work spans all aspects of astronomy, from the planets to the most distant galaxies and quasars, and the following examples are just a few European highlights from Hubble's second phase, 1994-96. A scarcity of midget stars Stars less massive and fainter than the Sun are much numerous in the Milky Way Galaxy than the big bright stars that catch the eye. Guido De Marchi and Francesco Paresce of the European Southern Observatory as Garching, Germany, have counted them. With the wide-field WFPC2 camera, they have taken sample censuses within six globular clusters, which are large gatherings of stars orbiting independently in the Galaxy. In every case they find that the commonest stars have an output of light that is only one-hundredth of the Sun's. They are ten times more numerous than stars like the Sun. More significant for theories of the Universe is a scarcity of very faint stars. Some astronomers have suggested that vast numbers of such stars could account for the mysterious dark matter, which makes stars and galaxies move about more rapidly than expected from the mass of visible matter. But that would require an ever-growing count of objects at low brightnesses, and De Marchi and Paresce find the opposite to be the case -- the numbers diminish. There may be a minimum size below which Nature finds starmaking difficult. The few examples of very small stars seen so far by astronomers may be, not the heralds of a multitude of dark-matter stars, but rareties. Unchanging habits in starmaking Confirmation that very small stars are scarce comes from Gerry Gilmore of the Institute of Astronomy in Cambridge (UK). He leads a European team that analyses long-exposure images in the WFPC2 camera, obtained as a by-product when another instrument is examining a selected object. The result is an almost random sample of well-observed stars and galaxies. The most remarkable general conclusion is that the make-up of stellar populations never seems to

NASA Astrophysics E/PO: A Quarter Century of Discovery and Inspiration with the Hubble Space Telescope

Science.gov (United States)

Jirdeh, Hussein; Straughn, Amber; Smith, Denise Anne; Eisenhamer, Bonnie

2015-08-01

April 24, 2015 marked the 25th anniversary of the launch of the Hubble Space Telescope. In its quarter-century in orbit, the Hubble Space Telescope has transformed the way we understand the Universe, helped us find our place among the stars, and paved the way to incredible advancements in science and technology.In this presentation, we explain how NASA and ESA, including the Space Telescope Science Institute (STScI) and partners, is using the 25th anniversary of Hubble’s launch as a unique opportunity to communicate to students, educators, and the public the significance of the past quarter-century of discovery with the Hubble Space Telescope. We describe the various programs, resources, and experiences we are utilizing to enhancethe public understanding of Hubble’s many contributions to the scientific world. These include educator professional development opportunities, exhibits, events, traditional and social media, and resources for educators (formal k-12, informal, and higher education). We also highlight how we are capitalizing on Hubble’s cultural popularity to make the scientific connection to NASA’s next Great Observatory, the James Webb Space Telescope.This presentation highlights many of the opportunities by which students, educators, and the public are joining in the anniversary activities, both in-person and online. Find out more at hubble25th.org and follow #Hubble25 on social media.

HUBBLE'S PANORAMIC PORTRAIT OF A VAST STAR-FORMING REGION

Science.gov (United States)

2002-01-01

NASA's Hubble Space Telescope has snapped a panoramic portrait of a vast, sculpted landscape of gas and dust where thousands of stars are being born. This fertile star-forming region, called the 30 Doradus Nebula, has a sparkling stellar centerpiece: the most spectacular cluster of massive stars in our cosmic neighborhood of about 25 galaxies. The mosaic picture shows that ultraviolet radiation and high-speed material unleashed by the stars in the cluster, called R136 [the large blue blob left of center], are weaving a tapestry of creation and destruction, triggering the collapse of looming gas and dust clouds and forming pillar-like structures that are incubators for nascent stars. The photo offers an unprecedented, detailed view of the entire inner region of 30 Doradus, measuring 200 light-years wide by 150 light-years high. The nebula resides in the Large Magellanic Cloud (a satellite galaxy of the Milky Way), 170,000 light-years from Earth. Nebulas like 30 Doradus are the 'signposts' of recent star birth. High-energy ultraviolet radiation from the young, hot, massive stars in R136 causes the surrounding gaseous material to glow. Previous Hubble telescope observations showed that R136 contains several dozen of the most massive stars known, each about 100 times the mass of the Sun and about 10 times as hot. These stellar behemoths all formed at the same time about 2 million years ago. The stars in R136 are producing intense 'stellar winds' (streams of material traveling at several million miles an hour), which are wreaking havoc on the gas and dust in the surrounding neighborhood. The winds are pushing the gas away from the cluster and compressing the inner regions of the surrounding gas and dust clouds [the pinkish material]. The intense pressure is triggering the collapse of parts of the clouds, producing a new generation of star formation around the central cluster. The new stellar nursery is about 30 to 50 light-years from R136. Most of the stars in the

First results from the Hubble OPAL Program: Jupiter in 2015

Science.gov (United States)

Simon, Amy A.; Wong, Michael H.; Orton, Glenn S.

2015-11-01

The Hubble 2020: Outer Planet Atmospheres Legacy (OPAL) program is a Director's Discretionary program designed to generate two yearly global maps for each of the outer planets to enable long term studies of atmospheric color, structure and two-dimensional wind fields. This presentation focuses on Jupiter results from the first year of the campaign. Data were acqured January 19, 2015 with the WFC3/UVIS camera and the F275W, F343N, F395N, F467M, F502N, F547M, F631N, F658N, and F889N filters. Global maps were generated and are publicly available through the High Level Science Products archive: https://archive.stsci.edu/prepds/opal/Using cross-correlation on the global maps, the zonal wind profile was measured between +/- 50 degrees latitude and is in family with Voyager and Cassini era profiles. There are some variations in mid to high latitude wind jet magnitudes, particularly at +40°and -35° planetographic latitude. The Great Red Spot continues to maintain an intense orange coloration, as it did in 2014. However, the interior shows changed structure, including a reduced core and new filamentary features. Finally, a wave not previously seen in Hubble images was also observed and is interpreted as a baroclinic instability with associated cyclone formation near 16° N latitude. A similar feature was observed faintly in Voyager 2 images, and is consistent with the Hubble feature in location and scale.

Hubble's Law Implies Benford's Law for Distances to Galaxies ...

Indian Academy of Sciences (India)

in both time and space, predicts that conformity to Benford's law will improve as more data on distances to galaxies becomes available. Con- versely, with the logical derivation of this law presented here, the recent empirical observations may beviewed as independent evidence of the validity of Hubble's law. Key words.

Remarks on the low value obtained for the Hubble constant

International Nuclear Information System (INIS)

Jaakkola, Toivo

1975-01-01

Some remarks are made on the basis of the data given by Sandage and Tamman, suggesting that these authors have over-estimated the distances to the most luminous galaxies and obtained a value too low for the Hubble constant [fr

An independent determination of the local Hubble constant

Science.gov (United States)

Fernández Arenas, David; Terlevich, Elena; Terlevich, Roberto; Melnick, Jorge; Chávez, Ricardo; Bresolin, Fabio; Telles, Eduardo; Plionis, Manolis; Basilakos, Spyros

2018-02-01

The relationship between the integrated H β line luminosity and the velocity dispersion of the ionized gas of H II galaxies and giant H II regions represents an exciting standard candle that presently can be used up to redshifts z ˜ 4. Locally it is used to obtain precise measurements of the Hubble constant by combining the slope of the relation obtained from nearby (z ≤ 0.2) H II galaxies with the zero-point determined from giant H II regions belonging to an `anchor sample' of galaxies for which accurate redshift-independent distance moduli are available. We present new data for 36 giant H II regions in 13 galaxies of the anchor sample that includes the megamaser galaxy NGC 4258. Our data are the result of the first 4 yr of observation of our primary sample of 130 giant H II regions in 73 galaxies with Cepheid determined distances. Our best estimate of the Hubble parameter is 71.0 ± 2.8(random) ± 2.1(systematic) km s- 1Mpc- 1. This result is the product of an independent approach and, although at present less precise than the latest SNIa results, it is amenable to substantial improvement.

Beyond the Hubble Constant

Science.gov (United States)

1995-08-01

of SN 1995K of about 22.7, but the uncertainty of this value is still so large that this measurement alone cannot be used to determine the value of q0. This will require many more observations of supernovae at least as distant as the present one, a daunting task that may nevertheless be possible within this broad, international programme. It is estimated that a reliable measurement of q0 may become possible when about 20 Type Ia supernovae with accurate peak magnitudes have been measured. According to the discovery predictions, this could be possible within the next couple of years. In this connection, it is of some importance that for this investigation, it is in principle not necessary to know the correct value of the Hubble constant H0 in advance; q0 may still be determined by comparing the relative distance scale of distant supernovae with that of nearby ones. This research is described in more detail in a forthcoming article in the September 1995 issue of the ESO Messenger. Notes: [1] Brian P. Schmidt (Mount Stromlo and Siding Spring Observatories, Australia), Bruno Leibundgut, Jason Spyromilio, Jeremy Walsh (ESO), Mark M. Phillips, Nicholas B. Suntzeff, Mario Hamuy, Robert A. Schommer (Cerro Tololo Inter-American Observatory), Roberto Aviles (formerly Cerro Tololo Inter-American Observatory; now at ESO), Robert P. Kirshner, Adam Riess, Peter Challis, Peter Garnavich (Center for Astrophysics, Cambridge, Massachussetts, U.S.A.), Christopher Stubbs, Craig Hogan (University of Washington, Seattle, U.S.A.), Alan Dressler (Carnegie Observatories, U.S.A.) and Robin Ciardullo (Pennsylvania State University, U.S.A.) [2] In astronomy, the redshift denotes the fraction by which the lines in the spectrum of an object are shifted towards longer wavelengths. The observed redshift of a distant galaxy gives a direct estimate of the apparent recession velocity as caused by the universal expansion. Since the expansion rate increases with the distance, the velocity is itself a

On the Luminosity Distance and the Hubble Constant

OpenAIRE

Yuri Heymann

2013-01-01

By differentiating luminosity distance with respect to time using its standard formula we find that the peculiar velocity is a time varying velocity of light. Therefore, a new definition of the luminosity distance is provided such that the peculiar velocity is equal to c. Using this definition a Hubble constant H0 = 67.3 km s−1 Mpc−1 is obtained from supernovae data.

The ESA Hubble 15th Anniversary Campaign: A Trans-European collaboration project

Science.gov (United States)

Zoulias, Manolis; Christensen, Lars Lindberg; Kornmesser, Martin

2006-08-01

On April 24th 2005, NASA/ESA Hubble Space Telescope had been in orbit for 15 years. The anniversary was celebrated by ESA with the production of an 83 min. scientific movie and a 120 pages book, both titled ``Hubble, 15 years of discovery''. In order to cross language and distribution barriers a network of 16 translators and 22 partners from more than 10 countries was established. The DVD was distributed in approximately 700,000 copies throughout Europe. The project was amongst the largest of its kind with respect to collaboration, distribution and audience impact. It clearly demonstrated how international collaboration can produce effective cross-cultural educational and outreach products for astronomy.

Dynamical friction: The Hubble diagram as a cosmological test

International Nuclear Information System (INIS)

Gunn, J.E.; Tinsley, B.M.

1976-01-01

Effects on the Hubble diagram of the frictional accretion of small cluster galaxies by large ones, to which Ostriker and Tremaine have recently drawn attention, must be accurately determined if the magnitude-redshift relation is to become a viable cosmological test. We find that the process might be detectable through the concomitant change in galaxy colors, but that its effect on the dispersion of magnitudes of first-ranked cluster galaxies would be negligible even if the change in average magnitude is very important. The sign of the effect of accretion on the luminosity observed within a given aperture depends on the structures of the galaxies involved. The size of the effect not only depends sensitively on the galaxy structures, but is also amplified when the relatively recent collapse times of the clusters are taken into account. It is vital to answer the complicated observational and theoretical questions raised by these preliminary calculations, because the Hubble diagram remains the most promising approach to the deceleration parameter q 0 . Local tests of the density of the universe do not give equivalent information

Hubble Space Telescope - Scientific, Technological and Social Contributions to the Public Discourse on Science

Science.gov (United States)

Wiseman, Jennifer

2012-01-01

The Hubble Space Telescope has unified the world with a sense of awe and wonder for 2 I years and is currently more scientifically powerful than ever. I will present highlights of discoveries made with the Hubble Space Telescope, including details of planetary weather, star formation, extra-solar planets, colliding galaxies, and a universe expanding with the acceleration of dark energy. I will also present the unique technical challenges and triumphs of this phenomenal observatory, and discuss how our discoveries in the cosmos affect our sense of human unity, significance, and wonder.

The Hubble Space Telescope: UV, Visible, and Near-Infrared Pursuits

Science.gov (United States)

Wiseman, Jennifer

2010-01-01

The Hubble Space Telescope continues to push the limits on world-class astrophysics. Cameras including the Advanced Camera for Surveys and the new panchromatic Wide Field Camera 3 which was installed nu last year's successful servicing mission S2N4,o{fer imaging from near-infrared through ultraviolet wavelengths. Spectroscopic studies of sources from black holes to exoplanet atmospheres are making great advances through the versatile use of STIS, the Space Telescope Imaging Spectrograph. The new Cosmic Origins Spectrograph, also installed last year, is the most sensitive UV spectrograph to fly io space and is uniquely suited to address particular scientific questions on galaxy halos, the intergalactic medium, and the cosmic web. With these outstanding capabilities on HST come complex needs for laboratory astrophysics support including atomic and line identification data. I will provide an overview of Hubble's current capabilities and the scientific programs and goals that particularly benefit from the studies of laboratory astrophysics.

A Scientific Revolution: The Hubble and James Webb Space Telescopes

Science.gov (United States)

Gardner, Jonathan P.

2010-01-01

Astronomy is going through a scientific revolution, responding to a flood of data from the Hubble Space Telescope, other space missions, and large telescopes on the ground. In this talk, I will discuss some of the important discoveries of the last decade, from dwarf planets in the outer Solar System to the mysterious dark energy that overcomes gravity to accelerate the expansion of the Universe. The next decade will be equally bright with the newly refurbished Hubble and the promise of its successor, the James Webb Space Telescope. An infrared-optimized 6.5m space telescope, Webb is designed to find the first galaxies that formed in the early universe and to peer into the dusty gas clouds where stars and planets are born. With MEMS technology, a deployed primary mirror and a tennis-court sized sunshield, the mission presents many technical challenges. I will describe Webb's scientific goals, its design and recent progress in constructing the observatory. Webb is scheduled for launch in 2014.

Distance to M33 determined from magnitude corrections to Hubble's original cepheid photometry

International Nuclear Information System (INIS)

Sandage, A.

1983-01-01

New photoelectric photometry in Selected Area 45, and transfers from a faint photoelectric sequence adjacent to the south-preceding arm in M33 have been made to the comparison stars for Hubble's Cepheids in M33. Progressive magnitude corrections are required to Hubble's M33 scales, reaching 2.8 mag at the limit of the Mount Wilson 2.5-m Hooker reflector. Hubble's Cepheid light curves have been corrected to the B photoelectric system, and new photometric parameters are given for 35 of his variables. The P-L relation agrees in zero point to within 0.2 mag of the P-L relation from independent data by Sandage and Carlson for 12 new Cepheids in an outlying region of M33. Application of an adopted absolute P-L relation, calibrated by Martin, Warren, and Feast, to these data gives an apparent blue modulus of (m-M)/sup AB//sub M33/ = 25.35, which is 0.67 mag fainter than a previously adopted value, and represents a factor of 4.2 increase of Hubble's earliest distance. Three consequences of this larger apparent distance modulus are (1) the mean absolute magnitude of the first three brightest red supergiants is M/sup max//sub left-angle-bracketV/(3)> = -8.7 rather than approx.-8.0 in M33, complicating but not destroying use of red supergiants as distance indicators, (2) the mean absolute magnitude of the two brightest blue irregular supergiant variables is M/sub left-angle-bracketB/(2)> = -9.95, which is close to the value for the brightest known supergiants in the galaxy, and (3) the absolute magnitude of M33 itself is brighter than heretofore assumed

Making Data Mobile: The Hubble Deep Field Academy iPad app

Science.gov (United States)

Eisenhamer, Bonnie; Cordes, K.; Davis, S.; Eisenhamer, J.

2013-01-01

Many school districts are purchasing iPads for educators and students to use as learning tools in the classroom. Educators often prefer these devices to desktop and laptop computers because they offer portability and an intuitive design, while having a larger screen size when compared to smart phones. As a result, we began investigating the potential of adapting online activities for use on Apple’s iPad to enhance the dissemination and usage of these activities in instructional settings while continuing to meet educators’ needs. As a pilot effort, we are developing an iPad app for the “Hubble Deep Field Academy” - an activity that is currently available online and commonly used by middle school educators. The Hubble Deep Field Academy app features the HDF-North image while centering on the theme of how scientists use light to explore and study the universe. It also includes features such as embedded links to vocabulary, images and videos, teacher background materials, and readings about Hubble’s other deep field surveys. It is our goal is to impact students’ engagement in STEM-related activities, while enhancing educators’ usage of NASA data via new and innovative mediums. We also hope to develop and share lessons learned with the E/PO community that can be used to support similar projects. We plan to test the Hubble Deep Field Academy app during the school year to determine if this new activity format is beneficial to the education community.

Quasar Host Galaxies/Neptune Rotation/Galaxy Building Blocks/Hubble Deep Field/Saturn Storm

Science.gov (United States)

2001-01-01

Computerized animations simulate a quasar erupting in the core of a normal spiral galaxy, the collision of two interacting galaxies, and the evolution of the universe. Hubble Space Telescope (HST) images show six quasars' host galaxies (including spirals, ellipticals, and colliding galaxies) and six clumps of galaxies approximately 11 billion light years away. A false color time lapse movie of Neptune displays the planet's 16-hour rotation, and the evolution of a storm on Saturn is seen though a video of the planet's rotation. A zoom sequence starts with a ground-based image of the constellation Ursa major and ends with the Hubble Deep Field through progressively narrower and deeper views.

MOVING OBJECTS IN THE HUBBLE ULTRA DEEP FIELD

Energy Technology Data Exchange (ETDEWEB)

Kilic, Mukremin; Gianninas, Alexandros [Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 W. Brooks St., Norman, OK 73019 (United States); Von Hippel, Ted, E-mail: kilic@ou.edu, E-mail: alexg@nhn.ou.edu, E-mail: ted.vonhippel@erau.edu [Embry-Riddle Aeronautical University, 600 S. Clyde Morris Blvd., Daytona Beach, FL 32114 (United States)

2013-09-01

We identify proper motion objects in the Hubble Ultra Deep Field (UDF) using the optical data from the original UDF program in 2004 and the near-infrared data from the 128 orbit UDF 2012 campaign. There are 12 sources brighter than I = 27 mag that display >3{sigma} significant proper motions. We do not find any proper motion objects fainter than this magnitude limit. Combining optical and near-infrared photometry, we model the spectral energy distribution of each point-source using stellar templates and state-of-the-art white dwarf models. For I {<=} 27 mag, we identify 23 stars with K0-M6 spectral types and two faint blue objects that are clearly old, thick disk white dwarfs. We measure a thick disk white dwarf space density of 0.1-1.7 Multiplication-Sign 10{sup -3} pc{sup -3} from these two objects. There are no halo white dwarfs in the UDF down to I = 27 mag. Combining the Hubble Deep Field North, South, and the UDF data, we do not see any evidence for dark matter in the form of faint halo white dwarfs, and the observed population of white dwarfs can be explained with the standard Galactic models.

Type I supernovae and angular anisotropy of the Hubble constant

International Nuclear Information System (INIS)

Le Denmat, Gerard; Vigier, J.-P.

1975-01-01

The observation of type I supernovae in distant galaxies yields an homogeneous sample of sources to evaluate their true distance. An examination of their distribution in the sky provides a significant confirmation of the angular anisotropy of the Hubble constant already observed by Rubin, Rubin and Ford [fr

UVUDF: Ultraviolet Imaging of the Hubble Ultra Deep Field with Wide-Field Camera 3

Science.gov (United States)

Teplitz, Harry I.; Rafelski, Marc; Kurczynski, Peter; Bond, Nicholas A.; Grogin, Norman; Koekemoer, Anton M.; Atek, Hakim; Brown, Thomas M.; Coe, Dan; Colbert, James W.; Ferguson, Henry C.; Finkelstein, Steven L.; Gardner, Jonathan P.; Gawiser, Eric; Giavalisco, Mauro; Gronwall, Caryl; Hanish, Daniel J.; Lee, Kyoung-Soo; de Mello, Duilia F.; Ravindranath, Swara; Ryan, Russell E.; Siana, Brian D.; Scarlata, Claudia; Soto, Emmaris; Voyer, Elysse N.; Wolfe, Arthur M.

2013-12-01

We present an overview of a 90 orbit Hubble Space Telescope treasury program to obtain near-ultraviolet imaging of the Hubble Ultra Deep Field using the Wide Field Camera 3 UVIS detector with the F225W, F275W, and F336W filters. This survey is designed to: (1) investigate the episode of peak star formation activity in galaxies at 1 dropouts at redshifts 1.7, 2.1, and 2.7 is largely consistent with the number predicted by published luminosity functions. We also confirm that the image mosaics have sufficient sensitivity and resolution to support the analysis of the evolution of star-forming clumps, reaching 28-29th magnitude depth at 5σ in a 0.''2 radius aperture depending on filter and observing epoch. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are #12534.

Hubble's View of Little Blue Dots

Science.gov (United States)

Kohler, Susanna

2018-02-01

The recent discovery of a new type of tiny, star-forming galaxy is the latest in a zoo of detections shedding light on our early universe. What can we learn from the unique little blue dots found in archival Hubble data?Peas, Berries, and DotsGreen pea galaxies identified by citizen scientists with Galaxy Zoo. [Richard Nowell Carolin Cardamone]As telescope capabilities improve and we develop increasingly deeper large-scale surveys of our universe, we continue to learn more about small, faraway galaxies. In recent years, increasing sensitivity first enabled the detection of green peas luminous, compact, low-mass (10 billion solar masses; compare this to the Milky Ways 1 trillion solar masses!) galaxies with high rates of star formation.Not long thereafter, we discovered galaxies that form stars similarly rapidly, but are even smaller only 330 million solar masses, spanning less than 3,000 light-years in size. These tiny powerhouses were termed blueberries for their distinctive color.Now, scientists Debra and Bruce Elmegreen (of Vassar College and IBM Research Division, respectively) report the discovery of galaxies that have even higher star formation rates and even lower masses: little blue dots.Exploring Tiny Star FactoriesThe Elmegreens discovered these unique galaxies by exploring archival Hubble data. The Hubble Frontier Fields data consist of deep images of six distant galaxy clusters and the parallel fields next to them. It was in the archival data for two Frontier Field Parallels, those for clusters Abell 2744 and MAS J0416.1-2403, that the authors noticed several galaxies that stand out as tiny, bright, blue objects that are nearly point sources.Top: a few examples of the little blue dots recently identified in two Hubble Frontier Field Parallels. Bottom: stacked images for three different groups of little blue dots. [Elmegreen Elmegreen 2017]The authors performed a search through the two Frontier Field Parallels, discovering a total of 55 little blue dots

Studying Galaxy Formation with the Hubble, Spitzer and James Webb Space Telescopes

Science.gov (United States)

Gardner, Jonathan P.

2009-01-01

The deepest optical to infrared observations of the universe include the Hubble Deep Fields, the Great Observatories Origins Deep Survey and the recent Hubble Ultra-Deep Field. Galaxies are seen in these surveys at redshifts z greater than 6, less than 1 Gyr after the Big Bang, at the end of a period when light from the galaxies has reionized Hydrogen in the inter-galactic medium. These observations, combined with theoretical understanding, indicate that the first stars and galaxies formed at z greater than 10, beyond the reach of the Hubble and Spitzer Space Telescopes. To observe the first galaxies, NASA is planning the James Webb Space Telescope (JWST), a large (6.5m), cold (less than 50K), infrared-optimized observatory to be launched early in the next decade into orbit around the second Earth-Sun Lagrange point. JWST will have four instruments: The Near-Infrared Camera, the Near-Infrared multi-object Spectrograph, and the Tunable Filter Imager will cover the wavelength range 0.6 to 5 microns, while the Mid-Infrared Instrument will do both imaging and spectroscopy from 5 to 28.5 microns. In addition to JWST's ability to study the formation and evolution of galaxies, I will also briefly review its expected contributions to studies of the formation of stars and planetary systems, and discuss recent progress in constructing the observatory.

A Guided Inquiry on Hubble Plots and the Big Bang

Science.gov (United States)

Forringer, Ted

2014-01-01

In our science for non-science majors course "21st Century Physics," we investigate modern "Hubble plots" (plots of velocity versus distance for deep space objects) in order to discuss the Big Bang, dark matter, and dark energy. There are two potential challenges that our students face when encountering these topics for the…

Nickel-hydrogen battery testing for Hubble Space Telescope

Science.gov (United States)

Baggett, Randy M.; Whitt, Thomas H.

1989-01-01

The authors identify objectives and provide data from several nickel-hydrogen battery tests designed to evaluate the possibility of launching Ni-H2 batteries on the Hubble Space Telescope (HST). Test results from a 14-cell battery, a 12-cell battery, and a 4-cell pack are presented. Results of a thermal vacuum test to verify the battery-module/bay heat rejection capacity are reported. A 6-battery system simulation breadboard is described, and test results are presented.

The Hubble Space Telescope nickel-hydrogen battery design

Science.gov (United States)

Nawrocki, D. E.; Armantrout, J. D.; Standlee, D. J.; Baker, R. C.; Lanier, J. R.

1990-01-01

Details are presented of the HST (Hubble Space Telescope) battery cell, battery package, and module mechanical and electrical designs. Also included are a summary of acceptance, qualification, and vibration tests and thermal vacuum testing. Unique details of battery cell charge retention performance characteristics associated with prelaunch hold conditions are discussed. Special charge control methods to minimize thermal dissipation during pad charging operations are summarized. This module design meets all NASA fracture control requirements for manned missions.

The effect of interacting dark energy on local measurements of the Hubble constant

International Nuclear Information System (INIS)

Odderskov, Io; Baldi, Marco; Amendola, Luca

2016-01-01

In the current state of cosmology, where cosmological parameters are being measured to percent accuracy, it is essential to understand all sources of error to high precision. In this paper we present the results of a study of the local variations in the Hubble constant measured at the distance scale of the Coma Cluster, and test the validity of correcting for the peculiar velocities predicted by gravitational instability theory. The study is based on N-body simulations, and includes models featuring a coupling between dark energy and dark matter, as well as two ΛCDM simulations with different values of σ 8 . It is found that the variance in the local flows is significantly larger in the coupled models, which increases the uncertainty in the local measurements of the Hubble constant in these scenarios. By comparing the results from the different simulations, it is found that most of the effect is caused by the higher value of σ 8 in the coupled cosmologies, though this cannot account for all of the additional variance. Given the discrepancy between different estimates of the Hubble constant in the universe today, cosmological models causing a greater cosmic variance is something that we should be aware of.

The effect of interacting dark energy on local measurements of the Hubble constant

Energy Technology Data Exchange (ETDEWEB)

Odderskov, Io [Department of Physics and Astronomy, University of Aarhus, Ny Munkegade 120, Aarhus C (Denmark); Baldi, Marco [Dipartimento di Fisica e Astronomia, Alma Mater Studiorum Università di Bologna, viale Berti Pichat 6/2, I-40127, Bologna (Italy); Amendola, Luca, E-mail: isho07@phys.au.dk, E-mail: marco.baldi5@unibo.it, E-mail: l.amendola@thphys.uni-heidelberg.de [Institut für Theoretische Physik, Ruprecht-Karls-Universität Heidelberg, Philosophenweg 16, 69120 Heidelberg (Germany)

2016-05-01

In the current state of cosmology, where cosmological parameters are being measured to percent accuracy, it is essential to understand all sources of error to high precision. In this paper we present the results of a study of the local variations in the Hubble constant measured at the distance scale of the Coma Cluster, and test the validity of correcting for the peculiar velocities predicted by gravitational instability theory. The study is based on N-body simulations, and includes models featuring a coupling between dark energy and dark matter, as well as two ΛCDM simulations with different values of σ{sub 8}. It is found that the variance in the local flows is significantly larger in the coupled models, which increases the uncertainty in the local measurements of the Hubble constant in these scenarios. By comparing the results from the different simulations, it is found that most of the effect is caused by the higher value of σ{sub 8} in the coupled cosmologies, though this cannot account for all of the additional variance. Given the discrepancy between different estimates of the Hubble constant in the universe today, cosmological models causing a greater cosmic variance is something that we should be aware of.

Astronomers celebrate a year of new Hubble results

Science.gov (United States)

1995-02-01

"We are beginning to understand that because of these observations we are going to have to change the way we look at the Universe," said ESA's Dr Duccio Macchetto, Associate Director for Science Programs at the Space Telescope Science Institute (STScI), Baltimore, Maryland, USA. The European Space Agency plays a major role in the Hubble Space Telescope programme. The Agency provided one of the telescope's four major instruments, called the Faint Object Camera, and two sets of electricity-generating solar arrays. In addition, 15 ESA scientific and technical staff work at the STScI. In return for this contribution, European astronomers are entitled to 15 percent of the telescope's observing time, although currently they account for 20 percent of all observations. "This is a testimony to the quality of the European science community", said Dr Roger Bonnet, Director of Science at ESA. "We are only guaranteed 15 percent of the telescope's use, but consistently receive much more than that." Astronomers from universities, observatories and research institutes across Europe lead more than 60 investigations planned for the telescope's fifth observing cycle, which begins this summer. Many more Europeans contribute to teams led by other astronomers. Looking back to the very start of time European astronomer Dr Peter Jakobsen used ESA's Faint Object Camera to confirm that helium was present in the early Universe. Astronomers had long predicted that 90 percent of the newly born Universe consisted of hydrogen, with helium making up the remainder. Before the refurbished Hubble came along, it was easy to detect the hydrogen, but the primordial helium remained elusive. The ultraviolet capabilities of the telescope, combined with the improvement in spatial resolution following the repair, made it possible for Dr Jakobsen to obtain an image of a quasar close to the edge of the known Universe. A spectral analysis of this picture revealed the quasar's light, which took 13 billion years

Hubble Space Telescope electrical power system

Science.gov (United States)

Whitt, Thomas H.; Bush, John R., Jr.

1990-01-01

The Hubble Space Telescope (HST) electrical power system (EPS) is supplying between 2000 and 2400 W of continuous power to the electrical loads. The major components of the EPS are the 5000-W back surface field reflector solar array, the six nickel-hydrogen (NiH2) 22-cell 88-Ah batteries, and the charge current controllers, which, in conjunction with the flight computer, control battery charging. The operation of the HST EPS and the results of the HST NiH2 six-battery test are discussed, and preliminary flight data are reviewed. The HST NiH2 six-battery test is a breadboard of the HST EPS on test at Marshall Space Flight Center.

Constraining the evolution of the Hubble Parameter using cosmic chronometers

Science.gov (United States)

Dickinson, Hugh

2017-08-01

Substantial investment is being made in space- and ground-based missions with the goal of revealing the nature of the observed cosmic acceleration. This is one of the most important unsolved problems in cosmology today.We propose here to constrain the evolution of the Hubble parameter [H(z)] between 1.3 fundamental nature of dark energy.

"HUBBLE, the astronomer, the telescope, the results"

CERN Multimedia

CERN. Geneva

2011-01-01

The fundamental discoveries made by Edwin Hubble in the first quarter of the last century will be presented. The space telescope bearing his name will be introduced, as well as the strategy put in place by NASA and the European Space Agency for its operation and its maintenance on-orbit. The personal experience of the speaker having participated in two of five servicing mission will be exposed and illustrated by pictures taken on-orbit. Finally, the main results obtained by the orbital observatory will be presented, in particular the ones related to the large scale structure of the Universe and its early history

Hubble Images Reveal Jupiter's Auroras

Science.gov (United States)

1996-01-01

These images, taken by the Hubble Space Telescope, reveal changes in Jupiter's auroral emissions and how small auroral spots just outside the emission rings are linked to the planet's volcanic moon, Io. The images represent the most sensitive and sharply-detailed views ever taken of Jovian auroras.The top panel pinpoints the effects of emissions from Io, which is about the size of Earth's moon. The black-and-white image on the left, taken in visible light, shows how Io and Jupiter are linked by an invisible electrical current of charged particles called a 'flux tube.' The particles - ejected from Io (the bright spot on Jupiter's right) by volcanic eruptions - flow along Jupiter's magnetic field lines, which thread through Io, to the planet's north and south magnetic poles. This image also shows the belts of clouds surrounding Jupiter as well as the Great Red Spot.The black-and-white image on the right, taken in ultraviolet light about 15 minutes later, shows Jupiter's auroral emissions at the north and south poles. Just outside these emissions are the auroral spots. Called 'footprints,' the spots are created when the particles in Io's 'flux tube' reach Jupiter's upper atmosphere and interact with hydrogen gas, making it fluoresce. In this image, Io is not observable because it is faint in the ultraviolet.The two ultraviolet images at the bottom of the picture show how the auroral emissions change in brightness and structure as Jupiter rotates. These false-color images also reveal how the magnetic field is offset from Jupiter's spin axis by 10 to 15 degrees. In the right image, the north auroral emission is rising over the left limb; the south auroral oval is beginning to set. The image on the left, obtained on a different date, shows a full view of the north aurora, with a strong emission inside the main auroral oval.The images were taken by the telescope's Wide Field and Planetary Camera 2 between May 1994 and September 1995.This image and other images and data

The Hubble series: convergence properties and redshift variables

International Nuclear Information System (INIS)

Cattoen, Celine; Visser, Matt

2007-01-01

In cosmography, cosmokinetics and cosmology, it is quite common to encounter physical quantities expanded as a Taylor series in the cosmological redshift z. Perhaps the most well-known exemplar of this phenomenon is the Hubble relation between distance and redshift. However, we now have considerable high-z data available; for instance, we have supernova data at least back to redshift z ∼ 1.75. This opens up the theoretical question as to whether or not the Hubble series (or more generally any series expansion based on the z-redshift) actually converges for large redshift. Based on a combination of mathematical and physical reasonings, we argue that the radius of convergence of any series expansion in z is less than or equal to 1, and that z-based expansions must break down for z > 1, corresponding to a universe less than half of its current size. Furthermore, we shall argue on theoretical grounds for the utility of an improved parametrization y = z/(1 + z). In terms of the y-redshift, we again argue that the radius of convergence of any series expansion in y is less than or equal to 1, so that y-based expansions are likely to be good all the way back to the big bang (y = 1), but that y-based expansions must break down for y < -1, now corresponding to a universe more than twice its current size

The variance of the locally measured Hubble parameter explained with different estimators

DEFF Research Database (Denmark)

Odderskov, Io Sandberg Hess; Hannestad, Steen; Brandbyge, Jacob

2017-01-01

We study the expected variance of measurements of the Hubble constant, H0, as calculated in either linear perturbation theory or using non-linear velocity power spectra derived from N-body simulations. We compare the variance with that obtained by carrying out mock observations in the N......-body simulations, and show that the estimator typically used for the local Hubble constant in studies based on perturbation theory is different from the one used in studies based on N-body simulations. The latter gives larger weight to distant sources, which explains why studies based on N-body simulations tend...... to obtain a smaller variance than that found from studies based on the power spectrum. Although both approaches result in a variance too small to explain the discrepancy between the value of H0 from CMB measurements and the value measured in the local universe, these considerations are important in light...

The Hubble Tarantula Treasury Project

Science.gov (United States)

Sabbi, Elena; Lennon, D. J.; Anderson, J.; Van Der Marel, R. P.; Aloisi, A.; Boyer, M. L.; Cignoni, M.; De Marchi, G.; de Mink, S. E.; Evans, C. J.; Gallagher, J. S.; Gordon, K. D.; Gouliermis, D.; Grebel, E.; Koekemoer, A. M.; Larsen, S. S.; Panagia, N.; Ryon, J. E.; Smith, L. J.; Tosi, M.; Zaritsky, D. F.

2014-01-01

The Tarantula Nebula (a.k.a. 30 Doradus) in the Large Magellanic Cloud is one of the most famous objects in astronomy, with first astronomical references being more than 150 years old. Today the Tarantula Nebula and its ionizing cluster R136 are considered one of the few known starburst regions in the Local Group and an ideal test bed to investigate the temporal and spatial evolution of a prototypical starburst on a sub-cluster scale. The Hubble Tarantula Treasury Project (HTTP) is a panchromatic imaging survey of the stellar populations and ionized gas in the Tarantula Nebula that reaches into the sub-solar mass regime (eBook that explains how stars form and evolve using images from HTTP. The eBook utilizes emerging technology that works in conjunction with the built-in accessibility features in the Apple iPad to allow totally blind users to interactively explore complex astronomical images.

Astronaut Anna Fisher in NBS Training For Hubble Space Telescope

Science.gov (United States)

1980-01-01

The Hubble Space Telescope (HST) is a cooperative program of the European Space Agency (ESA) and the National Aeronautical and Space Administration (NASA) to operate a long-lived space-based observatory. It was the flagship mission of NASA's Great Observatories program. The HST program began as an astronomical dream in the 1940s. During the 1970s and 1980s, the HST was finally designed and built becoming operational in the 1990s. The HST was deployed into a low-Earth orbit on April 25, 1990 from the cargo bay of the Space Shuttle Discovery (STS-31). The design of the HST took into consideration its length of service and the necessity of repairs and equipment replacement by making the body modular. In doing so, subsequent shuttle missions could recover the HST, replace faulty or obsolete parts and be re-released. Marshall Space Flight Center's (MSFC's) Neutral Buoyancy Simulator (NBS) served as the test center for shuttle astronauts training for Hubble related missions. Shown is astronaut Anna Fisher training on a mock-up of a modular section of the HST for an axial scientific instrument change out.

Solar system anomalies: Revisiting Hubble's law

Science.gov (United States)

Plamondon, R.

2017-12-01

This paper investigates the impact of a new metric recently published [R. Plamondon and C. Ouellet-Plamondon, in On Recent Developments in Theoretical and Experimental General Relativity, Astrophysics, and Relativistic Field Theories, edited by K. Rosquist, R. T. Jantzen, and R. Ruffini (World Scientific, Singapore, 2015), p. 1301] for studying the space-time geometry of a static symmetric massive object. This metric depends on a complementary error function (erfc) potential that characterizes the emergent gravitation field predicted by the model. This results in two types of deviations as compared to computations made on the basis of a Newtonian potential: a constant and a radial outcome. One key feature of the metric is that it postulates the existence of an intrinsic physical constant σ , the massive object-specific proper length that scales measurements in its surroundings. Although σ must be evaluated experimentally, we use a heuristic to estimate its value and point out some latent relationships between the Hubble constant, the secular increase in the astronomical unit, and the Pioneers delay. Indeed, highlighting the systematic errors that emerge when the effect of σ is neglected, one can link the Hubble constant H 0 to σ Sun and the secular increase V AU to σ Earth . The accuracy of the resulting numerical predictions, H 0 = 74 . 42 ( 0 . 02 ) ( km / s ) / Mpc and V AU ≅ 7.8 cm yr-1 , calls for more investigations of this new metric by specific experts. Moreover, we investigate the expected impacts of the new metric on the flyby anomalies, and we revisit the Pioneers delay. It is shown that both phenomena could be partly taken into account within the context of this unifying paradigm, with quite accurate numerical predictions. A correction for the osculating asymptotic velocity at the perigee of the order of 10 mm/s and an inward radial acceleration of 8 . 34 × 10 - 10 m / s 2 affecting the Pioneer ! space crafts could be explained by this new model.

Dynamical interpretation of the Hubble sequence of galaxies

Energy Technology Data Exchange (ETDEWEB)

Dallaporta, N; Secco, L [Padua Univ. (Italy). Istituto di Astronomia

1977-08-01

Brosche (1970) has proposed a theory in which the energy loss due to collisions among gas clouds contained in a galaxy constitutes the driving mechanism for its evolution, through virial equilibrium states, which, from an initial spherical shape, makes it to contract towards an elongated form; moreover, the value of the total angular momentum, assumed as given by uniform rotation, is assumed to determine the galaxy type on the Hubble sequence and to influence strongly the contraction time from the initial spherical to the final flat configuration. The authors modify Brosche's scheme by assuming as models the rotating polytropes of Chandrasekhar and Lebovitz with variable density from centre to border. As a consequence of this change, centrifugal shedding of matter is attained at the equator of the contracting ellipsoid for a configuration with an axial ratio different from zero, so that, hereafter, a flat disk is formed surrounding the internal bulge, with a decreasing overall eccentricity; the rotation curve assumes then an aspect qualitatively similar to the one observed for spiral galaxies. The feedback of star formation which, by exhausting the material of the gas clouds, is able to stop the driving mechanism of evolution before the final flat stage is attained has also been considered at several positions according to the value of the angular momentum. Numerical calculations seem to indicate that one can obtain in this way, by varying the angular momentum and the initial number of clouds, different galaxy types (elliptical, lenticular, spiral) resembling those of the Hubble sequence.

Constraining dark energy with Hubble parameter measurements: an analysis including future redshift-drift observations

International Nuclear Information System (INIS)

Guo, Rui-Yun; Zhang, Xin

2016-01-01

The nature of dark energy affects the Hubble expansion rate (namely, the expansion history) H(z) by an integral over w(z). However, the usual observables are the luminosity distances or the angular diameter distances, which measure the distance.redshift relation. Actually, the property of dark energy affects the distances (and the growth factor) by a further integration over functions of H(z). Thus, the direct measurements of the Hubble parameter H(z) at different redshifts are of great importance for constraining the properties of dark energy. In this paper, we show how the typical dark energy models, for example, the ΛCDM, wCDM, CPL, and holographic dark energy models, can be constrained by the current direct measurements of H(z) (31 data used in total in this paper, covering the redshift range of z @ element of [0.07, 2.34]). In fact, the future redshift-drift observations (also referred to as the Sandage-Loeb test) can also directly measure H(z) at higher redshifts, covering the range of z @ element of [2, 5]. We thus discuss what role the redshift-drift observations can play in constraining dark energy with the Hubble parameter measurements. We show that the constraints on dark energy can be improved greatly with the H(z) data from only a 10-year observation of redshift drift. (orig.)

Asteroseismology of the Transiting Exoplanet Host HD 17156 with Hubble Space Telescope Fine Guidance Sensor

DEFF Research Database (Denmark)

Gilliland, Ronald L.; McCullough, Peter R.; Nelan, Edmund P.

2011-01-01

light curve. Using the density constraint from asteroseismology, and stellar evolution modeling results in M * = 1.285 ± 0.026 M sun, R * = 1.507 ± 0.012 R sun, and a stellar age of 3.2 ± 0.3 Gyr. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science......Observations conducted with the Fine Guidance Sensor on the Hubble Space Telescope (HST) providing high cadence and precision time-series photometry were obtained over 10 consecutive days in 2008 December on the host star of the transiting exoplanet HD 17156b. During this time, 1.0 × 1012 photons...... Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555....

THE PANCHROMATIC HUBBLE ANDROMEDA TREASURY

International Nuclear Information System (INIS)

Dalcanton, Julianne J.; Williams, Benjamin F.; Rosenfield, Philip; Weisz, Daniel R.; Gilbert, Karoline M.; Gogarten, Stephanie M.; Lang, Dustin; Lauer, Tod R.; Dong Hui; Kalirai, Jason S.; Boyer, Martha L.; Gordon, Karl D.; Seth, Anil C.; Dolphin, Andrew; Bell, Eric F.; Bianchi, Luciana C.; Caldwell, Nelson; Dorman, Claire E.; Guhathakurta, Puragra; Girardi, Léo

2012-01-01

The Panchromatic Hubble Andromeda Treasury is an ongoing Hubble Space Telescope Multi-Cycle Treasury program to image ∼1/3 of M31's star-forming disk in six filters, spanning from the ultraviolet (UV) to the near-infrared (NIR). We use the Wide Field Camera 3 (WFC3) and Advanced Camera for Surveys (ACS) to resolve the galaxy into millions of individual stars with projected radii from 0 to 20 kpc. The full survey will cover a contiguous 0.5 deg 2 area in 828 orbits. Imaging is being obtained in the F275W and F336W filters on the WFC3/UVIS camera, F475W and F814W on ACS/WFC, and F110W and F160W on WFC3/IR. The resulting wavelength coverage gives excellent constraints on stellar temperature, bolometric luminosity, and extinction for most spectral types. The data produce photometry with a signal-to-noise ratio of 4 at m F275W = 25.1, m F336W = 24.9, m F475W = 27.9, m F814W = 27.1, m F110W = 25.5, and m F160W = 24.6 for single pointings in the uncrowded outer disk; in the inner disk, however, the optical and NIR data are crowding limited, and the deepest reliable magnitudes are up to 5 mag brighter. Observations are carried out in two orbits per pointing, split between WFC3/UVIS and WFC3/IR cameras in primary mode, with ACS/WFC run in parallel. All pointings are dithered to produce Nyquist-sampled images in F475W, F814W, and F160W. We describe the observing strategy, photometry, astrometry, and data products available for the survey, along with extensive testing of photometric stability, crowding errors, spatially dependent photometric biases, and telescope pointing control. We also report on initial fits to the structure of M31's disk, derived from the density of red giant branch stars, in a way that is independent of assumed mass-to-light ratios and is robust to variations in dust extinction. These fits also show that the 10 kpc ring is not just a region of enhanced recent star formation, but is instead a dynamical structure containing a significant overdensity of

CONSTRAINING DUST AND COLOR VARIATIONS OF HIGH-z SNe USING NICMOS ON THE HUBBLE SPACE TELESCOPE

International Nuclear Information System (INIS)

Nobili, S.; Amanullah, R.; Goobar, A.

2009-01-01

We present data from the Supernova Cosmology Project for five high redshift Type Ia supernovae (SNe Ia) that were obtained using the NICMOS infrared camera on the Hubble Space Telescope. We add two SNe from this sample to a rest-frame I-band Hubble diagram, doubling the number of high redshift supernovae on this diagram. This I-band Hubble diagram is consistent with a flat universe (Ω M , Ω Λ ) = (0.29, 0.71). A homogeneous distribution of large grain dust in the intergalactic medium (replenishing dust) is incompatible with the data and is excluded at the 5σ confidence level, if the SN host galaxy reddening is corrected assuming R V = 1.75. We use both optical and infrared observations to compare photometric properties of distant SNe Ia with those of nearby objects. We find generally good agreement with the expected color evolution for all SNe except the highest redshift SN in our sample (SN 1997ek at z = 0.863) which shows a peculiar color behavior. We also present spectra obtained from ground-based telescopes for type identification and determination of redshift.

Hubble Space Telescope via the Web

Science.gov (United States)

O'Dea, Christopher P.

The Space Telescope Science Institute (STScI) makes available a wide variety of information concerning the Hubble Space Telescope (HST) via the Space Telescope Electronic Information Service (STEIS). STEIS is accessible via anonymous ftp, gopher, WAIS, and WWW. The information on STEIS includes how to propose for time on the HST, the current status of HST, reports on the scientific instruments, the observing schedule, data reduction software, calibration files, and a set of publicly available images in JPEG, GIF and TIFF format. STEIS serves both the astronomical community as well as the larger Internet community. WWW is currently the most widely used interface to STEIS. Future developments on STEIS are expected to include larger amounts of hypertext, especially HST images and educational material of interest to students, educators, and the general public, and the ability to query proposal status.

Eyes on the Universe: The Legacy of the Hubble Space Telescope and Looking to the Future with the James Webb Space Telescope

Science.gov (United States)

Straughn, Amber

2011-01-01

Over the past 20 years the Hubble Space Telescope has revolutionized our understanding of the Universe. Most recently, the complete refurbishment of Hubble in 2009 has given new life to the telescope and the new science instruments have already produced groundbreaking science results, revealing some of the most distant galaxy candidates ever discovered. Despite the remarkable advances in astrophysics that Hubble has provided, the new questions that have arisen demand a new space telescope with new technologies and capabilities. I will present the exciting new technology development and science goals of NASA's James Webb Space Telescope, which is currently being built and tested and will be launched this decade.

Metrical connection in space-time, Newton's and Hubble's laws

International Nuclear Information System (INIS)

Maeder, A.

1978-01-01

The theory of gravitation in general relativity is not scale invariant. Here, we follow Dirac's proposition of a scale invariant theory of gravitation (i.e. a theory in which the equations keep their form when a transformation of scale is made). We examine some concepts of Weyl's geometry, like the metrical connection, the scale transformations and invariance, and we discuss their consequences for the equation of the geodetic motion and for its Newtonian limit. Under general conditions, we show that the only non-vanishing component of the coefficient of metrical connection may be identified with Hubble's constant. In this framework, the equivalent to the Newtonian approximation for the equation of motion contains an additional acceleration term Hdr vector /dt, which produces an expansion of gravitational systems. The velocity of this expansion is shown to increase linearly with the distance between interacting objects. The relative importance of this new expansion term to the Newtonian one varies like (2rhosub(c)/rho)sup(1/2), where rhosub(c) is the critical density of the Einsteinde Sitter model and rho is the mean density of the considered gravitational configuration. Thus, this 'generalized expansion' is important essentially for systems of mean density not too much above the critical density. Finally, our main conclusion is that in the integrable Weyl geometry, Hubble's law - like Newton's law - would appear as an intrinsic property of gravitation, being only the most visible manifestation of a general effect characterizing the gravitational interaction. (orig.) [de

Hubble Space Telescope: The Telescope, the Observations & the Servicing Mission

Science.gov (United States)

1999-11-01

Today the HST Archives contain more than 260 000 astronomical observations. More than 13 000 astronomical objects have been observed by hundreds of different groups of scientists. Direct proof of the scientific significance of this project is the record-breaking number of papers published : over 2400 to date. Some of HST's most memorable achievements are: * the discovery of myriads of very faint galaxies in the early Universe, * unprecedented, accurate measurements of distances to the farthest galaxies, * significant improvement in the determination of the Hubble constant and thus the age of the Universe, * confirmation of the existence of blacks holes, * a far better understanding of the birth, life and death of stars, * a very detailed look at the secrets of the process by which planets are created. Europe and HST ESA's contribution to HST represents a nominal investment of 15%. ESA provided one of the two imaging instruments - the Faint Object Camera (FOC) - and the solar panels. It also has 15 scientists and computer staff working at the Space Telescope Science Institute in Baltimore (Maryland). In Europe the astronomical community receives observational assistance from the Space Telescope European Coordinating Facility (ST-ECF) located in Garching, Munich. In return for ESA's investment, European astronomers have access to approximately 15% of the observing time. In reality the actual observing time competitively allocated to European astronomers is closer to 20%. Looking back at almost ten years of operation, the head of ST-ECF, European HST Project Scientist Piero Benvenuti states: "Hubble has been of paramount importance to European astronomy, much more than the mere 20% of observing time. It has given the opportunity for European scientists to use a top class instrument that Europe alone would not be able to build and operate. In specific areas of research they have now, mainly due to HST, achieved international leadership." One of the major reasons for

Hubble Diagram Test of Expanding and Static Cosmological Models: The Case for a Slowly Expanding Flat Universe

Directory of Open Access Journals (Sweden)

Laszlo A. Marosi

2013-01-01

Full Text Available We present a new redshift (RS versus photon travel time ( test including 171 supernovae RS data points. We extended the Hubble diagram to a range of z = 0,0141–8.1 in the hope that at high RSs, the fitting of the calculated RS/ diagrams to the observed RS data would, as predicted by different cosmological models, set constraints on alternative cosmological models. The Lambda cold dark matter (ΛCDM, the static universe model, and the case for a slowly expanding flat universe (SEU are considered. We show that on the basis of the Hubble diagram test, the static and the slowly expanding models are favored.

An updated Type II supernova Hubble diagram

Science.gov (United States)

Gall, E. E. E.; Kotak, R.; Leibundgut, B.; Taubenberger, S.; Hillebrandt, W.; Kromer, M.; Burgett, W. S.; Chambers, K.; Flewelling, H.; Huber, M. E.; Kaiser, N.; Kudritzki, R. P.; Magnier, E. A.; Metcalfe, N.; Smith, K.; Tonry, J. L.; Wainscoat, R. J.; Waters, C.

2018-03-01

We present photometry and spectroscopy of nine Type II-P/L supernovae (SNe) with redshifts in the 0.045 ≲ z ≲ 0.335 range, with a view to re-examining their utility as distance indicators. Specifically, we apply the expanding photosphere method (EPM) and the standardized candle method (SCM) to each target, and find that both methods yield distances that are in reasonable agreement with each other. The current record-holder for the highest-redshift spectroscopically confirmed supernova (SN) II-P is PS1-13bni (z = 0.335-0.012+0.009), and illustrates the promise of Type II SNe as cosmological tools. We updated existing EPM and SCM Hubble diagrams by adding our sample to those previously published. Within the context of Type II SN distance measuring techniques, we investigated two related questions. First, we explored the possibility of utilising spectral lines other than the traditionally used Fe IIλ5169 to infer the photospheric velocity of SN ejecta. Using local well-observed objects, we derive an epoch-dependent relation between the strong Balmer line and Fe IIλ5169 velocities that is applicable 30 to 40 days post-explosion. Motivated in part by the continuum of key observables such as rise time and decline rates exhibited from II-P to II-L SNe, we assessed the possibility of using Hubble-flow Type II-L SNe as distance indicators. These yield similar distances as the Type II-P SNe. Although these initial results are encouraging, a significantly larger sample of SNe II-L would be required to draw definitive conclusions. Tables A.1, A.3, A.5, A.7, A.9, A.11, A.13, A.15 and A.17 are also available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/611/A25

The Great Attractor: At the Limits of Hubble's Law of the Expanding Universe.

Science.gov (United States)

Murdin, Paul

1991-01-01

Presents the origin and mathematics of Hubble's Law of the expanding universe. Discusses limitations to this law and the related concepts of standard candles, elliptical galaxies, and streaming motions, which are conspicuous deviations from the law. The third of three models proposed as explanations for streaming motions is designated: The Great…

THE HUBBLE SPACE TELESCOPE UV LEGACY SURVEY OF GALACTIC GLOBULAR CLUSTERS. VII. IMPLICATIONS FROM THE NEARLY UNIVERSAL NATURE OF HORIZONTAL BRANCH DISCONTINUITIES

Energy Technology Data Exchange (ETDEWEB)

Brown, T. M.; Bellini, A.; Anderson, J. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Cassisi, S.; Pietrinferni, A. [INAF-Osservatorio Astronomico di Teramo, Via Mentore Maggini s.n.c., I-64100 Teramo (Italy); D’Antona, F. [INAF-Osservatorio Astronomico di Roma, Via Frascati 33, I-00040 Monteporzio Catone, Roma (Italy); Salaris, M. [Astrophysics Research Institute,Liverpool John Moores University, Liverpool Science Park, IC2 Building, 146 Brownlow Hill, Liverpool L3 5RF (United Kingdom); Milone, A. P. [Research School of Astronomy and Astrophysics, The Australian National University, Cotter Road, Weston, ACT, 2611 (Australia); Dalessandro, E. [Dipartimento di Fisica e Astronomia, Università degli Studi di Bologna, Viale Berti Pichat 6/2, I-40127 Bologna (Italy); Piotto, G.; Ortolani, S.; Nardiello, D. [Dipartimento di Fisica e Astronomia “Galileo Galilei,”Università di Padova, Vicolo dell’Osservatorio 3, I-35122 Padova (Italy); Renzini, A.; Bedin, L. R. [INAF-Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, I-35122 Padova (Italy); Sweigart, A. V. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Sarajedini, A. [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611 (United States); Aparicio, A., E-mail: tbrown@stsci.edu, E-mail: jayander@stsci, E-mail: bellini@stsci.edu, E-mail: cassisi@oa-teramo.inaf.it, E-mail: pietrinferni@oa-teramo.inaf.it, E-mail: dantona@oa-roma.inaf.it, E-mail: M.Salaris@ljmu.ac.uk, E-mail: milone@mso.anu.edu.au [Instituto de Astrofísica de Canarias. Calle Vía Láctea s/n. E38200 — La Laguna, Tenerife, Canary Islands (Spain)

2016-05-01

The UV-initiative Hubble Space Telescope Treasury survey of Galactic globular clusters provides a new window into the phenomena that shape the morphological features of the horizontal branch (HB). Using this large and homogeneous catalog of UV and blue photometry, we demonstrate that the HB exhibits discontinuities that are remarkably consistent in color (effective temperature). This consistency is apparent even among some of the most massive clusters hosting multiple distinct sub-populations (such as NGC 2808, ω Cen, and NGC 6715), demonstrating that these phenomena are primarily driven by atmospheric physics that is independent of the underlying population properties. However, inconsistencies arise in the metal-rich clusters NGC 6388 and NGC 6441, where the discontinuity within the blue HB (BHB) distribution shifts ∼1000–2000 K hotter. We demonstrate that this shift is likely due to a large helium enhancement in the BHB stars of these clusters, which in turn affects the surface convection and evolution of such stars. Our survey also increases the number of Galactic globular clusters known to host blue-hook stars (also known as late hot flashers) from 6 to 23 clusters. These clusters are biased toward the bright end of the globular cluster luminosity function, confirming that blue-hook stars tend to form in the most massive clusters with significant self-enrichment.

New solution to the problem of the tension between the high-redshift and low-redshift measurements of the Hubble constant

Science.gov (United States)

Bolejko, Krzysztof

2018-01-01

During my talk I will present results suggesting that the phenomenon of emerging spatial curvature could resolve the conflict between Planck's (high-redshift) and Riess et al. (low-redshift) measurements of the Hubble constant. The phenomenon of emerging spatial curvature is absent in the Standard Cosmological Model, which has a flat and fixed spatial curvature (small perturbations are considered in the Standard Cosmological Model but their global average vanishes, leading to spatial flatness at all times).In my talk I will show that with the nonlinear growth of cosmic structures the global average deviates from zero. As a result, the spatial curvature evolves from spatial flatness of the early universe to a negatively curved universe at the present day, with Omega_K ~ 0.1. Consequently, the present day expansion rate, as measured by the Hubble constant, is a few percent higher compared to the high-redshift constraints. This provides an explanation why there is a tension between high-redshift (Planck) and low-redshift (Riess et al.) measurements of the Hubble constant. In the presence of emerging spatial curvature these two measurements should in fact be different: high redshift measurements should be slightly lower than the Hubble constant inferred from the low-redshift data.The presentation will be based on the results described in arXiv:1707.01800 and arXiv:1708.09143 (which discuss the phenomenon of emerging spatial curvature) and on a paper that is still work in progress but is expected to be posted on arxiv by the AAS meeting (this paper uses mock low-redshift data to show that starting from the Planck's cosmological models (in the early universe) but with the emerging spatial curvature taken into account, the low-redshift Hubble constant should be 72.4 km/s/Mpc.

The Carnegie-Chicago Hubble Program. I. An Independent Approach to the Extragalactic Distance Scale Using Only Population II Distance Indicators

Science.gov (United States)

Beaton, Rachael L.; Freedman, Wendy L.; Madore, Barry F.; Bono, Giuseppe; Carlson, Erika K.; Clementini, Gisella; Durbin, Meredith J.; Garofalo, Alessia; Hatt, Dylan; Jang, In Sung; Kollmeier, Juna A.; Lee, Myung Gyoon; Monson, Andrew J.; Rich, Jeffrey A.; Scowcroft, Victoria; Seibert, Mark; Sturch, Laura; Yang, Soung-Chul

2016-12-01

We present an overview of the Carnegie-Chicago Hubble Program, an ongoing program to obtain a 3% measurement of the Hubble constant (H 0) using alternative methods to the traditional Cepheid distance scale. We aim to establish a completely independent route to H 0 using RR Lyrae variables, the tip of the red giant branch (TRGB), and Type Ia supernovae (SNe Ia). This alternative distance ladder can be applied to galaxies of any Hubble type, of any inclination, and, using old stars in low-density environments, is robust to the degenerate effects of metallicity and interstellar extinction. Given the relatively small number of SNe Ia host galaxies with independently measured distances, these properties provide a great systematic advantage in the measurement of H 0 via the distance ladder. Initially, the accuracy of our value of H 0 will be set by the five Galactic RR Lyrae calibrators with Hubble Space Telescope Fine-Guidance Sensor parallaxes. With Gaia, both the RR Lyrae zero-point and TRGB method will be independently calibrated, the former with at least an order of magnitude more calibrators and the latter directly through parallax measurement of tip red giants. As the first end-to-end “distance ladder” completely independent of both Cepheid variables and the Large Magellanic Cloud, this path to H 0 will allow for the high-precision comparison at each rung of the traditional distance ladder that is necessary to understand tensions between this and other routes to H 0. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with programs #13472 and #13691.

Selections from 2017: Hubble Survey Explores Distant Galaxies

Science.gov (United States)

Kohler, Susanna

2017-12-01

Editors note:In these last two weeks of 2017, well be looking at a few selections that we havent yet discussed on AAS Nova from among the most-downloaded paperspublished in AAS journals this year. The usual posting schedule will resume in January.CANDELS Multi-Wavelength Catalogs: Source Identification and Photometry in the CANDELS COSMOSSurvey FieldPublished January2017Main takeaway:A publication led byHooshang Nayyeri(UC Irvine and UC Riverside) early this year details acatalog of sources built using the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey(CANDELS), a survey carried out by cameras on board the Hubble Space Telescope. The catalogliststhe properties of 38,000 distant galaxies visiblewithin the COSMOS field, a two-square-degree equatorial field explored in depthto answer cosmological questions.Why its interesting:Illustration showing the three-dimensional map of the dark matter distribution in theCOSMOS field. [Adapted from NASA/ESA/R. Massey(California Institute of Technology)]The depth and resolution of the CANDELS observations areuseful for addressingseveral major science goals, including the following:Studying the most distant objects in the universe at the epoch of reionization in the cosmic dawn.Understanding galaxy formation and evolution during the peak epoch of star formation in the cosmic high noon.Studying star formation from deep ultravioletobservations and studying cosmology from supernova observations.Why CANDELS is a major endeavor:CANDELS isthe largest multi-cycle treasury program ever approved on the Hubble Space Telescope using over 900 orbits between 2010 and 2013 withtwo cameras on board the spacecraftto study galaxy formation and evolution throughout cosmic time. The CANDELS images are all publicly available, and the new catalogrepresents an enormous source of information about distant objectsin our universe.CitationH. Nayyeri et al 2017 ApJS 228 7. doi:10.3847/1538-4365/228/1/7

The Hubble Constant from SN Refsdal

Science.gov (United States)

Vega-Ferrero, J.; Diego, J. M.; Miranda, V.; Bernstein, G. M.

2018-02-01

Hubble Space Telescope observations from 2015 December 11 detected the expected fifth counter-image of supernova (SN) Refsdal at z = 1.49. In this Letter, we compare the time-delay predictions from numerous models with the measured value derived by Kelly et al. from very early data in the light curve of the SN Refsdal and find a best value for {H}0={64}-11+9 {km} {{{s}}}-1 {{Mpc}}-1 (68% CL), in excellent agreement with predictions from cosmic microwave background and recent weak lensing data + baryon acoustic oscillations + Big Bang nucleosynthesis (from the DES Collaboration). This is the first constraint on H 0 derived from time delays between multiple-lensed SN images, and the first with a galaxy cluster lens, subject to systematic effects different from other time-delay H 0 estimates. Additional time-delay measurements from new multiply imaged SNe will allow derivation of competitive constraints on H 0.

Hubble diagram as a probe of minicharged particles

International Nuclear Information System (INIS)

Ahlers, Markus

2009-01-01

The luminosity-redshift relation of cosmological standard candles provides information about the relative energy composition of our Universe. In particular, the observation of type Ia supernovae up to a redshift of z∼2 indicates a universe which is dominated today by dark matter and dark energy. The propagation distance of light from these sources is of the order of the Hubble radius and serves as a very sensitive probe of feeble inelastic photon interactions with background matter, radiation, or magnetic fields. In this paper we discuss the limits on minicharged particle models arising from a dimming effect in supernova surveys. We briefly speculate about a strong dimming effect as an alternative to dark energy.

Hubble 3D: A Science and Hollywood Collaboration Made (Nearly) in Heaven

Science.gov (United States)

Showstack, Randy

2010-04-01

Just 2 days after the 2010 Academy Awards® ceremony in early March bestowed Oscars® for motion picture achievements, NASA deputy administrator Lori Garver touted a new film about the Hubble Space Telescope, Hubble 3D, for best drama, special effects, screenplay, actors and actress, and director and producer. The 43-minute IMAX and Warner Brothers Pictures production, which opened in theaters on 19 March, is an example of the ability of Hollywood and the science community to partner in providing a dynamic educational and entertaining product, according to a number of people associated with the film. Sharing the red carpet at the Smithsonian National Air and Space Museum in Washington, D. C., with astronauts and others to mark the world premiere, Garver said the film shows the drama of the astronauts’ efforts to repair the telescope while traveling 17,000 miles per hour and performing grueling space walks (see Figure 1). “We have literally opened our eyes on the universe through this telescope,” she said. “This is a taxpayer-funded agency, and we are giving back to the public the very story that they paid for.”

Testing the Interacting Dark Energy Model with Cosmic Microwave Background Anisotropy and Observational Hubble Data

Directory of Open Access Journals (Sweden)

Weiqiang Yang

2017-07-01

Full Text Available The coupling between dark energy and dark matter provides a possible approach to mitigate the coincidence problem of the cosmological standard model. In this paper, we assumed the interacting term was related to the Hubble parameter, energy density of dark energy, and equation of state of dark energy. The interaction rate between dark energy and dark matter was a constant parameter, which was, Q = 3 H ξ ( 1 + w x ρ x . Based on the Markov chain Monte Carlo method, we made a global fitting on the interacting dark energy model from Planck 2015 cosmic microwave background anisotropy and observational Hubble data. We found that the observational data sets slightly favored a small interaction rate between dark energy and dark matter; however, there was not obvious evidence of interaction at the 1 σ level.

Discovery of Hubble's Law as a Series of Type III Errors

Science.gov (United States)

Belenkiy, Ari

2015-01-01

Recently much attention has been paid to the history of the discovery of Hubble's law--the linear relation between the rate of recession of the remote galaxies and distance to them from Earth. Though historians of cosmology now mention several names associated with this law instead of just one, the motivation of each actor of that remarkable…

HUBBLE CAPTURES THE HEART OF STAR BIRTH

Science.gov (United States)

2002-01-01

NASA Hubble Space Telescope's Wide Field and Planetary Camera 2 (WFPC2) has captured a flurry of star birth near the heart of the barred spiral galaxy NGC 1808. On the left are two images, one superimposed over the other. The black-and-white picture is a ground-based view of the entire galaxy. The color inset image, taken with the Hubble telescope's Wide Field and Planetary Camera 2 (WFPC2), provides a close-up view of the galaxy's center, the hotbed of vigorous star formation. The ground-based image shows that the galaxy has an unusual, warped shape. Most spiral galaxies are flat disks, but this one has curls of dust and gas at its outer spiral arms (upper right-hand corner and lower left-hand corner). This peculiar shape is evidence that NGC 1808 may have had a close interaction with another nearby galaxy, NGC 1792, which is not in the picture Such an interaction could have hurled gas towards the nucleus of NGC 1808, triggering the exceptionally high rate of star birth seen in the WFPC2 inset image. The WFPC2 inset picture is a composite of images using colored filters that isolate red and infrared light as well as light from glowing hydrogen. The red and infrared light (seen as yellow) highlight older stars, while hydrogen (seen as blue) reveals areas of star birth. Colors were assigned to this false-color image to emphasize the vigorous star formation taking place around the galaxy's center. NGC 1808 is called a barred spiral galaxy because of the straight lines of star formation on both sides of the bright nucleus. This star formation may have been triggered by the rotation of the bar, or by matter which is streaming along the bar towards the central region (and feeding the star burst). Filaments of dust are being ejected from the core into a faint halo of stars surrounding the galaxy's disk (towards the upper left corner) by massive stars that have exploded as supernovae in the star burst region. The portion of the galaxy seen in this 'wide-field' image is

Super-Hubble de Sitter fluctuations and the dynamical RG

Energy Technology Data Exchange (ETDEWEB)

Burgess, C.P. [Department of Physics and Astronomy, McMaster University, Hamilton, Ontario (Canada); Leblond, L.; Shandera, S. [Perimeter Institute for Theoretical Physics, Waterloo, Ontario (Canada); Holman, R., E-mail: cburgess@perimeterinstitute.ca, E-mail: lleblond@perimeterinstitute.ca, E-mail: rha@andrew.cmu.edu, E-mail: sshandera@perimeterinstitute.ca [Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213 (United States)

2010-03-01

Perturbative corrections to correlation functions for interacting theories in de Sitter spacetime often grow secularly with time, due to the properties of fluctuations on super-Hubble scales. This growth can lead to a breakdown of perturbation theory at late times. We argue that Dynamical Renormalization Group (DRG) techniques provide a convenient framework for interpreting and resumming these secularly growing terms. In the case of a massless scalar field in de Sitter with quartic self-interaction, the resummed result is also less singular in the infrared, in precisely the manner expected if a dynamical mass is generated. We compare this improved infrared behavior with large-N expansions when applicable.

Electrostatic Studies for the 2008 Hubble Service Repair Mission

Science.gov (United States)

Buhler, C. R.; Clements, J. S.; Calle, C. I.

2012-01-01

High vacuum triboelectric testing of space materials was required to identify possible Electrostatic Discharge (ESD) concerns for the astronauts in space during electronics board replacement on the Hubble Space Telescope. Testing under high vacuum conditions with common materials resulted in some interesting results. Many materials were able to charge to high levels which did not dissipate quickly even when grounded. Certain materials were able to charge up in contact with grounded metals while others were not. An interesting result was that like materials did not exchange electrostatic charge under high vacuum conditions. The most surprising experimental result is the lack of brush discharges from charged insulators under high vacuum conditions.

HUBBLE SPACE TELESCOPE AND GROUND-BASED OBSERVATIONS OF V455 ANDROMEDAE POST-OUTBURST

Energy Technology Data Exchange (ETDEWEB)

Szkody, Paula; Mukadam, Anjum S.; Brown, Justin; Funkhouser, Kelsey [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Gänsicke, Boris T. [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Henden, Arne [AAVSO, 49 Bay State Road, Cambridge, MA 02138 (United States); Sion, Edward M. [Department of Astronomy and Astrophysics, Villanova University, Villanova, PA 19085 (United States); Townsley, Dean M. [Department of Physics and Astronomy, University of Alabama, Tuscaloosa, AL 35487 (United States); Christian, Damian [Department of Physics and Astronomy, California State University, Northridge, CA 91330 (United States); Falcon, Ross E. [Department of Astronomy, University of Texas, Austin, TX 78712 (United States); Pyrzas, Stylianos, E-mail: szkody@astro.washington.edu, E-mail: anjum@astro.washington.edu, E-mail: boris.gaensicke@warwick.ac.uk, E-mail: arne@aavso.org, E-mail: edward.sion@villanova.edu, E-mail: Dean.M.Townsley@ua.edu, E-mail: damian.christian@csun.edu, E-mail: cylver@astro.as.utexas.edu, E-mail: stylianos.pyrzas@gmail.com [Instituto de Astronomia, Universidad Catolica del Norte, Avenida Angamos 0619, Antofagasta (Chile)

2013-09-20

Hubble Space Telescope spectra obtained in 2010 and 2011, 3 and 4 yr after the large amplitude dwarf nova outburst of V455 And, were combined with optical photometry and spectra to study the cooling of the white dwarf, its spin, and possible pulsation periods after the outburst. The modeling of the ultraviolet (UV) spectra shows that the white dwarf temperature remains ∼600 K hotter than its quiescent value at 3 yr post-outburst, and still a few hundred degrees hotter at 4 yr post-outburst. The white dwarf spin at 67.6 s and its second harmonic at 33.8 s are visible in the optical within a month of outburst and are obvious in the later UV observations in the shortest wavelength continuum and the UV emission lines, indicating an origin in high-temperature regions near the accretion curtains. The UV light curves folded on the spin period show a double-humped modulation consistent with two-pole accretion. The optical photometry 2 yr after outburst shows a group of frequencies present at shorter periods (250-263 s) than the periods ascribed to pulsation at quiescence, and these gradually shift toward the quiescent frequencies (300-360 s) as time progresses past outburst. The most surprising result is that the frequencies near this period in the UV data are only prominent in the emission lines, not the UV continuum, implying an origin away from the white dwarf photosphere. Thus, the connection of this group of periods with non-radial pulsations of the white dwarf remains elusive.

The Hubble Legacy Archive ACS grism data

Science.gov (United States)

Kümmel, M.; Rosati, P.; Fosbury, R.; Haase, J.; Hook, R. N.; Kuntschner, H.; Lombardi, M.; Micol, A.; Nilsson, K. K.; Stoehr, F.; Walsh, J. R.

2011-06-01

A public release of slitless spectra, obtained with ACS/WFC and the G800L grism, is presented. Spectra were automatically extracted in a uniform way from 153 archival fields (or "associations") distributed across the two Galactic caps, covering all observations to 2008. The ACS G800L grism provides a wavelength range of 0.55-1.00 μm, with a dispersion of 40 Å/pixel and a resolution of ~80 Å for point-like sources. The ACS G800L images and matched direct images were reduced with an automatic pipeline that handles all steps from archive retrieval, alignment and astrometric calibration, direct image combination, catalogue generation, spectral extraction and collection of metadata. The large number of extracted spectra (73,581) demanded automatic methods for quality control and an automated classification algorithm was trained on the visual inspection of several thousand spectra. The final sample of quality controlled spectra includes 47 919 datasets (65% of the total number of extracted spectra) for 32 149 unique objects, with a median iAB-band magnitude of 23.7, reaching 26.5 AB for the faintest objects. Each released dataset contains science-ready 1D and 2D spectra, as well as multi-band image cutouts of corresponding sources and a useful preview page summarising the direct and slitless data, astrometric and photometric parameters. This release is part of the continuing effort to enhance the content of the Hubble Legacy Archive (HLA) with highly processed data products which significantly facilitate the scientific exploitation of the Hubble data. In order to characterize the slitless spectra, emission-line flux and equivalent width sensitivity of the ACS data were compared with public ground-based spectra in the GOODS-South field. An example list of emission line galaxies with two or more identified lines is also included, covering the redshift range 0.2 - 4.6. Almost all redshift determinations outside of the GOODS fields are new. The scope of science projects

UV/Visible Telescope with Hubble Disposal

Science.gov (United States)

Benford, Dominic J.

2013-01-01

Submission Overview: Our primary objective is to convey a sense of the significant advances possible in astrophysics investigations for major Cosmic Origins COR program goals with a 2.4m telescope asset outfitted with one or more advanced UV visible instruments. Several compelling science objectives were identified based on community meetings these science objectives drove the conceptual design of instruments studied by the COR Program Office during July September 2012. This RFI submission encapsulates the results of that study, and suggests that a more detailed look into the instrument suite should be conducted to prove viability and affordability to support the demonstrated scientific value. This study was conducted in the context of a larger effort to consider the options available for a mission to dispose safely of Hubble hence, the overall architecture considered for the mission we studied for the 2.4m telescope asset included resource sharing. This mitigates combined cost and risk and provides naturally for a continued US leadership role in astrophysics with an advanced, general-purpose UV visible space telescope.

HUBBLE STAYS ON TRAIL OF FADING GAMMA-RAY BURST FIREBALL

Science.gov (United States)

2002-01-01

A Hubble Space Telescope image of the fading fireball from one of the universe's most mysterious phenomena, a gamma-ray burst. Though the visible component has faded to 1/500th its brightness (27.7 magnitude) from the time it was first discovered by ground- based telescopes last March (the actual gamma-ray burst took place on February 28), Hubble continues to clearly see the fireball and discriminated a surrounding nebulosity (at 25th magnitude) which is considered a host galaxy. The continued visibility of the burst, and the rate of its fading, support theories that the light from a gamma-ray burst is an expanding relativistic (moving near the speed of light) fireball, possibly produced by the collision of two dense objects, such as an orbiting pair of neutron stars. If the burst happened nearby, within our own galaxy, the resulting fireball should have had only enough energy to propel it into space for a month. The fact that this fireball is still visible after six months means the explosion was truly titanic and, to match the observed brightness, must have happened at the vast distances of galaxies. The energy released in a burst, which can last from a fraction of a second to a few hundred seconds, is equal to all of the Sun's energy generated over its 10 billion year lifetime. The false-color image was taken Sept. 5, 1997 with the Space Telescope Imaging Spectrograph. Credit: Andrew Fruchter (STScI), Elena Pian (ITSRE-CNR), and NASA

Charge retention test experiences on Hubble Space Telescope nickel-hydrogen battery cells

Science.gov (United States)

Nawrocki, Dave E.; Driscoll, J. R.; Armantrout, J. D.; Baker, R. C.; Wajsgras, H.

1993-01-01

The Hubble Space Telescope (HST) nickel-hydrogen battery module was designed by Lockheed Missile & Space Co (LMSC) and manufactured by Eagle-Picher Ind. (EPI) for the Marshall Space Flight Center (MSFC) as an Orbital Replacement Unit (ORU) for the nickel-cadmium batteries originally selected for this low earth orbit mission. The design features of the HST nickel hydrogen battery are described and the results of an extended charge retention test are summarized.

The Hubble Constant to 1%: Physics beyond LambdaCDM

Science.gov (United States)

Riess, Adam

2017-08-01

By steadily advancing the precision and accuracy of the Hubble constant, we now see 3.4-sigma evidence for a deviation from the standard LambdaCDM model and thus the exciting chance of discovering new fundamental physics such as exotic dark energy, a new relativistic particle, dark matter interactions, or a small curvature, to name a few possibilities. We propose a coordinated program to accomplish three goals with one set of observations: (1) improve the precision of the best route to H_0 with HST observations of Cepheids in the hosts of 11 SNe Ia, lowering the uncertainty to 1.3% to reach the discovery threshold of 5-sigma and begin resolving the underlying source of the deviation; (2) continue testing the quality of Cepheid distances, so far the most accurate and reliable indicators in the near Universe, using the tip of the red giant branch (TRGB); and (3) use oxygen-rich Miras to confirm the present tension with the CMB and establish a future route available to JWST. We can achieve all three goals with one dataset and take the penultimate step to reach 1% precision in H_0 after Gaia. With its long-pass filter and NIR capability, we can collect these data with WFC3 many times faster than previously possible while overcoming the extinction and metallicity effects that challenged the first generation of H_0 measurements. Our results will complement the leverage available at high redshift from other cosmological tools such as BAO, the CMB, and SNe Ia, and will provide a 40% improvement on the WFIRST measurements of dark energy. Reaching this precision will be a fitting legacy for the telescope charged to resolve decades of uncertainty regarding the Hubble constant.

Second generation spectrograph for the Hubble Space Telescope

Science.gov (United States)

Woodgate, B. E.; Boggess, A.; Gull, T. R.; Heap, S. R.; Krueger, V. L.; Maran, S. P.; Melcher, R. W.; Rebar, F. J.; Vitagliano, H. D.; Green, R. F.; Wolff, S. C.; Hutchings, J. B.; Jenkins, E. B.; Linsky, J. L.; Moos, H. W.; Roesler, F.; Shine, R. A.; Timothy, J. G.; Weistrop, D. E.; Bottema, M.; Meyer, W.

1986-01-01

The preliminary design for the Space Telescope Imaging Spectrograph (STIS), which has been selected by NASA for definition study for future flight as a second-generation instrument on the Hubble Space Telescope (HST), is presented. STIS is a two-dimensional spectrograph that will operate from 1050 A to 11,000 A at the limiting HST resolution of 0.05 arcsec FWHM, with spectral resolutions of 100, 1200, 20,000, and 100,000 and a maximum field-of-view of 50 x 50 arcsec. Its basic operating modes include echelle model, long slit mode, slitless spectrograph mode, coronographic spectroscopy, photon time-tagging, and direct imaging. Research objectives are active galactic nuclei, the intergalactic medium, global properties of galaxies, the origin of stellar systems, stelalr spectral variability, and spectrographic mapping of solar system processes.

Hubble Observes Surface of Titan

Science.gov (United States)

1994-01-01

Scientists for the first time have made images of the surface of Saturn's giant, haze-shrouded moon, Titan. They mapped light and dark features over the surface of the satellite during nearly a complete 16-day rotation. One prominent bright area they discovered is a surface feature 2,500 miles across, about the size of the continent of Australia.Titan, larger than Mercury and slightly smaller than Mars, is the only body in the solar system, other than Earth, that may have oceans and rainfall on its surface, albeit oceans and rain of ethane-methane rather than water. Scientists suspect that Titan's present environment -- although colder than minus 289 degrees Fahrenheit, so cold that water ice would be as hard as granite -- might be similar to that on Earth billions of years ago, before life began pumping oxygen into the atmosphere.Peter H. Smith of the University of Arizona Lunar and Planetary Laboratory and his team took the images with the Hubble Space Telescope during 14 observing runs between Oct. 4 - 18. Smith announced the team's first results last week at the 26th annual meeting of the American Astronomical Society Division for Planetary Sciences in Bethesda, Md. Co-investigators on the team are Mark Lemmon, a doctoral candidate with the UA Lunar and Planetary Laboratory; John Caldwell of York University, Canada; Larry Sromovsky of the University of Wisconsin; and Michael Allison of the Goddard Institute for Space Studies, New York City.Titan's atmosphere, about four times as dense as Earth's atmosphere, is primarily nitrogen laced with such poisonous substances as methane and ethane. This thick, orange, hydrocarbon haze was impenetrable to cameras aboard the Pioneer and Voyager spacecraft that flew by the Saturn system in the late 1970s and early 1980s. The haze is formed as methane in the atmosphere is destroyed by sunlight. The hydrocarbons produced by this methane destruction form a smog similar to that found over large cities, but is much thicker

Initial Hubble Diagram Results from the Nearby Supernova Factory

Energy Technology Data Exchange (ETDEWEB)

Bailey, S. [Lab. Nuclear and High-Energy Physics (LPNHE), Paris (France); Aldering, G. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Antilogus, P. [Lab. Nuclear and High-Energy Physics (LPNHE), Paris (France); Aragon, C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Baltay, C. [Yale Univ., New Haven, CT (United States); Bongard, S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Buton, C [Inst. of Nuclear Physics of Lyon (France); Childress, M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Copin, Y. [Inst. of Nuclear Physics of Lyon (France); Gangler, E. [Inst. of Nuclear Physics of Lyon (France); Loken, S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Nugent, P. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Pain, R. [Lab. Nuclear and High-Energy Physics (LPNHE), Paris (France); Pecontal, E. [Center of Research Astrophysics of Lyon (CRAL) (France); Pereira, R. [Lab. Nuclear and High-Energy Physics (LPNHE), Paris (France); Perlmutter, S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Rabinowitz, D. [Yale Univ., New Haven, CT (United States); Rigaudier, G. [Center of Research Astrophysics of Lyon (CRAL) (France); Ripoche, P. [Lab. Nuclear and High-Energy Physics (LPNHE), Paris (France); Runge, K. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Scalzo, R. [Yale Univ., New Haven, CT (United States); Smadja, G. [Inst. of Nuclear Physics of Lyon (France); Tao, C. [Inst. of Nuclear Physics of Lyon (France); Thomas, R. C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wu, C. [Lab. Nuclear and High-Energy Physics (LPNHE), Paris (France)

2017-07-06

The use of Type Ia supernovae as distance indicators led to the discovery of the accelerating expansion of the universe a decade ago. Now that large second generation surveys have significantly increased the size and quality of the high-redshift sample, the cosmological constraints are limited by the currently available sample of ~50 cosmologically useful nearby supernovae. The Nearby Supernova Factory addresses this problem by discovering nearby supernovae and observing their spectrophotometric time development. Our data sample includes over 2400 spectra from spectral timeseries of 185 supernovae. This talk presents results from a portion of this sample including a Hubble diagram (relative distance vs. redshift) and a description of some analyses using this rich dataset.

Automation of Hubble Space Telescope Mission Operations

Science.gov (United States)

Burley, Richard; Goulet, Gregory; Slater, Mark; Huey, William; Bassford, Lynn; Dunham, Larry

2012-01-01

On June 13, 2011, after more than 21 years, 115 thousand orbits, and nearly 1 million exposures taken, the operation of the Hubble Space Telescope successfully transitioned from 24x7x365 staffing to 815 staffing. This required the automation of routine mission operations including telemetry and forward link acquisition, data dumping and solid-state recorder management, stored command loading, and health and safety monitoring of both the observatory and the HST Ground System. These changes were driven by budget reductions, and required ground system and onboard spacecraft enhancements across the entire operations spectrum, from planning and scheduling systems to payload flight software. Changes in personnel and staffing were required in order to adapt to the new roles and responsibilities required in the new automated operations era. This paper will provide a high level overview of the obstacles to automating nominal HST mission operations, both technical and cultural, and how those obstacles were overcome.

The Carnegie–Chicago Hubble Program. III. The Distance to NGC 1365 via the Tip of the Red Giant Branch

Science.gov (United States)

Jang, In Sung; Hatt, Dylan; Beaton, Rachael L.; Lee, Myung Gyoon; Freedman, Wendy L.; Madore, Barry F.; Hoyt, Taylor J.; Monson, Andrew J.; Rich, Jeffrey A.; Scowcroft, Victoria; Seibert, Mark

2018-01-01

The Carnegie–Chicago Hubble Program (CCHP) seeks to anchor the distance scale of Type Ia supernovae via the Tip of the Red Giant Branch (TRGB) method. Based on deep Hubble Space Telescope ACS/WFC imaging, we present an analysis of the TRGB for the metal-poor halo of NGC 1365, a giant spiral galaxy in the Fornax cluster that was host to the Type Ia supernova SN 2012fr. We have measured the extinction-corrected TRGB magnitude of NGC 1365 to be F814W = 27.34 ± 0.03stat ± 0.04sys mag. In advance of future direct calibration by Gaia, we adopt a provisional I-band TRGB luminosity set at the Large Magellanic Cloud and find a true distance modulus μ 0 = 31.29 ± 0.04stat ± 0.06sys mag or D = 18.1 ± 0.3stat ± 0.5sys Mpc. This measurement is in excellent agreement with recent Cepheid-based distances to NGC 1365 and reveals no significant difference in the distances derived from stars of Populations I and II for this galaxy. We revisit the error budget for the CCHP path to the Hubble constant based on the analysis presented here, i.e., that for one of the most distant Type Ia supernova hosts within our Program, and find that a 2.5% measurement is feasible with the current sample of galaxies and TRGB absolute calibration. Based in part on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program #13691.

PACMan to Help Sort Hubble Proposals

Science.gov (United States)

Kohler, Susanna

2017-04-01

Every year, astronomers submit over a thousand proposals requesting time on the Hubble Space Telescope (HST). Currently, humans must sort through each of these proposals by hand before sending them off for review. Could this burden be shifted to computers?A Problem of VolumeAstronomer Molly Peeples gathered stats on the HST submissions sent in last week for the upcoming HST Cycle 25 (the deadline was Friday night), relative to previous years. This years proposal round broke the record, with over 1200 proposals submitted in total for Cycle 25. [Molly Peeples]Each proposal cycle for HST time attracts on the order of 1100 proposals accounting for far more HST time than is available. The proposals are therefore carefully reviewed by around 150 international members of the astronomy community during a six-month process to select those with the highest scientific merit.Ideally, each proposal will be read by reviewers that have scientific expertise relevant to the proposal topic: if a proposal requests HST time to study star formation, for instance, then the reviewers assigned to it should have research expertise in star formation.How does this matching of proposals to reviewers occur? The current method relies on self-reported categorization of the submitted proposals. This is unreliable, however; proposals are often mis-categorized by submitters due to misunderstanding or ambiguous cases.As a result, the Science Policies Group at the Space Telescope Science Institute (STScI) which oversees the review of HST proposals must go through each of the proposals by hand and re-categorize them. The proposals are then matched to reviewers with self-declared expertise in the same category.With the number of HST proposals on the rise and the expectation that the upcoming James Webb Space Telescope (JWST) will elicit even more proposals for time than Hubble scientists at STScI and NASA are now asking: could the human hours necessary for this task be spared? Could a computer program

Shift Colors

Science.gov (United States)

Publications & News Shift Colors Pages default Sign In NPC Logo Banner : Shift Colors Search Navy Personnel Command > Reference Library > Publications & News > Shift Colors Top Link Bar Navy Personnel Library Expand Reference Library Quick Launch Shift Colors Shift Colors Archives Mailing Address How to

Dark energy and the quietness of the local Hubble flow

International Nuclear Information System (INIS)

Axenides, M.; Perivolaropoulos, L.

2002-01-01

The linearity and quietness of the local ( X (t 0 ) of dark energy obeying the time independent equation of state p X =wρ X . We find that dark energy can indeed cool the LHF. However the dark energy parameter values required to make the predicted velocity dispersion consistent with the observed value v rms ≅40 km/s have been ruled out by other observational tests constraining the dark energy parameters w and Ω X . Therefore despite the claims of recent qualitative studies, dark energy with time independent equation of state cannot by itself explain the quietness and linearity of the local Hubble flow

Lanthanide shift reagents, binding, shift mechanisms and exchange

International Nuclear Information System (INIS)

Boer, J.W.M. de

1977-01-01

Paramagnetic lanthanide shift reagents, when added to a solution of a substrate, induce shifts in the nuclear magnetic resonance (NMR) spectrum of the substrate molecules. The induced shifts contain information about the structure of the shift reagent substrate complex. The structural information, however, may be difficult to extract because of the following effects: (1) different complexes between shift reagent and substrate may be present in solution, e.g. 1:1 and 1:2 complexes, and the shift observed is a weighed average of the shifts of the substrate nuclei in the different complexes; (2) the Fermi contact interaction, arising from the spin density at the nucleus, contributes to the induced shift; (3) chemical exchange effects may complicate the NMR spectrum. In this thesis, the results of an investigation into the influence of these effects on the NMR spectra of solutions containing a substrate and LSR are presented. The equations describing the pseudo contact and the Fermi contact shift are derived. In addition, it is shown how the modified Bloch equations describing the effect of the chemical exchange processes occurring in the systems studied can be reduced to the familiar equations for a two-site exchange case. The binding of mono- and bifunctional ethers to the shift reagent are reported. An analysis of the induced shifts is given. Finally, the results of the experiments performed to study the exchange behavior of dimethoxyethane and heptafluorodimethyloctanedionato ligands are presented

VizieR Online Data Catalog: Hubble Source Catalog (V1 and V2) (Whitmore+, 2016)

Science.gov (United States)

Whitmore, B. C.; Allam, S. S.; Budavari, T.; Casertano, S.; Downes, R. A.; Donaldson, T.; Fall, S. M.; Lubow, S. H.; Quick, L.; Strolger, L.-G.; Wallace, G.; White, R. L.

2016-10-01

The HSC v1 contains members of the WFPC2, ACS/WFC, WFC3/UVIS and WFC3/IR Source Extractor source lists from HLA version DR8 (data release 8). The crossmatching process involves adjusting the relative astrometry of overlapping images so as to minimize positional offsets between closely aligned sources in different images. After correction, the astrometric residuals of crossmatched sources are significantly reduced, to typically less than 10mas. The relative astrometry is supported by using Pan-STARRS, SDSS, and 2MASS as the astrometric backbone for initial corrections. In addition, the catalog includes source nondetections. The crossmatching algorithms and the properties of the initial (Beta 0.1) catalog are described in Budavari & Lubow (2012ApJ...761..188B). The HSC v2 contains members of the WFPC2, ACS/WFC, WFC3/UVIS and WFC3/IR Source Extractor source lists from HLA version DR9.1 (data release 9.1). The crossmatching process involves adjusting the relative astrometry of overlapping images so as to minimize positional offsets between closely aligned sources in different images. After correction, the astrometric residuals of crossmatched sources are significantly reduced, to typically less than 10mas. The relative astrometry is supported by using Pan-STARRS, SDSS, and 2MASS as the astrometric backbone for initial corrections. In addition, the catalog includes source nondetections. The crossmatching algorithms and the properties of the initial (Beta 0.1) catalog are described in Budavari & Lubow (2012ApJ...761..188B). Hubble Source Catalog Acknowledgement: Based on observations made with the NASA/ESA Hubble Space Telescope, and obtained from the Hubble Legacy Archive, which is a collaboration between the Space Telescope Science Institute (STScI/NASA), the Space Telescope European Coordinating Facility (ST-ECF/ESAC/ESA) and the Canadian Astronomy Data Centre (CADC/NRC/CSA). (2 data files).

Tilt shift determinations with spatial-carrier phase-shift method in temporal phase-shift interferometry

International Nuclear Information System (INIS)

Liu, Qian; Wang, Yang; He, Jianguo; Ji, Fang; Wang, Baorui

2014-01-01

An algorithm is proposed to deal with tilt-shift errors in temporal phase-shift interferometry (PSI). In the algorithm, the tilt shifts are detected with the spatial-carrier phase-shift (SCPS) method and then the tilt shifts are applied as priori information to the least-squares fittings of phase retrieval. The algorithm combines the best features of the SCPS and the temporal PSI. The algorithm could be applied to interferograms of arbitrary aperture without data extrapolation for the Fourier transform is not involved. Simulations and experiments demonstrate the effectiveness of the algorithm. The statistics of simulation results show a satisfied accuracy in detecting tilt-shift errors. Comparisons of the measurements with and without environmental vibration show that the proposed algorithm could compensate tilt-shift errors and retrieve wavefront phase accurately. The algorithm provides an approach to retrieve wavefront phase for the temporal PSI in vibrating environment. (paper)

Reexploration of interacting holographic dark energy model. Cases of interaction term excluding the Hubble parameter

Energy Technology Data Exchange (ETDEWEB)

Li, Hai-Li; Zhang, Jing-Fei; Feng, Lu [Northeastern University, Department of Physics, College of Sciences, Shenyang (China); Zhang, Xin [Northeastern University, Department of Physics, College of Sciences, Shenyang (China); Peking University, Center for High Energy Physics, Beijing (China)

2017-12-15

In this paper, we make a deep analysis for the five typical interacting holographic dark energy models with the interaction terms Q = 3βH{sub 0}ρ{sub de}, Q = 3βH{sub 0}ρ{sub c}, Q = 3βH{sub 0}(ρ{sub de} + ρ{sub c}), Q = 3βH{sub 0}√(ρ{sub de}ρ{sub c}), and Q = 3βH{sub 0}(ρ{sub de}ρ{sub c})/(ρ{sub de}+ρ{sub c}), respectively. We obtain observational constraints on these models by using the type Ia supernova data (the Joint Light-Curve Analysis sample), the cosmic microwave background data (Planck 2015 distance priors), the baryon acoustic oscillations data, and the direct measurement of the Hubble constant. We find that the values of χ{sub min}{sup 2} for all the five models are almost equal (around 699), indicating that the current observational data equally favor these IHDE models. In addition, a comparison with the cases of an interaction term involving the Hubble parameter H is also made. (orig.)

Revisiting the stellar velocity ellipsoid-Hubble-type relation: observations versus simulations

Science.gov (United States)

Pinna, F.; Falcón-Barroso, J.; Martig, M.; Martínez-Valpuesta, I.; Méndez-Abreu, J.; van de Ven, G.; Leaman, R.; Lyubenova, M.

2018-04-01

The stellar velocity ellipsoid (SVE) in galaxies can provide important information on the processes that participate in the dynamical heating of their disc components (e.g. giant molecular clouds, mergers, spiral density waves, and bars). Earlier findings suggested a strong relation between the shape of the disc SVE and Hubble type, with later-type galaxies displaying more anisotropic ellipsoids and early types being more isotropic. In this paper, we revisit the strength of this relation using an exhaustive compilation of observational results from the literature on this issue. We find no clear correlation between the shape of the disc SVE and morphological type, and show that galaxies with the same Hubble type display a wide range of vertical-to-radial velocity dispersion ratios. The points are distributed around a mean value and scatter of σz/σR = 0.7 ± 0.2. With the aid of numerical simulations, we argue that different mechanisms might influence the shape of the SVE in the same manner and that the same process (e.g. mergers) does not have the same impact in all the galaxies. The complexity of the observational picture is confirmed by these simulations, which suggest that the vertical-to-radial axis ratio of the SVE is not a good indicator of the main source of disc heating. Our analysis of those simulations also indicates that the observed shape of the disc SVE may be affected by several processes simultaneously and that the signatures of some of them (e.g. mergers) fade over time.

Mach's Principle to Hubble's Law and Light Relativity

Science.gov (United States)

Zhang, Tianxi

2018-01-01

Discovery of the redshift-distance relation to be linear (i.e. Hubble's law) for galaxies in the end of 1920s instigated us to widely accept expansion of the universe, originated from a big bang around 14 billion years ago. Finding of the redshift-distance relation to be weaker than linear for distant type Ia supernovae nearly two decades ago further precipitated us to largely agree with recent acceleration of the universe, driven by the mysterious dark energy. The time dilation measured for supernovae has been claimed as a direct evidence for the expansion of the universe, but scientists could not explain why quasars and gamma-ray bursts had not similar time dilations. Recently, an anomaly was found in the standard template for the width of supernova light curves to be proportional to the wavelength, which exactly removed the time dilation of supernovae and hence was strongly inconsistent with the conventional redshift mechanism. In this study, we have derived a new redshift-distance relation from Mach's principle with light relativity that describes the effect of light on spacetime as well as the influence of disturbed spacetime on the light inertia or frequency. A moving object or photon, because of its continuously keeping on displacement, disturbs the rest of the entire universe or distorts/curves the spacetime. The distorted or curved spacetime then generates an effective gravitational force to act back on the moving object or photon, so that reduces the object inertia or photon frequency. Considering the disturbance of spacetime by a photon is extremely weak, we have modelled the effective gravitational force to be Newtonian and derived the new redshift-distance relation that can not only perfectly explain the redshift-distance measurement of distant type Ia supernovae but also inherently obtain Hubble's law as an approximate at small redshift. Therefore, the result obtained from this study does neither support the acceleration of the universe nor the

STS 31 PAYLOAD HUBBLE SPACE TELESCOPE ENCLOSED IN AN AIR-TIGHT PLASTIC BAG FOR PROTECTION IN VERTICA

Science.gov (United States)

1989-01-01

Preparations are made to enclose the Hubble Space Telescope [HST] inside an air-tight plastic bag in the VPF. Processing of the 94- inch primary mirror telescope for launch on the Discovery in March 1990, involves working within strict controls to prevent contamination.

PANCHROMATIC HUBBLE ANDROMEDA TREASURY. XVI. STAR CLUSTER FORMATION EFFICIENCY AND THE CLUSTERED FRACTION OF YOUNG STARS

Energy Technology Data Exchange (ETDEWEB)

Johnson, L. Clifton; Sandstrom, Karin [Center for Astrophysics and Space Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093 (United States); Seth, Anil C. [Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States); Dalcanton, Julianne J.; Beerman, Lori C.; Lewis, Alexia R.; Weisz, Daniel R.; Williams, Benjamin F. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Fouesneau, Morgan [Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Bell, Eric F. [Department of Astronomy, University of Michigan, 1085 South University Avenue, Ann Arbor, MI 48109 (United States); Dolphin, Andrew E. [Raytheon Company, 1151 East Hermans Road, Tucson, AZ 85756 (United States); Larsen, Søren S. [Department of Astrophysics, IMAPP, Radboud University Nijmegen, P.O. Box 9010, 6500 GL Nijmegen (Netherlands); Skillman, Evan D., E-mail: lcj@ucsd.edu [Minnesota Institute for Astrophysics, University of Minnesota, 116 Church Street SE, Minneapolis, MN 55455 (United States)

2016-08-10

We use the Panchromatic Hubble Andromeda Treasury survey data set to perform spatially resolved measurements of star cluster formation efficiency (Γ), the fraction of stellar mass formed in long-lived star clusters. We use robust star formation history and cluster parameter constraints, obtained through color–magnitude diagram analysis of resolved stellar populations, to study Andromeda’s cluster and field populations over the last ∼300 Myr. We measure Γ of 4%–8% for young, 10–100 Myr-old populations in M31. We find that cluster formation efficiency varies systematically across the M31 disk, consistent with variations in mid-plane pressure. These Γ measurements expand the range of well-studied galactic environments, providing precise constraints in an H i-dominated, low-intensity star formation environment. Spatially resolved results from M31 are broadly consistent with previous trends observed on galaxy-integrated scales, where Γ increases with increasing star formation rate surface density (Σ{sub SFR}). However, we can explain observed scatter in the relation and attain better agreement between observations and theoretical models if we account for environmental variations in gas depletion time ( τ {sub dep}) when modeling Γ, accounting for the qualitative shift in star formation behavior when transitioning from a H{sub 2}-dominated to a H i-dominated interstellar medium. We also demonstrate that Γ measurements in high Σ{sub SFR} starburst systems are well-explained by τ {sub dep}-dependent fiducial Γ models.

The Development of a Virtual Company to Support the Reengineering of the NASA/Goddard Hubble Space Telescope Control Center System

Science.gov (United States)

Lehtonen, Ken

1999-01-01

This is a report to the Third Annual International Virtual Company Conference, on The Development of a Virtual Company to Support the Reengineering of the NASA/Goddard Hubble Space Telescope (HST) Control Center System. It begins with a HST Science "Commercial": Brief Tour of Our Universe showing various pictures taken from the Hubble Space Telescope. The presentation then reviews the project background and goals. Evolution of the Control Center System ("CCS Inc.") is then reviewed. Topics of Interest to "virtual companies" are reviewed: (1) "How To Choose A Team" (2) "Organizational Model" (3) "The Human Component" (4) "'Virtual Trust' Among Teaming Companies" (5) "Unique Challenges to Working Horizontally" (6) "The Cultural Impact" (7) "Lessons Learned".

H0, q0 and the local velocity field. [Hubble and deceleration constants in Big Bang expansion

Science.gov (United States)

Sandage, A.; Tammann, G. A.

1982-01-01

An attempt is made to find a systematic deviation from linearity for distances that are under the control of the Virgo cluster, and to determine the value of the mean random motion about the systematic flow, in order to improve the measurement of the Hubble and the deceleration constants. The velocity-distance relation for large and intermediate distances is studied, and type I supernovae are calibrated relatively as distance indicators and absolutely to obtain a new value for the Hubble constant. Methods of determining the deceleration constant are assessed, including determination from direct measurement, mean luminosity density, virgocentric motion, and the time scale test. The very local velocity field is investigated, and a solution is preferred with a random peculiar radial velocity of very nearby field galaxies of 90-100 km/s, and a Virgocentric motion of the local group of 220 km/s, leading to an underlying expansion rate of 55, in satisfactory agreement with the global value.

The MUSE Hubble Ultra Deep Field Survey. IX. Evolution of galaxy merger fraction since z ≈ 6

Science.gov (United States)

Ventou, E.; Contini, T.; Bouché, N.; Epinat, B.; Brinchmann, J.; Bacon, R.; Inami, H.; Lam, D.; Drake, A.; Garel, T.; Michel-Dansac, L.; Pello, R.; Steinmetz, M.; Weilbacher, P. M.; Wisotzki, L.; Carollo, M.

2017-11-01

We provide, for the first time, robust observational constraints on the galaxy major merger fraction up to z ≈ 6 using spectroscopic close pair counts. Deep Multi Unit Spectroscopic Explorer (MUSE) observations in the Hubble Ultra Deep Field (HUDF) and Hubble Deep Field South (HDF-S) are used to identify 113 secure close pairs of galaxies among a parent sample of 1801 galaxies spread over a large redshift range (0.2 separation limit of 109.5 M⊙ or the median value of stellar mass computed in each redshift bin. Overall, the major close pair fraction for low-mass and massive galaxies follows the same trend. These new, homogeneous, and robust estimates of the major merger fraction since z ≈ 6 are in good agreement with recent predictions of cosmological numerical simulations. Based on observations made with ESO telescopes at the La Silla-Paranal Observatory under programmes 094.A-0289(B), 095.A-0010(A), 096.A-0045(A) and 096.A-0045(B).

Hubble evolution of fireball in relativistic nuclear collisions

International Nuclear Information System (INIS)

Zgura, Sorin; Besliu, Calin; Jipa, Alexandru

2004-01-01

The final state of Au + Au collisions at √s = 130 A GeV and 200 A GeV at RHIC has been reconstructed within the framework of the Buda-Lund hydro model, by performing a simultaneous fit to preliminary BRAHMS, PHENIX, PHOBOS and STAR data on two-particle Bose-Einstein correlations and identified single particle spectra. The Hubble constant is determined for cosmology. From this reconstructed final state and the knowledge of the equation of state of hot and dense hadronic matter (e.g. from lattice QCD calculations) one can, in principle, reconstruct the initial state of the reaction by running the (relativistic) hydrodynamical equations backwards in time and determine if this initial state had been in the QGP phase or not. Here we report on such a reconstruction within the framework of the Buda-Lund hydro model. This model fits are compared to RHIC's experiment data on identified particle spectra, two-particle Bose-Einstein or HBT correlations. (authors)

The Hubble Space Telescope from concept to success

CERN Document Server

Shayler, David J

2016-01-01

The highly successful Hubble Space Telescope was meant to change our view and understanding of the universe. Within weeks of its launch in 1990, however, the space community was shocked to find out that the primary mirror of the telescope was flawed. It was only the skills of scientists and engineers on the ground and the daring talents of astronauts sent to service the telescope in December 1993 that saved the mission. For over two decades NASA had developed the capabilities to service a payload in orbit. This involved numerous studies and the creation of a ground-based infrastructure to support the challenging missions. Unique tools and EVA hardware supported the skills developed in crew training that then enabled astronauts to complete a demanding series of spacewalks. Drawing upon first hand interviews with those closely involved in the project over thirty years ago this story explains the development of the servicing mission concept and the hurdles that had to be overcome to not only launch the telescope...

Theoretical colours and isochrones for some Hubble Space Telescope colour systems

Science.gov (United States)

Edvardsson, B.; Bell, R. A.

1989-01-01

Synthetic spectra for effective temperatures of 4000-7250 K, logarithmic surface gravities typical of dwarfs and subgiants, and metallicities from solar values to 0.001 of the solar metallicity were used to derive a grid of synthetic surface brightness magnitudes for 21 of the Hubble Space Telescope Wide Field Camera (WFC) band passes. The absolute magnitudes of these 21 band passes are also obtained for a set of globular cluster isochrones with different helium abundances, metallicities, oxygen abundances, and ages. The usefulness and efficiency of different sets of broad and intermediate bandwidth WFC colors for determining ages and metallicities for globular clusters are evaluated.

Observations of the Hubble Deep Field with the Infrared Space Observatory .2. Source detection and photometry

DEFF Research Database (Denmark)

Goldschmidt, P.; Oliver, S.J.; Serjeant, S.B.G.

1997-01-01

We present positions and fluxes of point sources found in the Infrared Space Observatory (ISO) images of the Hubble Deep Field (HDF) at 6.7 and 15 mu m. We have constructed algorithmically selected 'complete' flux-limited samples of 19 sources in the 15-mu m image, and seven sources in the 6.7-mu m...

A MULTIWAVELENGTH STUDY OF TADPOLE GALAXIES IN THE HUBBLE ULTRA DEEP FIELD

International Nuclear Information System (INIS)

Straughn, Amber N.; Eufrasio, Rafael T.; Gardner, Jonathan P.; Voyer, Elysse N.; Mello, Duilia de; Soto, Emmaris; Petty, Sara; Kassin, Susan; Ravindranath, Swara

2015-01-01

Multiwavelength data are essential in order to provide a complete picture of galaxy evolution and to inform studies of galaxies’ morphological properties across cosmic time. Here we present the results of a multiwavelength investigation of the morphologies of “tadpole” galaxies at intermediate redshift (0.314 < z < 3.175) in the Hubble Ultra Deep Field. These galaxies were previously selected from deep Hubble Space Telescope (HST) F775W data based on their distinct asymmetric knot-plus-tail morphologies. Here we use deep Wide Field Camera 3 near-infrared imaging in addition to the HST optical data in order to study the rest-frame UV/optical morphologies of these galaxies across the redshift range 0.3 < z < 3.2. This study reveals that the majority of these galaxies do retain their general asymmetric morphology in the rest-frame optical over this redshift range, if not the distinct “tadpole” shape. The average stellar mass of tadpole galaxies is lower than that of field galaxies, with the effect being slightly greater at higher redshift within the errors. Estimated from spectral energy distribution fits, the average age of tadpole galaxies is younger than that of field galaxies in the lower-redshift bin, and the average metallicity is lower (whereas the specific star formation rate for tadpoles is roughly the same as field galaxies across the redshift range probed here). These average effects combined support the conclusion that this subset of galaxies is in an active phase of assembly, either late-stage merging or cold gas accretion causing localized clumpy star formation

A MULTIWAVELENGTH STUDY OF TADPOLE GALAXIES IN THE HUBBLE ULTRA DEEP FIELD

Energy Technology Data Exchange (ETDEWEB)

Straughn, Amber N.; Eufrasio, Rafael T.; Gardner, Jonathan P. [Astrophysics Science Division, Goddard Space Flight Center, Code 665, Greenbelt, MD 20771 (United States); Voyer, Elysse N. [Randstad at Google, 1129 San Antonio Road, Palo Alto, CA (United States); Mello, Duilia de; Soto, Emmaris [Department of Physics, The Catholic University of America, Washington, DC 20064 (United States); Petty, Sara [Department of Physics, Virginia Tech, Blacksburg, VA 24061 (United States); Kassin, Susan; Ravindranath, Swara [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)

2015-12-01

Multiwavelength data are essential in order to provide a complete picture of galaxy evolution and to inform studies of galaxies’ morphological properties across cosmic time. Here we present the results of a multiwavelength investigation of the morphologies of “tadpole” galaxies at intermediate redshift (0.314 < z < 3.175) in the Hubble Ultra Deep Field. These galaxies were previously selected from deep Hubble Space Telescope (HST) F775W data based on their distinct asymmetric knot-plus-tail morphologies. Here we use deep Wide Field Camera 3 near-infrared imaging in addition to the HST optical data in order to study the rest-frame UV/optical morphologies of these galaxies across the redshift range 0.3 < z < 3.2. This study reveals that the majority of these galaxies do retain their general asymmetric morphology in the rest-frame optical over this redshift range, if not the distinct “tadpole” shape. The average stellar mass of tadpole galaxies is lower than that of field galaxies, with the effect being slightly greater at higher redshift within the errors. Estimated from spectral energy distribution fits, the average age of tadpole galaxies is younger than that of field galaxies in the lower-redshift bin, and the average metallicity is lower (whereas the specific star formation rate for tadpoles is roughly the same as field galaxies across the redshift range probed here). These average effects combined support the conclusion that this subset of galaxies is in an active phase of assembly, either late-stage merging or cold gas accretion causing localized clumpy star formation.

Planetary nebulae: 20 years of Hubble inquiry

Science.gov (United States)

Balick, Bruce

2012-08-01

The Hubble Space Telescope has served the critical roles of microscope and movie camera in the past 20 years of research on planetary nebulae (``PNe''). We have glimpsed the details of the evolving structures of neutral and ionized post-AGB objects, built ingenious heuristic models that mimic these structures, and constrained most of the relevant physical processes with careful observations and interpretation. We have searched for close physical binary stars with spatial resolution ~50 AU at 1 AU, located jets emerging from the nucleus at speeds up to 2000 km s-1 and matched newly discovered molecular and X-ray emission regions to physical substructures in order to better understand how stellar winds and ionizing radiation interact to form the lovely symmetries that are observed. Ultraviolet spectra of CNO in PNe help to uncover how stars process deep inside AGB stars with unstable nuclear burning zones. HST broadband imaging has been at the forefront of uncovering surprisingly complex wind morphologies produced at the tip of the AGB, and has led to an increasing realization of the potentially vital roles of close binary stars and emerging magnetic fields in shaping stellar winds.

THE 2012 HUBBLE ULTRA DEEP FIELD (UDF12): OBSERVATIONAL OVERVIEW

Energy Technology Data Exchange (ETDEWEB)

Koekemoer, Anton M. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Ellis, Richard S.; Schenker, Matthew A. [Department of Astrophysics, California Institute of Technology, MS 249-17, Pasadena, CA 91125 (United States); McLure, Ross J.; Dunlop, James S.; Bowler, Rebecca A. A.; Rogers, Alexander B.; Curtis-Lake, Emma; Cirasuolo, Michele; Wild, V.; Targett, T. [Institute for Astronomy, University of Edinburgh, Royal Observatory, Edinburgh EH9 3HJ (United Kingdom); Robertson, Brant E.; Schneider, Evan; Stark, Daniel P. [Department of Astronomy and Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Ono, Yoshiaki; Ouchi, Masami [Institute for Cosmic Ray Research, University of Tokyo, Kashiwa City, Chiba 277-8582 (Japan); Charlot, Stephane [UPMC-CNRS, UMR7095, Institut d' Astrophysique de Paris, F-75014, Paris (France); Furlanetto, Steven R. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States)

2013-11-01

We present the 2012 Hubble Ultra Deep Field campaign (UDF12), a large 128 orbit Cycle 19 Hubble Space Telescope program aimed at extending previous Wide Field Camera 3 (WFC3)/IR observations of the UDF by quadrupling the exposure time in the F105W filter, imaging in an additional F140W filter, and extending the F160W exposure time by 50%, as well as adding an extremely deep parallel field with the Advanced Camera for Surveys (ACS) in the F814W filter with a total exposure time of 128 orbits. The principal scientific goal of this project is to determine whether galaxies reionized the universe; our observations are designed to provide a robust determination of the star formation density at z ∼> 8, improve measurements of the ultraviolet continuum slope at z ∼ 7-8, facilitate the construction of new samples of z ∼ 9-10 candidates, and enable the detection of sources up to z ∼ 12. For this project we committed to combining these and other WFC3/IR imaging observations of the UDF area into a single homogeneous dataset to provide the deepest near-infrared observations of the sky. In this paper we present the observational overview of the project and describe the procedures used in reducing the data as well as the final products that were produced. We present the details of several special procedures that we implemented to correct calibration issues in the data for both the WFC3/IR observations of the main UDF field and our deep 128 orbit ACS/WFC F814W parallel field image, including treatment for persistence, correction for time-variable sky backgrounds, and astrometric alignment to an accuracy of a few milliarcseconds. We release the full, combined mosaics comprising a single, unified set of mosaics of the UDF, providing the deepest near-infrared blank-field view of the universe currently achievable, reaching magnitudes as deep as AB ∼ 30 mag in the near-infrared, and yielding a legacy dataset on this field.

THE 2012 HUBBLE ULTRA DEEP FIELD (UDF12): OBSERVATIONAL OVERVIEW

International Nuclear Information System (INIS)

Koekemoer, Anton M.; Ellis, Richard S.; Schenker, Matthew A.; McLure, Ross J.; Dunlop, James S.; Bowler, Rebecca A. A.; Rogers, Alexander B.; Curtis-Lake, Emma; Cirasuolo, Michele; Wild, V.; Targett, T.; Robertson, Brant E.; Schneider, Evan; Stark, Daniel P.; Ono, Yoshiaki; Ouchi, Masami; Charlot, Stephane; Furlanetto, Steven R.

2013-01-01

We present the 2012 Hubble Ultra Deep Field campaign (UDF12), a large 128 orbit Cycle 19 Hubble Space Telescope program aimed at extending previous Wide Field Camera 3 (WFC3)/IR observations of the UDF by quadrupling the exposure time in the F105W filter, imaging in an additional F140W filter, and extending the F160W exposure time by 50%, as well as adding an extremely deep parallel field with the Advanced Camera for Surveys (ACS) in the F814W filter with a total exposure time of 128 orbits. The principal scientific goal of this project is to determine whether galaxies reionized the universe; our observations are designed to provide a robust determination of the star formation density at z ∼> 8, improve measurements of the ultraviolet continuum slope at z ∼ 7-8, facilitate the construction of new samples of z ∼ 9-10 candidates, and enable the detection of sources up to z ∼ 12. For this project we committed to combining these and other WFC3/IR imaging observations of the UDF area into a single homogeneous dataset to provide the deepest near-infrared observations of the sky. In this paper we present the observational overview of the project and describe the procedures used in reducing the data as well as the final products that were produced. We present the details of several special procedures that we implemented to correct calibration issues in the data for both the WFC3/IR observations of the main UDF field and our deep 128 orbit ACS/WFC F814W parallel field image, including treatment for persistence, correction for time-variable sky backgrounds, and astrometric alignment to an accuracy of a few milliarcseconds. We release the full, combined mosaics comprising a single, unified set of mosaics of the UDF, providing the deepest near-infrared blank-field view of the universe currently achievable, reaching magnitudes as deep as AB ∼ 30 mag in the near-infrared, and yielding a legacy dataset on this field

A natural language query system for Hubble Space Telescope proposal selection

Science.gov (United States)

Hornick, Thomas; Cohen, William; Miller, Glenn

1987-01-01

The proposal selection process for the Hubble Space Telescope is assisted by a robust and easy to use query program (TACOS). The system parses an English subset language sentence regardless of the order of the keyword phases, allowing the user a greater flexibility than a standard command query language. Capabilities for macro and procedure definition are also integrated. The system was designed for flexibility in both use and maintenance. In addition, TACOS can be applied to any knowledge domain that can be expressed in terms of a single reaction. The system was implemented mostly in Common LISP. The TACOS design is described in detail, with particular attention given to the implementation methods of sentence processing.

Statistics of the Hubble diagram. I. Determination of q2 and luminosity evolution with application to quasars

International Nuclear Information System (INIS)

Turner, E.L.

1979-01-01

A rank statistic version of the magnitude-redshift q 0 test is developed. It may be applied to the Hubble diagram of objects with an arbitrary and unknown luminosity function; in particular, the objects need not be ''standard candles.'' Only the single restriction that the objects' luminosity function does not vary in functional form is placed on the sources' intrinsic properties. Density and/or luminosity evolution are taken into account. Corrections for sample selection biases are incorporated into the analysis. Tests for the presence of luminosity evolution are given. Methods for determining either q 0 or the luminosity evolution when the other is a priori known are described.Application of these techniques to a sample of 119 3CR and 4C quasars leads to the following results: The radio Hubble diagram is consistent with all values of q 0 , suggesting that the quasar radio luminosity function is a featureless power law. The optical Hubble diagram indicates one of these possibilities: (1) the value of q 0 is in the range 2--32, probably near 5; (2) the value of q 0 is more reasonable and there is strong optical luminosity evolution [e.g., if q/sub o/ approx. = 0.05, then the characteristic optical luminosity scales like approx. (1 + Z)/sup 7/3/]; or (3) the data are a low-probability (< or =0.05) statistical fluctuation. The second interpretation is probably the most sensible one.Generalizations of the rank statistic magnitude-redshift test are suggested for application to a variety of extragalactic and stellar problems. Specific examples of applications to unorthodox cosmologies are given. Even for the unfavorable (very broad luminosity function) case of the optical quasar data, the rank statistic analysis is sensitive to relative variations in the distance-modulus-redshift relation as small as approx.0.4 mag for 1/2 < or = Z < or = 2

Multi-Epoch Hubble Space Telescope Observations of IZw18 : Characterization of Variable Stars at Ultra-Low Metallicities

NARCIS (Netherlands)

Fiorentino, G.; Ramos, R. Contreras; Clementini, G.; Marconi, M.; Musella, I.; Aloisi, A.; Annibali, F.; Saha, A.; Tosi, M.; van der Marel, R. P.

2010-01-01

Variable stars have been identified for the first time in the very metal-poor blue compact dwarf galaxy IZw18, using deep multi-band (F606W, F814W) time-series photometry obtained with the Advanced Camera for Surveys on board the Hubble Space Telescope. We detected 34 candidate variable stars in the

Panchromatic Hubble Andromeda Treasury. IX. A photometric survey of planetary nebulae in M31

Energy Technology Data Exchange (ETDEWEB)

Veyette, Mark J.; Williams, Benjamin F.; Dalcanton, Julianne J.; Balick, Bruce; Fouesneau, Morgan [Department of Astronomy, University of Washington, P.O. Box 351580, Seattle, WA 98195 (United States); Caldwell, Nelson [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Girardi, Léo [Osservatorio Astronomico di Padova—INAF, Vicolo dell' Osservatorio 5, I-35122 Padova (Italy); Gordon, Karl D.; Kalirai, Jason [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Rosenfield, Philip [Department of Physics and Astronomy G. Galilei, University of Padova, Vicolo dell' Osservatorio 3, I-35122 Padova (Italy); Seth, Anil C., E-mail: mveyette@uw.edu [Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States)

2014-09-10

We search the Hubble Space Telescope (HST) Advanced Camera for Surveys and Wide Field Camera 3 broadband imaging data from the Panchromatic Hubble Andromeda Treasury (PHAT) survey to identify detections of cataloged planetary nebulae (PNs). Of the 711 PNs currently in the literature within the PHAT footprint, we find 467 detected in the broadband. For these 467, we are able to refine their astrometric accuracy from ∼0.''3 to 0.''05. Using the resolution of the HST, we are able to show that 152 objects currently in the catalogs are definitively not PNs, and we show that 32 objects thought to be extended in ground-based images are actually point-like and therefore good PN candidates. We also find one PN candidate that is marginally resolved. If this is a PN, it is up to 0.7 pc in diameter. With our new photometric data, we develop a method of measuring the level of excitation in individual PNs by comparing broadband and narrowband imaging and describe the effects of excitation on a PN's photometric signature. Using the photometric properties of the known PNs in the PHAT catalogs, we search for more PNs, but do not find any new candidates, suggesting that ground-based emission-line surveys are complete in the PHAT footprint to F475W ≅ 24.

A HUBBLE DIAGRAM FROM TYPE II SUPERNOVAE BASED SOLELY ON PHOTOMETRY: THE PHOTOMETRIC COLOR METHOD

International Nuclear Information System (INIS)

De Jaeger, T.; González-Gaitán, S.; Galbany, L.; Hamuy, M.; Gutiérrez, C. P.; Kuncarayakti, H.; Anderson, J. P.; Phillips, M. M.; Campillay, A.; Castellón, S.; Hsiao, E. Y.; Morrell, N.; Stritzinger, M. D.; Contreras, C.; Bolt, L.; Burns, C. R.; Folatelli, G.; Freedman, W. L.; Krisciunas, K.; Krzeminski, W.

2015-01-01

We present a Hubble diagram of SNe II using corrected magnitudes derived only from photometry, with no input of spectral information. We use a data set from the Carnegie Supernovae Project I for which optical and near-infrared light curves were obtained. The apparent magnitude is corrected by two observables, one corresponding to the slope of the plateau in the V band and the second a color term. We obtain a dispersion of 0.44 mag using a combination of the (V − i) color and the r band and we are able to reduce the dispersion to 0.39 mag using our golden sample. A comparison of our photometric color method (PCM) with the standardized candle method (SCM) is also performed. The dispersion obtained for the SCM (which uses both photometric and spectroscopic information) is 0.29 mag, which compares with 0.43 mag from the PCM for the same SN sample. The construction of a photometric Hubble diagram is of high importance in the coming era of large photometric wide-field surveys, which will increase the detection rate of supernovae by orders of magnitude. Such numbers will prohibit spectroscopic follow up in the vast majority of cases, and hence methods must be deployed which can proceed using solely photometric data

A HUBBLE DIAGRAM FROM TYPE II SUPERNOVAE BASED SOLELY ON PHOTOMETRY: THE PHOTOMETRIC COLOR METHOD

Energy Technology Data Exchange (ETDEWEB)

De Jaeger, T.; González-Gaitán, S.; Galbany, L.; Hamuy, M.; Gutiérrez, C. P.; Kuncarayakti, H. [Millennium Institute of Astrophysics, Santiago (Chile); Anderson, J. P. [European Southern Observatory, Alonso de Córdova 3107, Casilla 19, Santiago (Chile); Phillips, M. M.; Campillay, A.; Castellón, S.; Hsiao, E. Y.; Morrell, N. [Las Campanas Observatory, Carnegie Observatories, Casilla 601, La Serena (Chile); Stritzinger, M. D.; Contreras, C. [Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark); Bolt, L. [Argelander Institut für Astronomie, Universität Bonn, Auf dem Hgel 71, D-53111 Bonn (Germany); Burns, C. R. [Observatories of the Carnegie Institution for Science, Pasadena, CA 91101 (United States); Folatelli, G. [Instituto de Astrofísica de La Plata, CONICET, Paseo del Bosque S/N, B1900FWA, La Plata (Argentina); Freedman, W. L. [Department of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637 (United States); Krisciunas, K. [George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States); Krzeminski, W., E-mail: dthomas@das.uchile.cl [N. Copernicus Astronomical Center, ul. Bartycka 18, 00-716 Warszawa (Poland); and others

2015-12-20

We present a Hubble diagram of SNe II using corrected magnitudes derived only from photometry, with no input of spectral information. We use a data set from the Carnegie Supernovae Project I for which optical and near-infrared light curves were obtained. The apparent magnitude is corrected by two observables, one corresponding to the slope of the plateau in the V band and the second a color term. We obtain a dispersion of 0.44 mag using a combination of the (V − i) color and the r band and we are able to reduce the dispersion to 0.39 mag using our golden sample. A comparison of our photometric color method (PCM) with the standardized candle method (SCM) is also performed. The dispersion obtained for the SCM (which uses both photometric and spectroscopic information) is 0.29 mag, which compares with 0.43 mag from the PCM for the same SN sample. The construction of a photometric Hubble diagram is of high importance in the coming era of large photometric wide-field surveys, which will increase the detection rate of supernovae by orders of magnitude. Such numbers will prohibit spectroscopic follow up in the vast majority of cases, and hence methods must be deployed which can proceed using solely photometric data.

HUBBLE TARANTULA TREASURY PROJECT. V. THE STAR CLUSTER HODGE 301: THE OLD FACE OF 30 DORADUS

Energy Technology Data Exchange (ETDEWEB)

Cignoni, M. [Department of Physics—University of Pisa, Largo Pontecorvo, 3 Pisa, I-56127 (Italy); Sabbi, E.; Marel, R. P. van der; Aloisi, A.; Panagia, N. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD, 21218 (United States); Lennon, D. J. [European Space Astronomy Centre, Apdo. de Correo 78, E-28691 Villanueva de la Canada, Madrid (Spain); Tosi, M. [INAF-Osservatorio Astronomico di Bologna, Via Ranzani 1, I-40127 Bologna (Italy); Grebel, E. K. [Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg, Mönchhofstr. 12-14, D-69120 Heidelberg (Germany); Gallagher, J. S. III [Department of Astronomy, University of Wisconsin-Madison, WI 53706 (United States); Marchi, G. de [European Space Research and Technology Centre, Keplerlaan 1, NL-2200 AG Noordwijk (Netherlands); Gouliermis, D. A. [Zentrum für Astronomie der Universität Heidelberg, Institut für Theoretische Astrophysik, Albert-Ueberle-Str. 2, D-69120 Heidelberg (Germany); Larsen, S. [Department of Astrophysics, Radboud University, P.O. Box 9010, NL-6500 GL Nijmegen (Netherlands); Smith, L. J., E-mail: michele.cignoni@unipi.it [European Space Agency and Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)

2016-12-20

Based on color–magnitude diagrams (CMDs) from the Hubble Space Telescope  Hubble Tarantula Treasury Project (HTTP) survey, we present the star formation history of Hodge 301, the oldest star cluster in the Tarantula Nebula. The HTTP photometry extends faint enough to reach, for the first time, the cluster pre-main sequence (PMS) turn-on, where the PMS joins the main sequence. Using the location of this feature, along with synthetic CMDs generated with the latest PARSEC models, we find that Hodge 301 is older than previously thought, with an age between 26.5 and 31.5 Myr. From this age, we also estimate that between 38 and 61 Type II supernovae exploded in the region. The same age is derived from the main sequence turn-off, whereas the age derived from the post-main sequence stars is younger and between 20 and 25 Myr. Other relevant parameters are a total stellar mass of ≈8800 ± 800  M {sub ⊙} and average reddening E ( B − V ) ≈ 0.22–0.24 mag, with a differential reddening δE ( B − V ) ≈ 0.04 mag.

Probing Very Bright End of Galaxy Luminosity Function at z >~ 7 Using Hubble Space Telescope Pure Parallel Observations

Science.gov (United States)

Yan, Haojing; Yan, Lin; Zamojski, Michel A.; Windhorst, Rogier A.; McCarthy, Patrick J.; Fan, Xiaohui; Röttgering, Huub J. A.; Koekemoer, Anton M.; Robertson, Brant E.; Davé, Romeel; Cai, Zheng

2011-02-01

We report the first results from the Hubble Infrared Pure Parallel Imaging Extragalactic Survey, which utilizes the pure parallel orbits of the Hubble Space Telescope to do deep imaging along a large number of random sightlines. To date, our analysis includes 26 widely separated fields observed by the Wide Field Camera 3, which amounts to 122.8 arcmin2 in total area. We have found three bright Y 098-dropouts, which are candidate galaxies at z >~ 7.4. One of these objects shows an indication of peculiar variability and its nature is uncertain. The other two objects are among the brightest candidate galaxies at these redshifts known to date (L>2L*). Such very luminous objects could be the progenitors of the high-mass Lyman break galaxies observed at lower redshifts (up to z ~ 5). While our sample is still limited in size, it is much less subject to the uncertainty caused by "cosmic variance" than other samples because it is derived using fields along many random sightlines. We find that the existence of the brightest candidate at z ≈ 7.4 is not well explained by the current luminosity function (LF) estimates at z ≈ 8. However, its inferred surface density could be explained by the prediction from the LFs at z ≈ 7 if it belongs to the high-redshift tail of the galaxy population at z ≈ 7. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with programs 11700 and 11702.

Galaxy Size Evolution at High Redshift and Surface Brightness Selection Effects: Constraints from the Hubble Ultra Deep Field

Science.gov (United States)

Bouwens, R. J.; Illingworth, G. D.; Blakeslee, J. P.; Broadhurst, T. J.; Franx, M.

2004-08-01

We use the exceptional depth of the Ultra Deep Field (UDF) and UDF-parallel Advanced Camera for Surveys fields to study the sizes of high-redshift (z~2-6) galaxies and address long-standing questions about possible biases in the cosmic star formation rate due to surface brightness dimming. Contrasting B-, V-, and i-dropout samples culled from the deeper data with those obtained from the shallower Great Observatories Origins Deep Survey fields, we demonstrate that the shallower data are essentially complete at bright magnitudes to z~0.4", >~3 kpc) low surface brightness galaxies are rare. A simple comparison of the half-light radii of the Hubble Deep Field-North + Hubble Deep Field-South U-dropouts with B-, V-, and i-dropouts from the UDF shows that the sizes follow a (1+z)-1.05+/-0.21 scaling toward high redshift. A more rigorous measurement compares different scalings of our U-dropout sample with the mean profiles for a set of intermediate-magnitude (26.0dropouts from the UDF. The best fit is found with a (1+z)-0.94+0.19-0.25 size scaling (for fixed luminosity). This result is then verified by repeating this experiment with different size measures, low-redshift samples, and magnitude ranges. Very similar scalings are found for all comparisons. A robust measurement of size evolution is thereby demonstrated for galaxies from z~6 to 2.5 using data from the UDF. Based on observations made with the NASA/ESA Hubble Space Telescope, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

Infrared observations of giant elliptical galaxies: (V-K) colors and the infrared Hubble diagram

International Nuclear Information System (INIS)

Grasdalen, G.L.

1980-01-01

The (V-K) colors of giant elliptical galaxies as a function of redshift are discussed. Present data are consistent with mild color evolution at z approximately 0.45. An infrared Hubble (redshift-magnitude) diagram is given. Cosmological models with q 0 =0 and no luminosity evolution are clearly excluded by the present data. A wide variety of models including those with q 0 =0 are permissible if luminosity evolution is included. Instrumental and programmatic implications of these results are summarized. (Auth.)

The Hubble IR cutoff in holographic ellipsoidal cosmologies

Energy Technology Data Exchange (ETDEWEB)

Cataldo, Mauricio [Universidad del Bio-Bio, Departamento de Fisica, Facultad de Ciencias, Concepcion (Chile); Cruz, Norman [Grupo de Cosmologia y Gravitacion-UBB, Concepcion (Chile)

2018-01-15

It is well known that for spatially flat FRW cosmologies, the holographic dark energy disfavors the Hubble parameter as a candidate for the IR cutoff. For overcoming this problem, we explore the use of this cutoff in holographic ellipsoidal cosmological models, and derive the general ellipsoidal metric induced by a such holographic energy density. Despite the drawbacks that this cutoff presents in homogeneous and isotropic universes, based on this general metric, we developed a suitable ellipsoidal holographic cosmological model, filled with a dark matter and a dark energy components. At late time stages, the cosmic evolution is dominated by a holographic anisotropic dark energy with barotropic equations of state. The cosmologies expand in all directions in accelerated manner. Since the ellipsoidal cosmologies given here are not asymptotically FRW, the deviation from homogeneity and isotropy of the universe on large cosmological scales remains constant during all cosmic evolution. This feature allows the studied holographic ellipsoidal cosmologies to be ruled by an equation of state ω = p/ρ, whose range belongs to quintessence or even phantom matter. (orig.)

Large-q correlations from a Hubble-type pion source

International Nuclear Information System (INIS)

Barghouty, A.F.; Miller, J.; Frankel, K.A.

1993-01-01

In two-pion correlation measurements from relativistic nuclear collisions, the correlation function, C 2 (q), appears to exhibit an oscillatory structure at large (q ≥100 MeV/c) relative momentum. If real, this structure may have consequences for the determination of the space-time extent of the pion source. A qualitatively similar feature is seen in cellular automaton simulations of a Lorentz gas. It has been argued phenomenologically that the q-dependent oscillations can arise from an interplay between successive scattering probabilities and density variations of an exploding pion source. To further illustrate this interplay we consider a Hubble-type free expansion model for the source in which the density is time-folded from an initial Gaussian. This allows the source expansion to enter as a dynamical variable in the source density p[r(t); t] and thus C 2 , along with any signature of the interplay between scattering and source density

Shift Work Disorder and Mental and Physical Effects of Shift Work

Directory of Open Access Journals (Sweden)

Pinar Guzel Ozdemir

2018-03-01

Full Text Available With the growing prevalence of shift work all over the the world, the relationship between the daily lives of irregular lifestyles and rhythms is being investigated for those working as shift workers and their families. The effect of shift work on physical and mental health is a very important field of research in recent years. The onset and persistence of medical complications in shift workers includes impaired synchronization between work schedule rhythms and circadian clock. In this context, studies have been carried out showing the increased risk of sleep-wake disorders, gastrointestinal problems, and cardiovascular diseases. There is little information about the actual frequency, effect on health and treatment of shift work disorder, known as circadian rhythm sleep disorder. Shift work disorder includes insomnia and/or excessive sleepiness related with the work schedule. The aim of this rewiev, mentioning about the physical and mental effects of shift work, and to provide information about the diagnosis, clinic and treatment methods of shift-work disorder.

Hartmann wavefront sensing of the corrective optics for the Hubble Space Telescope

Science.gov (United States)

Davila, Pam S.; Eichhorn, William L.; Wilson, Mark E.

1994-06-01

There is no doubt that astronomy with the `new, improved' Hubble Space Telescope will significantly advance our knowledge and understanding of the universe for years to come. The Corrective Optics Space Telescope Axial Replacement (COSTAR) was designed to restore the image quality to nearly diffraction limited performance for three of the first generation instruments; the faint object camera, the faint object spectrograph, and the Goddard high resolution spectrograph. Spectacular images have been obtained from the faint object camera after the installation of the corrective optics during the first servicing mission in December of 1993. About 85% of the light in the central core of the corrected image is contained within a circle with a diameter of 0.2 arcsec. This is a vast improvement over the previous 15 to 17% encircled energies obtained before COSTAR. Clearly COSTAR is a success. One reason for the overwhelming success of COSTAR was the ambitious and comprehensive test program conducted by various groups throughout the program. For optical testing of COSTAR on the ground, engineers at Ball Aerospace designed and built the refractive Hubble simulator to produce known amounts of spherical aberration and astigmatism at specific points in the field of view. The design goal for this refractive aberrated simulator (RAS) was to match the aberrations of the Hubble Space Telescope to within (lambda) /20 rms over the field at a wavelength of 632.8 nm. When the COSTAR optics were combined with the RAS optics, the corrected COSTAR output images were produced. These COSTAR images were recorded with a high resolution 1024 by 1024 array CCD camera, the Ball image analyzer (BIA). The image quality criteria used for assessment of COSTAR performance was encircled energy in the COSTAR focal plane. This test with the BIA was very important because it was a direct measurement of the point spread function. But it was difficult with this test to say anything quantitative about the

Surface Brightness Profiles of Composite Images of Compact Galaxies at Z approximately equal 4-6 in the Hubble Ultra Deep Field

National Research Council Canada - National Science Library

Hathi, N. P; Jansen, R. A; Windhorst, R. A; Cohen, S. H; Keel, W. C; Corbin, M. R; Ryan, Jr, R. E

2007-01-01

The Hubble Ultra Deep Field (HUDF) contains a significant number of B-, V-, and iota'-band dropout objects, many of which were recently confirmed to be young star-forming galaxies at Z approximately equal 4-6...

A Type II Supernova Hubble diagram from the CSP-I, SDSS-II, and SNLS surveys

OpenAIRE

de Jaeger, T.; González-Gaitán, S.; Hamuy, M.; Galbany, L.; Anderson, J. P.; Phillips, M. M.; Stritzinger, M. D.; Carlberg, R. G.; Sullivan, M.; Gutiérrez, C. P.; Hook, I. M.; Howell, D. Andrew; Hsiao, E. Y.; Kuncarayakti, H.; Ruhlmann-Kleider, V.

2016-01-01

The coming era of large photometric wide-field surveys will increase the detection rate of supernovae by orders of magnitude. Such numbers will restrict spectroscopic follow-up in the vast majority of cases, and hence new methods based solely on photometric data must be developed. Here, we construct a complete Hubble diagram of Type II supernovae (SNe II) combining data from three different samples: the Carnegie Supernova Project-I, the Sloan Digital Sky Survey II SN, and th...

Probing the z > 6 Universe with the First Hubble Frontier Fields Cluster A2744

Science.gov (United States)

Atek, Hakim; Richard, Johan; Kneib, Jean-Paul; Clement, Benjamin; Egami, Eiichi; Ebeling, Harald; Jauzac, Mathilde; Jullo, Eric; Laporte, Nicolas; Limousin, Marceau; Natarajan, Priyamvada

2014-05-01

The Hubble Frontier Fields program combines the capabilities of the Hubble Space Telescope (HST) with the gravitational lensing of massive galaxy clusters to probe the distant universe to an unprecedented depth. Here, we present the results of the first combined HST and Spitzer observations of the cluster A-2744. We combine the full near-infrared data with ancillary optical images to search for gravitationally lensed high-redshift (z >~ 6) galaxies. We report the detection of 15 I 814 dropout candidates at z ~ 6-7 and one Y 105 dropout at z ~ 8 in a total survey area of 1.43 arcmin2 in the source plane. The predictions of our lens model also allow us to identify five multiply imaged systems lying at redshifts between z ~ 6 and z ~ 8. Thanks to constraints from the mass distribution in the cluster, we were able to estimate the effective survey volume corrected for completeness and magnification effects. This was in turn used to estimate the rest-frame ultraviolet luminosity function (LF) at z ~ 6-8. Our LF results are generally in agreement with the most recent blank field estimates, confirming the feasibility of surveys through lensing clusters. Although based on a shallower observations than what will be achieved in the final data set including the full Advanced Camera for Survey observations, the LF presented here goes down to M UV ~-18.5, corresponding to 0.2L sstarf at z ~ 7 with one identified object at M UV ~-15 thanks to the highly magnified survey areas. This early study forecasts the power of using massive galaxy clusters as cosmic telescopes and its complementarity to blank fields. Based on observations made with the NASA/ESA Hubble Space Telescope (HST), which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with programs 13495 and 11689. Based in part on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory

Non-occupational physical activity levels of shift workers compared with non-shift workers

Science.gov (United States)

Loef, Bette; Hulsegge, Gerben; Wendel-Vos, G C Wanda; Verschuren, W M Monique; Bakker, Marije F; van der Beek, Allard J; Proper, Karin I

2017-01-01

Objectives Lack of physical activity (PA) has been hypothesised as an underlying mechanism in the adverse health effects of shift work. Therefore, our aim was to compare non-occupational PA levels between shift workers and non-shift workers. Furthermore, exposure–response relationships for frequency of night shifts and years of shift work regarding non-occupational PA levels were studied. Methods Data of 5980 non-shift workers and 532 shift workers from the European Prospective Investigation into Cancer and Nutrition-Netherlands (EPIC-NL) were used in these cross-sectional analyses. Time spent (hours/week) in different PA types (walking/cycling/exercise/chores) and intensities (moderate/vigorous) were calculated based on self-reported PA. Furthermore, sports were operationalised as: playing sports (no/yes), individual versus non-individual sports, and non-vigorous-intensity versus vigorous-intensity sports. PA levels were compared between shift workers and non-shift workers using Generalized Estimating Equations and logistic regression. Results Shift workers reported spending more time walking than non-shift workers (B=2.3 (95% CI 1.2 to 3.4)), but shift work was not associated with other PA types and any of the sports activities. Shift workers who worked 1–4 night shifts/month (B=2.4 (95% CI 0.6 to 4.3)) and ≥5 night shifts/month (B=3.7 (95% CI 1.8 to 5.6)) spent more time walking than non-shift workers. No exposure–response relationships were found between years of shift work and PA levels. Conclusions Shift workers spent more time walking than non-shift workers, but we observed no differences in other non-occupational PA levels. To better understand if and how PA plays a role in the negative health consequences of shift work, our findings need to be confirmed in future studies. PMID:27872151

The Carnegie-Chicago Hubble Program: Discovery of the Most Distant Ultra-faint Dwarf Galaxy in the Local Universe

Science.gov (United States)

Lee, Myung Gyoon; Jang, In Sung; Beaton, Rachael; Seibert, Mark; Bono, Giuseppe; Madore, Barry

2017-02-01

Ultra-faint dwarf galaxies (UFDs) are the faintest known galaxies, and due to their incredibly low surface brightness, it is difficult to find them beyond the Local Group. We report a serendipitous discovery of a UFD, Fornax UFD1, in the outskirts of NGC 1316, a giant galaxy in the Fornax cluster. The new galaxy is located at a projected radius of 55 kpc in the south-east of NGC 1316. This UFD is found as a small group of resolved stars in the Hubble Space Telescope images of a halo field of NGC 1316, obtained as part of the Carnegie-Chicago Hubble Program. Resolved stars in this galaxy are consistent with being mostly metal-poor red giant branch (RGB) stars. Applying the tip of the RGB method to the mean magnitude of the two brightest RGB stars, we estimate the distance to this galaxy, 19.0 ± 1.3 Mpc. Fornax UFD1 is probably a member of the Fornax cluster. The color-magnitude diagram of these stars is matched by a 12 Gyr isochrone with low metallicity ([Fe/H] ≈ -2.4). Total magnitude and effective radius of Fornax UFD1 are MV ≈ -7.6 ± 0.2 mag and reff = 146 ± 9 pc, which are similar to those of Virgo UFD1 that was discovered recently in the intracluster field of Virgo by Jang & Lee. Fornax UFD1 is the most distant known UFD that is confirmed by resolved stars. This indicates that UFDs are ubiquitous and that more UFDs remain to be discovered in the Fornax cluster. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with programs #10505 and #13691.

Discovery of z ~ 8 Galaxies in the Hubble Ultra Deep Field from Ultra-Deep WFC3/IR Observations

Science.gov (United States)

Bouwens, R. J.; Illingworth, G. D.; Oesch, P. A.; Stiavelli, M.; van Dokkum, P.; Trenti, M.; Magee, D.; Labbé, I.; Franx, M.; Carollo, C. M.; Gonzalez, V.

2010-02-01

We utilize the newly acquired, ultra-deep WFC3/IR observations over the Hubble Ultra Deep Field (HUDF) to search for star-forming galaxies at z ~ 8-8.5, only 600 million years from recombination, using a Y 105-dropout selection. The new 4.7 arcmin2 WFC3/IR observations reach to ~28.8 AB mag (5σ) in the Y 105 J 125 H 160 bands. These remarkable data reach ~1.5 AB mag deeper than the previous data over the HUDF, and now are an excellent match to the HUDF optical ACS data. For our search criteria, we use a two-color Lyman break selection technique to identify z ~ 8-8.5Y 105-dropouts. We find five likely z ~ 8-8.5 candidates. The sources have H 160-band magnitudes of ~28.3 AB mag and very blue UV-continuum slopes, with a median estimated β of lsim-2.5 (where f λ vprop λβ). This suggests that z ~ 8 galaxies are not only essentially dust free but also may have very young ages or low metallicities. The observed number of Y 105-dropout candidates is smaller than the 20 ± 6 sources expected assuming no evolution from z ~ 6, but is consistent with the five expected extrapolating the Bouwens et al. luminosity function (LF) results to z ~ 8. These results provide evidence that the evolution in the LF seen from z ~ 7 to z ~ 3 continues to z ~ 8. The remarkable improvement in the sensitivity of WFC3/IR has enabled Hubble Space Telescope to cross a threshold, revealing star-forming galaxies at z~ 8-9. Based on observations made with the NASA/ESA Hubble Space Telescope, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with programs 11563, 9797.

Reduced Tolerance to Night Shift in Chronic Shift Workers: Insight From Fractal Regulation.

Science.gov (United States)

Li, Peng; Morris, Christopher J; Patxot, Melissa; Yugay, Tatiana; Mistretta, Joseph; Purvis, Taylor E; Scheer, Frank A J L; Hu, Kun

2017-07-01

Healthy physiology is characterized by fractal regulation (FR) that generates similar structures in the fluctuations of physiological outputs at different time scales. Perturbed FR is associated with aging and age-related pathological conditions. Shift work, involving repeated and chronic exposure to misaligned environmental and behavioral cycles, disrupts circadian coordination. We tested whether night shifts perturb FR in motor activity and whether night shifts affect FR in chronic shift workers and non-shift workers differently. We studied 13 chronic shift workers and 14 non-shift workers as controls using both field and in-laboratory experiments. In the in-laboratory study, simulated night shifts were used to induce a misalignment between the endogenous circadian pacemaker and the sleep-wake cycles (ie, circadian misalignment) while environmental conditions and food intake were controlled. In the field study, we found that FR was robust in controls but broke down in shift workers during night shifts, leading to more random activity fluctuations as observed in patients with dementia. The night shift effect was present even 2 days after ending night shifts. The in-laboratory study confirmed that night shifts perturbed FR in chronic shift workers and showed that FR in controls was more resilience to the circadian misalignment. Moreover, FR during real and simulated night shifts was more perturbed in those who started shift work at older ages. Chronic shift work causes night shift intolerance, which is probably linked to the degraded plasticity of the circadian control system. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

Constraints on inflation revisited. An analysis including the latest local measurement of the Hubble constant

Energy Technology Data Exchange (ETDEWEB)

Guo, Rui-Yun [Northeastern University, Department of Physics, College of Sciences, Shenyang (China); Zhang, Xin [Northeastern University, Department of Physics, College of Sciences, Shenyang (China); Peking University, Center for High Energy Physics, Beijing (China)

2017-12-15

We revisit the constraints on inflation models by using the current cosmological observations involving the latest local measurement of the Hubble constant (H{sub 0} = 73.00 ± 1.75 km s{sup -1} Mpc{sup -1}). We constrain the primordial power spectra of both scalar and tensor perturbations with the observational data including the Planck 2015 CMB full data, the BICEP2 and Keck Array CMB B-mode data, the BAO data, and the direct measurement of H{sub 0}. In order to relieve the tension between the local determination of the Hubble constant and the other astrophysical observations, we consider the additional parameter N{sub eff} in the cosmological model. We find that, for the ΛCDM+r+N{sub eff} model, the scale invariance is only excluded at the 3.3σ level, and ΔN{sub eff} > 0 is favored at the 1.6σ level. Comparing the obtained 1σ and 2σ contours of (n{sub s},r) with the theoretical predictions of selected inflation models, we find that both the convex and the concave potentials are favored at 2σ level, the natural inflation model is excluded at more than 2σ level, the Starobinsky R{sup 2} inflation model is only favored at around 2σ level, and the spontaneously broken SUSY inflation model is now the most favored model. (orig.)

Non-occupational physical activity levels of shift workers compared with non-shift workers.

Science.gov (United States)

Loef, Bette; Hulsegge, Gerben; Wendel-Vos, G C Wanda; Verschuren, W M Monique; Vermeulen, Roel C H; Bakker, Marije F; van der Beek, Allard J; Proper, Karin I

2017-05-01

Lack of physical activity (PA) has been hypothesised as an underlying mechanism in the adverse health effects of shift work. Therefore, our aim was to compare non-occupational PA levels between shift workers and non-shift workers. Furthermore, exposure-response relationships for frequency of night shifts and years of shift work regarding non-occupational PA levels were studied. Data of 5980 non-shift workers and 532 shift workers from the European Prospective Investigation into Cancer and Nutrition-Netherlands (EPIC-NL) were used in these cross-sectional analyses. Time spent (hours/week) in different PA types (walking/cycling/exercise/chores) and intensities (moderate/vigorous) were calculated based on self-reported PA. Furthermore, sports were operationalised as: playing sports (no/yes), individual versus non-individual sports, and non-vigorous-intensity versus vigorous-intensity sports. PA levels were compared between shift workers and non-shift workers using Generalized Estimating Equations and logistic regression. Shift workers reported spending more time walking than non-shift workers (B=2.3 (95% CI 1.2 to 3.4)), but shift work was not associated with other PA types and any of the sports activities. Shift workers who worked 1-4 night shifts/month (B=2.4 (95% CI 0.6 to 4.3)) and ≥5 night shifts/month (B=3.7 (95% CI 1.8 to 5.6)) spent more time walking than non-shift workers. No exposure-response relationships were found between years of shift work and PA levels. Shift workers spent more time walking than non-shift workers, but we observed no differences in other non-occupational PA levels. To better understand if and how PA plays a role in the negative health consequences of shift work, our findings need to be confirmed in future studies. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Low-redshift effects of local structure on the Hubble parameter in presence of a cosmological constant

Energy Technology Data Exchange (ETDEWEB)

Romano, Antonio Enea [University of Crete, Department of Physics and CCTP, Heraklion (Greece); Kyoto University, Yukawa Institute for Theoretical Physics, Kyoto (Japan); Universidad de Antioquia, Instituto de Fisica, Medellin (Colombia); Vallejo, Sergio Andres [Kyoto University, Yukawa Institute for Theoretical Physics, Kyoto (Japan); Universidad de Antioquia, Instituto de Fisica, Medellin (Colombia)

2016-04-15

In order to estimate the effects of a local structure on the Hubble parameter we calculate the low-redshift expansion for H(z) and (δH)/(H) for an observer at the center of a spherically symmetric matter distribution in the presence of a cosmological constant. We then test the accuracy of the formulas comparing them with fully relativistic non-perturbative numerical calculations for different cases for the density profile. The low-redshift expansion we obtain gives results more precise than perturbation theory since it is based on the use of an exact solution of Einstein's field equations. For larger density contrasts the low-redshift formulas accuracy improves respect to the perturbation theory accuracy because the latter is based on the assumption of a small density contrast, while the former does not rely on such an assumption. The formulas can be used to take into account the effects on the Hubble expansion parameter due to the monopole component of the local structure. If the H(z) observations will show deviations from the ΛCDM prediction compatible with the formulas we have derived, this could be considered an independent evidence of the existence of a local inhomogeneity, and the formulas could be used to determine the characteristics of this local structure. (orig.)

SPECTROSCOPIC CONFIRMATION OF FAINT LYMAN BREAK GALAXIES NEAR REDSHIFT FIVE IN THE HUBBLE ULTRA DEEP FIELD

International Nuclear Information System (INIS)

Rhoads, James E.; Malhotra, Sangeeta; Cohen, Seth; Grogin, Norman; Hathi, Nimish; Ryan, Russell; Straughn, Amber; Windhorst, Rogier A.; Pirzkal, Norbert; Xu Chun; Koekemoer, Anton; Panagia, Nino; Dickinson, Mark; Ferreras, Ignacio; Gronwall, Caryl; Kuemmel, Martin; Walsh, Jeremy; Meurer, Gerhardt; Pasquali, Anna; Yan, H.-J.

2009-01-01

We present the faintest spectroscopically confirmed sample of z ∼ 5 Lyman break galaxies (LBGs) to date. The sample is based on slitless grism spectra of the Hubble Ultra Deep Field region from the Grism ACS Program for Extragalactic Science (GRAPES) and Probing Evolution and Reionization Spectroscopically (PEARS) projects, using the G800L grism on the Hubble Space Telescope Advanced Camera for Surveys. We report here confirmations of 39 galaxies, preselected as candidate LBGs using photometric selection criteria. We compare a 'traditional' V-dropout selection, based on the work of Giavalisco et al., to a more liberal one (with V - i > 0.9), and find that the traditional criteria are about 64% complete and 81% reliable. We also study the Lyα emission properties of our sample. We find that Lyα emission is detected in ∼1/4 of the sample, and that the liberal V-dropout color selection includes ∼55% of previously published line-selected Lyα sources. Finally, we examine our stacked two-dimensional spectra. We demonstrate that strong, spatially extended (∼1'') Lyα emission is not a generic property of these LBGs, but that a modest extension of the Lyα photosphere (compared to the starlight) may be present in those galaxies with prominent Lyα emission.

Light dark photon and fermionic dark radiation for the Hubble constant and the structure formation

OpenAIRE

Ko, P.; Tang, Yong

2018-01-01

Motivated by the tensions in the Hubble constant $H_0$ and the structure growth $\\sigma_8$ between $Planck$ results and other low redshift measurements, we discuss some cosmological effects of a dark sector model in which dark matter (DM) interacts with fermionic dark radiation (DR) through a light gauge boson (dark photon). Such kind of models are very generic in particle physics with a dark sector with dark gauge symmetries. The effective number of neutrinos is increased by $\\delta N_{eff} ...

A knowledge-based system for monitoring the electrical power system of the Hubble Space Telescope

Science.gov (United States)

Eddy, Pat

1987-01-01

The design and the prototype for the expert system for the Hubble Space Telescope's electrical power system are discussed. This prototype demonstrated the capability to use real time data from a 32k telemetry stream and to perform operational health and safety status monitoring, detect trends such as battery degradation, and detect anomalies such as solar array failures. This prototype, along with the pointing control system and data management system expert systems, forms the initial Telemetry Analysis for Lockheed Operated Spacecraft (TALOS) capability.

Hubble Space Telescope Snapshot Survey for Resolved Companions of Galactic Cepheids

Science.gov (United States)

Evans, Nancy Remage; Bond, Howard E.; Schaefer, Gail H.; Mason, Brian D.; Tingle, Evan; Karovska, Margarita; Pillitteri, Ignazio

2016-05-01

We have conducted an imaging survey with the Hubble Space Telescope Wide Field Camera 3 (WFC3) of 70 Galactic Cepheids, typically within 1 kpc, with the aim of finding resolved physical companions. The WFC3 field typically covers the 0.1 pc area where companions are expected. In this paper, we identify 39 Cepheids having candidate companions, based on their positions in color-magnitude diagrams, and having separations ⩾ 5'' from the Cepheids. We use follow-up observations of 14 of these candidates with XMM-Newton, and of one of them with ROSAT, to separate X-ray-active young stars (probable physical companions) from field stars (chance alignments). Our preliminary estimate, based on the optical and X-ray observations, is that only 3% of the Cepheids in the sample have wide companions. Our survey easily detects resolved main-sequence companions as faint as spectral type K. Thus the fact that the two most probable companions (those of FF Aql and RV Sco) are earlier than type K is not simply a function of the detection limit. We find no physical companions having separations larger than 4000 au in the X-ray survey. Two Cepheids are exceptions in that they do have young companions at significantly larger separations (δ Cep and S Nor), but both belong to a cluster or a loose association, so our working model is that they are not gravitationally bound binary members, but rather cluster/association members. All of these properties provide constraints on both star formation and subsequent dynamical evolution. The low frequency of true physical companions at separations > 5'' is confirmed by examination of the subset of the nearest Cepheids and also the density of the fields. Based on observations with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

Blue and red shifted temperature dependence of implicit phonon shifts in graphene

Science.gov (United States)

Mann, Sarita; Jindal, V. K.

2017-07-01

We have calculated the implicit shift for various modes of frequency in a pure graphene sheet. Thermal expansion and Grüneisen parameter which are required for implicit shift calculation have already been studied and reported. For this calculation, phonon frequencies are obtained using force constants derived from dynamical matrix calculated using VASP code where the density functional perturbation theory (DFPT) is used in interface with phonopy software. The implicit phonon shift shows an unusual behavior as compared to the bulk materials. The frequency shift is large negative (red shift) for ZA and ZO modes and the value of negative shift increases with increase in temperature. On the other hand, blue shift arises for all other longitudinal and transverse modes with a similar trend of increase with increase in temperature. The q dependence of phonon shifts has also been studied. Such simultaneous red and blue shifts in transverse or out plane modes and surface modes, respectively leads to speculation of surface softening in out of plane direction in preference to surface melting.

Hubble Space Telescope Observations of cD Galaxies and Their Globular Cluster Systems

Science.gov (United States)

Jordán, Andrés; Côté, Patrick; West, Michael J.; Marzke, Ronald O.; Minniti, Dante; Rejkuba, Marina

2004-01-01

We have used WFPC2 on the Hubble Space Telescope (HST) to obtain F450W and F814W images of four cD galaxies (NGC 541 in Abell 194, NGC 2832 in Abell 779, NGC 4839 in Abell 1656, and NGC 7768 in Abell 2666) in the range 5400 km s-1cluster (GC) systems reveals no anomalies in terms of specific frequencies, metallicity gradients, average metallicities, or the metallicity offset between the globular clusters and the host galaxy. We show that the latter offset appears roughly constant at Δ[Fe/H]~0.8 dex for early-type galaxies spanning a luminosity range of roughly 4 orders of magnitude. We combine the globular cluster metallicity distributions with an empirical technique described in a series of earlier papers to investigate the form of the protogalactic mass spectrum in these cD galaxies. We find that the observed GC metallicity distributions are consistent with those expected if cD galaxies form through the cannibalism of numerous galaxies and protogalactic fragments that formed their stars and globular clusters before capture and disruption. However, the properties of their GC systems suggest that dynamical friction is not the primary mechanism by which these galaxies are assembled. We argue that cD's instead form rapidly, via hierarchical merging, prior to cluster virialization. Based on observations with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555 Based in part on observations obtained at the European Southern Observatory, for VLT program 68.D-0130(A).

OpenShift Workshop

CERN Multimedia

CERN. Geneva; Rodriguez Peon, Alberto

2017-01-01

Workshop to introduce developers to the OpenShift platform available at CERN. Several use cases will be shown, including deploying an existing application into OpenShift. We expect attendees to realize about OpenShift features and general architecture of the service.

Contributors to shift work tolerance in South Korean nurses working rotating shift.

Science.gov (United States)

Jung, Hye-Sun; Lee, Bokim

2015-05-01

Shift workers have rapidly increased in South Korea; however, there is no published research exploring shift work tolerance among South Korean workers. This study aimed to investigate factors related to shift work tolerance in South Korean nurses. The sample comprised of 660 nurses who worked shifts in a large hospital in South Korea. A structured questionnaire included following comprehensive variables: demographic (age and number of children), individual (morningness and self-esteem), psychosocial (social support and job stress), lifestyle (alcohol consumption, physical activity, and BMI), and working condition factors (number of night shifts and working hours). Shift work tolerance was measured in terms of insomnia, fatigue, and depression. The results of hierarchical regressions indicate that all variables, except for three, number of children, BMI, and working hours, were related to at least one of the symptoms associated with shift work tolerance. Based on these results, we offer some practical implications to help improve shift work tolerance of workers. Copyright © 2014 Elsevier Inc. All rights reserved.

Hubble Space Telescope, Faint Object Camera

Science.gov (United States)

1981-01-01

This drawing illustrates Hubble Space Telescope's (HST's), Faint Object Camera (FOC). The FOC reflects light down one of two optical pathways. The light enters a detector after passing through filters or through devices that can block out light from bright objects. Light from bright objects is blocked out to enable the FOC to see background images. The detector intensifies the image, then records it much like a television camera. For faint objects, images can be built up over long exposure times. The total image is translated into digital data, transmitted to Earth, and then reconstructed. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Cornecticut, developed the optical system and guidance sensors.

Expert system application for prioritizing preventive actions for shift work: shift expert.

Science.gov (United States)

Esen, Hatice; Hatipoğlu, Tuğçen; Cihan, Ahmet; Fiğlali, Nilgün

2017-09-19

Shift patterns, work hours, work arrangements and worker motivations have increasingly become key factors for job performance. The main objective of this article is to design an expert system that identifies the negative effects of shift work and prioritizes mitigation efforts according to their importance in preventing these negative effects. The proposed expert system will be referred to as the shift expert. A thorough literature review is conducted to determine the effects of shift work on workers. Our work indicates that shift work is linked to demographic variables, sleepiness and fatigue, health and well-being, and social and domestic conditions. These parameters constitute the sections of a questionnaire designed to focus on 26 important issues related to shift work. The shift expert is then constructed to provide prevention advice at the individual and organizational levels, and it prioritizes this advice using a fuzzy analytic hierarchy process model, which considers comparison matrices provided by users during the prioritization process. An empirical study of 61 workers working on three rotating shifts is performed. After administering the questionnaires, the collected data are analyzed statistically, and then the shift expert produces individual and organizational recommendations for these workers.

Implementing OpenShift

CERN Document Server

Miller, Adam

2013-01-01

A standard tutorial-based approach to using OpenShift and deploying custom or pre-built web applications to the OpenShift Online cloud.This book is for software developers and DevOps alike who are interested in learning how to use the OpenShift Platform-as-a-Service for developing and deploying applications, how the environment works on the back end, and how to deploy their very own open source Platform-as-a-Service based on the upstream OpenShift Origin project.

CANDELS : THE COSMIC ASSEMBLY NEAR-INFRARED DEEP EXTRAGALACTIC LEGACY SURVEY-THE HUBBLE SPACE TELESCOPE OBSERVATIONS, IMAGING DATA PRODUCTS, AND MOSAICS

NARCIS (Netherlands)

Koekemoer, Anton M.; Faber, S. M.; Ferguson, Henry C.; Grogin, Norman A.; Kocevski, Dale D.; Koo, David C.; Lai, Kamson; Lotz, Jennifer M.; Lucas, Ray A.; McGrath, Elizabeth J.; Ogaz, Sara; Rajan, Abhijith; Riess, Adam G.; Rodney, Steve A.; Strolger, Louis; Casertano, Stefano; Castellano, Marco; Dahlen, Tomas; Dickinson, Mark; Dolch, Timothy; Fontana, Adriano; Giavalisco, Mauro; Grazian, Andrea; Guo, Yicheng; Hathi, Nimish P.; Huang, Kuang-Han; van der Wel, Arjen; Yan, Hao-Jing; Acquaviva, Viviana; Alexander, David M.; Almaini, Omar; Ashby, Matthew L. N.; Barden, Marco; Bell, Eric F.; Bournaud, Frederic; Brown, Thomas M.; Caputi, Karina I.; Cassata, Paolo; Challis, Peter J.; Chary, Ranga-Ram; Cheung, Edmond; Cirasuolo, Michele; Conselice, Christopher J.; Cooray, Asantha Roshan; Croton, Darren J.; Daddi, Emanuele; Dave, Romeel; de Mello, Duilia F.; de Ravel, Loic; Dekel, Avishai; Donley, Jennifer L.; Dunlop, James S.; Dutton, Aaron A.; Elbaz, David; Fazio, Giovanni G.; Filippenko, Alexei V.; Finkelstein, Steven L.; Frazer, Chris; Gardner, Jonathan P.; Garnavich, Peter M.; Gawiser, Eric; Gruetzbauch, Ruth; Hartley, Will G.; Haeussler, Boris; Herrington, Jessica; Hopkins, Philip F.; Huang, Jia-Sheng; Jha, Saurabh W.; Johnson, Andrew; Kartaltepe, Jeyhan S.; Khostovan, Ali A.; Kirshner, Robert P.; Lani, Caterina; Lee, Kyoung-Soo; Li, Weidong; Madau, Piero; McCarthy, Patrick J.; McIntosh, Daniel H.; McLure, Ross J.; McPartland, Conor; Mobasher, Bahram; Moreira, Heidi; Mortlock, Alice; Moustakas, Leonidas A.; Mozena, Mark; Nandra, Kirpal; Newman, Jeffrey A.; Nielsen, Jennifer L.; Niemi, Sami; Noeske, Kai G.; Papovich, Casey J.; Pentericci, Laura; Pope, Alexandra; Primack, Joel R.; Ravindranath, Swara; Reddy, Naveen A.; Renzini, Alvio; Rix, Hans-Walter; Robaina, Aday R.; Rosario, David J.; Rosati, Piero; Salimbeni, Sara; Scarlata, Claudia; Siana, Brian; Simard, Luc; Smidt, Joseph; Snyder, Diana; Somerville, Rachel S.; Spinrad, Hyron; Straughn, Amber N.; Telford, Olivia; Teplitz, Harry I.; Trump, Jonathan R.; Vargas, Carlos; Villforth, Carolin; Wagner, Cory R.; Wandro, Pat; Wechsler, Risa H.; Weiner, Benjamin J.; Wiklind, Tommy; Wild, Vivienne; Wilson, Grant; Wuyts, Stijn; Yun, Min S.

2011-01-01

This paper describes the Hubble Space Telescope imaging data products and data reduction procedures for the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS). This survey is designed to document the evolution of galaxies and black holes at z approximate to 1.5-8, and to study

A 2.4% DETERMINATION OF THE LOCAL VALUE OF THE HUBBLE CONSTANT

Energy Technology Data Exchange (ETDEWEB)

Riess, Adam G.; Scolnic, Dan; Jones, David O. [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD (United States); Macri, Lucas M.; Hoffmann, Samantha L.; Yuan, Wenlong; Brown, Peter J. [George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Department of Physics and Astronomy, Texas A and M University, College Station, TX (United States); Casertano, Stefano [Space Telescope Science Institute, Baltimore, MD (United States); Filippenko, Alexei V.; Tucker, Brad E. [Department of Astronomy, University of California, Berkeley, CA (United States); Reid, Mark J.; Challis, Peter [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States); Silverman, Jeffrey M. [Department of Astronomy, University of Texas, Austin, TX (United States); Chornock, Ryan [Astrophysical Institute, Department of Physics and Astronomy, Ohio University, Athens, OH (United States); Foley, Ryan J., E-mail: ariess@stsci.edu [Department of Physics, University of Illinois at Urbana-Champaign, Urbana, IL (United States)

2016-07-20

We use the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST) to reduce the uncertainty in the local value of the Hubble constant from 3.3% to 2.4%. The bulk of this improvement comes from new near-infrared (NIR) observations of Cepheid variables in 11 host galaxies of recent type Ia supernovae (SNe Ia), more than doubling the sample of reliable SNe Ia having a Cepheid-calibrated distance to a total of 19; these in turn leverage the magnitude-redshift relation based on ∼300 SNe Ia at z < 0.15. All 19 hosts as well as the megamaser system NGC 4258 have been observed with WFC3 in the optical and NIR, thus nullifying cross-instrument zeropoint errors in the relative distance estimates from Cepheids. Other noteworthy improvements include a 33% reduction in the systematic uncertainty in the maser distance to NGC 4258, a larger sample of Cepheids in the Large Magellanic Cloud (LMC), a more robust distance to the LMC based on late-type detached eclipsing binaries (DEBs), HST observations of Cepheids in M31, and new HST -based trigonometric parallaxes for Milky Way (MW) Cepheids. We consider four geometric distance calibrations of Cepheids: (i) megamasers in NGC 4258, (ii) 8 DEBs in the LMC, (iii) 15 MW Cepheids with parallaxes measured with HST /FGS, HST /WFC3 spatial scanning and/or Hipparcos , and (iv) 2 DEBs in M31. The Hubble constant from each is 72.25 ± 2.51, 72.04 ± 2.67, 76.18 ± 2.37, and 74.50 ± 3.27 km s{sup 1} Mpc{sup 1}, respectively. Our best estimate of H {sub 0} = 73.24 ± 1.74 km s{sup 1} Mpc{sup 1} combines the anchors NGC 4258, MW, and LMC, yielding a 2.4% determination (all quoted uncertainties include fully propagated statistical and systematic components). This value is 3.4 σ higher than 66.93 ± 0.62 km s{sup 1} Mpc{sup 1} predicted by ΛCDM with 3 neutrino flavors having a mass of 0.06 eV and the new Planck data, but the discrepancy reduces to 2.1 σ relative to the prediction of 69.3 ± 0.7 km s{sup 1} Mpc{sup 1} based on the

HFF-DeepSpace Photometric Catalogs of the 12 Hubble Frontier Fields, Clusters, and Parallels: Photometry, Photometric Redshifts, and Stellar Masses

Science.gov (United States)

Shipley, Heath V.; Lange-Vagle, Daniel; Marchesini, Danilo; Brammer, Gabriel B.; Ferrarese, Laura; Stefanon, Mauro; Kado-Fong, Erin; Whitaker, Katherine E.; Oesch, Pascal A.; Feinstein, Adina D.; Labbé, Ivo; Lundgren, Britt; Martis, Nicholas; Muzzin, Adam; Nedkova, Kalina; Skelton, Rosalind; van der Wel, Arjen

2018-03-01

We present Hubble multi-wavelength photometric catalogs, including (up to) 17 filters with the Advanced Camera for Surveys and Wide Field Camera 3 from the ultra-violet to near-infrared for the Hubble Frontier Fields and associated parallels. We have constructed homogeneous photometric catalogs for all six clusters and their parallels. To further expand these data catalogs, we have added ultra-deep K S -band imaging at 2.2 μm from the Very Large Telescope HAWK-I and Keck-I MOSFIRE instruments. We also add post-cryogenic Spitzer imaging at 3.6 and 4.5 μm with the Infrared Array Camera (IRAC), as well as archival IRAC 5.8 and 8.0 μm imaging when available. We introduce the public release of the multi-wavelength (0.2–8 μm) photometric catalogs, and we describe the unique steps applied for the construction of these catalogs. Particular emphasis is given to the source detection band, the contamination of light from the bright cluster galaxies (bCGs), and intra-cluster light (ICL). In addition to the photometric catalogs, we provide catalogs of photometric redshifts and stellar population properties. Furthermore, this includes all the images used in the construction of the catalogs, including the combined models of bCGs and ICL, the residual images, segmentation maps, and more. These catalogs are a robust data set of the Hubble Frontier Fields and will be an important aid in designing future surveys, as well as planning follow-up programs with current and future observatories to answer key questions remaining about first light, reionization, the assembly of galaxies, and many more topics, most notably by identifying high-redshift sources to target.

The Evolution of the Observed Hubble Sequence over the past 6Gyr

Science.gov (United States)

Delgado-Serrano, R.; Hammer, F.; Yang, Y. B.; Puech, M.; Flores, H.; Rodrigues, M.

2011-10-01

During the past years we have confronted serious problems of methodology concerning the morphological and kinematic classification of distant galaxies. This has forced us to create a new simple and effective morphological classification methodology, in order to guarantee a morpho-kinematic correlation, make the reproducibility easier and restrict the classification subjectivity. Giving the characteristic of our morphological classification, we have thus been able to apply the same methodology, using equivalent observations, to representative samples of local and distant galaxies. It has allowed us to derive, for the first time, the distant Hubble sequence (~6 Gyr ago), and determine a morphological evolution of galaxies over the past 6 Gyr. Our results strongly suggest that more than half of the present-day spirals had peculiar morphologies, 6 Gyr ago.

Constraining the evolution of the Hubble Parameter using cosmic chronometer

Science.gov (United States)

Scarlata, Claudia; Dickinson, Hugh

2018-01-01

The Lambda-CDM model of Big Bang cosmology relies heavily on the assumption that two components - dark energy and dark matter - encompass 95% of the energy density of the Universe. Despite the dominant influence of these components, their nature is still entirely unknown.We present the initial results from a project that aims to provide new insights regarding the Dark Energy component. We do this by deriving independent constraints on the time-evolution of the Hubble parameter (H_0) using the “cosmic chronometer” method.By analyzing the HST NIR spectra from a large archival sample of passively evolving galaxies in distinct redshift bins between 1.3 and 2 we measure the typical stellar population ages (A) for the galaxies in each bin. The differential evolution of stellar population age with redshift (dA/dz) can be used to infer the corresponding evolution of H_0 which will provide important constraints on the nature of Dark Energy and its equation of state.

A TYPE Ia SUPERNOVA AT REDSHIFT 1.55 IN HUBBLE SPACE TELESCOPE INFRARED OBSERVATIONS FROM CANDELS

International Nuclear Information System (INIS)

Rodney, Steven A.; Riess, Adam G.; Jones, David O.; Dahlen, Tomas; Ferguson, Henry C.; Casertano, Stefano; Grogin, Norman A.; Strolger, Louis-Gregory; Hjorth, Jens; Frederiksen, Teddy F.; Weiner, Benjamin J.; Mobasher, Bahram; Challis, Peter; Kirshner, Robert P.; Faber, S. M.; Filippenko, Alexei V.; Garnavich, Peter; Hayden, Brian; Graur, Or; Jha, Saurabh W.

2012-01-01

We report the discovery of a Type Ia supernova (SN Ia) at redshift z = 1.55 with the infrared detector of the Wide Field Camera 3 (WFC3-IR) on the Hubble Space Telescope (HST). This object was discovered in CANDELS imaging data of the Hubble Ultra Deep Field and followed as part of the CANDELS+CLASH Supernova project, comprising the SN search components from those two HST multi-cycle treasury programs. This is the highest redshift SN Ia with direct spectroscopic evidence for classification. It is also the first SN Ia at z > 1 found and followed in the infrared, providing a full light curve in rest-frame optical bands. The classification and redshift are securely defined from a combination of multi-band and multi-epoch photometry of the SN, ground-based spectroscopy of the host galaxy, and WFC3-IR grism spectroscopy of both the SN and host. This object is the first of a projected sample at z > 1.5 that will be discovered by the CANDELS and CLASH programs. The full CANDELS+CLASH SN Ia sample will enable unique tests for evolutionary effects that could arise due to differences in SN Ia progenitor systems as a function of redshift. This high-z sample will also allow measurement of the SN Ia rate out to z ≈ 2, providing a complementary constraint on SN Ia progenitor models.

The white dwarf mass-radius relation with Gaia, Hubble and FUSE

Science.gov (United States)

Joyce, Simon R. G.; Barstow, Martin A.; Casewell, Sarah L.; Holberg, Jay B.; Bond, Howard E.

2018-04-01

White dwarfs are becoming useful tools for many areas of astronomy. They can be used as accurate chronometers over Gyr timescales. They are also clues to the history of star formation in our galaxy. Many of these studies require accurate estimates of the mass of the white dwarf. The theoretical mass-radius relation is often invoked to provide these mass estimates. While the theoretical mass-radius relation is well developed, observational tests of this relation show a much larger scatter in the results than expected. High precision observational tests to confirm this relation are required. Gaia is providing distance measurements which will remove one of the main source of uncertainty affecting most previous observations. We combine Gaia distances with spectra from the Hubble and FUSE satelites to make precise tests of the white dwarf mass-radius relation.

The Cardassian expansion revisited: constraints from updated Hubble parameter measurements and type Ia supernova data

Science.gov (United States)

Magaña, Juan; Amante, Mario H.; Garcia-Aspeitia, Miguel A.; Motta, V.

2018-05-01

Motivated by an updated compilation of observational Hubble data (OHD) that consist of 51 points in the redshift range of 0.07 Ia supernova (SN Ia) using the compressed and full joint-light-analysis (JLA) samples (Betoule et al.). We also perform a joint analysis using the combination OHD plus compressed JLA. Our results show that the OC and MPC models are in agreement with the standard cosmology and naturally introduce a cosmological-constant-like extra term in the canonical Friedmann equation with the capability of accelerating the Universe without dark energy.

Observations of the Hubble Deep Field with the Infrared Space Observatory .3. Source counts and P(D) analysis

DEFF Research Database (Denmark)

Oliver, S.J.; Goldschmidt, P.; Franceschini, A.

1997-01-01

We present source counts at 6.7 and 15 mu m from our maps of the Hubble Deep Field (HDF) region, reaching 38.6 mu Jy at 6.7 mu m and 255 mu Jy at 15 mu m. These are the first ever extragalactic number counts to be presented at 6.7 mu m, and are three decades fainter than IRAS at 12 mu m. Both...

Shifting schedules: the health effects of reorganizing shift work.

Science.gov (United States)

Bambra, Clare L; Whitehead, Margaret M; Sowden, Amanda J; Akers, Joanne; Petticrew, Mark P

2008-05-01

Approximately one fifth of workers are engaged in some kind of shift work. The harmful effects of shift work on the health and work-life balance of employees are well known. A range of organizational interventions has been suggested to address these negative effects. This study undertook the systematic review (following Quality Of Reporting Of Meta [QUORUM] analyses guidelines) of experimental and quasi-experimental studies, from any country (in any language) that evaluated the effects on health and work-life balance of organizational-level interventions that redesign shift work schedules. Twenty-seven electronic databases (medical, social science, economic) were searched. Data extraction and quality appraisal were carried out by two independent reviewers. Narrative synthesis was performed. The review was conducted between October 2005 and November 2006. Twenty-six studies were found relating to a variety of organizational interventions. No one type of intervention was found to be consistently harmful to workers. However, three types were found to have beneficial effects on health and work-life balance: (1) switching from slow to fast rotation, (2) changing from backward to forward rotation, and (3) self-scheduling of shifts. Improvements were usually at little or no direct organizational cost. However, there were concerns about the generalizability of the evidence, and no studies reported on impacts on health inequalities. This review reinforces the findings of epidemiologic and laboratory-based research by suggesting that certain organizational-level interventions can improve the health of shift workers, their work-life balance, or both. This evidence could be useful when designing interventions to improve the experience of shift work.

New Target for an Old Method: Hubble Measures Globular Cluster Parallax

Science.gov (United States)

Hensley, Kerry

2018-05-01

Measuring precise distances to faraway objects has long been a challenge in astrophysics. Now, one of the earliest techniques used to measure the distance to astrophysical objects has been applied to a metal-poor globular cluster for the first time.A Classic TechniqueAn artists impression of the European Space Agencys Gaia spacecraft. Gaia is on track to map the positions and motions of a billion stars. [ESA]Distances to nearby stars are often measured using the parallax technique tracing the tiny apparent motion of a target star against the background of more distant stars as Earth orbits the Sun. This technique has come a long way since it was first used in the 1800s to measure the distance to stars a few tens of light-years away; with the advent of space observatories like Hipparcos and Gaia, parallax can now be used to map the positions of stars out to thousands of light-years.Precise distance measurements arent only important for setting the scale of the universe, however; they can also help us better understand stellar evolution over the course of cosmic history. Stellar evolution models are often anchored to a reference star cluster, the properties of which must be known precisely. These precise properties can be readily determined for young, nearby open clusters using parallax measurements. But stellar evolution models that anchor on themore-distant, ancient, metal-poor globular clusters have been hampered by theless-precise indirect methods used tomeasure distance to these faraway clusters until now.Top: An image of NGC 6397 overlaid with the area scanned by Hubble (dashed green) and the footprint of the camera (solid green). The blue ellipse represents the parallax motion of a star in the cluster, exaggerated by a factor of ten thousand. Bottom: An example scan from this field. [Adapted from Brown et al. 2018]New Measurement to an Old ClusterThomas Brown (Space Telescope Science Institute) and collaborators used the Hubble Space Telescope todetermine the

Spike: Artificial intelligence scheduling for Hubble space telescope

Science.gov (United States)

Johnston, Mark; Miller, Glenn; Sponsler, Jeff; Vick, Shon; Jackson, Robert

1990-01-01

Efficient utilization of spacecraft resources is essential, but the accompanying scheduling problems are often computationally intractable and are difficult to approximate because of the presence of numerous interacting constraints. Artificial intelligence techniques were applied to the scheduling of the NASA/ESA Hubble Space Telescope (HST). This presents a particularly challenging problem since a yearlong observing program can contain some tens of thousands of exposures which are subject to a large number of scientific, operational, spacecraft, and environmental constraints. New techniques were developed for machine reasoning about scheduling constraints and goals, especially in cases where uncertainty is an important scheduling consideration and where resolving conflicts among conflicting preferences is essential. These technique were utilized in a set of workstation based scheduling tools (Spike) for HST. Graphical displays of activities, constraints, and schedules are an important feature of the system. High level scheduling strategies using both rule based and neural network approaches were developed. While the specific constraints implemented are those most relevant to HST, the framework developed is far more general and could easily handle other kinds of scheduling problems. The concept and implementation of the Spike system are described along with some experiments in adapting Spike to other spacecraft scheduling domains.

Josephson shift registers

International Nuclear Information System (INIS)

Przybysz, J.X.

1989-01-01

This paper gives a review of Josephson shift register circuits that were designed, fabricated, or tested, with emphasis on work in the 1980s. Operating speed is most important, since it often limits system performance. Older designs used square-wave clocks, but most modern designs use offset sine waves, with either two or three phases. Operating margins and gate bias uniformity are key concerns. The fastest measured Josephson shift register operated at 2.3 GHz, which compares well with a GaAs shift register that consumes 250 times more power. The difficulties of high-speed testing have prevented many Josephson shift registers from being operated at their highest speeds. Computer simulations suggest that 30-GHz operation is possible with current Nb/Al 2 O 3 /Nb technology. Junctions with critical current densities near 10 kA/cm 2 would make 100-GHz shift registers feasible

HUBBLE CLICKS IMAGES OF IO SWEEPING ACROSS JUPITER

Science.gov (United States)

2002-01-01

While hunting for volcanic plumes on Io, NASA's Hubble Space Telescope captured these images of the volatile moon sweeping across the giant face of Jupiter. Only a few weeks before these dramatic images were taken, the orbiting telescope snapped a portrait of one of Io's volcanoes spewing sulfur dioxide 'snow.' These stunning images of the planetary duo are being released to commemorate the ninth anniversary of the Hubble telescope's launch on April 24, 1990. All of these images were taken with the Wide Field and Planetary Camera 2. The three overlapping snapshots show in crisp detail Io passing above Jupiter's turbulent clouds. The close-up picture of Io (bottom right) reveal a 120-mile-high (200-kilometer) plume of sulfur dioxide 'snow' emanating from Pillan, one of the moon's active volcanoes. 'Other observations have inferred sulfur dioxide 'snow' in Io's plumes, but this image offers direct observational evidence for sulfur dioxide 'snow' in an Io plume,' explains John R. Spencer of Lowell Observatory in Flagstaff, Ariz. A Trip Around Jupiter The three snapshots of the volcanic moon rounding Jupiter were taken over a 1.8-hour time span. Io is roughly the size of Earth's moon but 2,000 times farther away. In two of the images, Io appears to be skimming Jupiter's cloud tops, but it's actually 310,000 miles (500,000 kilometers) away. Io zips around Jupiter in 1.8 days, whereas the moon circles Earth every 28 days. The conspicuous black spot on Jupiter is Io's shadow and is about the size of the moon itself (2,262 miles or 3,640 kilometers across). This shadow sails across the face of Jupiter at 38,000 mph (17 kilometers per second). The smallest details visible on Io and Jupiter measure 93 miles (150 kilometers) across, or about the size of Connecticut. These images were further sharpened through image reconstruction techniques. The view is so crisp that one would have to stand on Io to see this much detail on Jupiter with the naked eye. The bright patches on Io

Cosmological Parameters and Hyper-Parameters: The Hubble Constant from Boomerang and Maxima

Science.gov (United States)

Lahav, Ofer

Recently several studies have jointly analysed data from different cosmological probes with the motivation of estimating cosmological parameters. Here we generalise this procedure to allow freedom in the relative weights of various probes. This is done by including in the joint likelihood function a set of `Hyper-Parameters', which are dealt with using Bayesian considerations. The resulting algorithm, which assumes uniform priors on the log of the Hyper-Parameters, is very simple to implement. We illustrate the method by estimating the Hubble constant H0 from different sets of recent CMB experiments (including Saskatoon, Python V, MSAM1, TOCO, Boomerang and Maxima). The approach can be generalised for a combination of cosmic probes, and for other priors on the Hyper-Parameters. Reference: Lahav, Bridle, Hobson, Lasenby & Sodre, 2000, MNRAS, in press (astro-ph/9912105)

Hubble space telescope: The GO and GTO observing programs, version 3.0

Science.gov (United States)

Downes, Ron

1992-01-01

A portion of the observing time with the Hubble Space Telescope (HST) was awarded by NASA to scientists involved in the development of the HST and its instruments. These scientists are the Guaranteed Time Observers (GTO's). Observing time was also awarded to General Observers (GO's) on the basis of the proposal reviews in 1989 and 1991. The majority of the 1989 programs have been completed during 'Cycle 1', while the 1991 programs will be completed during 'Cycle 2', nominally a 12-month period beginning July 1992. This document presents abstracts of these GO and GTO programs, and detailed listings of the specific targets and exposures contained in them. These programs and exposures are protected by NASA policy, as detailed in the HST Call for Proposals (CP), and are not to be duplicated by new programs.

Dwarf Galaxies with Gentle Star Formation and the Counts of Galaxies in the Hubble Deep Field

OpenAIRE

Campos, Ana

1997-01-01

In this paper the counts and colors of the faint galaxies observed in the Hubble Deep Field are fitted by means of simple luminosity evolution models that incorporate a numerous population of fading dwarfs. The observed color distribution of the very faint galaxies now allows us to put constraints on the star formation history in dwarfs. It is shown that the star-forming activity in these small systems has to proceed in a gentle way, i.e., through episodes where each one lasts much longer tha...

Results of a technical analysis of the Hubble Space Telescope nickel-cadmium and nickel-hydrogen batteries

Science.gov (United States)

Manzo, Michelle A.

1991-01-01

The Hubble Space Telescope (HST) Program Office requested the expertise of the NASA Aerospace Flight Battery Systems Steering Committee (NAFBSSC) in the conduct of an independent assessment of the HST's battery system to assist in their decision of whether to fly nickel-cadmium or nickel-hydrogen batteries on the telescope. In response, a subcommittee to the NAFBSSC was organized with membership comprised of experts with background in the nickel-cadmium/nickel-hydrogen secondary battery/power systems areas. The work and recommendations of that subcommittee are presented.

Long term trending of engineering data for the Hubble Space Telescope

Science.gov (United States)

Cox, Ross M.

1993-01-01

A major goal in spacecraft engineering analysis is the detection of component failures before the fact. Trending is the process of monitoring subsystem states to discern unusual behaviors. This involves reducing vast amounts of data about a component or subsystem into a form that helps humans discern underlying patterns and correlations. A long term trending system has been developed for the Hubble Space Telescope. Besides processing the data for 988 distinct telemetry measurements each day, it produces plots of 477 important parameters for the entire 24 hours. Daily updates to the trend files also produce 339 thirty day trend plots each month. The total system combines command procedures to control the execution of the C-based data processing program, user-written FORTRAN routines, and commercial off-the-shelf plotting software. This paper includes a discussion the performance of the trending system and of its limitations.

Science from a glimpse: Hubble SNAPshot observations of massive galaxy clusters

Science.gov (United States)

Repp, A.; Ebeling, H.

2018-06-01

Hubble Space Telescope SNAPshot surveys of 86 X-ray selected galaxy clusters at 0.3 0.3. Examining the evolution of the slope of the cluster red sequence, we observe at best a slight decrease with redshift, indicating minimal age contribution since z ˜ 1. Congruent to previous studies' findings, we note that the two BCGs which are significantly bluer (≥5σ) than their clusters' red sequences reside in relaxed clusters and exhibit pronounced internal structure. Thanks to our targets' high X-ray luminosity, the subset of our sample observed with Chandra adds valuable leverage to the X-ray luminosity-optical richness relation, which, albeit with substantial scatter, is now clearly established from groups to extremely massive clusters of galaxies. We conclude that SNAPshot observations of MACS clusters stand to continue to play a vital pathfinder role for astrophysical investigations across the entire electromagnetic spectrum.

Artificial neural network for the determination of Hubble Space Telescope aberration from stellar images

Science.gov (United States)

Barrett, Todd K.; Sandler, David G.

1993-01-01

An artificial-neural-network method, first developed for the measurement and control of atmospheric phase distortion, using stellar images, was used to estimate the optical aberration of the Hubble Space Telescope. A total of 26 estimates of distortion was obtained from 23 stellar images acquired at several secondary-mirror axial positions. The results were expressed as coefficients of eight orthogonal Zernike polynomials: focus through third-order spherical. For all modes other than spherical the measured aberration was small. The average spherical aberration of the estimates was -0.299 micron rms, which is in good agreement with predictions obtained when iterative phase-retrieval algorithms were used.

New Cosmic Horizons: Space Astronomy from the V2 to the Hubble Space Telescope

Science.gov (United States)

Leverington, David

2001-02-01

Preface; 1. The sounding rocket era; 2. The start of the space race; 3. Initial exploration of the Solar System; 4. Lunar exploration; 5. Mars and Venus; early results; 6. Mars and Venus; the middle period; 7. Venus, Mars and cometary spacecraft post-1980; 8. Early missions to the outer planets; 9. The Voyager missions to the outer planets; 10. The Sun; 11. Early spacecraft observations of non-solar system sources; 12. A period of rapid growth; 13. The high energy astronomy observatory programme; 14. IUE, IRAS and Exosat - spacecraft for the early 1980s; 15. Hiatus; 16. Business as usual; 17. The Hubble Space Telescope.

The Chrysalis Opens? Photometry from the η Carinae Hubble Space Telescope Treasury Project, 2002-2006

Science.gov (United States)

Martin, J. C.; Davidson, Kris; Koppelman, M. D.

2006-12-01

During the past decade η Car has brightened markedly, possibly indicating a change of state. Here we summarize photometry gathered by the Hubble Space Telescope (HST) as part of the HST Treasury Project on this object. Our data include Space Telescope Imaging Spectrograph (STIS) CCD acquisition images, Advanced Camera for Surveys HRC images in four filters, and synthetic photometry in flux-calibrated STIS spectra. The HST's spatial resolution allows us to examine the central star separate from the bright circumstellar ejecta. Its apparent brightness continued to increase briskly during 2002-2006, especially after the mid-2003 spectroscopic event. If this trend continues, the central star will soon become brighter than its ejecta, quite different from the state that existed only a few years ago. One precedent may be the rapid change observed in 1938-1953. We conjecture that the star's mass-loss rate has been decreasing throughout the past century. This research was conducted as part of the η Car Hubble Space Telescope Treasury project via grant GO-9973 from the Space Telescope Science Institute. HST is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. Some of the data presented in this paper were obtained from the Multimission Archive at the Space Telescope Science Institute (MAST). STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. Support for MAST for non-HST data is provided by the NASA Office of Space Science via grant NAG5-7584 and by other grants and contracts.

SN 2016jhj at redshift 0.34: extending the Type II supernova Hubble diagram using the standard candle method

Science.gov (United States)

de Jaeger, T.; Galbany, L.; Filippenko, A. V.; González-Gaitán, S.; Yasuda, N.; Maeda, K.; Tanaka, M.; Morokuma, T.; Moriya, T. J.; Tominaga, N.; Nomoto, K.; Komiyama, Y.; Anderson, J. P.; Brink, T. G.; Carlberg, R. G.; Folatelli, G.; Hamuy, M.; Pignata, G.; Zheng, W.

2017-12-01

Although Type Ia supernova cosmology has now reached a mature state, it is important to develop as many independent methods as possible to understand the true nature of dark energy. Recent studies have shown that Type II supernovae (SNe II) offer such a path and could be used as alternative distance indicators. However, the majority of these studies were unable to extend the Hubble diagram above redshift z = 0.3 because of observational limitations. Here, we show that we are now ready to move beyond low redshifts and attempt high-redshift (z ≳ 0.3) SN II cosmology as a result of new-generation deep surveys such as the Subaru/Hyper Suprime-Cam survey. Applying the 'standard candle method' to SN 2016jhj (z = 0.3398 ± 0.0002; discovered by HSC) together with a low-redshift sample, we are able to construct the highest-redshift SN II Hubble diagram to date with an observed dispersion of 0.27 mag (i.e. 12-13 per cent in distance). This work demonstrates the bright future of SN II cosmology in the coming era of large, wide-field surveys like that of the Large Synoptic Survey Telescope.

Shifting Attention

Science.gov (United States)

Ingram, Jenni

2014-01-01

This article examines the shifts in attention and focus as one teacher introduces and explains an image that represents the processes involved in a numeric problem that his students have been working on. This paper takes a micro-analytic approach to examine how the focus of attention shifts through what the teacher and students do and say in the…

Hubble Servicing Challenges Drive Innovation of Shuttle Rendezvous Techniques

Science.gov (United States)

Goodman, John L.; Walker, Stephen R.

2009-01-01

Hubble Space Telescope (HST) servicing, performed by Space Shuttle crews, has contributed to what is arguably one of the most successful astronomy missions ever flown. Both nominal and contingency proximity operations techniques were developed to enable successful servicing, while lowering the risk of damage to HST systems, and improve crew safety. Influencing the development of these techniques were the challenges presented by plume impingement and HST performance anomalies. The design of both the HST and the Space Shuttle was completed before the potential of HST contamination and structural damage by shuttle RCS jet plume impingement was fully understood. Relative navigation during proximity operations has been challenging, as HST was not equipped with relative navigation aids. Since HST reached orbit in 1990, proximity operations design for servicing missions has evolved as insight into plume contamination and dynamic pressure has improved and new relative navigation tools have become available. Servicing missions have provided NASA with opportunities to gain insight into servicing mission design and development of nominal and contingency procedures. The HST servicing experiences and lessons learned are applicable to other programs that perform on-orbit servicing and rendezvous, both human and robotic.

The Hubble law and the spiral structures of galaxies from equations of motion in general relativity

International Nuclear Information System (INIS)

Sachs, M.

1975-01-01

Fully exploiting the Lie group that characterizes the underlying symmetry of general relativity theory, Einstein's tensor formalism factorizes, yielding a generalized (16-component) quaternion field formalism. The associated generalized geodesic equation, taken as the equation of motion of a star, predicts the Hubble law from one approximation for the generally covariant equations of motion, and the spiral structure of galaxies from another approximation. These results depend on the imposition of appropriate boundary conditions. The Hubble law follows when the boundary conditions derive from the oscillating model cosmology, and not from the other cosmological models. The spiral structures of the galaxies follow from the same boundary conditions, but with a different time scale than for the whole universe. The solutions that imply the spiral motion are Fresnel integrals. These predict the star's motion to be along the 'Cornu Spiral'. The part of this spiral in the first quadrant is the imploding phase of the galaxy, corresponding to a motion with continually decreasing radii, approaching the galactic center as time increases. The part of the Cornu Spiral' in the third quadrant is the exploding phase, corresponding to continually increasing radii, as the star moves out from the hub. The spatial origin in the coordinate system of this curve is the inflection point, where the explosion changes to implosion. The two- (or many-) armed spiral galaxies are explained here in terms of two (or many) distinct explosions occurring at displaced times, in the domain of the rotating, planar galaxy. (author)

Spectroscopic Properties of Star-Forming Host Galaxies and Type Ia Supernova Hubble Residuals in a Nearly Unbiased Sample

Energy Technology Data Exchange (ETDEWEB)

D' Andrea, Chris B. [Univ. of Pennsylvania, Philadelphia, PA (United States); et al.

2011-12-20

We examine the correlation between supernova host galaxy properties and their residuals on the Hubble diagram. We use supernovae discovered during the Sloan Digital Sky Survey II - Supernova Survey, and focus on objects at a redshift of z < 0.15, where the selection effects of the survey are known to yield a complete Type Ia supernova sample. To minimize the bias in our analysis with respect to measured host-galaxy properties, spectra were obtained for nearly all hosts, spanning a range in magnitude of -23 < M_r < -17. In contrast to previous works that use photometric estimates of host mass as a proxy for global metallicity, we analyze host-galaxy spectra to obtain gas-phase metallicities and star-formation rates from host galaxies with active star formation. From a final sample of ~ 40 emission-line galaxies, we find that light-curve corrected Type Ia supernovae are ~ 0.1 magnitudes brighter in high-metallicity hosts than in low-metallicity hosts. We also find a significant (> 3{\\sigma}) correlation between the Hubble residuals of Type Ia supernovae and the specific star-formation rate of the host galaxy. We comment on the importance of supernova/host-galaxy correlations as a source of systematic bias in future deep supernova surveys.

Constraints on Λ(t)CDM models as holographic and agegraphic dark energy with the observational Hubble parameter data

Energy Technology Data Exchange (ETDEWEB)

Zhai, Zhong-Xu; Liu, Wen-Biao [Department of Physics, Institute of Theoretical Physics, Beijing Normal University, Beijing, 100875 (China); Zhang, Tong-Jie, E-mail: zzx@mail.bnu.edu.cn, E-mail: tjzhang@bnu.edu.cn, E-mail: wbliu@bnu.edu.cn [Department of Astronomy, Beijing Normal University, Beijing, 100875 (China)

2011-08-01

The newly released observational H(z) data (OHD) is used to constrain Λ(t)CDM models as holographic and agegraphic dark energy. By the use of the length scale and time scale as the IR cut-off including Hubble horizon (HH), future event horizon (FEH), age of the universe (AU), and conformal time (CT), we achieve four different Λ(t)CDM models which can describe the present cosmological acceleration respectively. In order to get a comparison between such Λ(t)CDM models and standard ΛCDM model, we use the information criteria (IC), Om(z) diagnostic, and statefinder diagnostic to measure the deviations. Furthermore, by simulating a larger Hubble parameter data sample in the redshift range of 0.1 < z < 2.0, we get the improved constraints and more sufficient comparison. We show that OHD is not only able to play almost the same role in constraining cosmological parameters as SNe Ia does but also provides the effective measurement of the deviation of the DE models from standard ΛCDM model. In the holographic and agegraphic scenarios, the results indicate that the FEH is more preferable than HH scenario. However, both two time scenarios show better approximations to ΛCDM model than the length scenarios.

Work shift duration: a review comparing eight hour and 12 hour shift systems.

Science.gov (United States)

Smith, L; Folkard, S; Tucker, P; Macdonald, I

1998-04-01

Shiftwork is now a major feature of working life across a broad range of industries. The features of the shift systems operated can impact on the wellbeing, performance, and sleep of shiftworkers. This paper reviews the current state of knowledge on one major characteristic of shift rotas-namely, shift duration. Evidence comparing the relative effects of eight hour and 12 hour shifts on fatigue and job performance, safety, sleep, and physical and psychological health are considered. At the organisational level, factors such as the mode of system implementation, attitudes towards shift rotas, sickness absence and turnover, overtime, and moonlighting are discussed. Manual and electronic searches of the shiftwork research literature were conducted to obtain information on comparisons between eight hour and 12 hour shifts. The research findings are largely equivocal. The bulk of the evidence suggests few differences between eight and 12 hour shifts in the way they affect people. There may even be advantages to 12 hour shifts in terms of lower stress levels, better physical and psychological wellbeing, improved durations and quality of off duty sleep as well as improvements in family relations. On the negative side, the main concerns are fatigue and safety. It is noted that a 12 hour shift does not equate with being active for only 12 hours. There can be considerable extension of the person's time awake either side of the shift. However, the effects of longer term exposure to extended work days have been relatively uncharted in any systematic way. Longitudinal comparative research into the chronic impact of the compressed working week is needed.

Third ventricle midline shift on computed tomography as an alternative to septum pellucidum shift

International Nuclear Information System (INIS)

Santiago, Carlos Francis A.; Oropilla, Jean Quint L; Alvarez, Victor M.

2000-01-01

The cerebral midline shift is measured using the displacement from midline of the third ventricle. It is an easily determined criterion from which CT scans of patients with spontaneous intracerebral hematoma may be investigated. Midline shift is a significant criteria in which to gauge the neurological status of patients. In a retrospective study of 32 patients with spontaneous unilateral intracerebral hemorrhage, a midline third ventricle shift correlated well with septum pellucidum shift. A greater than 7 mm midline third ventricle shift was associated with a significantly lower Glasgow Coma scale score compared a shift less than 7mm. For the septum pellucidum, a greater than 10 mm shift was similarly associated with a significantly lower Glasgow Coma scale score. (Author)

Insomnia in shift work.

Science.gov (United States)

Vallières, Annie; Azaiez, Aïda; Moreau, Vincent; LeBlanc, Mélanie; Morin, Charles M

2014-12-01

Shift work disorder involves insomnia and/or excessive sleepiness associated with the work schedule. The present study examined the impact of insomnia on the perceived physical and psychological health of adults working on night and rotating shift schedules compared to day workers. A total of 418 adults (51% women, mean age 41.4 years), including 51 night workers, 158 rotating shift workers, and 209 day workers were selected from an epidemiological study. An algorithm was used to classify each participant of the two groups (working night or rotating shifts) according to the presence or absence of insomnia symptoms. Each of these individuals was paired with a day worker according to gender, age, and income. Participants completed several questionnaires measuring sleep, health, and psychological variables. Night and rotating shift workers with insomnia presented a sleep profile similar to that of day workers with insomnia. Sleep time was more strongly related to insomnia than to shift work per se. Participants with insomnia in the three groups complained of anxiety, depression, and fatigue, and reported consuming equal amounts of sleep-aid medication. Insomnia also contributed to chronic pain and otorhinolaryngology problems, especially among rotating shift workers. Work productivity and absenteeism were more strongly related to insomnia. The present study highlights insomnia as an important component of the sleep difficulties experienced by shift workers. Insomnia may exacerbate certain physical and mental health problems of shift workers, and impair their quality of life. Copyright © 2014 Elsevier B.V. All rights reserved.

Effects of extended work shifts and shift work on patient safety, productivity, and employee health.

Science.gov (United States)

Keller, Simone M

2009-12-01

It is estimated 1.3 million health care errors occur each year and of those errors 48,000 to 98,000 result in the deaths of patients (Barger et al., 2006). Errors occur for a variety of reasons, including the effects of extended work hours and shift work. The need for around-the-clock staff coverage has resulted in creative ways to maintain quality patient care, keep health care errors or adverse events to a minimum, and still meet the needs of the organization. One way organizations have attempted to alleviate staff shortages is to create extended work shifts. Instead of the standard 8-hour shift, workers are now working 10, 12, 16, or more hours to provide continuous patient care. Although literature does support these staffing patterns, it cannot be denied that shifts beyond the traditional 8 hours increase staff fatigue, health care errors, and adverse events and outcomes and decrease alertness and productivity. This article includes a review of current literature on shift work, the definition of shift work, error rates and adverse outcomes related to shift work, health effects on shift workers, shift work effects on older workers, recommended optimal shift length, positive and negative effects of shift work on the shift worker, hazards associated with driving after extended shifts, and implications for occupational health nurses. Copyright 2009, SLACK Incorporated.

A determination of H-0 with the class gravitational lens B1608+656. II. Mass models and the Hubble constant from lensing

NARCIS (Netherlands)

Koopmans, LVE; Fassnacht, CD

1999-01-01

We present mass models of the four-image gravitational lens system B1608 + 656, based on information obtained through VLBA imaging, VLA monitoring, and Hubble Space Telescope (HST) WFPC2 and NICMOS imaging. We have determined a mass model for the lens galaxies that reproduces (1) all image positions

Modelling a Nurse Shift Schedule with Multiple Preference Ranks for Shifts and Days-Off

Directory of Open Access Journals (Sweden)

Chun-Cheng Lin

2014-01-01

Full Text Available When it comes to nurse shift schedules, it is found that the nursing staff have diverse preferences about shift rotations and days-off. The previous studies only focused on the most preferred work shift and the number of satisfactory days-off of the schedule at the current schedule period but had few discussions on the previous schedule periods and other preference levels for shifts and days-off, which may affect fairness of shift schedules. As a result, this paper proposes a nurse scheduling model based upon integer programming that takes into account constraints of the schedule, different preference ranks towards each shift, and the historical data of previous schedule periods to maximize the satisfaction of all the nursing staff's preferences about the shift schedule. The main contribution of the proposed model is that we consider that the nursing staff’s satisfaction level is affected by multiple preference ranks and their priority ordering to be scheduled, so that the quality of the generated shift schedule is more reasonable. Numerical results show that the planned shifts and days-off are fair and successfully meet the preferences of all the nursing staff.

Shift systems in nuclear power plants - aspects for planning, shift systems, utility practice

International Nuclear Information System (INIS)

Grauf, E.

1986-01-01

This lecture contains the most important aspects of shift structure and shift organisation. The criteria for shift planning involving essential tasks, duties, laws and regulations, medical aspects, social aspects, will be presented. In the Federal Republic of Germany some basic models were established, which will be shown and explained with special reference to the number of teams, size of shift crews and absence regulations. Moreover, the lecture will deal with rotation systems and provisions for the transfer of shift responsibilities. By example of a utility plant commissioning time scale (1300 MW PWR) the practice of shift installations will be shown as well as the most important points of education and training. Within this compass the criteria and requirements for training and education of operational personnel in the Federal Republic of Germany will also be touched. (orig.)

Nurses' shift reports

DEFF Research Database (Denmark)

Buus, Niels; Hoeck, Bente; Hamilton, Bridget Elizabeth

2017-01-01

AIMS AND OBJECTIVES: To identify reporting practices that feature in studies of nurses' shift reports across diverse nursing specialities. The objectives were to perform an exhaustive systematic literature search and to critically review the quality and findings of qualitative field studies...... of nurses' shift reports. BACKGROUND: Nurses' shift reports are routine occurrences in healthcare organisations that are viewed as crucial for patient outcomes, patient safety and continuity of care. Studies of communication between nurses attend primarily to 1:1 communication and analyse the adequacy...... and accuracy of patient information and feature handovers at the bedside. Still, verbal reports between groups of nurses about patients are commonplace. Shift reports are obvious sites for studying the situated accomplishment of professional nursing at the group level. This review is focused exclusively...

CONFRONTING THREE-DIMENSIONAL TIME-DEPENDENT JET SIMULATIONS WITH HUBBLE SPACE TELESCOPE OBSERVATIONS

International Nuclear Information System (INIS)

Staff, Jan E.; Niebergal, Brian P.; Ouyed, Rachid; Pudritz, Ralph E.; Cai, Kai

2010-01-01

We perform state-of-the-art, three-dimensional, time-dependent simulations of magnetized disk winds, carried out to simulation scales of 60 AU, in order to confront optical Hubble Space Telescope observations of protostellar jets. We 'observe' the optical forbidden line emission produced by shocks within our simulated jets and compare these with actual observations. Our simulations reproduce the rich structure of time-varying jets, including jet rotation far from the source, an inner (up to 400 km s -1 ) and outer (less than 100 km s -1 ) component of the jet, and jet widths of up to 20 AU in agreement with observed jets. These simulations when compared with the data are able to constrain disk wind models. In particular, models featuring a disk magnetic field with a modest radial spatial variation across the disk are favored.

Dynamic auroral storms on Saturn as observed by the Hubble Space Telescope.

Science.gov (United States)

Nichols, J D; Badman, S V; Baines, K H; Brown, R H; Bunce, E J; Clarke, J T; Cowley, S W H; Crary, F J; Dougherty, M K; Gérard, J-C; Grocott, A; Grodent, D; Kurth, W S; Melin, H; Mitchell, D G; Pryor, W R; Stallard, T S

2014-05-28

We present observations of significant dynamics within two UV auroral storms observed on Saturn using the Hubble Space Telescope in April/May 2013. Specifically, we discuss bursts of auroral emission observed at the poleward boundary of a solar wind-induced auroral storm, propagating at ∼330% rigid corotation from near ∼01 h LT toward ∼08 h LT. We suggest that these are indicative of ongoing, bursty reconnection of lobe flux in the magnetotail, providing strong evidence that Saturn's auroral storms are caused by large-scale flux closure. We also discuss the later evolution of a similar storm and show that the emission maps to the trailing region of an energetic neutral atom enhancement. We thus identify the auroral form with the upward field-aligned continuity currents flowing into the associated partial ring current.

Gravitational Contraction and Fusion Plasma Burn. Universal Expansion and the Hubble Law

International Nuclear Information System (INIS)

Wilhelmsson, Hans

2002-01-01

A dynamic approach is developed for the two principle phases of (i) gravitational condensation, and (ii) burning fusion plasma evolution. Comparison is made with conceptual descriptions of star formation and of subsequent decay towards red giant stars, white dwarfs, and other condensed core objects like neutron stars and black holes. The possibility of treating the expansion of the Universe by means of a similar approach is also discussed. The concept of negative diffusion is introduced for the contraction phase of star formation. The coefficients of defining the nonlinear diffusion are determined uniquely by physical conditions and for the case of the expansion of the universe, by the observation of the Hubble law. The contraction and evolution of large scale 3-D stars and 2-D galactic systems can thus be dynamically surveyed. In particular the time-scales can be determined

Hubble Space Telescope Photometry of Hodge 301: An ``Old'' Star Cluster in 30 Doradus

Science.gov (United States)

Grebel, Eva K.; Chu, You-Hua

2000-02-01

We present Hubble Space Telescope Planetary Camera UVI data for Hodge 301, the little-studied cluster 3' northwest of the central ionizing cluster R136 in 30 Doradus. The average reddening of Hodge 301 is found to be =0.28+/-0.05 mag from published infrared and ultraviolet photometry. Using two different sets of evolutionary models, we derive an age of about 20-25 Myr for Hodge 301, which makes it roughly 10 times as old as R136. Hodge 301 is the most prominent representative of the oldest population in the 30 Dor starburst region, a region that has undergone multiple star formation events. This range of ages is an important consideration for the modeling of starburst regions. Hodge 301 shows a widened upper main sequence largely caused by Be stars. We present a list of Be star candidates. The slope of the initial mass function for intermediate-mass, main-sequence stars ranging from 10 to 1.3 Msolar is found to be Γ=-1.4+/-0.1, in good agreement with a Salpeter law. There is no indication for a truncation or change of slope of the initial mass function (IMF) within this mass range. In accordance with the age of Hodge 301, no obvious pre-main-sequence stars are seen down to about 1 Msolar. We estimate that up to 41+/-7 stars with masses more than 12 Msolar may have turned into supernovae since the formation of the cluster. Multiple supernova explosions are the most likely origin of the extremely violent gas motions and the diffuse X-ray emission observed in the cluster surroundings. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc. under NASA contract NAS5-26555.

Probing the z > 6 universe with the first Hubble frontier fields cluster A2744

International Nuclear Information System (INIS)

Atek, Hakim; Kneib, Jean-Paul; Richard, Johan; Clement, Benjamin; Egami, Eiichi; Ebeling, Harald; Jauzac, Mathilde; Jullo, Eric; Limousin, Marceau; Laporte, Nicolas; Natarajan, Priyamvada

2014-01-01

The Hubble Frontier Fields program combines the capabilities of the Hubble Space Telescope (HST) with the gravitational lensing of massive galaxy clusters to probe the distant universe to an unprecedented depth. Here, we present the results of the first combined HST and Spitzer observations of the cluster A-2744. We combine the full near-infrared data with ancillary optical images to search for gravitationally lensed high-redshift (z ≳ 6) galaxies. We report the detection of 15 I 814 dropout candidates at z ∼ 6-7 and one Y 105 dropout at z ∼ 8 in a total survey area of 1.43 arcmin 2 in the source plane. The predictions of our lens model also allow us to identify five multiply imaged systems lying at redshifts between z ∼ 6 and z ∼ 8. Thanks to constraints from the mass distribution in the cluster, we were able to estimate the effective survey volume corrected for completeness and magnification effects. This was in turn used to estimate the rest-frame ultraviolet luminosity function (LF) at z ∼ 6-8. Our LF results are generally in agreement with the most recent blank field estimates, confirming the feasibility of surveys through lensing clusters. Although based on a shallower observations than what will be achieved in the final data set including the full Advanced Camera for Survey observations, the LF presented here goes down to M UV ∼–18.5, corresponding to 0.2L * at z ∼ 7 with one identified object at M UV ∼–15 thanks to the highly magnified survey areas. This early study forecasts the power of using massive galaxy clusters as cosmic telescopes and its complementarity to blank fields.

Probing the z > 6 universe with the first Hubble frontier fields cluster A2744

Energy Technology Data Exchange (ETDEWEB)

Atek, Hakim; Kneib, Jean-Paul [Laboratoire d' Astrophysique, Ecole Polytechnique Fédérale de Lausanne, Observatoire de Sauverny, CH-1290 Versoix (Switzerland); Richard, Johan [CRAL, Observatoire de Lyon, Université Lyon 1, 9 Avenue Ch. André, 69561 Saint Genis Laval Cedex (France); Clement, Benjamin; Egami, Eiichi [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ, 85721 (United States); Ebeling, Harald [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, Hawaii 96822 (United States); Jauzac, Mathilde [Astrophysics and Cosmology Research Unit, School of Mathematical Sciences, University of KwaZulu-Natal, Durban, 4041 South Africa (South Africa); Jullo, Eric; Limousin, Marceau [Aix Marseille Université, CNRS, LAM (Laboratoire d' Astrophysique de Marseille) UMR 7326, 13388, Marseille (France); Laporte, Nicolas [Instituto de Astrofisica de Canarias (IAC), E-38200 La Laguna, Tenerife (Spain); Natarajan, Priyamvada [Department of Astronomy, Yale University, 260 Whitney Avenue, New Haven, CT 06511 (United States)

2014-05-01

The Hubble Frontier Fields program combines the capabilities of the Hubble Space Telescope (HST) with the gravitational lensing of massive galaxy clusters to probe the distant universe to an unprecedented depth. Here, we present the results of the first combined HST and Spitzer observations of the cluster A-2744. We combine the full near-infrared data with ancillary optical images to search for gravitationally lensed high-redshift (z ≳ 6) galaxies. We report the detection of 15 I {sub 814} dropout candidates at z ∼ 6-7 and one Y {sub 105} dropout at z ∼ 8 in a total survey area of 1.43 arcmin{sup 2} in the source plane. The predictions of our lens model also allow us to identify five multiply imaged systems lying at redshifts between z ∼ 6 and z ∼ 8. Thanks to constraints from the mass distribution in the cluster, we were able to estimate the effective survey volume corrected for completeness and magnification effects. This was in turn used to estimate the rest-frame ultraviolet luminosity function (LF) at z ∼ 6-8. Our LF results are generally in agreement with the most recent blank field estimates, confirming the feasibility of surveys through lensing clusters. Although based on a shallower observations than what will be achieved in the final data set including the full Advanced Camera for Survey observations, the LF presented here goes down to M {sub UV} ∼–18.5, corresponding to 0.2L {sup *} at z ∼ 7 with one identified object at M {sub UV} ∼–15 thanks to the highly magnified survey areas. This early study forecasts the power of using massive galaxy clusters as cosmic telescopes and its complementarity to blank fields.

[Sleep quality of nurses working in shifts - Hungarian adaptation of the Bergen Shift Work Sleep Questionnaire].

Science.gov (United States)

Fusz, Katalin; Tóth, Ákos; Fullér, Noémi; Müller, Ágnes; Oláh, András

2015-12-06

Sleep disorders among shift workers are common problems due to the disturbed circadian rhythm. The Bergen Shift Work Sleep Questionnaire assesses discrete sleep problems related to work shifts (day, evening and night shifts) and rest days. The aim of the study was to develop the Hungarian version of this questionnaire and to compare the sleep quality of nurses in different work schedules. 326 nurses working in shifts filled in the questionnaire. The authors made convergent and discriminant validation of the questionnaire with the Athens Insomnia Scale and the Perceived Stress Questionnaire. The questionnaire based on psychometric characteristics was suitable to assess sleep disorders associated with shift work in a Hungarian sample. The frequency of discrete symptoms significantly (pshifts. Nurses experienced the worst sleep quality and daytime fatigue after the night shift. Nurses working in irregular shift system had worse sleep quality than nurses working in regular and flexible shift system (pworking in shifts should be assessed with the Hungarian version of the Bergen Shift Work Sleep Questionnaire on a nationally representative sample, and the least burdensome shift system could be established.

Age differences in strategy shift: retrieval avoidance or general shift reluctance?

Science.gov (United States)

Frank, David J; Touron, Dayna R; Hertzog, Christopher

2013-09-01

Previous studies of metacognitive age differences in skill acquisition strategies have relied exclusively on tasks with a processing shift from an algorithm to retrieval strategy. Older adults' demonstrated reluctance to shift strategies in such tasks could reflect either a specific aversion to a memory retrieval strategy or a general, inertial resistance to strategy change. Haider and Frensch's (1999) alphabet verification task (AVT) affords a non-retrieval-based strategy shift. Participants verify the continuation of alphabet strings such as D E F G [4] L, with the bracketed digit indicating a number of letters to be skipped. When all deviations are restricted to the letter-digit-letter portion, participants can speed their responses by selectively attending to only that part of the stimulus. We adapted the AVT to include conditions that promoted shift to a retrieval strategy, a selective attention strategy, or both strategies. Item-level strategy reports were validated by eye movement data. Older adults shifted more slowly to the retrieval strategy but more quickly to the selective attention strategy than young adults, indicating a retrieval-strategy avoidance. Strategy confidence and perceived strategy difficulty correlated with shift to the two strategies in both age groups. Perceived speed of responses with each strategy specifically correlated with older adults' strategy choices, suggesting that some older adults avoid retrieval because they do not appreciate its efficiency benefits.

Age Differences in Strategy Shift: Retrieval Avoidance or General Shift Reluctance?

Science.gov (United States)

Frank, David J.; Touron, Dayna R.; Hertzog, Christopher

2013-01-01

Previous studies of metacognitive age differences in skill acquisition strategies have relied exclusively on tasks with a processing shift from an algorithm to retrieval strategy. Older adults’ demonstrated reluctance to shift strategies in such tasks could reflect either a specific aversion to a memory retrieval strategy or a general, inertial resistance to strategy change. Haider and Frensch’s (1999) alphabet verification task (AVT) affords a non-retrieval-based strategy shift. Participants verify the continuation of alphabet strings such as D E F G [4] L, with the bracketed digit indicating a number of letters to be skipped. When all deviations are restricted to the letter-digit-letter portion, participants can speed their responses by selectively attend only to that part of the stimulus. We adapted the AVT to include conditions which promoted shift to a retrieval strategy, a selective attention strategy, or both strategies. Item-level strategy reports were validated by eye movement data. Older adults shifted more slowly to the retrieval strategy but more quickly to the selective attention strategy than young adults, indicating a retrieval-strategy avoidance. Strategy confidence and perceived strategy difficulty correlated with shift to the two strategies in both age groups. Perceived speed of responses with each strategy specifically correlated with older adults’ strategy choices, suggesting that some older adults avoid retrieval because they do not appreciate its efficiency benefits. PMID:23088195

Non-occupational physical activity levels of shift workers compared with non-shift workers

NARCIS (Netherlands)

Loef, Bette; Hulsegge, Gerben; Wendel-Vos, G C Wanda; Verschuren, W M Monique; Vermeulen, Roel C H; Bakker, Marije F.; van der Beek, Allard J.; Proper, Karin I

2017-01-01

OBJECTIVES: Lack of physical activity (PA) has been hypothesised as an underlying mechanism in the adverse health effects of shift work. Therefore, our aim was to compare non-occupational PA levels between shift workers and non-shift workers. Furthermore, exposure-response relationships for

The Carnegie Hubble Program: The Leavitt Law at 3.6 microns and 4.5 microns in the Large Magellanic Cloud

Science.gov (United States)

Scowcroft, Victoria; Freedman, Wendy L.; Madore, Barry F.; Monson, Andrew J.; Persson, S. E.; Seibert, Mark; Rigby, Jane R.; Sturch, Laura

2011-01-01

The Carnegie Hubble Program (CHP) is designed to improve the extragalactic distance scale using data from the post-cryogenic era of Spitzer. The ultimate goal is a determination of the Hubble constant to an accuracy of 2%. This paper is the first in a series on the Cepheid population of the Large Magellanic Cloud, and focuses on the period-luminosity relations (Leavitt laws) that will be used, in conjunction with observations of Milky Way Cepheids, to set the slope and zero-point of the Cepheid distance scale in the mid-infrared. To this end, we have obtained uniformly-sampled light curves for 85 LMC Cepheids, having periods between 6 and 140 days. Period- luminosity and period-color relations are presented in the 3.6 micron and 4.5 micron bands. We demonstrate that the 3.6 micron band is a superb distance indicator. The cyclical variation of the [3.6]-[4.5] color has been measured for the first time. We attribute the amplitude and phase of the color curves to the dissociation and recombination of CO molecules in the Cepheid s atmosphere. The CO affects only the 4.5 micron flux making it a potential metallicity indicator.

Proper Motions of Dwarf Spheroidal Galaxies from Hubble Space Telescope Imaging. IV. Measurement for Sculptor

Science.gov (United States)

Piatek, Slawomir; Pryor, Carlton; Bristow, Paul; Olszewski, Edward W.; Harris, Hugh C.; Mateo, Mario; Minniti, Dante; Tinney, Christopher G.

2006-03-01

This article presents a measurement of the proper motion of the Sculptor dwarf spheroidal galaxy determined from images taken with the Hubble Space Telescope using the Space Telescope Imaging Spectrograph in the imaging mode. Each of two distinct fields contains a quasi-stellar object that serves as the ``reference point.'' The measured proper motion of Sculptor, expressed in the equatorial coordinate system, is (μα, μδ)=(9+/-13, 2+/-13) mas century-1. Removing the contributions from the motion of the Sun and the motion of the local standard of rest produces the proper motion in the Galactic rest frame: (μGrfα, μGrfδ)=(-23+/-13, 45+/-13) mas century-1. The implied space velocity with respect to the Galactic center has a radial component of Vr=79+/-6 km s-1 and a tangential component of Vt=198+/-50 km s-1. Integrating the motion of Sculptor in a realistic potential for the Milky Way produces orbital elements. The perigalacticon and apogalacticon are 68 (31, 83) and 122 (97, 313) kpc, respectively, where the values in the parentheses represent the 95% confidence interval derived from Monte Carlo experiments. The eccentricity of the orbit is 0.29 (0.26, 0.60), and the orbital period is 2.2 (1.5, 4.9) Gyr. Sculptor is on a polar orbit around the Milky Way: the angle of inclination is 86° (83°, 90°). Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

Dissecting the Gravitational lens B1608+656 : II. Precision Measurements of the Hubble Constant, Spatial Curvature, and the Dark Energy Equation of State

NARCIS (Netherlands)

Suyu, S. H.; Marshall, P. J.; Auger, M. W.; Hilbert, S.; Blandford, R. D.; Koopmans, L. V. E.; Fassnacht, C. D.; Treu, T.

2010-01-01

Strong gravitational lens systems with measured time delays between the multiple images provide a method for measuring the "time-delay distance" to the lens, and thus the Hubble constant. We present a Bayesian analysis of the strong gravitational lens system B1608+656, incorporating (1) new, deep

Hubble Space Telescope Trigonometric Parallax of Polaris B, Companion of the Nearest Cepheid

Science.gov (United States)

Bond, Howard E.; Nelan, Edmund P.; Remage Evans, Nancy; Schaefer, Gail H.; Harmer, Dianne

2018-01-01

Polaris, the nearest and brightest Cepheid, is a potential anchor point for the Leavitt period–luminosity relation. However, its distance is a matter of contention, with recent advocacy for a parallax of ∼10 mas, in contrast with the Hipparcos measurement of 7.54 ± 0.11 mas. We report an independent trigonometric parallax determination, using the Fine Guidance Sensors (FGS) on the Hubble Space Telescope. Polaris itself is too bright for FGS, so we measured its eighth-magnitude companion Polaris B, relative to a network of background reference stars. We converted the FGS relative parallax to absolute, using estimated distances to the reference stars from ground-based photometry and spectral classification. Our result, 6.26 ± 0.24 mas, is even smaller than that found by Hipparcos. We note other objects for which Hipparcos appears to have overestimated parallaxes, including the well-established case of the Pleiades. We consider possible sources of systematic error in the FGS parallax, but find no evidence they are significant. If our “long” distance is correct, the high luminosity of Polaris indicates that it is pulsating in the second overtone of its fundamental mode. Our results raise several puzzles, including a long pulsation period for Polaris compared to second-overtone pulsators in the Magellanic Clouds, and a conflict between the isochrone age of Polaris B (∼2.1 Gyr) and the much younger age of Polaris A. We discuss possibilities that B is not a physical companion of A, in spite of the strong evidence that it is, or that one of the stars is a merger remnant. These issues may be resolved when Gaia provides parallaxes for both stars. Based in part on observations made with the NASA/ESA Hubble Space Telescope, obtained by the Space Telescope Science Institute. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

HUBBLE-BUBBLE 1. A computer program for the analysis of non-equilibrium flows of water

International Nuclear Information System (INIS)

Mather, D.J.

1978-02-01

A description is given of the computer program HUBBLE-BUBBLE I which simulates the non-equilibrium flow of water and steam in a pipe. The code is designed to examine the transient flow developing in a pipe containing hot compressed water following the rupture of a retaining diaphragm. Allowance is made for an area change in the pipe. Particular attention is paid to the non-equilibrium development of vapour bubbles and to the transition from a bubble-liquid regime to a droplet-vapour regime. The mathematical and computational model is described together with a summary of the FORTRAN subroutines and listing of data input. (UK)

Stable exponential cosmological solutions with zero variation of G and three different Hubble-like parameters in the Einstein-Gauss-Bonnet model with a Λ-term

Energy Technology Data Exchange (ETDEWEB)

Ernazarov, K.K. [RUDN University, Institute of Gravitation and Cosmology, Moscow (Russian Federation); Ivashchuk, V.D. [RUDN University, Institute of Gravitation and Cosmology, Moscow (Russian Federation); VNIIMS, Center for Gravitation and Fundamental Metrology, Moscow (Russian Federation)

2017-06-15

We consider a D-dimensional gravitational model with a Gauss-Bonnet term and the cosmological term Λ. We restrict the metrics to diagonal cosmological ones and find for certain Λ a class of solutions with exponential time dependence of three scale factors, governed by three non-coinciding Hubble-like parameters H > 0, h{sub 1} and h{sub 2}, corresponding to factor spaces of dimensions m > 2, k{sub 1} > 1 and k{sub 2} > 1, respectively, with k{sub 1} ≠ k{sub 2} and D = 1 + m + k{sub 1} + k{sub 2}. Any of these solutions describes an exponential expansion of 3d subspace with Hubble parameter H and zero variation of the effective gravitational constant G. We prove the stability of these solutions in a class of cosmological solutions with diagonal metrics. (orig.)

Chemical shift imaging: a review

International Nuclear Information System (INIS)

Brateman, L.

1986-01-01

Chemical shift is the phenomenon that is seen when an isotope possessing a nuclear magnetic dipole moment resonates at a spectrum of resonance frequencies in a given magnetic field. These resonance frequencies, or chemical shifts, depend on the chemical environments of particular nuclei. Mapping the spatial distribution of nuclei associated with a particular chemical shift (e.g., hydrogen nuclei associated with water molecules or with lipid groups) is called chemical shift imaging. Several techniques of proton chemical shift imaging that have been applied in vivo are presented, and their clinical findings are reported and summarized. Acquiring high-resolution spectra for large numbers of volume elements in two or three dimensions may be prohibitive because of time constraints, but other methods of imaging lipid of water distributions (i.e., selective excitation, selective saturation, or variations in conventional magnetic resonance imaging pulse sequences) can provide chemical shift information. These techniques require less time, but they lack spectral information. Since fat deposition seen by chemical shift imaging may not be demonstrated by conventional magnetic resonance imaging, certain applications of chemical shift imaging, such as in the determination of fatty liver disease, have greater diagnostic utility than conventional magnetic resonance imaging. Furthermore, edge artifacts caused by chemical shift effects can be eliminated by certain selective methods of data acquisition employed in chemical shift imaging

Adaptation of Shift Sequence Based Method for High Number in Shifts Rostering Problem for Health Care Workers

Directory of Open Access Journals (Sweden)

Mindaugas Liogys

2013-08-01

Full Text Available Purpose—is to investigate a shift sequence-based approach efficiency then problem consisting of a high number of shifts.Research objectives:• Solve health care workers rostering problem using a shift sequence based method.• Measure its efficiency then number of shifts increases.Design/methodology/approach—Usually rostering problems are highly constrained. Constraints are classified to soft and hard constraints. Soft and hard constraints of the problem are additionally classified to: sequence constraints, schedule constraints and roster constraints. Sequence constraints are considered when constructing shift sequences. Schedule constraints are considered when constructing a schedule. Roster constraints are applied, then constructing overall solution, i.e. combining all schedules.Shift sequence based approach consists of two stages:• Shift sequences construction,• The construction of schedules.In the shift sequences construction stage, the shift sequences are constructed for each set of health care workers of different skill, considering sequence constraints. Shifts sequences are ranked by their penalties for easier retrieval in later stage.In schedules construction stage, schedules for each health care worker are constructed iteratively, using the shift sequences produced in stage 1.Shift sequence based method is an adaptive iterative method where health care workers who received the highest schedule penalties in the last iteration are scheduled first at the current iteration.During the roster construction, and after a schedule has been generated for the current health care worker, an improvement method based on an efficient greedy local search is carried out on the partial roster. It simply swaps any pair of shifts between two health care workers in the (partial roster, as long as the swaps satisfy hard constraints and decrease the roster penalty.Findings—Using shift sequence method for solving health care workers rostering problem

Adaptation of Shift Sequence Based Method for High Number in Shifts Rostering Problem for Health Care Workers

Directory of Open Access Journals (Sweden)

Mindaugas Liogys

2011-08-01

Full Text Available Purpose—is to investigate a shift sequence-based approach efficiency then problem consisting of a high number of shifts. Research objectives:• Solve health care workers rostering problem using a shift sequence based method.• Measure its efficiency then number of shifts increases. Design/methodology/approach—Usually rostering problems are highly constrained.Constraints are classified to soft and hard constraints. Soft and hard constraints of the problem are additionally classified to: sequence constraints, schedule constraints and roster constraints. Sequence constraints are considered when constructing shift sequences. Schedule constraints are considered when constructing a schedule. Roster constraints are applied, then constructing overall solution, i.e. combining all schedules.Shift sequence based approach consists of two stages:• Shift sequences construction,• The construction of schedules.In the shift sequences construction stage, the shift sequences are constructed for each set of health care workers of different skill, considering sequence constraints. Shifts sequences are ranked by their penalties for easier retrieval in later stage.In schedules construction stage, schedules for each health care worker are constructed iteratively, using the shift sequences produced in stage 1. Shift sequence based method is an adaptive iterative method where health care workers who received the highest schedule penalties in the last iteration are scheduled first at the current iteration. During the roster construction, and after a schedule has been generated for the current health care worker, an improvement method based on an efficient greedy local search is carried out on the partial roster. It simply swaps any pair of shifts between two health care workers in the (partial roster, as long as the swaps satisfy hard constraints and decrease the roster penalty.Findings—Using shift sequence method for solving health care workers rostering

Combined chemical shift changes and amino acid specific chemical shift mapping of protein-protein interactions

Energy Technology Data Exchange (ETDEWEB)

Schumann, Frank H.; Riepl, Hubert [University of Regensburg, Institute of Biophysics and Physical Biochemistry (Germany); Maurer, Till [Boehringer Ingelheim Pharma GmbH and Co. KG, Analytical Sciences Department (Germany); Gronwald, Wolfram [University of Regensburg, Institute of Biophysics and Physical Biochemistry (Germany); Neidig, Klaus-Peter [Bruker BioSpin GmbH, Software Department (Germany); Kalbitzer, Hans Robert [University of Regensburg, Institute of Biophysics and Physical Biochemistry (Germany)], E-mail: hans-robert.kalbitzer@biologie.uni-regensburg.de

2007-12-15

Protein-protein interactions are often studied by chemical shift mapping using solution NMR spectroscopy. When heteronuclear data are available the interaction interface is usually predicted by combining the chemical shift changes of different nuclei to a single quantity, the combined chemical shift perturbation {delta}{delta}{sub comb}. In this paper different procedures (published and non-published) to calculate {delta}{delta}{sub comb} are examined that include a variety of different functional forms and weighting factors for each nucleus. The predictive power of all shift mapping methods depends on the magnitude of the overlap of the chemical shift distributions of interacting and non-interacting residues and the cut-off criterion used. In general, the quality of the prediction on the basis of chemical shift changes alone is rather unsatisfactory but the combination of chemical shift changes on the basis of the Hamming or the Euclidian distance can improve the result. The corrected standard deviation to zero of the combined chemical shift changes can provide a reasonable cut-off criterion. As we show combined chemical shifts can also be applied for a more reliable quantitative evaluation of titration data.

Atmospheric and Fundamental Parameters of Stars in Hubble's Next Generation Spectral Library

Science.gov (United States)

Heap, Sally

2010-01-01

Hubble's Next Generation Spectral Library (NGSL) consists of R approximately 1000 spectra of 374 stars of assorted temperature, gravity, and metallicity. We are presently working to determine the atmospheric and fundamental parameters of the stars from the NGSL spectra themselves via full-spectrum fitting of model spectra to the observed (extinction-corrected) spectrum over the full wavelength range, 0.2-1.0 micron. We use two grids of model spectra for this purpose: the very low-resolution spectral grid from Castelli-Kurucz (2004), and the grid from MARCS (2008). Both the observed spectrum and the MARCS spectra are first degraded in resolution to match the very low resolution of the Castelli-Kurucz models, so that our fitting technique is the same for both model grids. We will present our preliminary results with a comparison with those from the Sloan/Segue Stellar Parameter Pipeline, ELODIE, and MILES, etc.

Comparison of sleep disturbances in shift workers and people working with a fixed shift

Directory of Open Access Journals (Sweden)

Zohreh Yazdi

2013-11-01

Full Text Available Background: Different types of sleep disturbances can have a serious negative effect on a person’s ability, function and overall well-being. One of the most important issues that can result in sleep disturbances are occupational causes, the most important among them is shift work. The objective of this study was to compare the prevalence of sleep disturbances between shift work and non-shift workers. Material and Methods: This study was designed as a case-control study in 196 shift workers and 204 non-shift workers in a textile factory. The data were collected by using a comprehensive questionnaire including Pittsburg Sleep Quality Index questionnaire, Berlin Questionnaire, Epworth Sleepiness Scale, Insomnia Severity Index and Restless Leg Syndrome Questionnaire. Data analyses were carried out using the SPSS software version 13 by student's t-test, Chi square and multiple logistic regressions. Results: The duration of night sleep in shift workers was less than day workers (p<0.001. Prevalence of poor sleep quality and insomnia were higher in shift workers significantly than non shift workers (p<0.001, OR=2.3 95% CI: 1.7-2.9. The most prevalent type of insomnia was problems in initiating sleep (P=0.022, OR=2.2 95% CI: 1.5-3.2. There was no difference in the prevalence of excessive day-time sleepiness, restless leg syndrome, snoring, obstructive sleep apnea and different types of parasomnias between two groups. Conclusion: Reduced length of sleep and higher prevalence of poor sleep quality and insomnia in shift workers emphasizes the importance of serious attention to sleep disorders in shift workers.

Legacy ExtraGalactic UV Survey with The Hubble Space Telescope: Stellar Cluster Catalogs and First Insights Into Cluster Formation and Evolution in NGC 628

NARCIS (Netherlands)

Adamo, A.; Ryon, J.E.; Messa, M.; Kim, H.; Grasha, K.; Cook, D.O.; Calzetti, D.; Lee, J.C.; Whitmore, B.C.; Elmegreen, B.G.; Ubeda, L.; Smith, L.J.; Bright, S.N.; Runnholm, A.; Andrews, J.E.; Fumagalli, M.; Gouliermis, D.A.; Kahre, L.; Nair, P.; Thilker, D.; Walterbos, R.; Wofford, A.; Aloisi, A.; Ashworth, G.; Brown, T.M.; Chandar, R.; Christian, C.; Cignoni, M.; Clayton, G.C.; Dale, D.A.; de Mink, S.E.; Dobbs, C.; Elmegreen, D.M.; Evans, A.S.; Gallagher III, J.S.; Grebel, E.K.; Herrero, A.; Hunter, D.A.; Johnson, K.E.; Kennicutt, R.C.; Krumholz, M.R.; Lennon, D.; Levay, K.; Martin, C.; Nota, A.; Östlin, G.; Pellerin, A.; Prieto, J.; Regan, M.W.; Sabbi, E.; Sacchi, E.; Schaerer, D.; Schiminovich, D.; Shabani, F.; Tosi, M.; Van Dyk, S.D.; Zackrisson, E.

2017-01-01

We report the large effort that is producing comprehensive high-level young star cluster (YSC) catalogs for a significant fraction of galaxies observed with the Legacy ExtraGalactic UV Survey (LEGUS) Hubble treasury program. We present the methodology developed to extract cluster positions, verify

Cosmological model-independent test of ΛCDM with two-point diagnostic by the observational Hubble parameter data

Science.gov (United States)

Cao, Shu-Lei; Duan, Xiao-Wei; Meng, Xiao-Lei; Zhang, Tong-Jie

2018-04-01

Aiming at exploring the nature of dark energy (DE), we use forty-three observational Hubble parameter data (OHD) in the redshift range 0 measurements. The binning methods turn out to be promising and considered to be robust. By applying the two-point diagnostic to the binned data, we find that although the best-fit values of Omh^2 fluctuate as the continuous redshift intervals change, on average, they are continuous with being constant within 1 σ confidence interval. Therefore, we conclude that the ΛCDM model cannot be ruled out.

Chemical shift homology in proteins

International Nuclear Information System (INIS)

Potts, Barbara C.M.; Chazin, Walter J.

1998-01-01

The degree of chemical shift similarity for homologous proteins has been determined from a chemical shift database of over 50 proteins representing a variety of families and folds, and spanning a wide range of sequence homologies. After sequence alignment, the similarity of the secondary chemical shifts of C α protons was examined as a function of amino acid sequence identity for 37 pairs of structurally homologous proteins. A correlation between sequence identity and secondary chemical shift rmsd was observed. Important insights are provided by examining the sequence identity of homologous proteins versus percentage of secondary chemical shifts that fall within 0.1 and 0.3 ppm thresholds. These results begin to establish practical guidelines for the extent of chemical shift similarity to expect among structurally homologous proteins

Adaptation to shift work: physiologically based modeling of the effects of lighting and shifts' start time.

Directory of Open Access Journals (Sweden)

Svetlana Postnova

Full Text Available Shift work has become an integral part of our life with almost 20% of the population being involved in different shift schedules in developed countries. However, the atypical work times, especially the night shifts, are associated with reduced quality and quantity of sleep that leads to increase of sleepiness often culminating in accidents. It has been demonstrated that shift workers' sleepiness can be improved by a proper scheduling of light exposure and optimizing shifts timing. Here, an integrated physiologically-based model of sleep-wake cycles is used to predict adaptation to shift work in different light conditions and for different shift start times for a schedule of four consecutive days of work. The integrated model combines a model of the ascending arousal system in the brain that controls the sleep-wake switch and a human circadian pacemaker model. To validate the application of the integrated model and demonstrate its utility, its dynamics are adjusted to achieve a fit to published experimental results showing adaptation of night shift workers (n = 8 in conditions of either bright or regular lighting. Further, the model is used to predict the shift workers' adaptation to the same shift schedule, but for conditions not considered in the experiment. The model demonstrates that the intensity of shift light can be reduced fourfold from that used in the experiment and still produce good adaptation to night work. The model predicts that sleepiness of the workers during night shifts on a protocol with either bright or regular lighting can be significantly improved by starting the shift earlier in the night, e.g.; at 21:00 instead of 00:00. Finally, the study predicts that people of the same chronotype, i.e. with identical sleep times in normal conditions, can have drastically different responses to shift work depending on their intrinsic circadian and homeostatic parameters.

Adaptation to shift work: physiologically based modeling of the effects of lighting and shifts' start time.

Science.gov (United States)

Postnova, Svetlana; Robinson, Peter A; Postnov, Dmitry D

2013-01-01

Shift work has become an integral part of our life with almost 20% of the population being involved in different shift schedules in developed countries. However, the atypical work times, especially the night shifts, are associated with reduced quality and quantity of sleep that leads to increase of sleepiness often culminating in accidents. It has been demonstrated that shift workers' sleepiness can be improved by a proper scheduling of light exposure and optimizing shifts timing. Here, an integrated physiologically-based model of sleep-wake cycles is used to predict adaptation to shift work in different light conditions and for different shift start times for a schedule of four consecutive days of work. The integrated model combines a model of the ascending arousal system in the brain that controls the sleep-wake switch and a human circadian pacemaker model. To validate the application of the integrated model and demonstrate its utility, its dynamics are adjusted to achieve a fit to published experimental results showing adaptation of night shift workers (n = 8) in conditions of either bright or regular lighting. Further, the model is used to predict the shift workers' adaptation to the same shift schedule, but for conditions not considered in the experiment. The model demonstrates that the intensity of shift light can be reduced fourfold from that used in the experiment and still produce good adaptation to night work. The model predicts that sleepiness of the workers during night shifts on a protocol with either bright or regular lighting can be significantly improved by starting the shift earlier in the night, e.g.; at 21:00 instead of 00:00. Finally, the study predicts that people of the same chronotype, i.e. with identical sleep times in normal conditions, can have drastically different responses to shift work depending on their intrinsic circadian and homeostatic parameters.

HUBBLE SPACE TELESCOPE PHOTOMETRY OF GLOBULAR CLUSTERS IN M81

International Nuclear Information System (INIS)

Nantais, Julie B.; Huchra, John P.; Zezas, Andreas; Gazeas, Kosmas; Strader, Jay

2011-01-01

We perform aperture photometry and profile fitting on 419 globular cluster (GC) candidates with m V ≤ 23 mag identified in Hubble Space Telescope/Advanced Camera for Surveys BVI imaging, and estimate the effective radii of the clusters. We identify 85 previously known spectroscopically confirmed clusters, and newly identify 136 objects as good cluster candidates within the 3σ color and size ranges defined by the spectroscopically confirmed clusters, yielding a total of 221 probable GCs. The luminosity function peak for the 221 probable GCs with estimated total dereddening applied is V ∼ (20.26 ± 0.13) mag, corresponding to a distance of ∼3.7 ± 0.3 Mpc. The blue and red GC candidates, and the metal-rich and metal-poor spectroscopically confirmed clusters, respectively, are similar in half-light radius. Red confirmed clusters are about 6% larger in median half-light radius than blue confirmed clusters, and red and blue good GC candidates are nearly identical in half-light radius. The total population of confirmed and 'good' candidates shows an increase in half-light radius as a function of galactocentric distance.

Shift Work, Chronotype, and Melatonin Patterns among Female Hospital Employees on Day and Night Shifts.

Science.gov (United States)

Leung, Michael; Tranmer, Joan; Hung, Eleanor; Korsiak, Jill; Day, Andrew G; Aronson, Kristan J

2016-05-01

Shift work-related carcinogenesis is hypothesized to be mediated by melatonin; however, few studies have considered the potential effect modification of this underlying pathway by chronotype or specific aspects of shift work such as the number of consecutive nights in a rotation. In this study, we examined melatonin patterns in relation to shift status, stratified by chronotype and number of consecutive night shifts, and cumulative lifetime exposure to shift work. Melatonin patterns of 261 female personnel (147 fixed-day and 114 on rotations, including nights) at Kingston General Hospital were analyzed using cosinor analysis. Urine samples were collected from all voids over a 48-hour specimen collection period for measurement of 6-sulfatoxymelatonin concentrations using the Buhlmann ELISA Kit. Chronotypes were assessed using mid-sleep time (MSF) derived from the Munich Chronotype Questionnaire (MCTQ). Sociodemographic, health, and occupational information were collected by questionnaire. Rotational shift nurses working nights had a lower mesor and an earlier time of peak melatonin production compared to day-only workers. More pronounced differences in mesor and acrophase were seen among later chronotypes, and shift workers working ≥3 consecutive nights. Among nurses, cumulative shift work was associated with a reduction in mesor. These results suggest that evening-types and/or shift workers working ≥3 consecutive nights are more susceptible to adverse light-at-night effects, whereas long-term shift work may also chronically reduce melatonin levels. Cumulative and current exposure to shift work, including nights, affects level and timing of melatonin production, which may be related to carcinogenesis and cancer risk. Cancer Epidemiol Biomarkers Prev; 25(5); 830-8. ©2016 AACR. ©2016 American Association for Cancer Research.

Precise Estimates of the Physical Parameters for the Exoplanet System HD 17156 Enabled by Hubble Space Telescope Fine Guidance Sensor Transit and Asteroseismic Observations

DEFF Research Database (Denmark)

Nutzman, Philip; Gilliland, Ronald L.; McCullough, Peter R.

2011-01-01

We present observations of three distinct transits of HD 17156b obtained with the Fine Guidance Sensors on board the Hubble Space Telescope. We analyzed both the transit photometry and previously published radial velocities to find the planet-star radius ratio Rp /R sstarf = 0.07454 ± 0.00035, in......We present observations of three distinct transits of HD 17156b obtained with the Fine Guidance Sensors on board the Hubble Space Telescope. We analyzed both the transit photometry and previously published radial velocities to find the planet-star radius ratio Rp /R sstarf = 0.07454 ± 0......-composition gas giant of the same mass and equilibrium temperature. For the three transits, we determine the times of mid-transit to a precision of 6.2 s, 7.6 s, and 6.9 s, and the transit times for HD 17156 do not show any significant departures from a constant period. The joint analysis of transit photometry...

Correcting a statistical artifact in the estimation of the Hubble; constant based on Type Ia Supernovae results in a change in estimate; of 1.2%

DEFF Research Database (Denmark)

Petersen, JH; Holst, KK; Budtz-Jørgensen, Esben

2010-01-01

The Hubble constant enters big bang cosmology by quantifying the expansion rate of the universe. Existing statistical methods used to estimate Hubble’s constant only partially take into account random measurement errors. As a consequence, estimates of Hubble’s constant are statistically...

A Type II Supernova Hubble Diagram from the CSP-I, SDSS-II, and SNLS Surveys

Science.gov (United States)

de Jaeger, T.; González-Gaitán, S.; Hamuy, M.; Galbany, L.; Anderson, J. P.; Phillips, M. M.; Stritzinger, M. D.; Carlberg, R. G.; Sullivan, M.; Gutiérrez, C. P.; Hook, I. M.; Howell, D. Andrew; Hsiao, E. Y.; Kuncarayakti, H.; Ruhlmann-Kleider, V.; Folatelli, G.; Pritchet, C.; Basa, S.

2017-02-01

The coming era of large photometric wide-field surveys will increase the detection rate of supernovae by orders of magnitude. Such numbers will restrict spectroscopic follow-up in the vast majority of cases, and hence new methods based solely on photometric data must be developed. Here, we construct a complete Hubble diagram of Type II supernovae (SNe II) combining data from three different samples: the Carnegie Supernova Project-I, the Sloan Digital Sky Survey II SN, and the Supernova Legacy Survey. Applying the Photometric Color Method (PCM) to 73 SNe II with a redshift range of 0.01-0.5 and with no spectral information, we derive an intrinsic dispersion of 0.35 mag. A comparison with the Standard Candle Method (SCM) using 61 SNe II is also performed and an intrinsic dispersion in the Hubble diagram of 0.27 mag, I.e., 13% in distance uncertainties, is derived. Due to the lack of good statistics at higher redshifts for both methods, only weak constraints on the cosmological parameters are obtained. However, assuming a flat universe and using the PCM, we derive the universe’s matter density: {{{Ω }}}m={0.32}-0.21+0.30 providing a new independent evidence for dark energy at the level of two sigma. This paper includes data gathered with the 6.5 m Magellan Telescopes, with the du Pont and Swope telescopes located at Las Campanas Observatory, Chile; and the Gemini Observatory, Cerro Pachon, Chile (Gemini Program N-2005A-Q-11, GN-2005B-Q-7, GN-2006A-Q-7, GS-2005A-Q-11, GS-2005B-Q-6, and GS-2008B-Q-56). Based on observations collected at the European Organization for Astronomical Research in the Southern Hemisphere, Chile (ESO Programmes 076.A-0156,078.D-0048, 080.A-0516, and 082.A-0526).

Effect of Shift Work on Nocturia.

Science.gov (United States)

Kim, Jin Wook

2016-01-01

To identify the circadian sensitive component of nocturia by comparing nocturia in patients who voluntarily choose a disrupted circadian rhythm, that is, shift workers, with those who maintain normal day-night cycles. Between 2011 and 2013, a total of 1741 untreated patients, 1376 nonshift workers and 365 shift workers, were compared for nocturia indices based on frequency volume charts (FVCs). General linear model of 8-hour interval urine production and frequency were compared between FVCs of nonshift workers, FVCs of night-shift workers, and FVCs of day-shift workers. Nocturia frequency was increased in the night-shift workers (2.38 ± 1.44) compared with nonshift workers (2.18 ± 1.04) (P night-shift workers, 0.34 ± 0.13 for nonshift workers, P = .24), nocturnal bladder capacity index increased significantly (1.41 ± 1.06 for night-shift workers, 1.26 ± 0.92 for nonshift workers, P shift (P shift changes (P = .35). Patients in alternating work shifts showed increased nocturia, especially during their night shift. These changes tended to be more associated with decreased nocturnal bladder capacity than increased nocturnal polyuria. Copyright © 2015 Elsevier Inc. All rights reserved.

Associations between number of consecutive night shifts and impairment of neurobehavioral performance during a subsequent simulated night shift.

Science.gov (United States)

Magee, Michelle; Sletten, Tracey L; Ferguson, Sally A; Grunstein, Ronald R; Anderson, Clare; Kennaway, David J; Lockley, Steven W; Rajaratnam, Shantha Mw

2016-05-01

This study aimed to investigate sleep and circadian phase in the relationships between neurobehavioral performance and the number of consecutive shifts worked. Thirty-four shift workers [20 men, mean age 31.8 (SD 10.9) years] worked 2-7 consecutive night shifts immediately prior to a laboratory-based, simulated night shift. For 7 days prior, participants worked their usual shift sequence, and sleep was assessed with logs and actigraphy. Participants completed a 10-minute auditory psychomotor vigilance task (PVT) at the start (~21:00 hours) and end (~07:00 hours) of the simulated night shift. Mean reaction times (RT), number of lapses and RT distribution was compared between those who worked 2-3 consecutive night shifts versus those who worked 4-7 shifts. Following 4-7 shifts, night shift workers had significantly longer mean RT at the start and end of shift, compared to those who worked 2-3 shifts. The slowest and fastest 10% RT were significantly slower at the start, but not end, of shift among participants who worked 4-7 nights. Those working 4-7 nights also demonstrated a broader RT distribution at the start and end of shift and had significantly slower RT based on cumulative distribution analysis (5 (th), 25 (th), 50 (th), 75 (th)percentiles at the start of shift; 75th percentile at the end of shift). No group differences in sleep parameters were found for 7 days and 24 hours prior to the simulated night shift. A greater number of consecutive night shifts has a negative impact on neurobehavioral performance, likely due to cognitive slowing.

Change from an 8-hour shift to a 12-hour shift, attitudes, sleep, sleepiness and performance.

Science.gov (United States)

Lowden, A; Kecklund, G; Axelsson, J; Akerstedt, T

1998-01-01

The present study sought to evaluate the effect of a change from a rotating 3-shift (8-hour) to a 2-shift shift (12 hour) schedule on sleep, sleepiness, performance, perceived health, and well-being. Thirty-two shift workers at a chemical plant (control room operators) responded to a questionnaire a few months before a change was made in their shift schedule and 10 months after the change. Fourteen workers also filled out a diary, carried activity loggers, and carried out reaction-time tests (beginning and end of shift). Fourteen day workers served as a reference group for the questionnaires and 9 were intensively studied during a week with workdays and a free weekend. The questionnaire data showed that the shift change increased satisfaction with workhours, sleep, and time for social activities. Health, perceived accident risk, and reaction-time performance were not negatively affected. Alertness improved and subjective recovery time after night work decreased. The quick changes in the 8-hour schedule greatly increased sleep problems and fatigue. Sleepiness integrated across the entire shift cycle showed that the shift workers were less alert than the day workers, across workdays and days off (although alertness increased with the 12-hour shift). The change from 8-hour to 12-hour shifts was positive in most respects, possibly due to the shorter sequences of the workdays, the longer sequences of consecutive days off, the fewer types of shifts (easier planning), and the elimination of quick changes. The results may differ in groups with a higher work load.

SHIFT: server for hidden stops analysis in frame-shifted translation.

Science.gov (United States)

Gupta, Arun; Singh, Tiratha Raj

2013-02-23

Frameshift is one of the three classes of recoding. Frame-shifts lead to waste of energy, resources and activity of the biosynthetic machinery. In addition, some peptides synthesized after frame-shifts are probably cytotoxic which serve as plausible cause for innumerable number of diseases and disorders such as muscular dystrophies, lysosomal storage disorders, and cancer. Hidden stop codons occur naturally in coding sequences among all organisms. These codons are associated with the early termination of translation for incorrect reading frame selection and help to reduce the metabolic cost related to the frameshift events. Researchers have identified several consequences of hidden stop codons and their association with myriad disorders. However the wealth of information available is speckled and not effortlessly acquiescent to data-mining. To reduce this gap, this work describes an algorithmic web based tool to study hidden stops in frameshifted translation for all the lineages through respective genetic code systems. This paper describes SHIFT, an algorithmic web application tool that provides a user-friendly interface for identifying and analyzing hidden stops in frameshifted translation of genomic sequences for all available genetic code systems. We have calculated the correlation between codon usage frequencies and the plausible contribution of codons towards hidden stops in an off-frame context. Markovian chains of various order have been used to model hidden stops in frameshifted peptides and their evolutionary association with naturally occurring hidden stops. In order to obtain reliable and persuasive estimates for the naturally occurring and predicted hidden stops statistical measures have been implemented. This paper presented SHIFT, an algorithmic tool that allows user-friendly exploration, analysis, and visualization of hidden stop codons in frameshifted translations. It is expected that this web based tool would serve as a useful complement for

LQG and maximum entropy control design for the Hubble Space Telescope

Science.gov (United States)

Collins, Emmanuel G., Jr.; Richter, Stephen

Solar array vibrations are responsible for serious pointing control problems on the Hubble Space Telescope (HST). The original HST control law was not designed to attenuate these disturbances because they were not perceived to be a problem prior to launch. However, significant solar array vibrations do occur due to large changes in the thermal environment as the HST orbits the earth. Using classical techniques, Marshall Space Flight Center in conjunction with Lockheed Missiles and Space Company developed modified HST controllers that were able to suppress the influence of the vibrations of the solar arrays on the line-of-sight (LOS) performance. Substantial LOS improvement was observed when two of these controllers were implemented on orbit. This paper describes the development of modified HST controllers by using modern control techniques, particularly linear-quadratic-gaussian (LQG) design and Maximum Entropy robust control design, a generalization of LQG that incorporates robustness constraints with respect to modal errors. The fundamental issues are discussed candidly and controllers designed using these modern techniques are described.

Discovery of an Unusual Optical Transient with the Hubble Space Telescope

Energy Technology Data Exchange (ETDEWEB)

The Supernova Cosmology Project; Barbary, Kyle; Dawson, Kyle S.; Tokita, Kouichi; Aldering, Greg; Amanullah, Rahman; Connolly, Natalia V.; Doi, Mamoru; Faccioli, Lorenzo; Fadeyev, Vitaliy; Fruchter, Andrew S.; Goldhaber, Gerson; Goobar, Ariel; Gude, Alexander; Huang, Xiaosheng; Ihara, Yutaka; Konishi, Kohki; Kowalski, Marek; Lidman, Chris; Meyers, Josh; Morokuma, Tomoki; Nugent, Peter; Perlmutter, Saul; Rubin, David; Schlegel, David; Spadafora, Anthony L.; Suzuki, Nao; Swift, Hannah K.; Takanashi, Naohiro; Thomas, Rollin C.; Yasuda, Naoki

2008-09-08

We present observations of SCP 06F6, an unusual optical transient discovered during the Hubble Space Telescope Cluster Supernova Survey. The transient brightened over a period of ~;;100 days, reached a peak magnitude of ~;;21.0 in both i_775 and z_850, and then declined over a similar timescale. There is no host galaxy or progenitor star detected at the location of the transient to a 3 sigma upper limit of i_775 = 26.4 and z_850 = 26.1, giving a corresponding lower limit on the flux increase of a factor of ~;;120. Multiple spectra show five broad absorption bands between 4100 AA and 6500 AA and a mostly featureless continuum longward of 6500 AA. The shape of the lightcurve is inconsistent with microlensing. The transient's spectrum, in addition to being inconsistent with all known supernova types, is not matched to any spectrum in the Sloan Digital Sky Survey (SDSS) database. We suggest that the transient may be one of a new class.

The Carnegie Hubble Program: The Infrared Leavitt Law in IC 1613

Science.gov (United States)

Scowcroft, Victoria; Freedman, Wendy L.; Madore, Barry F.; Monson, Andrew J.; Persson, S. E.; Seibert, Mark; Rigby, Jane R.; Melbourne, Jason

2013-01-01

We have observed the dwarf galaxy IC 1613 at multiple epochs in the midinfrared using Spitzer and the in the near-infrared using the new FourStar near-IR camera on Magellan. We have constructed Cepheid period luminosity relations in the J, H, Ks, [3.6] and [4.5] bands and have used the run of their apparent distance moduli as a function of wavelength to derive the line of sight reddening and distance to IC 1613. Using a nineband fit, we find E(BV ) = 0.050.01 mag and an extinction corrected distance modulus of 0 = 24.29 0.03statistical 0.03systematic mag. By comparing our multiband and [3.6] distance moduli to results from the tip of the red giant branch and red clump distance indicators, we find that metallicity has no measurable effect on Cepheid distances at 3.6 m in the metallicity range 1.0 [Fe/H] 0.2, hence derivations of the Hubble constant at this wavelength require no correction for metallicity.

Shifted-modified Chebyshev filters

OpenAIRE

ŞENGÜL, Metin

2013-01-01

This paper introduces a new type of filter approximation method that utilizes shifted-modified Chebyshev filters. Construction of the new filters involves the use of shifted-modified Chebyshev polynomials that are formed using the roots of conventional Chebyshev polynomials. The study also includes 2 tables containing the shifted-modified Chebyshev polynomials and the normalized element values for the low-pass prototype filters up to degree 6. The transducer power gain, group dela...

Ultracompact Blue Dwarf Galaxies: Hubble Space Telescope Imaging and Stellar Population Analysis

Science.gov (United States)

Corbin, Michael R.; Vacca, William D.; Cid Fernandes, Roberto; Hibbard, John E.; Somerville, Rachel S.; Windhorst, Rogier A.

2006-11-01

We present deep Hubble Space Telescope (HST) Advanced Camera for Surveys/High Resolution Channel U-, narrow-V-, and I-band images of nine ``ultracompact'' blue dwarf galaxies (UCBDs) selected from the Sloan Digital Sky Survey (SDSS). We define UCBDs as local (zPOX 186, but the structure of several of them suggests that their current star formation has been triggered by the collisions/mergers of smaller clumps of stars. In one case, HS 0822+3542, the images resolve what may be two small (~100 pc) components that have recently collided, supporting this interpretation. In six of the objects much of the star formation is concentrated in young massive clusters, contributing to their compactness in ground-based images. The evidence that the galaxies consist mainly of ~10 Gyr old stars establishes that they are not protogalaxies, forming their first generation of stars. Their low metallicities are more likely to be the result of the escape of supernova ejecta, rather than youth.

OpenShift cookbook

CERN Document Server

Gulati, Shekhar

2014-01-01

If you are a web application developer who wants to use the OpenShift platform to host your next big idea but are looking for guidance on how to achieve this, then this book is the first step you need to take. This is a very accessible cookbook where no previous knowledge of OpenShift is needed.

Performance and sleepiness in nurses working 12-h day shifts or night shifts in a community hospital.

Science.gov (United States)

Wilson, Marian; Permito, Regan; English, Ashley; Albritton, Sandra; Coogle, Carlana; Van Dongen, Hans P A

2017-10-05

Hospitals are around-the-clock operations and nurses are required to care for patients night and day. The nursing shortage and desire for a more balanced work-to-home life has popularized 12-h shifts for nurses. The present study investigated sleep/wake cycles and fatigue levels in 22 nurses working 12-h shifts, comparing day versus night shifts. Nurses (11day shift and 11 night shift) were recruited from a suburban acute-care medical center. Participants wore a wrist activity monitor and kept a diary to track their sleep/wake cycles for 2 weeks. They also completed a fatigue test battery, which included the Psychomotor Vigilance Test (PVT) and the Karolinska Sleepiness Scale (KSS), at the beginning, middle and end of 4 duty shifts. Daily sleep duration was 7.1h on average. No overall difference in mean daily sleep duration was found between nurses working day shifts versus night shifts. Objective performance on the PVT remained relatively good and stable at the start, middle, and end of duty shifts in day shift workers, but gradually degraded across duty time in night shift workers. Compared to day shift workers, night shift workers also exhibited more performance variability among measurement days and between participants at each testing time point. The same pattern was observed for subjective sleepiness on the KSS. However, congruence between objective and subjective measures of fatigue was poor. Our findings suggest a need for organizations to evaluate practices and policies to mitigate the inevitable fatigue that occurs during long night shifts, in order to improve patient and healthcare worker safety. Examination of alternative shift lengths or sanctioned workplace napping may be strategies to consider. Copyright © 2017 Elsevier Ltd. All rights reserved.

Shift Verification and Validation

Energy Technology Data Exchange (ETDEWEB)

Pandya, Tara M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Evans, Thomas M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Davidson, Gregory G [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Johnson, Seth R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Godfrey, Andrew T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2016-09-07

This documentation outlines the verification and validation of Shift for the Consortium for Advanced Simulation of Light Water Reactors (CASL). Five main types of problems were used for validation: small criticality benchmark problems; full-core reactor benchmarks for light water reactors; fixed-source coupled neutron-photon dosimetry benchmarks; depletion/burnup benchmarks; and full-core reactor performance benchmarks. We compared Shift results to measured data and other simulated Monte Carlo radiation transport code results, and found very good agreement in a variety of comparison measures. These include prediction of critical eigenvalue, radial and axial pin power distributions, rod worth, leakage spectra, and nuclide inventories over a burn cycle. Based on this validation of Shift, we are confident in Shift to provide reference results for CASL benchmarking.

Choice Shifts in Groups

OpenAIRE

Kfir Eliaz; Debraj Ray

2004-01-01

The phenomenon of "choice shifts" in group decision-making is fairly ubiquitous in the social psychology literature. Faced with a choice between a ``safe" and ``risky" decision, group members appear to move to one extreme or the other, relative to the choices each member might have made on her own. Both risky and cautious shifts have been identified in different situations. This paper demonstrates that from an individual decision-making perspective, choice shifts may be viewed as a systematic...

Ultradeep Near-Infrared ISAAC Observations of the Hubble Deep Field South: Observations, Reduction, Multicolor Catalog, and Photometric Redshifts

Science.gov (United States)

Labbé, Ivo; Franx, Marijn; Rudnick, Gregory; Schreiber, Natascha M. Förster; Rix, Hans-Walter; Moorwood, Alan; van Dokkum, Pieter G.; van der Werf, Paul; Röttgering, Huub; van Starkenburg, Lottie; van der Wel, Arjen; Kuijken, Konrad; Daddi, Emanuele

2003-03-01

We present deep near-infrared (NIR) Js-, H-, and Ks-band ISAAC imaging of the Wide Field Planetary Camera 2 (WFPC2) field of the Hubble Deep Field South (HDF-S). The 2.5‧×2.5‧ high Galactic latitude field was observed with the Very Large Telescope under the best seeing conditions, with integration times amounting to 33.6 hr in Js, 32.3 hr in H, and 35.6 hr in Ks. We reach total AB magnitudes for point sources of 26.8, 26.2, and 26.2, respectively (3 σ), which make it the deepest ground-based NIR observation to date and the deepest Ks-band data in any field. The effective seeing of the co-added images is ~0.45" in Js, ~0.48" in H, and ~0.46" in Ks. Using published WFPC2 optical data, we constructed a Ks-limited multicolor catalog containing 833 sources down to Ktots,AB2.3 (in Johnson magnitudes). Because they are extremely faint in the observed optical, they would be missed by ultraviolet-optical selection techniques, such as the U-dropout method. Based on service mode observations collected at the European Southern Observatory, Paranal, Chile (ESO Program 164.O-0612). Also based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy (AURA), Inc., under NASA contract NAS 5-26555.

UVUDF: Ultraviolet imaging of the Hubble ultra deep field with wide-field camera 3

Energy Technology Data Exchange (ETDEWEB)

Teplitz, Harry I.; Rafelski, Marc; Colbert, James W.; Hanish, Daniel J. [Infrared Processing and Analysis Center, MS 100-22, Caltech, Pasadena, CA 91125 (United States); Kurczynski, Peter; Gawiser, Eric [Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08854 (United States); Bond, Nicholas A.; Gardner, Jonathan P.; De Mello, Duilia F. [Laboratory for Observational Cosmology, Astrophysics Science Division, Code 665, Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Grogin, Norman; Koekemoer, Anton M.; Brown, Thomas M.; Coe, Dan; Ferguson, Henry C. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Atek, Hakim [Laboratoire d' Astrophysique, École Polytechnique Fédérale de Lausanne (EPFL), Observatoire, CH-1290 Sauverny (Switzerland); Finkelstein, Steven L. [Department of Astronomy, The University of Texas at Austin, Austin, TX 78712 (United States); Giavalisco, Mauro [Astronomy Department, University of Massachusetts, Amherst, MA 01003 (United States); Gronwall, Caryl [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Lee, Kyoung-Soo [Department of Physics, Purdue University, 525 Northwestern Avenue, West Lafayette, IN 47907 (United States); Ravindranath, Swara, E-mail: hit@ipac.caltech.edu [Inter-University Centre for Astronomy and Astrophysics, Pune (India); and others

2013-12-01

We present an overview of a 90 orbit Hubble Space Telescope treasury program to obtain near-ultraviolet imaging of the Hubble Ultra Deep Field using the Wide Field Camera 3 UVIS detector with the F225W, F275W, and F336W filters. This survey is designed to: (1) investigate the episode of peak star formation activity in galaxies at 1 < z < 2.5; (2) probe the evolution of massive galaxies by resolving sub-galactic units (clumps); (3) examine the escape fraction of ionizing radiation from galaxies at z ∼ 2-3; (4) greatly improve the reliability of photometric redshift estimates; and (5) measure the star formation rate efficiency of neutral atomic-dominated hydrogen gas at z ∼ 1-3. In this overview paper, we describe the survey details and data reduction challenges, including both the necessity of specialized calibrations and the effects of charge transfer inefficiency. We provide a stark demonstration of the effects of charge transfer inefficiency on resultant data products, which when uncorrected, result in uncertain photometry, elongation of morphology in the readout direction, and loss of faint sources far from the readout. We agree with the STScI recommendation that future UVIS observations that require very sensitive measurements use the instrument's capability to add background light through a 'post-flash'. Preliminary results on number counts of UV-selected galaxies and morphology of galaxies at z ∼ 1 are presented. We find that the number density of UV dropouts at redshifts 1.7, 2.1, and 2.7 is largely consistent with the number predicted by published luminosity functions. We also confirm that the image mosaics have sufficient sensitivity and resolution to support the analysis of the evolution of star-forming clumps, reaching 28-29th magnitude depth at 5σ in a 0.''2 radius aperture depending on filter and observing epoch.

NASA and ESA astronauts visit ESO. Hubble repair team meets European astronomers in Garching.

Science.gov (United States)

1994-02-01

On Wednesday, February 16, 1994, seven NASA and ESA astronauts and their spouses will spend a day at the Headquarters of the European Southern Observatory. They are the members of the STS-61 crew that successfully repaired the Hubble Space Telescope during a Space Shuttle mission in December 1993. This will be the only stop in Germany during their current tour of various European countries. ESO houses the Space Telescope European Coordinating Facility (ST/ECF), a joint venture by the European Space Agency and ESO. This group of astronomers and computer specialists provide all services needed by European astronomers for observations with the Space Telescope. Currently, the European share is about 20 of the total time available at this telescope. During this visit, a Press Conference will be held on Wednesday, February 16, 11:45 - 12:30 at the ESO Headquarters Karl-Schwarzschild-Strasse 2 D-85748 Garching bei Munchen. Please note that participation in this Press Conference is by invitation only. Media representatives may obtain invitations from Mrs. E. Volk, ESO Information Service at this address (Tel.: +49-89-32006276; Fax.: +49-89-3202362), until Friday, February 11, 1994. After the Press Conference, between 12:30 - 14:00, a light refreshment will be served at the ESO Headquarters to all participants. >From 14:00 - 15:30, the astronauts will meet with students and teachers from the many scientific institutes in Garching in the course of an open presentation at the large lecture hall of the Physics Department of the Technical University. It is a 10 minute walk from ESO to the hall. Later the same day, the astronauts will be back at ESO for a private discussion of various space astronomy issues with their astronomer colleagues, many of whom are users of the Hubble Space Telescope, as well as ground-based telescopes at the ESO La Silla Observatory and elsewhere. The astronauts continue to Switzerland in the evening.

Night shift work exposure profile and obesity: Baseline results from a Chinese night shift worker cohort.

Science.gov (United States)

Sun, Miaomiao; Feng, Wenting; Wang, Feng; Zhang, Liuzhuo; Wu, Zijun; Li, Zhimin; Zhang, Bo; He, Yonghua; Xie, Shaohua; Li, Mengjie; Fok, Joan P C; Tse, Gary; Wong, Martin C S; Tang, Jin-Ling; Wong, Samuel Y S; Vlaanderen, Jelle; Evans, Greg; Vermeulen, Roel; Tse, Lap Ah

2018-01-01

This study aimed to evaluate the associations between types of night shift work and different indices of obesity using the baseline information from a prospective cohort study of night shift workers in China. A total of 3,871 workers from five companies were recruited from the baseline survey. A structured self-administered questionnaire was employed to collect the participants' demographic information, lifetime working history, and lifestyle habits. Participants were grouped into rotating, permanent and irregular night shift work groups. Anthropometric parameters were assessed by healthcare professionals. Multiple logistic regression models were used to evaluate the associations between night shift work and different indices of obesity. Night shift workers had increased risk of overweight and obesity, and odds ratios (ORs) were 1.17 (95% CI, 0.97-1.41) and 1.27 (95% CI, 0.74-2.18), respectively. Abdominal obesity had a significant but marginal association with night shift work (OR = 1.20, 95% CI, 1.01-1.43). A positive gradient between the number of years of night shift work and overweight or abdominal obesity was observed. Permanent night shift work showed the highest odds of being overweight (OR = 3.94, 95% CI, 1.40-11.03) and having increased abdominal obesity (OR = 3.34, 95% CI, 1.19-9.37). Irregular night shift work was also significantly associated with overweight (OR = 1.56, 95% CI, 1.13-2.14), but its association with abdominal obesity was borderline (OR = 1.26, 95% CI, 0.94-1.69). By contrast, the association between rotating night shift work and these parameters was not significant. Permanent and irregular night shift work were more likely to be associated with overweight or abdominal obesity than rotating night shift work. These associations need to be verified in prospective cohort studies.

Night shift work exposure profile and obesity: Baseline results from a Chinese night shift worker cohort

Science.gov (United States)

Feng, Wenting; Wang, Feng; Zhang, Liuzhuo; Wu, Zijun; Li, Zhimin; Zhang, Bo; He, Yonghua; Xie, Shaohua; Li, Mengjie; Fok, Joan P. C.; Tse, Gary; Wong, Martin C. S.; Tang, Jin-ling; Wong, Samuel Y. S.; Vlaanderen, Jelle; Evans, Greg; Vermeulen, Roel; Tse, Lap Ah

2018-01-01

Aims This study aimed to evaluate the associations between types of night shift work and different indices of obesity using the baseline information from a prospective cohort study of night shift workers in China. Methods A total of 3,871 workers from five companies were recruited from the baseline survey. A structured self-administered questionnaire was employed to collect the participants’ demographic information, lifetime working history, and lifestyle habits. Participants were grouped into rotating, permanent and irregular night shift work groups. Anthropometric parameters were assessed by healthcare professionals. Multiple logistic regression models were used to evaluate the associations between night shift work and different indices of obesity. Results Night shift workers had increased risk of overweight and obesity, and odds ratios (ORs) were 1.17 (95% CI, 0.97–1.41) and 1.27 (95% CI, 0.74–2.18), respectively. Abdominal obesity had a significant but marginal association with night shift work (OR = 1.20, 95% CI, 1.01–1.43). A positive gradient between the number of years of night shift work and overweight or abdominal obesity was observed. Permanent night shift work showed the highest odds of being overweight (OR = 3.94, 95% CI, 1.40–11.03) and having increased abdominal obesity (OR = 3.34, 95% CI, 1.19–9.37). Irregular night shift work was also significantly associated with overweight (OR = 1.56, 95% CI, 1.13–2.14), but its association with abdominal obesity was borderline (OR = 1.26, 95% CI, 0.94–1.69). By contrast, the association between rotating night shift work and these parameters was not significant. Conclusion Permanent and irregular night shift work were more likely to be associated with overweight or abdominal obesity than rotating night shift work. These associations need to be verified in prospective cohort studies. PMID:29763461

Hubble Space Telescope Image of Omega Nebula

Science.gov (United States)

2002-01-01

This sturning image, taken by the newly installed Advanced Camera for Surveys (ACS) aboard the Hubble Space Telescope (HST), is an image of the center of the Omega Nebula. It is a hotbed of newly born stars wrapped in colorful blankets of glowing gas and cradled in an enormous cold, dark hydrogen cloud. The region of nebula shown in this photograph is about 3,500 times wider than our solar system. The nebula, also called M17 and the Swan Nebula, resides 5,500 light-years away in the constellation Sagittarius. The Swan Nebula is illuminated by ultraviolet radiation from young, massive stars, located just beyond the upper-right corner of the image. The powerful radiation from these stars evaporates and erodes the dense cloud of cold gas within which the stars formed. The blistered walls of the hollow cloud shine primarily in the blue, green, and red light emitted by excited atoms of hydrogen, nitrogen, oxygen, and sulfur. Particularly striking is the rose-like feature, seen to the right of center, which glows in the red light emitted by hydrogen and sulfur. As the infant stars evaporate the surrounding cloud, they expose dense pockets of gas that may contain developing stars. One isolated pocket is seen at the center of the brightest region of the nebula. Other dense pockets of gas have formed the remarkable feature jutting inward from the left edge of the image. The color image is constructed from four separate images taken in these filters: blue, near infrared, hydrogen alpha, and doubly ionized oxygen. Credit: NASA, H. Ford (JHU), G. Illingworth (USCS/LO), M. Clampin (STScI), G. Hartig (STScI), the ACS Science Team, and ESA.

Shift schedule, work-family relationships, marital communication, job satisfaction and health among transport service shift workers.

Science.gov (United States)

Iskra-Golec, Irena; Smith, Lawrence; Wilczek-Rużyczka, Ewa; Siemiginowska, Patrycja; Wątroba, Joanna

2017-02-21

Existing research has documented that shiftwork consequences may depend on the shift system parameters. Fast rotating systems (1-3 shifts of the same kind in a row) and day work have been found to be less disruptive biologically and socially than slower rotating systems and afternoon and night work. The aim of this study was to compare day workers and shift workers of different systems in terms of rotation speed and shifts worked with regard to work-family and family-work positive and negative spillover, marital communication style, job satisfaction and health. Employees (N = 168) of the maintenance workshops of transportation service working different shift systems (day shift, weekly rotating 2 and 3‑shift system, and fast rotating 3-shift system) participated in the study. They completed the Work- Family Spillover Questionnaire, Marital Communication Questionnaire, Minnesota Job Satisfaction Questionnaire and the Physical Health Questionnaire (a part of the Standard Shiftwork Index). The workers of quicker rotating 3-shift systems reported significantly higher scores of family-to-work facilitation (F(3, 165) = 4.175, p = 0.007) and a higher level of constructive style of marital communication (Engagement F(3, 165) = 2.761, p = 0.044) than the workers of slower rotating 2-shift systems. There were no differences between the groups of workers with regard to health and job satisfaction. A higher level of work-family facilitation and a more constructive style of marital communication were found among the workers of faster rotating 3-shift system when compared to the workers of a slower rotating 2-shift system (afternoon, night). This may indicate that the fast rotating shift system in contrary to the slower rotating one is more friendly for the work and family domains and for the relationship between them. Int J Occup Med Environ Health 2017;30(1):121-131. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

Shift schedule, work–family relationships, marital communication, job satisfaction and health among transport service shift workers

Directory of Open Access Journals (Sweden)

Irena Iskra-Golec

2017-02-01

Full Text Available Objectives: Existing research has documented that shiftwork consequences may depend on the shift system parameters. Fast rotating systems (1–3 shifts of the same kind in a row and day work have been found to be less disruptive biologically and socially than slower rotating systems and afternoon and night work. The aim of this study was to compare day workers and shift workers of different systems in terms of rotation speed and shifts worked with regard to work–family and family–work positive and negative spillover, marital communication style, job satisfaction and health. Material and Methods: Employees (N = 168 of the maintenance workshops of transportation service working different shift systems (day shift, weekly rotating 2 and 3‑shift system, and fast rotating 3-shift system participated in the study. They completed the Work– Family Spillover Questionnaire, Marital Communication Questionnaire, Minnesota Job Satisfaction Questionnaire and the Physical Health Questionnaire (a part of the Standard Shiftwork Index. Results: The workers of quicker rotating 3-shift systems reported significantly higher scores of family-to-work facilitation (F(3, 165 = 4.175, p = 0.007 and a higher level of constructive style of marital communication (Engagement F(3, 165 = 2.761, p = 0.044 than the workers of slower rotating 2-shift systems. There were no differences between the groups of workers with regard to health and job satisfaction. Conclusions: A higher level of work–family facilitation and a more constructive style of marital communication were found among the workers of faster rotating 3-shift system when compared to the workers of a slower rotating 2-shift system (afternoon, night. This may indicate that the fast rotating shift system in contrary to the slower rotating one is more friendly for the work and family domains and for the relationship between them. Int J Occup Med Environ Health 2017;30(1:121–131

The universe in a mirror the saga of the Hubble Space Telescope and the visionaries who built it

CERN Document Server

Zimmerman, Robert

2008-01-01

The Hubble Space Telescope has produced the most stunning images of the cosmos humanity has ever seen. It has transformed our understanding of the universe around us, revealing new information about its age and evolution, the life cycle of stars, and the very existence of black holes, among other startling discoveries. But it took an amazing amount of work and perseverance to get the first space telescope up and running. The Universe in a Mirror tells the story of this telescope and the visionaries responsible for its extraordinary accomplishments. Robert Zimmerman takes readers beh

Real life working shift assignment problem

Science.gov (United States)

Sze, San-Nah; Kwek, Yeek-Ling; Tiong, Wei-King; Chiew, Kang-Leng

2017-07-01

This study concerns about the working shift assignment in an outlet of Supermarket X in Eastern Mall, Kuching. The working shift assignment needs to be solved at least once in every month. Current approval process of working shifts is too troublesome and time-consuming. Furthermore, the management staff cannot have an overview of manpower and working shift schedule. Thus, the aim of this study is to develop working shift assignment simulation and propose a working shift assignment solution. The main objective for this study is to fulfill manpower demand at minimum operation cost. Besides, the day off and meal break policy should be fulfilled accordingly. Demand based heuristic is proposed to assign working shift and the quality of the solution is evaluated by using the real data.

Dynamics and computation in functional shifts

Science.gov (United States)

Namikawa, Jun; Hashimoto, Takashi

2004-07-01

We introduce a new type of shift dynamics as an extended model of symbolic dynamics, and investigate the characteristics of shift spaces from the viewpoints of both dynamics and computation. This shift dynamics is called a functional shift, which is defined by a set of bi-infinite sequences of some functions on a set of symbols. To analyse the complexity of functional shifts, we measure them in terms of topological entropy, and locate their languages in the Chomsky hierarchy. Through this study, we argue that considering functional shifts from the viewpoints of both dynamics and computation gives us opposite results about the complexity of systems. We also describe a new class of shift spaces whose languages are not recursively enumerable.

VizieR Online Data Catalog: Hubble Legacy Archive ACS grism data (Kuemmel+, 2011)

Science.gov (United States)

Kuemmel, M.; Rosati, P.; Fosbury, R.; Haase, J.; Hook, R. N.; Kuntschner, H.; Lombardi, M.; Micol, A.; Nilsson, K. K.; Stoehr, F.; Walsh, J. R.

2011-09-01

A public release of slitless spectra, obtained with ACS/WFC and the G800L grism, is presented. Spectra were automatically extracted in a uniform way from 153 archival fields (or "associations") distributed across the two Galactic caps, covering all observations to 2008. The ACS G800L grism provides a wavelength range of 0.55-1.00um, with a dispersion of 40Å/pixel and a resolution of ~80Å for point-like sources. The ACS G800L images and matched direct images were reduced with an automatic pipeline that handles all steps from archive retrieval, alignment and astrometric calibration, direct image combination, catalogue generation, spectral extraction and collection of metadata. The large number of extracted spectra (73,581) demanded automatic methods for quality control and an automated classification algorithm was trained on the visual inspection of several thousand spectra. The final sample of quality controlled spectra includes 47919 datasets (65% of the total number of extracted spectra) for 32149 unique objects, with a median iAB-band magnitude of 23.7, reaching 26.5 AB for the faintest objects. Each released dataset contains science-ready 1D and 2D spectra, as well as multi-band image cutouts of corresponding sources and a useful preview page summarising the direct and slitless data, astrometric and photometric parameters. This release is part of the continuing effort to enhance the content of the Hubble Legacy Archive (HLA) with highly processed data products which significantly facilitate the scientific exploitation of the Hubble data. In order to characterize the slitless spectra, emission-line flux and equivalent width sensitivity of the ACS data were compared with public ground-based spectra in the GOODS-South field. An example list of emission line galaxies with two or more identified lines is also included, covering the redshift range 0.2-4.6. Almost all redshift determinations outside of the GOODS fields are new. The scope of science projects possible

Associations of rotational shift work and night shift status with hypertension: a systematic review and meta-analysis.

Science.gov (United States)

Manohar, Sandhya; Thongprayoon, Charat; Cheungpasitporn, Wisit; Mao, Michael A; Herrmann, Sandra M

2017-10-01

The reported risks of hypertension (HTN) in rotating shift and night shift workers are controversial. The objective of this meta-analysis was to assess the association between shift work status and HTN. A literature search was performed using MEDLINE, EMBASE and Cochrane Database from inception through October 2016. Studies that reported odds ratios (OR) comparing the risk of HTN in shift workers were included. A prespecified subgroup analysis by rotating shift and night shift statuses were also performed. Pooled OR and 95% confidence interval (CI) were calculated using a random-effect, generic inverse variance method. The protocol for this study is registered with International Prospective Register of Systematic Reviews; no. CRD42016051843. Twenty-seven observational studies (nine cohort and 18 cross-sectional studies) with a total of 394 793 individuals were enrolled. The pooled ORs of HTN in shift workers in cohort and cross-sectional studies were 1.31 (95% CI, 1.07-1.60) and 1.10 (95% CI, 1.00-1.20), respectively. When meta-analysis was restricted only to cohort studies in rotating shift, the pooled OR of HTN in rotating shift workers was 1.34 (95% CI, 1.08-1.67). The data regarding night shift and HTN in cohort studies was limited. The pooled OR of HTN in night shift workers in cross-sectional studies was 1.07 (95% CI, 0.85-1.35). Based on the findings of our meta-analysis, shiftwork status may play an important role in HTN, as there is a significant association between rotating shift work and HTN. However, there is no significant association between night shift status and risk of HTN.

Micropatch Antenna Phase Shifting

National Research Council Canada - National Science Library

Thursby, Michael

2000-01-01

.... We have been looking at the ability of embedded element to adjust the phase shift seen by the element with the goal of being able to remove the phase shifting devices from the antenna and replace...

Micropatch Antenna Phase Shifting

National Research Council Canada - National Science Library

Thursby, Michael

1999-01-01

.... We have been looking at the ability of embedded element to adjust the phase shift seen by the element wit the goal of being able to remove the phase shifting devices from the antenna and replace...

Influences on Dietary Choices during Day versus Night Shift in Shift Workers: A Mixed Methods Study.

Science.gov (United States)

Bonnell, Emily K; Huggins, Catherine E; Huggins, Chris T; McCaffrey, Tracy A; Palermo, Claire; Bonham, Maxine P

2017-02-26

Shift work is associated with diet-related chronic conditions such as obesity and cardiovascular disease. This study aimed to explore factors influencing food choice and dietary intake in shift workers. A fixed mixed method study design was undertaken on a convenience sample of firefighters who continually work a rotating roster. Six focus groups ( n = 41) were conducted to establish factors affecting dietary intake whilst at work. Dietary intake was assessed using repeated 24 h dietary recalls ( n = 19). Interviews were audio recorded, transcribed verbatim, and interpreted using thematic analysis. Dietary data were entered into FoodWorks and analysed using Wilcoxon signed-rank test; p night shift. Energy intakes (kJ/day) did not differ between days that included a day or night shift but greater energy density (ED energy , kJ/g/day) of the diet was observed on night shift compared with day shift. This study has identified a number of dietary-specific shift-related factors that may contribute to an increase in unhealthy behaviours in a shift-working population. Given the increased risk of developing chronic diseases, organisational change to support workers in this environment is warranted.

A compressed shift schedule: dealing with some of the problems of shift work

Energy Technology Data Exchange (ETDEWEB)

Cunningham, J B [Victoria University, Victoria, BC (Canada). School of Public Administration

1989-07-01

This study examines some of the psychological and behavioural effects of a 12-hour compressed shift schedule on coal miners in two organisations in Western Canada. It suggests that young, married compressed shift workers are more satisfied with their family relationship. They spend less of their leisure time with spouses when working shifts, and do not spend any more time with them on their days off. They have less time available for many leisure activities on their workdays. The extra time on days off is not reallocated to the leisure activities they were unable to do on their workdays. Some extra leisure time on days off may be spent on personal hobbies. There is no suggestion that the compressed shift schedule has any negative effect on the individual's health. 38 refs., 3 tabs.

Shift work as an oxidative stressor

OpenAIRE

Pasalar Parvin; Farahani Saeed; Sharifian Akbar; Gharavi Marjan; Aminian Omid

2005-01-01

Abstract Background Some medical disorders have higher prevalence in shift workers than others. This study was designed to evaluate the effect of night-shift-working on total plasma antioxidant capacity, with respect to the causative role of oxidative stress in induction of some of these disorders. Methods Two blood samples were taken from 44 workers with a rotational shift schedule, one after their day shift and one after their night shift. The total plasma antioxidant capacity of each worke...

Influences on Dietary Choices during Day versus Night Shift in Shift Workers: A Mixed Methods Study

Science.gov (United States)

Bonnell, Emily K.; Huggins, Catherine E.; Huggins, Chris T.; McCaffrey, Tracy A.; Palermo, Claire; Bonham, Maxine P.

2017-01-01

Shift work is associated with diet-related chronic conditions such as obesity and cardiovascular disease. This study aimed to explore factors influencing food choice and dietary intake in shift workers. A fixed mixed method study design was undertaken on a convenience sample of firefighters who continually work a rotating roster. Six focus groups (n = 41) were conducted to establish factors affecting dietary intake whilst at work. Dietary intake was assessed using repeated 24 h dietary recalls (n = 19). Interviews were audio recorded, transcribed verbatim, and interpreted using thematic analysis. Dietary data were entered into FoodWorks and analysed using Wilcoxon signed-rank test; p shift schedule; attitudes and decisions of co-workers; time and accessibility; and knowledge of the relationship between food and health. Participants reported consuming more discretionary foods and limited availability of healthy food choices on night shift. Energy intakes (kJ/day) did not differ between days that included a day or night shift but greater energy density (EDenergy, kJ/g/day) of the diet was observed on night shift compared with day shift. This study has identified a number of dietary-specific shift-related factors that may contribute to an increase in unhealthy behaviours in a shift-working population. Given the increased risk of developing chronic diseases, organisational change to support workers in this environment is warranted. PMID:28245625

Faktor Dan Penjadualan Shift Kerja

OpenAIRE

Maurits, Lientje Setyawati; Widodo, Imam Djati

2008-01-01

Work shift has negative effect in physical and mental health, work performance and job accident. Disturbance of circadian rhythms is indicated as source of the problems. This article explores some researches related to the impacts of work shift and establishes basic principles of work shift scheduling that considers human need and limitation.

Visual attention shifting in autism spectrum disorders.

Science.gov (United States)

Richard, Annette E; Lajiness-O'Neill, Renee

2015-01-01

Abnormal visual attention has been frequently observed in autism spectrum disorders (ASD). Abnormal shifting of visual attention is related to abnormal development of social cognition and has been identified as a key neuropsychological finding in ASD. Better characterizing attention shifting in ASD and its relationship with social functioning may help to identify new targets for intervention and improving social communication in these disorders. Thus, the current study investigated deficits in attention shifting in ASD as well as relationships between attention shifting and social communication in ASD and neurotypicals (NT). To investigate deficits in visual attention shifting in ASD, 20 ASD and 20 age- and gender-matched NT completed visual search (VS) and Navon tasks with attention-shifting demands as well as a set-shifting task. VS was a feature search task with targets defined in one of two dimensions; Navon required identification of a target letter presented at the global or local level. Psychomotor and processing speed were entered as covariates. Relationships between visual attention shifting, set shifting, and social functioning were also examined. ASD and NT showed comparable costs of shifting attention. However, psychomotor and processing speed were slower in ASD than in NT, and psychomotor and processing speed were positively correlated with attention-shifting costs on Navon and VS, respectively, for both groups. Attention shifting on VS and Navon were correlated among NT, while attention shifting on Navon was correlated with set shifting among ASD. Attention-shifting costs on Navon were positively correlated with restricted and repetitive behaviors among ASD. Relationships between attention shifting and psychomotor and processing speed, as well as relationships between measures of different aspects of visual attention shifting, suggest inefficient top-down influences over preattentive visual processing in ASD. Inefficient attention shifting may be

Shift work as an oxidative stressor

Directory of Open Access Journals (Sweden)

Pasalar Parvin

2005-12-01

Full Text Available Abstract Background Some medical disorders have higher prevalence in shift workers than others. This study was designed to evaluate the effect of night-shift-working on total plasma antioxidant capacity, with respect to the causative role of oxidative stress in induction of some of these disorders. Methods Two blood samples were taken from 44 workers with a rotational shift schedule, one after their day shift and one after their night shift. The total plasma antioxidant capacity of each worker was measured through the FRAP method. The impacts of age and weight were also assessed. Results The total plasma antioxidant capacity was measured in 44 shift-workers with a mean age of 36.57 years (SD: 10.18 and mean BMI of 26.06 (SD: 4.37 after their day and night shifts. The mean reduction of total plasma antioxidant capacity after the night shift was 105.8 μmol/L (SD: 146.39. Also, a significant correlation was shown between age and weight and total plasma antioxidant capacity. Age and weight were found to be inversely related to total plasma antioxidant capacity; as age and weight increased, the total plasma antioxidant capacity decreased. Conclusion Shift work can act as an oxidative stressor and may induce many medical disorders. Aging and obesity in shift workers makes them more sensitive to this hazardous effect.

Shift work-related health problems in

Directory of Open Access Journals (Sweden)

S. Khavaji

2010-04-01

Full Text Available Background and aimsShift work is a major feature of working life that affects diverse aspects of human life. The main purposes of this study were to investigate shift work-related health problems and their risk factors among workers of "12-hour shift" schedule.MethodsThis cross-sectional study was carried out at 8 petrochemical industries in Asalooyeh area. Study population consisted of 1203 workers including 549 shift worker (46% and 654 day worker (54%. Data on personal details, shift schedule and adverse effects of shift work werecollected by anonymous questionnaire. Statistical analyses were performed using SPSS, version 11.5. The level of significance was set at 5%.ResultsAlthough, the results showed that health problems among shift workers was more prevalent than day workers, but the differences were just significant in gastrointestinal and musculoskeletal disorders (p<0.05. Multiple linear regressions indicated that in addition to shift working, other variants such as long work hours, type of employment, second job, number of children and job title were associated with health problems.ConclusionPrevalence rates of gastrointestinal and musculoskeletal problems among shift workers were significantly higher than that of day workers. Although, working in shift system was the main significant factor associated with the reported problems, but other demographic andwork variables were also found to have association.

Comparison of Mental Health and Quality of Life between Shift and Non-shift Employees of Service Industries

Directory of Open Access Journals (Sweden)

Nahal Salimi

2016-12-01

Full Text Available This study examined the relationship between the employment practices and employees' mental health and quality of life in Iran. In particular, the study compared the mental health and quality of life of shift and non-shift workers in sensitive employment settings. Using a cross-sectional survey design, 120 individuals employed in two airline companies as either shift or non-shift employees completed the survey for the study. Data was collected using General Health Question (GHQ28 for mental health, the Short Form (36 Health Survey (SF-36 for Quality of Life and a demographic questionnaire. Multivariate analysis of variance (MANOVA was used to analyze the collected data. The results showed that (1 type of work (shift or non-shift has an effect on mental health and quality of life; and (2 there are significant differences in dimensions of quality of life and mental health between shift and non-shift staff.

SimShiftDB; local conformational restraints derived from chemical shift similarity searches on a large synthetic database

Energy Technology Data Exchange (ETDEWEB)

Ginzinger, Simon W. [Center of Applied Molecular Engineering, University of Salzburg, Department of Molecular Biology, Division of Bioinformatics (Austria)], E-mail: simon@came.sbg.ac.at; Coles, Murray [Max-Planck-Institute for Developmental Biology, Department of Protein Evolution (Germany)], E-mail: Murray.Coles@tuebingen.mpg.de

2009-03-15

We present SimShiftDB, a new program to extract conformational data from protein chemical shifts using structural alignments. The alignments are obtained in searches of a large database containing 13,000 structures and corresponding back-calculated chemical shifts. SimShiftDB makes use of chemical shift data to provide accurate results even in the case of low sequence similarity, and with even coverage of the conformational search space. We compare SimShiftDB to HHSearch, a state-of-the-art sequence-based search tool, and to TALOS, the current standard tool for the task. We show that for a significant fraction of the predicted similarities, SimShiftDB outperforms the other two methods. Particularly, the high coverage afforded by the larger database often allows predictions to be made for residues not involved in canonical secondary structure, where TALOS predictions are both less frequent and more error prone. Thus SimShiftDB can be seen as a complement to currently available methods.

SimShiftDB; local conformational restraints derived from chemical shift similarity searches on a large synthetic database

International Nuclear Information System (INIS)

Ginzinger, Simon W.; Coles, Murray

2009-01-01

We present SimShiftDB, a new program to extract conformational data from protein chemical shifts using structural alignments. The alignments are obtained in searches of a large database containing 13,000 structures and corresponding back-calculated chemical shifts. SimShiftDB makes use of chemical shift data to provide accurate results even in the case of low sequence similarity, and with even coverage of the conformational search space. We compare SimShiftDB to HHSearch, a state-of-the-art sequence-based search tool, and to TALOS, the current standard tool for the task. We show that for a significant fraction of the predicted similarities, SimShiftDB outperforms the other two methods. Particularly, the high coverage afforded by the larger database often allows predictions to be made for residues not involved in canonical secondary structure, where TALOS predictions are both less frequent and more error prone. Thus SimShiftDB can be seen as a complement to currently available methods

Fuzzy Determination of Target Shifting Time and Torque Control of Shifting Phase for Dry Dual Clutch Transmission

Directory of Open Access Journals (Sweden)

Zhiguo Zhao

2014-01-01

Full Text Available Based on the independently developed five-speed dry dual clutch transmission (DDCT, the paper proposes the torque coordinating control strategy between engine and two clutches, which obtains engine speed and clutch transferred torque in the shifting process, adequately reflecting the driver intention and improving the shifting quality. Five-degree-of-freedom (DOF shifting dynamics model of DDCT with single intermediate shaft is firstly established according to its physical characteristics. Then the quantitative control objectives of the shifting process are presented. The fuzzy decision of shifting time and the model-based torque coordinating control strategy are proposed and also verified by simulating under different driving intentions in up-/downshifting processes with the DCT model established on the MATLAB/Simulink. Simulation results validate that the shifting control algorithm proposed in this paper can not only meet the shifting quality requirements, but also adapt to the various shifting intentions, having a strong robustness.

HUBBLE SPACE TELESCOPE OBSERVATIONS OF MAIN-BELT COMET (596) SCHEILA

International Nuclear Information System (INIS)

Jewitt, David; Weaver, Harold; Mutchler, Max; Larson, Stephen; Agarwal, Jessica

2011-01-01

We present Hubble Space Telescope Observations of (596) Scheila during its recent dust outburst. The nucleus remained point-like with absolute magnitude H V = 8.85 ± 0.02 in our data, equal to the pre-outburst value, with no secondary fragments of diameter ≥100 m (for assumed albedos 0.04). We find a coma having a peak scattering cross section ∼2.2x10 4 km 2 , corresponding to a mass in micron-sized particles of ∼4x10 7 kg. The particles are deflected by solar radiation pressure on projected spatial scales ∼2x10 4 km, in the sunward direction, and swept from the vicinity of the nucleus on timescales of weeks. The coma fades by ∼30% between observations on UT 2010 December 27 and 2011 January 4. The observed mass loss is inconsistent with an origin either by rotational instability of the nucleus or by electrostatic ejection of regolith charged by sunlight. Dust ejection could be caused by the sudden but unexplained exposure of buried ice. However, the data are most simply explained by the impact, at ∼5 km s -1 , of a previously unknown asteroid ∼35 m in diameter.

Hubble Space Telescope Imaging and Spectral Analysis of Two Brown Dwarf Binaries at the L Dwarf/T Dwarf Transition

OpenAIRE

Burgasser, Adam J.; Gagliuffi, Daniella C. Bardalez; Gizis, John E.

2010-01-01

We present a detailed examination of the brown dwarf multiples 2MASS J08503593+1057156 and 2MASS J17281150+3948593, both suspected of harboring components that straddle the L dwarf/T dwarf transition. Resolved photometry from Hubble Space Telescope/NICMOS show opposite trends in the relative colors of the components, with the secondary of 2MASS J0850+1057 being redder than its primary, while that of 2MASS J1728+3948 is bluer. We determine near-infrared component types by matching combined-lig...

Individual vulnerability to insomnia, excessive sleepiness and shift work disorder amongst healthcare shift workers. A systematic review.

Science.gov (United States)

Booker, Lauren A; Magee, Michelle; Rajaratnam, Shantha M W; Sletten, Tracey L; Howard, Mark E

2018-03-27

Shift workers often experience reduced sleep quality, duration and/or excessive sleepiness due to the imposed conflict between work and their circadian system. About 20-30% of shift workers experience prominent insomnia symptoms and excessive daytime sleepiness consistent with the circadian rhythm sleep disorder known as shift work disorder. Individual factors may influence this vulnerability to shift work disorder or sleep-related impairment associated with shift work. This paper was registered with Prospero and was conducted using recommended standards for systematic reviews and meta-analyses. Published literature that measured sleep-related impairment associated with shift work including reduced sleep quality and duration and increased daytime sleepiness amongst healthcare shift workers and explored characteristics associated with individual variability were reviewed. Fifty-eight studies were included. Older age, morning-type, circadian flexibility, being married or having children, increased caffeine intake, higher scores on neuroticism and lower on hardiness were related to a higher risk of sleep-related impairment in response to shift work, whereas physical activity was a protective factor. The review highlights the diverse range of measurement tools used to evaluate the impact of shift work on sleep. Use of standardised and validated tools would enable cross-study comparisons. Longitudinal studies are required to establish causal relationships between individual factors and the development of shift work disorder. Copyright © 2018 Elsevier Ltd. All rights reserved.

Homogeneous bilateral block shifts

Indian Academy of Sciences (India)

Douglas class were classified in [3]; they are unilateral block shifts of arbitrary block size (i.e. dim H(n) can be anything). However, no examples of irreducible homogeneous bilateral block shifts of block size larger than 1 were known until now.

Quantized beam shifts in graphene

Energy Technology Data Exchange (ETDEWEB)

de Melo Kort-Kamp, Wilton Junior [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sinitsyn, Nikolai [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dalvit, Diego Alejandro Roberto [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2015-10-08

We predict the existence of quantized Imbert-Fedorov, Goos-Hanchen, and photonic spin Hall shifts for light beams impinging on a graphene-on-substrate system in an external magnetic field. In the quantum Hall regime the Imbert-Fedorov and photonic spin Hall shifts are quantized in integer multiples of the fine structure constant α, while the Goos-Hanchen ones in multiples of α². We investigate the influence on these shifts of magnetic field, temperature, and material dispersion and dissipation. An experimental demonstration of quantized beam shifts could be achieved at terahertz frequencies for moderate values of the magnetic field.

Space Telescope and Optical Reverberation Mapping Project.I. Ultraviolet Observations of the Seyfert 1 Galaxy NGC 5548 with the Cosmic Origins Spectrograph on Hubble Space Telescope

NARCIS (Netherlands)

De Rosa, G.; Peterson, B.M.; Ely, J.; Kriss, G.A.; Crenshaw, D.M.; Horne, K.; Korista, K.T.; Netzer, H.; Pogge, R.W.; Arévalo, P.; Barth, A.J.; Bentz, M.C.; Brandt, W.N.; Breeveld, A.A.; Brewer, B.J.; Dalla Bontà, E.; De Lorenzo-Cáceres, A.; Denney, K.D.; Dietrich, M.; Edelson, R.; Evans, P.A.; Fausnaugh, M.M.; Gehrels, N.; Gelbord, J.M.; Goad, M.R.; Grier, C.J.; Grupe, D.; Hall, P.B.; Kaastra, J.; Kelly, B.C.; Kennea, J.A.; Kochanek, C.S.; Lira, P.; Mathur, S.; McHardy, I.M.; Nousek, J.A.; Pancoast, A.; Papadakis, I.; Pei, L.; Schimoia, J.S.; Siegel, M.; Starkey, D.; Treu, T.; Uttley, P.; Vaughan, S.; Vestergaard, M.; Villforth, C.; Yan, H.; Young, S.; Zu, Y.

2015-01-01

We describe the first results from a six-month long reverberation-mapping experiment in the ultraviolet based on 171 observations of the Seyfert 1 galaxy NGC 5548 with the Cosmic Origins Spectrograph on the Hubble Space Telescope. Significant correlated variability is found in the continuum and

Fluid Shifts

Science.gov (United States)

Stenger, M. B.; Hargens, A. R.; Dulchavsky, S. A.; Arbeille, P.; Danielson, R. W.; Ebert, D. J.; Garcia, K. M.; Johnston, S. L.; Laurie, S. S.; Lee, S. M. C.;

Isotope shifting capacity of rock

International Nuclear Information System (INIS)

Blattner, P.; Department of Scientific and Industrial Research, Lower Hutt

1980-01-01

Any oxygen isotope shifted rock volume exactly defines a past throughput of water. An expression is derived that relates the throughput of an open system to the isotope shift of reservoir rock and present-day output. The small isotope shift of Ngawha reservoir rock and the small, high delta oxygen-18 output are best accounted for by a magmatic water source

PROBING VERY BRIGHT END OF GALAXY LUMINOSITY FUNCTION AT z ∼> 7 USING HUBBLE SPACE TELESCOPE PURE PARALLEL OBSERVATIONS

International Nuclear Information System (INIS)

Yan Haojing; Yan Lin; Zamojski, Michel A.; Windhorst, Rogier A.; McCarthy, Patrick J.; Fan Xiaohui; Dave, Romeel; Roettgering, Huub J. A.; Koekemoer, Anton M.; Robertson, Brant E.; Cai Zheng

2011-01-01

We report the first results from the Hubble Infrared Pure Parallel Imaging Extragalactic Survey, which utilizes the pure parallel orbits of the Hubble Space Telescope to do deep imaging along a large number of random sightlines. To date, our analysis includes 26 widely separated fields observed by the Wide Field Camera 3, which amounts to 122.8 arcmin 2 in total area. We have found three bright Y 098 -dropouts, which are candidate galaxies at z ∼> 7.4. One of these objects shows an indication of peculiar variability and its nature is uncertain. The other two objects are among the brightest candidate galaxies at these redshifts known to date (L>2L*). Such very luminous objects could be the progenitors of the high-mass Lyman break galaxies observed at lower redshifts (up to z ∼ 5). While our sample is still limited in size, it is much less subject to the uncertainty caused by 'cosmic variance' than other samples because it is derived using fields along many random sightlines. We find that the existence of the brightest candidate at z ∼ 7.4 is not well explained by the current luminosity function (LF) estimates at z ∼ 8. However, its inferred surface density could be explained by the prediction from the LFs at z ∼ 7 if it belongs to the high-redshift tail of the galaxy population at z ∼ 7.

Sleep and satisfaction in 8- and 12-h forward-rotating shift systems: Industrial employees prefer 12-h shifts.

Science.gov (United States)

Karhula, Kati; Härmä, Mikko; Ropponen, Annina; Hakola, Tarja; Sallinen, Mikael; Puttonen, Sampsa

2016-01-01

Twelve-hour shift systems have become more popular in industry. Survey data of shift length, shift rotation speed, self-rated sleep, satisfaction and perceived health were investigated for the associations among 599 predominantly male Finnish industrial employees. The studied forward-rotating shift systems were 12-h fast (12fast, DDNN------, n = 268), 8-h fast (8fast, MMEENN----, n = 161) and 8-h slow (8slow, MMMM-EEEE-NNNN, n = 170). Satisfaction with shift system differed between the groups (p effects on sleep and alertness were rare (8%) in the 12fast group (53% 8fast, 66% 8 slow, p effects of the current shift system on general health (12fast 4%, 8fast 30%, 8slow 41%, p work-life balance (12fast 8%, 8fast 52%, 8slow 63%, p effects of shift work were dependent on both shift length and shift rotation speed: employees in the 12-h rapidly forward-rotating shift system were most satisfied, perceived better work-life balance and slept better than the employees in the 8fast or especially the employees in the 8-h slowly rotating systems.

Tempo of Diversification of Global Amphibians: One-Constant Rate, One-Continuous Shift or Multiple-Discrete Shifts?

Directory of Open Access Journals (Sweden)

Youhua Chen

2014-01-01

Full Text Available In this brief report, alternative time-varying diversification rate models were fitted onto the phylogeny of global amphibians by considering one-constant-rate (OCR, one-continuous-shift (OCS and multiplediscrete- shifts (MDS situations. The OCS diversification model was rejected by γ statistic (γ=-5.556, p⁄ 0.001, implying the existence of shifting diversification rates for global amphibian phylogeny. Through model selection, MDS diversification model outperformed OCS and OCR models using “laser” package under R environment. Moreover, MDS models, implemented using another R package “MEDUSA”, indicated that there were sixteen shifts over the internal nodes for amphibian phylogeny. Conclusively, both OCS and MDS models are recommended to compare so as to better quantify rate-shifting trends of species diversification. MDS diversification models should be preferential for large phylogenies using “MEDUSA” package in which any arbitrary numbers of shifts are allowed to model.

Phenological shifts conserve thermal niches in North American birds and reshape expectations for climate-driven range shifts.

Science.gov (United States)

Socolar, Jacob B; Epanchin, Peter N; Beissinger, Steven R; Tingley, Morgan W

2017-12-05

Species respond to climate change in two dominant ways: range shifts in latitude or elevation and phenological shifts of life-history events. Range shifts are widely viewed as the principal mechanism for thermal niche tracking, and phenological shifts in birds and other consumers are widely understood as the principal mechanism for tracking temporal peaks in biotic resources. However, phenological and range shifts each present simultaneous opportunities for temperature and resource tracking, although the possible role for phenological shifts in thermal niche tracking has been widely overlooked. Using a canonical dataset of Californian bird surveys and a detectability-based approach for quantifying phenological signal, we show that Californian bird communities advanced their breeding phenology by 5-12 d over the last century. This phenological shift might track shifting resource peaks, but it also reduces average temperatures during nesting by over 1 °C, approximately the same magnitude that average temperatures have warmed over the same period. We further show that early-summer temperature anomalies are correlated with nest success in a continental-scale database of bird nests, suggesting avian thermal niches might be broadly limited by temperatures during nesting. These findings outline an adaptation surface where geographic range and breeding phenology respond jointly to constraints imposed by temperature and resource phenology. By stabilizing temperatures during nesting, phenological shifts might mitigate the need for range shifts. Global change ecology will benefit from further exploring phenological adjustment as a potential mechanism for thermal niche tracking and vice versa.

Thermally Induced Vibrations of the Hubble Space Telescope's Solar Array 3 in a Test Simulated Space Environment

Science.gov (United States)

Early, Derrick A.; Haile, William B.; Turczyn, Mark T.; Griffin, Thomas J. (Technical Monitor)

2001-01-01

NASA Goddard Space Flight Center and the European Space Agency (ESA) conducted a disturbance verification test on a flight Solar Array 3 (SA3) for the Hubble Space Telescope using the ESA Large Space Simulator (LSS) in Noordwijk, the Netherlands. The LSS cyclically illuminated the SA3 to simulate orbital temperature changes in a vacuum environment. Data acquisition systems measured signals from force transducers and accelerometers resulting from thermally induced vibrations of the SAI The LSS with its seismic mass boundary provided an excellent background environment for this test. This paper discusses the analysis performed on the measured transient SA3 responses and provides a summary of the results.

Cosmological red shift in the Seeliger-Einstein stationary Universe

International Nuclear Information System (INIS)

Kropotkin, P.N.

1988-01-01

A problem of Seeliger-Einstein stationary Universe is considered. Simple empirical relations between cosmological and physical constants to which attention was paid by Stanukovich K., Dikke R., Dirac P. testify to the supposition on stationary Universe. The Universe expansion being absent, a hypothesis of ''photon aging'' suggested in 1929 by Belopolskij A. and Zwicky F. must be accepted for explanation of Hubble effect. It is stated that abandon the Seeliger-Einstein stationary cosmological model would be premature. Study and comparison of different mechanisms suggested for validation of photon aging hypothesis is necessary

[Burden and health effects of shift work].

Science.gov (United States)

Heitmann, Jörg

2010-10-01

In Germany aprox. 15% of all employees have irregular or flexible working hours. Disturbed sleep and/or hypersomnia are direct consequences of shift work and therefore described as shift work disorder. Beyond this, shift work can also be associated with specific pathological disorders. There are individual differences in tolerance to shift work. Optimization of both shift schedules and sleep to "non-physiological" times of the day are measures to counteract the negative effects of shift work. There is still not enough evidence to recommend drugs for routine use in shift workers. © Georg Thieme Verlag Stuttgart · New York.

Bayesian `hyper-parameters' approach to joint estimation: the Hubble constant from CMB measurements

Science.gov (United States)

Lahav, O.; Bridle, S. L.; Hobson, M. P.; Lasenby, A. N.; Sodré, L.

2000-07-01

Recently several studies have jointly analysed data from different cosmological probes with the motivation of estimating cosmological parameters. Here we generalize this procedure to allow freedom in the relative weights of various probes. This is done by including in the joint χ2 function a set of `hyper-parameters', which are dealt with using Bayesian considerations. The resulting algorithm, which assumes uniform priors on the log of the hyper-parameters, is very simple: instead of minimizing \\sum \\chi_j2 (where \\chi_j2 is per data set j) we propose to minimize \\sum Nj (\\chi_j2) (where Nj is the number of data points per data set j). We illustrate the method by estimating the Hubble constant H0 from different sets of recent cosmic microwave background (CMB) experiments (including Saskatoon, Python V, MSAM1, TOCO and Boomerang). The approach can be generalized for combinations of cosmic probes, and for other priors on the hyper-parameters.

Theoretical colours and isochrones for some Hubble Space Telescope colour systems. II

Science.gov (United States)

Paltoglou, G.; Bell, R. A.

1991-01-01

A grid of synthetic surface brightness magnitudes for 14 bandpasses of the Hubble Space Telescope Faint Object Camera is presented, as well as a grid of UBV, uvby, and Faint Object Camera surface brightness magnitudes derived from the Gunn-Stryker spectrophotometric atlas. The synthetic colors are used to examine the transformations between the ground-based Johnson UBV and Stromgren uvby systems and the Faint Object Camera UBV and uvby. Two new four-color systems, similar to the Stromgren system, are proposed for the determination of abundance, temperature, and surface gravity. The synthetic colors are also used to calculate color-magnitude isochrones from the list of theoretical tracks provided by VandenBerg and Bell (1990). It is shown that by using the appropriate filters it is possible to minimize the dependence of this color difference on metallicity. The effects of interstellar reddening on various Faint Object Camera colors are analyzed as well as the observational requirements for obtaining data of a given signal-to-noise for each of the 14 bandpasses.

Shifted Independent Component Analysis

DEFF Research Database (Denmark)

Mørup, Morten; Madsen, Kristoffer Hougaard; Hansen, Lars Kai

2007-01-01

Delayed mixing is a problem of theoretical interest and practical importance, e.g., in speech processing, bio-medical signal analysis and financial data modelling. Most previous analyses have been based on models with integer shifts, i.e., shifts by a number of samples, and have often been carried...

The impact of shift work on the psychological and physical health of nurses in a general hospital: a comparison between rotating night shifts and day shifts.

Science.gov (United States)

Ferri, Paola; Guadi, Matteo; Marcheselli, Luigi; Balduzzi, Sara; Magnani, Daniela; Di Lorenzo, Rosaria

2016-01-01

Shift work is considered necessary to ensure continuity of care in hospitals and residential facilities. In particular, the night shift is one of the most frequent reasons for the disruption of circadian rhythms, causing significant alterations of sleep and biological functions that can affect physical and psychological well-being and negatively impact work performance. The aim of this study was to highlight if shift work with nights, as compared with day work only, is associated with risk factors predisposing nurses to poorer health conditions and lower job satisfaction. This cross-sectional study was conducted from June 1, 2015 to July 31, 2015 in 17 wards of a general hospital and a residential facility of a northern Italian city. This study involved 213 nurses working in rotating night shifts and 65 in day shifts. The instrument used for data collection was the "Standard Shift Work Index," validated in Italian. Data were statistically analyzed. The response rate was 86%. The nurses engaged in rotating night shifts were statistically significantly younger, more frequently single, and had Bachelors and Masters degrees in nursing. They reported the lowest mean score in the items of job satisfaction, quality and quantity of sleep, with more frequent chronic fatigue, psychological, and cardiovascular symptoms in comparison with the day shift workers, in a statistically significant way. Our results suggest that nurses with rotating night schedule need special attention due to the higher risk for both job dissatisfaction and undesirable health effects.

Dynamical 3-Space: Supernovae and the Hubble Expansion — the Older Universe without Dark Energy

Directory of Open Access Journals (Sweden)

Cahill R. T.

2007-10-01

Full Text Available We apply the new dynamics of 3-space to cosmology by deriving a Hubble expansion solution. This dynamics involves two constants; G and — the fine structure constant. This solution gives an excellent parameter-free fit to the recent supernova and gamma- ray burst redshift data without the need for “dark energy” or “dark matter”. The data and theory together imply an older age for the universe of some 14.7Gyrs. The 3-space dynamics has explained the bore hole anomaly, spiral galaxy flat rotation speeds, the masses of black holes in spherical galaxies, gravitational light bending and lensing, all without invoking “dark matter” or “dark energy”. These developments imply that a new understanding of the universe is now available.

THE CARNEGIE HUBBLE PROGRAM: THE LEAVITT LAW AT 3.6 μm AND 4.5 μm IN THE LARGE MAGELLANIC CLOUD

International Nuclear Information System (INIS)

Scowcroft, Victoria; Freedman, Wendy L.; Madore, Barry F.; Monson, Andrew J.; Persson, S. E.; Seibert, Mark; Rigby, Jane R.; Sturch, Laura

2011-01-01

The Carnegie Hubble Program is designed to improve the extragalactic distance scale using data from the post-cryogenic era of Spitzer. The ultimate goal is a determination of the Hubble constant to an accuracy of 2%. This paper is the first in a series on the Cepheid population of the Large Magellanic Cloud, and focusses on the period-luminosity (PL) relations (Leavitt laws) that will be used, in conjunction with observations of Milky Way Cepheids, to set the slope and zero point of the Cepheid distance scale in the mid-infrared. To this end, we have obtained uniformly sampled light curves for 85 LMC Cepheids, having periods between 6 and 140 days. PL and period-color relations are presented in the 3.6 μm and 4.5 μm bands. We demonstrate that the 3.6 μm band is a superb distance indicator. The cyclical variation of the [3.6]–[4.5] color has been measured for the first time. We attribute the amplitude and phase of the color curves to the dissociation and recombination of CO molecules in the Cepheid's atmosphere. The CO affects only the 4.5 μm flux making it a potential metallicity indicator.

Cα chemical shift tensors in helical peptides by dipolar-modulated chemical shift recoupling NMR

International Nuclear Information System (INIS)

Yao Xiaolan; Yamaguchi, Satoru; Hong Mei

2002-01-01

The Cα chemical shift tensors of proteins contain information on the backbone conformation. We have determined the magnitude and orientation of the Cα chemical shift tensors of two peptides with α-helical torsion angles: the Ala residue in G*AL (φ=-65.7 deg., ψ=-40 deg.), and the Val residue in GG*V (φ=-81.5 deg., ψ=-50.7 deg.). The magnitude of the tensors was determined from quasi-static powder patterns recoupled under magic-angle spinning, while the orientation of the tensors was extracted from Cα-Hα and Cα-N dipolar modulated powder patterns. The helical Ala Cα chemical shift tensor has a span of 36 ppm and an asymmetry parameter of 0.89. Its σ 11 axis is 116 deg. ± 5 deg. from the Cα-Hα bond while the σ 22 axis is 40 deg. ± 5 deg. from the Cα-N bond. The Val tensor has an anisotropic span of 25 ppm and an asymmetry parameter of 0.33, both much smaller than the values for β-sheet Val found recently (Yao and Hong, 2002). The Val σ 33 axis is tilted by 115 deg. ± 5 deg. from the Cα-Hα bond and 98 deg. ± 5 deg. from the Cα-N bond. These represent the first completely experimentally determined Cα chemical shift tensors of helical peptides. Using an icosahedral representation, we compared the experimental chemical shift tensors with quantum chemical calculations and found overall good agreement. These solid-state chemical shift tensors confirm the observation from cross-correlated relaxation experiments that the projection of the Cα chemical shift tensor onto the Cα-Hα bond is much smaller in α-helices than in β-sheets

Isochrone Fitting of Hubble Photometry in UV–VIS–IR Bands

Science.gov (United States)

Barker, Hallie; Paust, Nathaniel E. Q.

2018-03-01

We present new isochrone fits to color–magnitude diagrams from Hubble Space Telescope Wide Field Camera 3 and Advanced Camera for Surveys photometry of the globular clusters M13 and M80 in five bands from the ultraviolet to near-infrared. Isochrone fits to the photometry using the Dartmouth Stellar Evolution Program (DSEP), the PAdova and TRieste Stellar Evolution Code (PARSEC), and MESA Isochrones and Stellar Tracks (MIST) are examined to study the isochrone morphology. Additionally, cluster ages, extinctions, and distances are found from the visible-infrared color–magnitude diagrams. We conduct careful qualitative analysis on the inconsistencies of the fits across twelve color combinations of the five observed bands, and find that the (F606W‑F814W) color generally produces very good fits, but that there are large discrepancies when the data is fit using colors including UV bands for all three models. We also find that the best fits in the UV are achieved using MIST isochrones, but that they require metallicities that are lower than the other two models, as well published spectroscopic values. Finally, we directly compare DSEP and PARSEC by performing isochrone-isochrone fitting, and find that, for globular cluster aged populations, similar appearing PARSEC isochrones are on average 1.5 Gyr younger than DSEP isochrones. We find that the two models become less discrepant at lower metallicities.

Methodological aspects of shift-work research.

Science.gov (United States)

Knutsson, Anders

2004-01-01

A major issue in shift-work research is to understand the possible ways in which shift work can impact performance and health. Nearly all body functions, from those of the cellular level to those of the entire body, are circadian rhythmic. Disturbances of these rhythms as well as the social consequences of odd work hours are of importance for the health and well-being of shift workers. This article reviews a number of common methodological issues which are of relevance to epidemiological studies in this area of research. It discusses conceptual problems regarding the use of the term "shift work," and it underscores the need to develop models that explain the mechanisms of disease in shift workers.

Variability search in M 31 using principal component analysis and the Hubble Source Catalogue

Science.gov (United States)

Moretti, M. I.; Hatzidimitriou, D.; Karampelas, A.; Sokolovsky, K. V.; Bonanos, A. Z.; Gavras, P.; Yang, M.

2018-06-01

Principal component analysis (PCA) is being extensively used in Astronomy but not yet exhaustively exploited for variability search. The aim of this work is to investigate the effectiveness of using the PCA as a method to search for variable stars in large photometric data sets. We apply PCA to variability indices computed for light curves of 18 152 stars in three fields in M 31 extracted from the Hubble Source Catalogue. The projection of the data into the principal components is used as a stellar variability detection and classification tool, capable of distinguishing between RR Lyrae stars, long-period variables (LPVs) and non-variables. This projection recovered more than 90 per cent of the known variables and revealed 38 previously unknown variable stars (about 30 per cent more), all LPVs except for one object of uncertain variability type. We conclude that this methodology can indeed successfully identify candidate variable stars.

SAT in shift manager training

International Nuclear Information System (INIS)

Lecuyer, F.

1995-01-01

EDF has improved the organization of the operation shift teams with the replacement of shift supervisor in shift manager function. The shift manager is not only responsible for tasks associated to plant operation (production), but he is also responsible for safety of these tasks and for management of shift team members. A job analysis of this new job position has been performed in order to design the training programme. It resulted in a 10-month training programme that includes 8 weeks in safety-related topics and 12 weeks in soft-skills related topics. The safety related training courses are mandatory, the other courses are optional courses depending on individual trainee needs. The training also includes the development of management competencies. During the 10 month period, each trainee develops an individual project that is evaluated by NPP manager. As well, as group project is undertaken by the trainees and overseen by a steering committee. The steering committee participates in the evaluation process and provides operational experience feedback to the trainee groups and to the overall programme

Individual differences in shift work tolerance

NARCIS (Netherlands)

Lammers-van der Holst, H.M.

2016-01-01

Shift work is a key feature of our contemporary 24/7 society, employing several successive work teams to sustain around-the-clock operations. However, numerous studies imply that frequently shifting the periods of sleep and wakefulness poses a serious threat to the shift worker’s physical, mental

Emission-Line Galaxies from the PEARS Hubble Ultra Deep Field: A 2-D Detection Method and First Results

Science.gov (United States)

Gardner, J. P.; Straughn, Amber N.; Meurer, Gerhardt R.; Pirzkal, Norbert; Cohen, Seth H.; Malhotra, Sangeeta; Rhoads, james; Windhorst, Rogier A.; Gardner, Jonathan P.; Hathi, Nimish P.;

The UDF05 Follow-up of the Hubble Ultra Deep Field. III. The Luminosity Function at z ~ 6

Science.gov (United States)

Su, Jian; Stiavelli, Massimo; Oesch, Pascal; Trenti, Michele; Bergeron, Eddie; Bradley, Larry; Carollo, Marcella; Dahlen, Tomas; Ferguson, Henry C.; Giavalisco, Mauro; Koekemoer, Anton; Lilly, Simon; Lucas, Ray A.; Mobasher, Bahram; Panagia, Nino; Pavlovsky, Cheryl

2011-09-01

In this paper, we present a derivation of the rest-frame 1400 Å luminosity function (LF) at redshift six from a new application of the maximum likelihood method by exploring the five deepest Hubble Space Telescope/Advanced Camera for Surveys (HST/ACS) fields, i.e., the Hubble Ultra Deep Field, two UDF05 fields, and two Great Observatories Origins Deep Survey fields. We work on the latest improved data products, which makes our results more robust than those of previous studies. We use unbinned data and thereby make optimal use of the information contained in the data set. We focus on the analysis to a magnitude limit where the completeness is larger than 50% to avoid possibly large errors in the faint end slope that are difficult to quantify. We also take into account scattering in and out of the dropout sample due to photometric errors by defining for each object a probability that it belongs to the dropout sample. We find the best-fit Schechter parameters to the z ~ 6 LF are α = 1.87 ± 0.14, M * = -20.25 ± 0.23, and phi* = 1.77+0.62 -0.49 × 10-3 Mpc-3. Such a steep slope suggests that galaxies, especially the faint ones, are possibly the main sources of ionizing photons in the universe at redshift six. We also combine results from all studies at z ~ 6 to reach an agreement in the 95% confidence level that -20.45 Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program 10632 and 11563.

Are Ultra-faint Galaxies at z = 6-8 Responsible for Cosmic Reionization? Combined Constraints from the Hubble Frontier Fields Clusters and Parallels

Science.gov (United States)

Atek, Hakim; Richard, Johan; Jauzac, Mathilde; Kneib, Jean-Paul; Natarajan, Priyamvada; Limousin, Marceau; Schaerer, Daniel; Jullo, Eric; Ebeling, Harald; Egami, Eiichi; Clement, Benjamin

2015-11-01

We use deep Hubble Space Telescope imaging of the Frontier Fields to accurately measure the galaxy rest-frame ultraviolet luminosity function (UV LF) in the redshift range z ˜ 6-8. We combine observations in three lensing clusters, A2744, MACS 0416, and MACS 0717, and their associated parallel fields to select high-redshift dropout candidates. We use the latest lensing models to estimate the flux magnification and the effective survey volume in combination with completeness simulations performed in the source plane. We report the detection of 227 galaxy candidates at z = 6-7 and 25 candidates at z ˜ 8. While the total survey area is about 4 arcmin2 in each parallel field, it drops to about 0.6-1 arcmin2 in the cluster core fields because of the strong lensing. We compute the UV LF at z ˜ 7 using the combined galaxy sample and perform Monte Carlo simulations to determine the best-fit Schechter parameters. We are able to reliably constrain the LF down to an absolute magnitude of MUV = -15.25, which corresponds to 0.005 L⋆. More importantly, we find that the faint-end slope remains steep down to this magnitude limit with α =-{2.04}-0.17+0.13. We find a characteristic magnitude of {M}\\star =-{20.89}-0.72+0.60 and log(ϕ⋆) = -{3.54}-0.45+0.48. Our results confirm the most recent results in deep blank fields but extend the LF measurements more than two magnitudes deeper. The UV LF at z ˜ 8 is not very well constrained below MUV = -18 owing to the small number statistics and incompleteness uncertainties. To assess the contribution of galaxies to cosmic reionization, we derive the UV luminosity density at z ˜ 7 by integrating the UV LF down to an observational limit of MUV = -15. We show that our determination of log(ρUV) = 26.2 ± 0.13 (erg s-1 Hz-1 Mpc-3) can be sufficient to maintain reionization with an escape fraction of ionizing radiation of fesc = 10%-15%. Future Hubble Frontier Fields observations will certainly improve the constraints on the UV LF at

A Hubble Space Telescope Survey of the Disk Cluster Population of M31. II. Advanced Camera for Surveys Pointings

Science.gov (United States)

Krienke, O. K.; Hodge, P. W.

2008-01-01

This paper reports on a survey of star clusters in M31 based on archival images from the Hubble Space Telescope. Paper I reported results from images obtained with the Wide Field Planetary Camera 2 (WFPC2) and this paper reports results from the Advanced Camera for Surveys (ACS). The ACS survey has yielded a total of 339 star clusters, 52 of which—mostly globular clusters—were found to have been cataloged previously. As for the previous survey, the luminosity function of the clusters drops steeply for absolute magnitudes fainter than MV = -3 the implied cluster mass function has a turnover for masses less than a few hundred solar masses. The color-integrated magnitude diagram of clusters shows three significant features: (1) a group of very red, luminous objects: the globular clusters, (2) a wide range in color for the fainter clusters, representing a considerable range in age and reddening, and (3) a maximum density of clusters centered approximately at V = 21, B - V = 0.30, V - I = 0.50, where there are intermediate-age, intermediate-mass clusters with ages close to 500 million years and masses of about 2000 solar masses. We give a brief qualitative interpretation of the distribution of clusters in the CMDs in terms of their formation and destruction rates. Based on observations with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for research in astronomy, Inc., under NASA contract NAS 5-26555.

An analysis of clock-shift experiments: is scatter increased and deflection reduced in clock-shifted homing pigeons?

Science.gov (United States)

Chappell

1997-01-01

Clock-shifting (altering the phase of the internal clock) in homing pigeons leads to a deflection in the vanishing bearing of the clock-shifted group relative to controls. However, two unexplained phenomena are common in clock-shift experiments: the vanishing bearings of the clock-shifted group are often more scattered (with a shorter vector length) than those of the control group, and the deflection of the mean bearing of the clock-shifted group from that of the controls is often smaller than expected theoretically. Here, an analysis of 55 clock-shift experiments performed in four countries over 21 years is reported. The bearings of the clock-shifted groups were significantly more scattered than those of controls and less deflected than expected, but these effects were not significantly different at familiar and unfamiliar sites. The possible causes of the effects are discussed and evaluated with reference to this analysis and other experiments. The most likely causes appear to be conflict between the directions indicated by the sun compass and either unshifted familiar visual landmarks (at familiar sites only) or the unshifted magnetic compass (possible at both familiar and unfamiliar sites).

Examining paid sickness absence by shift workers.

Science.gov (United States)

Catano, V M; Bissonnette, A B

2014-06-01

Shift workers are at greater risk than day workers with respect to psychological and physical health, yet little research has linked shift work to increased sickness absence. To investigate the relationship between shift work and sickness absence while controlling for organizational and individual characteristics and shift work attributes that have confounded previous research. The study used archive data collected from three national surveys in Canada, each involving over 20000 employees and 6000 private-sector firms in 14 different occupational groups. The employees reported the number of paid sickness absence days in the past 12 months. Data were analysed using both chi-squared statistics and hierarchical regressions. Contrary to previous research, shift workers took less paid sickness absence than day workers. There were no differences in the length of the sickness absence between both groups or in sickness absence taken by female and male workers whether working days or shifts. Only job tenure, the presence of a union in the workplace and working rotating shifts predicted sickness absence in shift workers. The results were consistent across all three samples. In general, shift work does not seem to be linked to increased sickness absence. However, such associations may be true for specific industries. Male and female workers did not differ in the amount of sickness absence taken. Rotating shifts, regardless of industry, predicted sickness absence among shift workers. Consideration should be given to implementing scheduled time off between shift changes. © The Author 2014. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

HUBBLE SPACE TELESCOPE ASTROMETRY OF THE PROCYON SYSTEM

Energy Technology Data Exchange (ETDEWEB)

Bond, Howard E. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Gilliland, Ronald L.; Kozhurina-Platais, Vera; Nelan, Edmund P. [Space Telescope Science Institute, 3700 San Martin Dr., Baltimore, MD 21218 (United States); Schaefer, Gail H. [The CHARA Array of Georgia State University, Mount Wilson Observatory, Mount Wilson, CA 91023 (United States); Demarque, Pierre; Girard, Terrence M. [Department of Astronomy, Yale University, Box 208101, New Haven, CT 06520 (United States); Holberg, Jay B. [Lunar and Planetary Laboratory, University of Arizona, 1541 E. University Blvd., Tucson, AZ 85721 (United States); Gudehus, Donald [Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30303 (United States); Mason, Brian D. [U.S. Naval Observatory, 3450 Massachusetts Ave., Washington, DC 20392 (United States); Burleigh, Matthew R.; Barstow, Martin A., E-mail: heb11@psu.edu [Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH (United Kingdom)

2015-11-10

The nearby star Procyon is a visual binary containing the F5 IV-V subgiant Procyon A, orbited in a 40.84-year period by the faint DQZ white dwarf (WD) Procyon B. Using images obtained over two decades with the Hubble Space Telescope, and historical measurements back to the 19th century, we have determined precise orbital elements. Combined with measurements of the parallax and the motion of the A component, these elements yield dynamical masses of 1.478 ± 0.012 M{sub ⊙} and 0.592 ± 0.006 M{sub ⊙} for A and B, respectively. The mass of Procyon A agrees well with theoretical predictions based on asteroseismology and its temperature and luminosity. Use of a standard core-overshoot model agrees best for a surprisingly high amount of core overshoot. Under these modeling assumptions, Procyon A’s age is ∼2.7 Gyr. Procyon B’s location in the H-R diagram is in excellent agreement with theoretical cooling tracks for WDs of its dynamical mass. Its position in the mass–radius plane is also consistent with theory, assuming a carbon–oxygen core and a helium-dominated atmosphere. Its progenitor’s mass was 1.9–2.2 M{sub ⊙}, depending on its amount of core overshoot. Several astrophysical puzzles remain. In the progenitor system, the stars at periastron were separated by only ∼5 AU, which might have led to tidal interactions and even mass transfer; yet there is no direct evidence that these have occurred. Moreover the orbital eccentricity has remained high (∼0.40). The mass of Procyon B is somewhat lower than anticipated from the initial-to-final-mass relation seen in open clusters. The presence of heavy elements in its atmosphere requires ongoing accretion, but the place of origin is uncertain.

Hubble Space Telescope Image, Supernova Remnant Cassiopeia A

Science.gov (United States)

2000-01-01

The colorful streamers that float across the sky in this photo taken by NASA's Hubble Space Telescope (HST) were created by the universe's biggest firecracker, the titanic supernova explosion of a massive star. The light from the exploding star reached Earth 320 years ago, nearly a century before the United States celebrated its birth with a bang. The dead star's shredded remains are called Cassiopeia A, or 'Cas A' for short. Cas A is the youngest known supernova remnant in our Milky Way Galaxy and resides 10,000 light-years away in the constellation Cassiopeia, so the star actually blew up 10,000 years before the light reached Earth in the late 1600s. This HST image of Cas A shows for the first time that the debris is arranged into thousands of small, cooling knots of gas. This material eventually will be recycled into building new generations of stars and planets. Our own Sun and planets are constructed from the debris of supernovae that exploded billions of years ago. This photo shows the upper rim of the super nova remnant's expanding shell. Near the top of the image are dozens of tiny clumps of matter. Each small clump, originally just a small fragment of the star, is tens of times larger than the diameter of our solar system. The colors highlight parts of the debris where chemical elements are glowing. The dark blue fragments, for example, are richest in oxygen; the red material is rich in sulfur. The images were taken with the Wide Field and Planetary Camera 2 in January 2000 and January 2002. Image Credit: NASA and HST team (Stoics/AURA). Acknowledgment: R. Fesen (Darmouth) and J. Morse ( Univ. of Colorado).

Hubble Space Telescope Astrometry of the Procyon System

Science.gov (United States)

Bond, Howard E.; Gilliland, Ronald L.; Schaefer, Gail H.; Demarque, Pierre; Girard, Terrence M.; Holberg, Jay B.; Gudehus, Donald; Mason, Brian D.; Kozhurina-Platais, Vera; Burleigh, Matthew R.

2015-01-01

The nearby star Procyon is a visual binary containing the F5 IV-V subgiant Procyon A, orbited in a 40.84-year period by the faint DQZ white dwarf (WD) Procyon B. Using images obtained over two decades with the Hubble Space Telescope, and historical measurements back to the 19th century, we have determined precise orbital elements. Combined with measurements of the parallax and the motion of the A component, these elements yield dynamical masses of 1.478 plus or minus 0.012M and 0.592 plus or minus 0.006M for A and B, respectively. The mass of Procyon A agrees well with theoretical predictions based on asteroseismology and its temperature and luminosity. Use of a standard core-overshoot model agrees best for a surprisingly high amount of core overshoot. Under these modeling assumptions, Procyon A's age is approximately 2.7 Gyr. Procyon B's location in the H-R diagram is in excellent agreement with theoretical cooling tracks for WDs of its dynamical mass. Its position in the mass-radius plane is also consistent with theory, assuming a carbon-oxygen core and a helium-dominated atmosphere. Its progenitor's mass was 1.9-2.2M, depending on its amount of core overshoot. Several astrophysical puzzles remain. In the progenitor system, the stars at periastron were separated by only approximately AU, which might have led to tidal interactions and even mass transfer; yet there is no direct evidence that these have occurred. Moreover the orbital eccentricity has remained high (approximately 0.40). The mass of Procyon B is somewhat lower than anticipated from the initial-to-final-mass relation seen in open clusters. The presence of heavy elements in its atmosphere requires ongoing accretion, but the place of origin is uncertain.

Hubble Space Telescope EVA Power Ratchet Tool redesign

Science.gov (United States)

Richards, Paul W.; Park, Chan; Brown, Lee

The Power Ratchet Tool (PRT) is a self contained, power-driven, 3/8 inch drive ratchet wrench which will be used by astronauts during Extravehicular Activities (EVA). This battery-powered tool is controlled by a dedicated electonic controller. The PRT was flown during the Hubble Space Telescope (HST) Deployment Mission STS-31 to deploy the solar arrays if the automatic mechanisms failed. The PRT is currently intended for use during the first HST Servicing Mission STS-61 as a general purpose power tool. The PRT consists of three major components; the wrench, the controller, and the battery module. Fourteen discrete combinations of torque, turns, and speed may be programmed into the controller before the EVA. The crewmember selects the desired parameter profile by a switch mounted on the controller. The tool may also be used in the manual mode as a non-powered ratchet wrench. The power is provided by a silver-zinc battery module, which fits into the controller and is replaceable during an EVA. The original PRT did not meet the design specification of torque output and hours of operation. To increase efficiency and reliability the PRT underwent a redesign effort. The majority of this effort focused on the wrench. The original PRT drive train consisted of a low torque, high speed brushless DC motor, a face gear set, and a planocentric gear assembly. The total gear reduction was 300:1. The new PRT wrench consists of a low speed, high torque brushless DC motor, two planetary gear sets and a bevel gear set. The total gear reduction is now 75:1. A spline clutch has also been added to disengage the drive train in the manual mode. The design changes to the controller will consist of only those modifications necessary to accomodate the redesigned wrench.

Thick Disks in the Hubble Space Telescope Frontier Fields

Energy Technology Data Exchange (ETDEWEB)

Elmegreen, Bruce G. [IBM Research Division, T.J. Watson Research Center, 1101 Kitchawan Road, Yorktown Heights, NY 10598 (United States); Elmegreen, Debra Meloy; Tompkins, Brittany; Jenks, Leah G., E-mail: bge@us.ibm.com, E-mail: elmegreen@vassar.edu [Department of Physics and Astronomy, Vassar College, Poughkeepsie, NY 12604 (United States)

2017-09-20

Thick disk evolution is studied using edge-on galaxies in two Hubble Space Telescope Frontier Field Parallels. The galaxies were separated into 72 clumpy types and 35 spiral types with bulges. Perpendicular light profiles in F435W, F606W, and F814W ( B , V , and I ) passbands were measured at 1 pixel intervals along the major axes and fitted to sech{sup 2} functions convolved with the instrument line spread function (LSF). The LSF was determined from the average point spread function of ∼20 stars in each passband and field, convolved with a line of uniform brightness to simulate disk blurring. A spread function for a clumpy disk was also used for comparison. The resulting scale heights were found to be proportional to galactic mass, with the average height for a 10{sup 10±0.5} M {sub ⊙} galaxy at z = 2 ± 0.5 equal to 0.63 ± 0.24 kpc. This value is probably the result of a blend between thin and thick disk components that cannot be resolved. Evidence for such two-component structure is present in an inverse correlation between height and midplane surface brightness. Models suggest that the thick disk is observed best between the clumps, and there the average scale height is 1.06 ± 0.43 kpc for the same mass and redshift. A 0.63 ± 0.68 mag V − I color differential with height is also evidence for a mixture of thin and thick components.

Molecular Electronic Shift Registers

Science.gov (United States)

Beratan, David N.; Onuchic, Jose N.

1990-01-01

Molecular-scale shift registers eventually constructed as parts of high-density integrated memory circuits. In principle, variety of organic molecules makes possible large number of different configurations and modes of operation for such shift-register devices. Several classes of devices and implementations in some specific types of molecules proposed. All based on transfer of electrons or holes along chains of repeating molecular units.

Blue-shifted and red-shifted hydrogen bonds: Theoretical study of the CH3CHO· · ·HNO complexes

Science.gov (United States)

Yang, Yong; Zhang, Weijun; Gao, Xiaoming

The blue-shifted and red-shifted H-bonds have been studied in complexes CH3CHO?HNO. At the MP2/6-31G(d), MP2/6-31+G(d,p) MP2/6-311++G(d,p), B3LYP/6-31G(d), B3LYP/6-31+G(d,p) and B3LYP/6-311++G(d,p) levels, the geometric structures and vibrational frequencies of complexes CH3CHO?HNO are calculated by both standard and CP-corrected methods, respectively. Complex A exhibits simultaneously red-shifted C bond H?O and blue-shifted N bond H?O H-bonds. Complex B possesses simultaneously two blue-shifted H-bonds: C bond H?O and N bond H?O. From NBO analysis, it becomes evident that the red-shifted C bond H?O H-bond can be explained on the basis of the two opposite effects: hyperconjugation and rehybridization. The blue-shifted C bond H?O H-bond is a result of conjunct C bond H bond strengthening effects of the hyperconjugation and the rehybridization due to existence of the significant electron density redistribution effect. For the blue-shifted N bond H?O H-bonds, the hyperconjugation is inhibited due to existence of the electron density redistribution effect. The large blue shift of the N bond H stretching frequency is observed because the rehybridization dominates the hyperconjugation.

Observations of the Hubble Deep Field with the Infrared Space Observatory .1. Data reduction, maps and sky coverage

DEFF Research Database (Denmark)

Serjeant, S.B.G.; Eaton, N.; Oliver, S.J.

1997-01-01

We present deep imaging at 6.7 and 15 mu m from the CAM instrument on the Infrared Space Observatory (ISO), centred on the Hubble Deep Field (HDF). These are the deepest integrations published to date at these wavelengths in any region of sky. We discuss the observational strategy and the data...... reduction. The observed source density appears to approach the CAM confusion limit at 15 mu m, and fluctuations in the 6.7-mu m sky background may be identifiable with similar spatial fluctuations in the HDF galaxy counts. ISO appears to be detecting comparable field galaxy populations to the HDF, and our...

Shift Work: Improving Daytime Sleep

Science.gov (United States)

... night. Good daytime sleep is possible, though, if shift work is a necessary part of your work life. ... mayoclinic.org/healthy-lifestyle/adult-health/expert-answers/shift-work/faq-20057991 . Mayo Clinic Footer Legal Conditions and ...

The Black Hole Mass-Bulge Luminosity Relationship for Active Galactic Nuclei From Reverberation Mapping and Hubble Space Telescope Imaging

DEFF Research Database (Denmark)

Bentz, Misty C.; Peterson, Bradley M.; Pogge, Richard W.

2009-01-01

We investigate the relationship between black hole mass and bulge luminosity for active galactic nuclei (AGNs) with reverberation-based black hole mass measurements and bulge luminosities from two-dimensional decompositions of Hubble Space Telescope host galaxy images. We find that the slope...... of the relationship for AGNs is 0.76-0.85 with an uncertainty of ~0.1, somewhat shallower than the M BH vprop L 1.0±0.1 relationship that has been fit to nearby quiescent galaxies with dynamical black hole mass measurements. This difference is somewhat perplexing, as the AGN black hole masses include an overall...

Night shift work and modifiable lifestyle factors.

Science.gov (United States)

Pepłońska, Beata; Burdelak, Weronika; Krysicka, Jolanta; Bukowska, Agnieszka; Marcinkiewicz, Andrzej; Sobala, Wojciech; Klimecka-Muszyńska, Dorota; Rybacki, Marcin

2014-10-01

Night shift work has been linked to some chronic diseases. Modification of lifestyle by night work may partially contribute to the development of these diseases, nevertheless, so far epidemiological evidence is limited. The aim of the study was to explore association between night shift work and lifestyle factors using data from a cross-sectional study among blue-collar workers employed in industrial plants in Łódź, Poland. The anonymous questionnaire was self-administered among 605 employees (236 women and 369 men, aged 35 or more) - 434 individuals currently working night shifts. Distribution of the selected lifestyle related factors such as smoking, alcohol drinking, physical activity, body mass index (BMI), number of main meals and the hour of the last meal was compared between current, former, and never night shift workers. Adjusted ORs or predicted means were calculated, as a measure of the associations between night shift work and lifestyle factors, with age, marital status and education included in the models as covariates. Recreational inactivity (defined here as less than one hour per week of recreational physical activity) was associated with current night shift work when compared to never night shift workers (OR = 2.43, 95% CI: 1.13-5.22) among men. Alcohol abstinence and later time of the last meal was associated with night shift work among women. Statistically significant positive relationship between night shift work duration and BMI was observed among men (p = 0.029). This study confirms previous studies reporting lower exercising among night shift workers and tendency to increase body weight. This finding provides important public health implication for the prevention of chronic diseases among night shift workers. Initiatives promoting physical activity addressed in particular to the night shift workers are recommended.

Night shift work and modifiable lifestyle factors

Directory of Open Access Journals (Sweden)

Beata Pepłońska

2014-10-01

Full Text Available Objectives: Night shift work has been linked to some chronic diseases. Modification of lifestyle by night work may partially contribute to the development of these diseases, nevertheless, so far epidemiological evidence is limited. The aim of the study was to explore association between night shift work and lifestyle factors using data from a cross-sectional study among blue-collar workers employed in industrial plants in Łódź, Poland. Material and Methods: The anonymous questionnaire was self-administered among 605 employees (236 women and 369 men, aged 35 or more - 434 individuals currently wor­king night shifts. Distribution of the selected lifestyle related factors such as smoking, alcohol drinking, physical activity, body mass index (BMI, number of main meals and the hour of the last meal was compared between current, former, and never night shift workers. Adjusted ORs or predicted means were calculated, as a measure of the associations between night shift work and lifestyle factors, with age, marital status and education included in the models as covariates. Results: Recreational inactivity (defined here as less than one hour per week of recreational physical activity was associated with current night shift work when compared to never night shift workers (OR = 2.43, 95% CI: 1.13-5.22 among men. Alcohol abstinence and later time of the last meal was associated with night shift work among women. Statistically significant positive relationship between night shift work duration and BMI was observed among men (p = 0.029. Conclusions: This study confirms previous studies reporting lower exercising among night shift workers and tendency to increase body weight. This finding provides important public health implication for the prevention of chronic diseases among night shift workers. Initiatives promoting physical activity addressed in particular to the night shift workers are recommended.

The Carnegie-Chicago Hubble Program. II. The Distance to IC 1613: The Tip of the Red Giant Branch and RR Lyrae Period-luminosity Relations

Science.gov (United States)

Hatt, Dylan; Beaton, Rachael L.; Freedman, Wendy L.; Madore, Barry F.; Jang, In-Sung; Hoyt, Taylor J.; Lee, Myung Gyoon; Monson, Andrew J.; Rich, Jeffrey A.; Scowcroft, Victoria; Seibert, Mark

2017-08-01

IC 1613 is an isolated dwarf galaxy within the Local Group. Low foreground and internal extinction, low metallicity, and low crowding make it an invaluable testbed for the calibration of the local distance ladder. We present new, high-fidelity distance estimates to IC 1613 via its Tip of the Red Giant Branch (TRGB) and its RR Lyrae (RRL) variables as part of the Carnegie-Chicago Hubble Program, which seeks an alternate local route to H 0 using Population II stars. We have measured a TRGB magnitude {I}{ACS}{TRGB}=20.35+/- {0.01}{stat}+/- {0.01}{sys} mag using wide-field observations obtained from the IMACS camera on the Magellan-Baade telescope. We have further constructed optical and near-infrared RRL light curves using archival BI- and new H-band observations from the ACS/WFC and WFC3/IR instruments on board the Hubble Space Telescope (HST). In advance of future Gaia data releases, we set provisional values for the TRGB luminosity via the Large Magellanic Cloud and Galactic RRL zero-points via HST parallaxes. We find corresponding true distance moduli {μ }0{TRGB}=24.30+/- {0.03}{stat}+/- {0.05}{sys} {mag} and =24.28+/- {0.04}{stat+{sys}} mag. We compare our results to a body of recent publications on IC 1613 and find no statistically significant difference between the distances derived from Population I and II stars. Based in part on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with programs #10505 and #13691. Additional observations are credited to the Observatories of the Carnegie Institution of Washington for the use of Magellan-Baade IMACS. Presented as part of a dissertation to the Department of Astronomy and Astrophysics, The University of Chicago, in partial fulfillment of the requirements for the Ph.D. degree.

Study of insomnia in rotating shift-workers

Directory of Open Access Journals (Sweden)

Kaushik Chatterjee

2017-01-01

Full Text Available Background: Shift-workers commonly suffer from insomnia. This study evaluates different domains of insomnia. Aim: This study was aimed to study sleep and insomnia in rotating shift-workers and compare with day-workers. Materials and Methods: This was case–control study. The sleep of rotating shift-workers is compared with day workers using Athens Insomnia Scale. Results: Rotating shift-workers had significantly higher scores on Athens insomnia scale on domains of initial, intermediate and terminal insomnia than day workers. Duration and quality of sleep and sense of well-being are lower in rotating shift-workers. Rotating shift-workers also experienced more day-time sleepiness than day workers. However, there was no difference in perceived physical and mental functioning between the two groups. Conclusion: Individuals working in rotating shifts for more than 15 days have significantly higher prevalence of insomnia than day-workers.

The effects of consecutive night shifts and shift length on cognitive performance and sleepiness: a field study.

Science.gov (United States)

Haidarimoghadam, Rashid; Kazemi, Reza; Motamedzadeh, Majid; Golmohamadi, Rostam; Soltanian, Alireza; Zoghipaydar, Mohamad Reza

2017-06-01

The aim of this study was to evaluate the effects of consecutive night shifts (CNS) and shift length on cognitive performance and sleepiness. This study evaluated the sleepiness and performance of 30 control room operators (CROs) working in 7 nights, 7 days, 7 days off (7N7D7O) and 30 CROs working in 4 nights, 7 days, 3 nights, 7 days off (4N7D3N7O) shift patterns in a petrochemical complex on the last night shift before swinging into the day shift. To assess cognitive performance, the n-back test, continuous performance test and simple reaction time test were employed. To assess sleepiness, the Karolinska sleepiness scale was used. Both schedules indicated that the correct responses and response times of working memory were reduced (p = 0.001), while intentional errors and sleepiness increased during the shift work (p = 0.001). CNS had a significant impact on reaction time and commission errors (p = 0.001). The main duty of CROs at a petrochemical plant is checking hazardous processes which require appropriate alertness and cognitive performance. As a result, planning for appropriate working hours and suitable number of CNS in a rotating shift system is a contribution to improving CRO performance and enhancing safety.

Study of nanometer-level precise phase-shift system used in electronic speckle shearography and phase-shift pattern interferometry

Science.gov (United States)

Jing, Chao; Liu, Zhongling; Zhou, Ge; Zhang, Yimo

2011-11-01

The nanometer-level precise phase-shift system is designed to realize the phase-shift interferometry in electronic speckle shearography pattern interferometry. The PZT is used as driving component of phase-shift system and translation component of flexure hinge is developed to realize micro displacement of non-friction and non-clearance. Closed-loop control system is designed for high-precision micro displacement, in which embedded digital control system is developed for completing control algorithm and capacitive sensor is used as feedback part for measuring micro displacement in real time. Dynamic model and control model of the nanometer-level precise phase-shift system is analyzed, and high-precision micro displacement is realized with digital PID control algorithm on this basis. It is proved with experiments that the location precision of the precise phase-shift system to step signal of displacement is less than 2nm and the location precision to continuous signal of displacement is less than 5nm, which is satisfied with the request of the electronic speckle shearography and phase-shift pattern interferometry. The stripe images of four-step phase-shift interferometry and the final phase distributed image correlated with distortion of objects are listed in this paper to prove the validity of nanometer-level precise phase-shift system.

Tempo of Diversification of Global Amphibians: One-Constant Rate, One-Continuous Shift or Multiple-Discrete Shifts?

OpenAIRE

Youhua Chen

2014-01-01

In this brief report, alternative time-varying diversification rate models were fitted onto the phylogeny of global amphibians by considering one-constant-rate (OCR), one-continuous-shift (OCS) and multiplediscrete- shifts (MDS) situations. The OCS diversification model was rejected by γ statistic (γ=-5.556, p⁄ 0.001), implying the existence of shifting diversification rates for global amphibian phylogeny. Through model selection, MDS diversification model outperformed OCS and OCR...

Infall of nearby galaxies into the Virgo cluster as traced with Hubble space telescope

Energy Technology Data Exchange (ETDEWEB)

Karachentsev, Igor D. [Special Astrophysical Observatory RAS, Nizhnij Arkhyz, Karachai-Cherkessian Republic 369167 (Russian Federation); Tully, R. Brent; Wu, Po-Feng [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Shaya, Edward J. [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Dolphin, Andrew E., E-mail: ikar@sao.ru [Raytheon Company, 1151 East Hermans Road, Tucson, AZ 85756 (United States)

2014-02-10

We measured the tip of the red giant branch distances to nine galaxies in the direction to the Virgo cluster using the Advanced Camera for Surveys on the Hubble Space Telescope. These distances put seven galaxies (GR 34, UGC 7512, NGC 4517, IC 3583, NGC 4600, VCC 2037, and KDG 215) in front of Virgo and two galaxies (IC 3023 and KDG 177) likely inside the cluster. Distances and radial velocities of the galaxies situated between us and the Virgo core clearly exhibit the infall phenomenon toward the cluster. In the case of spherically symmetric radial infall, we estimate the radius of the 'zero-velocity surface' to be (7.2 ± 0.7) Mpc, which yields a total mass of the Virgo cluster of (8.0 ± 2.3) × 10{sup 14} M {sub ☉}, in good agreement with its virial mass estimates. We conclude that the Virgo outskirts do not contain significant amounts of dark matter beyond their virial radius.

Anxiety about starting three-shift work among female workers: findings from the Female Shift Workers' Health Study.

Science.gov (United States)

Kubo, Tatsuhiko; Maruyama, Takashi; Shirane, Kiyoyumi; Otomo, Hajime; Matsumoto, Tetsuro; Oyama, Ichiro

2008-03-01

In 1999, the Japanese Law on Equal Employment Opportunity and Conditions was amended and the previous prohibition of the assignment of female workers to night work was abolished. Subsequently, the number of female shift workers has been increasing in Japan, necessitating greater attention to the health care of this population. The aim of the current study is to evaluate the relationship between anxiety expressed about starting three-shift work and background characteristics among female workers who were being assigned to three-shift work for the first time. The subjects were 38 middle-aged female workers (age range: 44 to 59 years) who were working at a chemical plant. The women completed a self-administered questionnaire before starting three-shift work. Levels of anxiety about starting three-shift work were assessed by the question 'Do you feel anxious about starting three-shift work?' The available responses were: 'Very agree', 'Considerably agree', 'Rather agree', 'Slightly agree' and 'Not agree at all', and 63% of the subjects gave one of the first two answers, which were defined as indicating anxiety. We also acquired information regarding lifestyle and occupation for each subject, including the following factors: frequency of breakfast consumption, subjective sleep insufficiency, previous experience of similar work before beginning shift work, previous experience of two-shift work, and responsibility for household duties. In the study, we found a marginally statistically significant trend association between frequent breakfast consumption and anxiety about starting three-shift work (P(trend) = 0.09). Anxiety was also high among subjects with sleep disorders, especially those suffering from subjective sleep insufficiency (P = 0.08). Due to the small study population, these results should be interpreted with caution and confirmed by future studies.

Using chemical shift perturbation to characterise ligand binding.

Science.gov (United States)

Williamson, Mike P

2013-08-01

Chemical shift perturbation (CSP, chemical shift mapping or complexation-induced changes in chemical shift, CIS) follows changes in the chemical shifts of a protein when a ligand is added, and uses these to determine the location of the binding site, the affinity of the ligand, and/or possibly the structure of the complex. A key factor in determining the appearance of spectra during a titration is the exchange rate between free and bound, or more specifically the off-rate koff. When koff is greater than the chemical shift difference between free and bound, which typically equates to an affinity Kd weaker than about 3μM, then exchange is fast on the chemical shift timescale. Under these circumstances, the observed shift is the population-weighted average of free and bound, which allows Kd to be determined from measurement of peak positions, provided the measurements are made appropriately. (1)H shifts are influenced to a large extent by through-space interactions, whereas (13)Cα and (13)Cβ shifts are influenced more by through-bond effects. (15)N and (13)C' shifts are influenced both by through-bond and by through-space (hydrogen bonding) interactions. For determining the location of a bound ligand on the basis of shift change, the most appropriate method is therefore usually to measure (15)N HSQC spectra, calculate the geometrical distance moved by the peak, weighting (15)N shifts by a factor of about 0.14 compared to (1)H shifts, and select those residues for which the weighted shift change is larger than the standard deviation of the shift for all residues. Other methods are discussed, in particular the measurement of (13)CH3 signals. Slow to intermediate exchange rates lead to line broadening, and make Kd values very difficult to obtain. There is no good way to distinguish changes in chemical shift due to direct binding of the ligand from changes in chemical shift due to allosteric change. Ligand binding at multiple sites can often be characterised, by

A Butterfly in the Making: Revealing the Near-Infrared Structure of Hubble 12

Science.gov (United States)

Hora, Joseph L.; Latter, William B.

1996-01-01

We present deep narrowband near-IR images and moderate resolution spectra of the young planetary nebula Hubble 12. These data are the first to show clearly the complex structure for this important planetary nebula. Images were obtained at lambda = 2.12, 2.16, and 2.26 micron. The lambda = 2.12 Am image reveals the bipolar nature of the nebula, as well as complex structure near the central star in the equatorial region. The images show an elliptical region of emission, which may indicate a ring or a cylindrical source structure. This structure is possibly related to the mechanism that is producing the bipolar flow. The spectra show the nature of several distinct components. The central object is dominated by recombination lines of H I and He I. The core is not a significant source of molecular hydrogen emission. The east position in the equatorial region is rich in lines of ultraviolet-excited fluorescent H2. A spectrum of part of the central region shows strong [Fe II] emission, which might indicate the presence of shocks.

Images From Hubbles's ACS Tell A Tale Of Two Record-Breaking Galaxy Clusters

Science.gov (United States)

2004-01-01

Looking back in time nearly 9 billion years, an international team of astronomers found mature galaxies in a young universe. The galaxies are members of a cluster of galaxies that existed when the universe was only 5 billion years old, or about 35 percent of its present age. This compelling evidence that galaxies must have started forming just after the big bang was bolstered by observations made by the same team of astronomers when they peered even farther back in time. The team found embryonic galaxies a mere 1.5 billion years after the birth of the cosmos, or 10 percent of the universe's present age. The "baby galaxies" reside in a still-developing cluster, the most distant proto-cluster ever found. The Advanced Camera for Surveys (ACS) aboard NASA's Hubble Space Telescope was used to make observations of the massive cluster, RDCS 1252.9-2927, and the proto-cluster, TN J1338-1942. Observations by NASA's Chandra X-ray Observatory yielded the mass and heavy element content of RDCS 1252, the most massive known cluster for that epoch. These observations are part of a coordinated effort by the ACS science team to track the formation and evolution of clusters of galaxies over a broad range of cosmic time. The ACS was built especially for studies of such distant objects. These findings further support observations and theories that galaxies formed relatively early in the history of the cosmos. The existence of such massive clusters in the early universe agrees with a cosmological model wherein clusters form from the merger of many sub-clusters in a universe dominated by cold dark matter. The precise nature of cold dark matter, however, is still not known. The first Hubble study estimated that galaxies in RDCS 1252 formed the bulk of their stars more than 11 billion years ago (at redshifts greater than 3). The results were published in the Oct. 20, 2003 issue of the Astrophysical Journal. The paper's lead author is John Blakeslee of the Johns Hopkins University in

Working the Night Shift: The Impact of Compensating Wages and Local Economic Conditions on Shift Choice

OpenAIRE

Colene Trent; Walter J. Mayer

2014-01-01

The theory of compensating differentials asserts that night shift workers should receive compensating wage differentials due to undesirable work conditions. In weak local economies, workers may have difficulty finding jobs; thus, these workers might be more likely to accept night shift work and be less concerned with the size of the compensating differential for night shifts. Using CPS data from 2001, this paper employs maximum likelihood estimation of an endogenous switching regression model...

Chemical shift-dependent apparent scalar couplings: An alternative concept of chemical shift monitoring in multi-dimensional NMR experiments

International Nuclear Information System (INIS)

Kwiatkowski, Witek; Riek, Roland

2003-01-01

The paper presents an alternative technique for chemical shift monitoring in a multi-dimensional NMR experiment. The monitored chemical shift is coded in the line-shape of a cross-peak through an apparent residual scalar coupling active during an established evolution period or acquisition. The size of the apparent scalar coupling is manipulated with an off-resonance radio-frequency pulse in order to correlate the size of the coupling with the position of the additional chemical shift. The strength of this concept is that chemical shift information is added without an additional evolution period and accompanying polarization transfer periods. This concept was incorporated into the three-dimensional triple-resonance experiment HNCA, adding the information of 1 H α chemical shifts. The experiment is called HNCA coded HA, since the chemical shift of 1 H α is coded in the line-shape of the cross-peak along the 13 C α dimension

Doppler interpretation of quasar red shifts.

Science.gov (United States)

Zapolsky, H S

1966-08-05

The hypothesis that the quasistellar sources (quasars) are local objects moving with velocities close to the speed of light is examined. Provided there is no observational cutoff on apparent bolometric magnitude for the quasars, the transverse Doppler effect leads to the expectation of fewer blue shifts than red shifts for an isotropic distribution of velocities. Such a distribution also yields a function N(z), the number of objects with red shift less than z which is not inconsistent with the present data. On the basis of two extreme assumptions concerning the origin of such rapidly moving sources, we computed curves of red shift plotted against magnitude. In particular, the curve obtained on the assumption that the quasars originated from an explosion in or nearby our own galaxy is in as good agreement with the observations as the curve of cosmological red shift plotted against magnitude.

Goos-Haenchen shift in complex crystals

Energy Technology Data Exchange (ETDEWEB)

Longhi, Stefano; Della Valle, Giuseppe; Staliunas, Kestutis [Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano (Italy); Departament de Fisica i Enginyeria Nuclear, Instituci Catalana de Recerca i Estudis Avanats (ICREA), Universitat Politcnica de Catalunya, Colom 11, E-08222 Terrassa, Barcelona (Spain)

2011-10-15

The Goos-Haenchen (GH) effect for wave scattering from complex PT-symmetric periodic potentials (complex crystals) is theoretically investigated, with specific reference to optical GH shift in photonic crystal slabs with a sinusoidal periodic modulation of both real and imaginary parts of the dielectric constant. The analysis highlights some distinct and rather unique features as compared to the GH shift found in ordinary crystals. In particular, as opposed to GH shift in ordinary crystals, which is large at the band gap edges, in complex crystals the GH shift can be large inside the reflection (amplification) band and becomes extremely large as the PT symmetry-breaking threshold is approached.

Optimal control of the gear shifting process for shift smoothness in dual-clutch transmissions

Science.gov (United States)

Li, Guoqiang; Görges, Daniel

2018-03-01

The control of the transmission system in vehicles is significant for the driving comfort. In order to design a controller for smooth shifting and comfortable driving, a dynamic model of a dual-clutch transmission is presented in this paper. A finite-time linear quadratic regulator is proposed for the optimal control of the two friction clutches in the torque phase for the upshift process. An integral linear quadratic regulator is introduced to regulate the relative speed difference between the engine and the slipping clutch under the optimization of the input torque during the inertia phase. The control objective focuses on smoothing the upshift process so as to improve the driving comfort. Considering the available sensors in vehicles for feedback control, an observer design is presented to track the immeasurable variables. Simulation results show that the jerk can be reduced both in the torque phase and inertia phase, indicating good shift performance. Furthermore, compared with conventional controllers for the upshift process, the proposed control method can reduce shift jerk and improve shift quality.

Astrometry with Hubble Space Telescope Fine Guidance Sensor 3: The Parallax of the Cataclysmic Variable RW Triangulum

Science.gov (United States)

McArthur, B. E.; Benedict, G. F.; Lee, J.; Lu, C.-L.; van Altena, W. F.; Deliyannis, C. P.; Girard, T.; Fredrick, L. W.; Nelan, E.; Duncombe, R. L.; Hemenway, P. D.; Jefferys, W. H.; Shelus, P. J.; Franz, O. G.; Wasserman, L. H.

1999-07-01

RW Triangulum (RW Tri) is a 13th magnitude nova-like cataclysmic variable star with an orbital period of 0.2319 days (5.56 hr). Infrared observations of RW Tri indicate that its secondary is most likely a late-K dwarf (Dhillon). Past analyses predicted a distance of 270 pc, derived from a blackbody fit to the spectrum of the central part of the disk (Rutten, van Paradijs, & Tinbergen). Recently completed Hubble Space Telescope Fine Guidance Sensor interferometric observations allow us to determine the first trigonometric parallax to RW Tri. This determination puts the distance of RW Tri at 341-31+38, one of the most distant objects with a direct parallax measurement. We compare our result with methods previously employed to estimate distances to cataclysmic variables.

Type-Ia supernova rates to redshift 2.4 from clash: The cluster lensing and supernova survey with Hubble

International Nuclear Information System (INIS)

Graur, O.; Rodney, S. A.; Riess, A. G.; Medezinski, E.; Maoz, D.; Jha, S. W.; Holoien, T. W.-S.; McCully, C.; Patel, B.; Postman, M.; Dahlen, T.; Strolger, L.-G.; Coe, D.; Bradley, L.; Koekemoer, A.; Benítez, N.; Molino, A.; Jouvel, S.; Nonino, M.; Balestra, I.

2014-01-01

We present the supernova (SN) sample and Type-Ia SN (SN Ia) rates from the Cluster Lensing And Supernova survey with Hubble (CLASH). Using the Advanced Camera for Surveys and the Wide Field Camera 3 on the Hubble Space Telescope (HST), we have imaged 25 galaxy-cluster fields and parallel fields of non-cluster galaxies. We report a sample of 27 SNe discovered in the parallel fields. Of these SNe, ∼13 are classified as SN Ia candidates, including four SN Ia candidates at redshifts z > 1.2. We measure volumetric SN Ia rates to redshift 1.8 and add the first upper limit on the SN Ia rate in the range 1.8 < z < 2.4. The results are consistent with the rates measured by the HST/GOODS and Subaru Deep Field SN surveys. We model these results together with previous measurements at z < 1 from the literature. The best-fitting SN Ia delay-time distribution (DTD; the distribution of times that elapse between a short burst of star formation and subsequent SN Ia explosions) is a power law with an index of −1.00 −0.06(0.10) +0.06(0.09) (statistical) −0.08 +0.12 (systematic), where the statistical uncertainty is a result of the 68% and 95% (in parentheses) statistical uncertainties reported for the various SN Ia rates (from this work and from the literature), and the systematic uncertainty reflects the range of possible cosmic star-formation histories. We also test DTD models produced by an assortment of published binary population synthesis (BPS) simulations. The shapes of all BPS double-degenerate DTDs are consistent with the volumetric SN Ia measurements, when the DTD models are scaled up by factors of 3-9. In contrast, all BPS single-degenerate DTDs are ruled out by the measurements at >99% significance level.

CONFIRMATION OF THE COMPACTNESS OF A z = 1.91 QUIESCENT GALAXY WITH HUBBLE SPACE TELESCOPE'S WIDE FIELD CAMERA 3

International Nuclear Information System (INIS)

Szomoru, Daniel; Franx, Marijn; Bouwens, Rychard J.; Van Dokkum, Pieter G.; Trenti, Michele; Illingworth, Garth D.; Labbe, Ivo; Oesch, Pascal A.; Carollo, C. Marcella

2010-01-01

We present very deep Wide Field Camera 3 (WFC3) photometry of a massive, compact galaxy located in the Hubble Ultra Deep Field. This quiescent galaxy has a spectroscopic redshift z = 1.91 and has been identified as an extremely compact galaxy by Daddi et al. We use new H F160W imaging data obtained with Hubble Space Telescope/WFC3 to measure the deconvolved surface brightness profile to H ∼ 28 mag arcsec -2 . We find that the surface brightness profile is well approximated by an n = 3.7 Sersic profile. Our deconvolved profile is constructed by a new technique which corrects the best-fit Sersic profile with the residual of the fit to the observed image. This allows for galaxy profiles which deviate from a Sersic profile. We determine the effective radius of this galaxy: r e = 0.42 ± 0.14 kpc in the observed H F160W band. We show that this result is robust to deviations from the Sersic model used in the fit. We test the sensitivity of our analysis to faint 'wings' in the profile using simulated galaxy images consisting of a bright compact component and a faint extended component. We find that due to the combination of the WFC3 imaging depth and our method's sensitivity to extended faint emission we can accurately trace the intrinsic surface brightness profile, and that we can therefore confidently rule out the existence of a faint extended envelope around the observed galaxy down to our surface brightness limit. These results confirm that the galaxy lies a factor ∼10 off from the local mass-size relation.

THE HUBBLE SPACE TELESCOPE UV LEGACY SURVEY OF GALACTIC GLOBULAR CLUSTERS. III. A QUINTUPLE STELLAR POPULATION IN NGC 2808

International Nuclear Information System (INIS)

Milone, A. P.; Marino, A. F.; Jerjen, H.; Piotto, G.; Renzini, A.; Bedin, L. R.; Anderson, J.; Bellini, A.; Cassisi, S.; Pietrinferni, A.; D’Antona, F.; Ventura, P.

2015-01-01

In this study we present the first results from multi-wavelength Hubble Space Telescope (HST) observations of the Galactic globular cluster (GC) NGC 2808 as an extension of the Hubble Space Telescope UV Legacy Survey of Galactic GCs (GO-13297 and previous proprietary and HST archive data). Our analysis allowed us to disclose a multiple-stellar-population phenomenon in NGC 2808 even more complex than previously thought. We have separated at least five different populations along the main sequence and the red giant branch (RGB), which we name A, B, C, D, and E (though an even finer subdivision may be suggested by the data). We identified the RGB bump in four out of the five RGBs. To explore the origin of this complex color–magnitude diagram, we have combined our multi-wavelength HST photometry with synthetic spectra, generated by assuming different chemical compositions. The comparison of observed colors with synthetic spectra suggests that the five stellar populations have different contents of light elements and helium. Specifically, if we assume that NGC 2808 is homogeneous in [Fe/H] (as suggested by spectroscopy for Populations B, C, D, E, but lacking for Population A) and that population A has a primordial helium abundance, we find that populations B, C, D, E are enhanced in helium by ΔY ∼ 0.03, 0.03, 0.08, 0.13, respectively. We obtain similar results by comparing the magnitude of the RGB bumps with models. Planned spectroscopic observations will test whether Population A also has the same metallicity, or whether its photometric differences with Population B can be ascribed to small [Fe/H] and [O/H] differences rather than to helium

Temporal dynamics of circadian phase shifting response to consecutive night shifts in healthcare workers: role of light-dark exposure.

Science.gov (United States)

Stone, Julia E; Sletten, Tracey L; Magee, Michelle; Ganesan, Saranea; Mulhall, Megan D; Collins, Allison; Howard, Mark; Lockley, Steven W; Rajaratnam, Shantha M W

2018-03-28

Shift work is highly prevalent and is associated with significant adverse health impacts. There is substantial inter-individual variability in the way the circadian clock responds to changing shift cycles. The mechanisms underlying this variability are not well understood. We tested the hypothesis that light-dark exposure is a significant contributor to this variability; when combined with diurnal preference, the relative timing of light exposure accounted for 71% of individual variability in circadian phase response to night shift work. These results will drive development of personalised approaches to manage circadian disruption among shift workers and other vulnerable populations to potentially reduce the increased risk of disease in these populations. Night shift workers show highly variable rates of circadian adaptation. This study examined the relationship between light exposure patterns and the magnitude of circadian phase resetting in response to night shift work. In 21 participants (nursing and medical staff in an intensive care unit) circadian phase was measured using 6-sulphatoxymelatonin at baseline (day/evening shifts or days off) and after 3-4 consecutive night shifts. Daily light exposure was examined relative to individual circadian phase to quantify light intensity in the phase delay and phase advance portions of the light phase response curve (PRC). There was substantial inter-individual variability in the direction and magnitude of phase shift after three or four consecutive night shifts (mean phase delay -1:08 ± 1:31 h; range -3:43 h delay to +3:07 h phase advance). The relative difference in the distribution of light relative to the PRC combined with diurnal preference accounted for 71% of the variability in phase shift. Regression analysis incorporating these factors estimated phase shift to within ±60 min in 85% of participants. No participants met criteria for partial adaptation to night work after three or four consecutive night

Update on the Status of the Space Telescope Imaging Spectrograph onboard the Hubble Space Telescope

Science.gov (United States)

Hernandez, Svea; Aloisi, A.; Bostroem, K. A.; Cox, C.; Debes, J. H.; DiFelice, A.; Roman-Duval, J.; Hodge, P.; Holland, S.; Lindsay, K.; Lockwood, S. A.; Mason, E.; Oliveira, C. M.; Penton, S. V.; Proffitt, C. R.; Sonnentrucker, P.; Taylor, J. M.; Wheeler, T.

2013-06-01

The Space Telescope Imaging Spectrograph (STIS) has been on orbit for approximately 16 years as one of the 2nd generation instruments on the Hubble Space Telescope (HST). Its operations were interrupted by an electronics failure in 2004, but STIS was successfully repaired in May 2009 during Service Mission 4 (SM4) allowing it to resume science observations. The Instrument team continues to monitor its performance and work towards improving the quality of its products. Here we present updated information on the status of the FUV and NUV MAMA and the CCD detectors onboard STIS and describe recent changes to the STIS calibration pipeline. We also discuss the status of efforts to apply a pixel-based correction for charge transfer inefficiency (CTI) effects to STIS CCD data. These techniques show promise for ameliorating the effects of ongoing radiation damage on the quality of STIS CCD data.

Hubble Space Telescope Ultraviolet Light Curves Reveal Interesting Properties of CC Sculptoris and RZ Leonis

Energy Technology Data Exchange (ETDEWEB)

Szkody, Paula; Mukadam, Anjum S. [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Toloza, Odette; Gänsicke, Boris T.; Pala, Anna F. [Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Dai, Zhibin [Yunnan Observatories, Chinese Academy of Sciences, 396 Yangfangwang, Guandu District, Kunming, 650216 (China); Waagen, Elizabeth O. [AAVSO, 48 Bay State Rd, Cambridge, MA 02138 (United States); Godon, Patrick; Sion, Edward M., E-mail: szkody@astro.washington.edu [Department of Astrophysics and Planetary Science, Villanova University, Villanova, PA 19085 (United States)

2017-03-01

Time-tag ultraviolet data obtained on the Hubble Space Telescope in 2013 reveal interesting variability related to the white dwarf spin in the two cataclysmic variables RZ Leo and CC Scl. RZ Leo shows a period at 220 s and its harmonic at 110 s, thus identifying it as a likely Intermediate Polar (IP). The spin signal is not visible in a short single night of ground-based data in 2016, but the shorter exposures in that data set indicate a possible partial eclipse. The much larger UV amplitude of the spin signal in the known IP CC Scl allows the spin of 389 s, previously only seen at outburst, to be visible at quiescence. Spectra created from the peaks and troughs of the spin times indicate a hotter temperature of several thousand degrees during the peak phases, with multiple components contributing to the UV light.

Understanding and controlling chromaticity shift in LED devices

Energy Technology Data Exchange (ETDEWEB)

Davis, Lynn; Mills, Karmann; Lamvik, Michael; Perkins, Curtis; Bobashev, Georgiy; Young, Joseph; Yaga, Robert; Johnson, Cortina

2017-05-30

Chromaticity shift in light-emitting diode (LED) devices arises from multiple mechanisms, and at least five different chromaticity shift modes (CSMs) have been identified to date. This paper focuses on the impacts of irreversible phosphor degradation as a cause of chromaticity shifts in LED devices. The nitride phosphors used to produce warm white LEDs are especially vulnerable to degradation due to thermal and chemical effects such as reactions with oxygen and water. As a result, LED devices utilizing these phosphors were found to undergo either a green shift or, less commonly, a red shift depending on the phosphor mix in the LED devices. These types of chromaticity shifts are classified as CSM-2 (green shift) and CSM-5 (red shift). This paper provides an overview of the kinetic processes responsible for green and red chromaticity shifts along with examples from accelerated stress testing of 6” downlights. Both CSMs appear to proceed through analogous mechanisms that are initiated at the surface of the phosphor. A green shift is produced by the surface oxidation of the nitride phosphor that changes the emission profile to lower wavelengths. As the surface oxidation reaction proceeds, reactant limitations slow the rate and bulk oxidation processes become more prevalent. We found that a red chromaticity shift arises from quenching of the green phosphor, also possibly due to surface reactions of oxygen, which shift the emission chromaticity in the red direction. In conclusion, we discuss the implications of these findings on projecting chromaticity.

The development of shifting radioactive material

International Nuclear Information System (INIS)

Chen Haiteng; Chen Yonghong; Yin Fujun; Che Mingsheng; Hu Xiaodan; Yao Shouzhong

2010-01-01

In nuclear field, When the nuclear material shifting from the glove-box,use the technology of plastic welding package in accordance with tradition. There are some defects in this technology because of the plastic character, such as package pierced easily, wrapper not fitted storage for long term, etc. Because of this limit. Plastic shifting technology is only fit for shifting radwaste and nuclear material not need storage from radioactive close area to non-radioactive open area for long term.As the nuclear material exiting leak when shifting in plastic package,and the plastic material don't meet the need of storaging safely for long term.We research into a new technology of nuclear material shifting. When nuclear material is carried out from the glove box. It should be sealed by welding case, then it can be storaged safely for long term. At the same time, nuclear material wouldn't pollute the glove box outside.The study achieved well effect in apply. (authors)

Association between rotating night shift work and metabolic syndrome in Korean workers: differences between 8-hour and 12-hour rotating shift work.

Science.gov (United States)

Oh, Jae-Il; Yim, Hyeon Woo

2018-02-07

This study aimed to analyze the association between the shift work schedule and metabolic syndrome (MetS). This is a retrospective longitudinal study based on the 2015 health checkup data of 2,090 workers evaluated for MetS in 2010 at a general hospital in Korea. The participants were divided according to their shift work schedule into daytime, three-shift (8-h rotation), and two-shift (12-h rotation) workers. The index that indicates the association between the shift work schedule and MetS is the odds ratio (OR) calculated using multivariate logistic regression. The analysis for the entire group of workers indicated that there was positive association between two-shift rotation and MetS (OR=1.58, 95% confidence interval [CI]: 1.09, 2.29). In the analysis of rotating night-shift workers, the years of rotating night shifts, frequency of night-shift work, and sleep disturbance were added to the confounding variables, and two-shift work remained positively associated with MetS (OR=1.72, 95% CI: 1.10, 2.70). The risk of MetS differs based on the shift work schedules they engage in. Hence, structural changes to the shift work schedules are required to prevent MetS in night-shift workers.

Shift work and age in the offshore petroleum industry

OpenAIRE

Waage, Siri; Pallesen, Ståle; Moen, Bente Elisabeth; Bjorvatn, Bjørn

2010-01-01

Background. Shift work is associated with sleep and health problems. Tolerance to shift work is reported to decrease with age. Shift work tolerance should be considered in different shift work populations. The aim of the study was to examine the relationship between age, shift work exposure, shift type, and morningness and sleep/health problems in oil rig shift workers. Material and methods. A total of 199 workers participated. They worked either two weeks of 12-h day shifts (n = 96) or tw...

Flexible Schedules and Shift Work.

Science.gov (United States)

Beers, Thomas M.

2000-01-01

Flexible work hours have gained prominence, as more than 25 million workers (27.6% of all full-time workers) can now vary their schedules. However, there has been little change since the mid-1980s in the proportion who work a shift other than a regular daytime shift. (JOW)

Galaxies at z~7-8: z850-Dropouts in the Hubble Ultra Deep Field

Science.gov (United States)

Bouwens, R. J.; Thompson, R. I.; Illingworth, G. D.; Franx, M.; van Dokkum, P. G.; Fan, X.; Dickinson, M. E.; Eisenstein, D. J.; Rieke, M. J.

2004-12-01

We have detected likely z~7-8 galaxies in the 144''×144'' Near-Infrared Camera and Multi-Object Spectrometer (NICMOS) observations of the Hubble Ultra Deep Field. Objects are required to be >=3 σ detections in both NICMOS bands, J110 and H160. The selection criteria for this sample are (z850-J110)AB>0.8, (z850-J110)AB>0.66(J110-H160)AB+0.8, (J110-H160)ABdropout galaxies and are clustered within a 1 arcmin2 region. Because all five sources are near the limit of the NICMOS data, we have carefully evaluated their reality. Each of the candidates is visible in different splits of the data and a median stack. We analyzed several noise images and estimate the number of spurious sources to be 1+/-1. A search using an independent reduction of this same data set clearly revealed three of the five candidates and weakly detected a fourth candidate, suggesting that the contamination could be higher. For comparison with predictions from lower redshift samples, we take a conservative approach and adopt four z~7-8 galaxies as our sample. With the same detection criteria on simulated data sets, assuming no evolution from z~3.8, we predict 10 sources at z~7-8, or 14 if we use a more realistic (1+z)-1 size scaling. We estimate that the rest-frame continuum UV (~1800 Å) luminosity density at z~7.5 (integrated down to 0.3L*z=3) is just 0.20+0.12-0.08 times that found at z~3.8 (or 0.20+0.23-0.12 times this quantity including cosmic variance). Effectively this sets an upper limit on the luminosity density down to 0.3L*z=3 and is consistent with significant evolution at the bright end of the luminosity function from z~7.5 to 3.8. Even with the lower UV luminosity density at z~7.5, it appears that galaxies could still play an important role in reionization at these redshifts, although definitive measurements remain to be made. Based on observations made with the NASA/ESA Hubble Space Telescope, which is operated by the Association of Universities for Research in Astronomy, Inc., under

Ecosystem regime shifts disrupt trophic structure.

Science.gov (United States)

Hempson, Tessa N; Graham, Nicholas A J; MacNeil, M Aaron; Hoey, Andrew S; Wilson, Shaun K

2018-01-01

Regime shifts between alternative stable ecosystem states are becoming commonplace due to the combined effects of local stressors and global climate change. Alternative states are characterized as substantially different in form and function from pre-disturbance states, disrupting the delivery of ecosystem services and functions. On coral reefs, regime shifts are typically characterized by a change in the benthic composition from coral to macroalgal dominance. Such fundamental shifts in the benthos are anticipated to impact associated fish communities that are reliant on the reef for food and shelter, yet there is limited understanding of how regime shifts propagate through the fish community over time, relative to initial or recovery conditions. This study addresses this knowledge gap using long-term data of coral reef regime shifts and recovery on Seychelles reefs following the 1998 mass bleaching event. It shows how trophic structure of the reef fish community becomes increasingly dissimilar between alternative reef ecosystem states (regime-shifted vs. recovering) with time since disturbance. Regime-shifted reefs developed a concave trophic structure, with increased biomass in base trophic levels as herbivorous species benefitted from increased algal resources. Mid trophic level species, including specialists such as corallivores, declined with loss of coral habitat, while biomass was retained in upper trophic levels by large-bodied, generalist invertivores. Recovering reefs also experienced an initial decline in mid trophic level biomass, but moved toward a bottom-heavy pyramid shape, with a wide range of feeding groups (e.g., planktivores, corallivores, omnivores) represented at mid trophic levels. Given the importance of coral reef fishes in maintaining the ecological function of coral reef ecosystems and their associated fisheries, understanding the effects of regime shifts on these communities is essential to inform decisions that enhance ecological

Achieving excellence on shift through teamwork

International Nuclear Information System (INIS)

Newman, L.

1988-01-01

Anyone familiar with the nuclear industry realizes the importance of operators. Operators can achieve error-free plant operations, i.e., excellence on shift through teamwork. As a shift supervisor (senior reactor operator/shift technical advisor) the author went through the plant's first cycle of operations with no scrams and no equipment damaged by operator error, having since changed roles (and companies) to one of assessing plant operations. This change has provided the opportunity to see objectively the importance of operators working together and of the team building and teamwork that contribute to the shift's success. This paper uses examples to show the effectiveness of working together and outlines steps for building a group of operators into a team

Shift in Food Intake and Changes in Metabolic Regulation and Gene Expression during Simulated Night-Shift Work : A Rat Model

NARCIS (Netherlands)

Marti, Andrea Rørvik; Meerlo, Peter; Grønli, Janne; van Hasselt, Sjoerd Johan; Mrdalj, Jelena; Pallesen, Ståle; Pedersen, Torhild Thue; Henriksen, Tone Elise Gjøtterud; Skrede, Silje

2016-01-01

Night-shift work is linked to a shift in food intake toward the normal sleeping period, and to metabolic disturbance. We applied a rat model of night-shift work to assess the immediate effects of such a shift in food intake on metabolism. Male Wistar rats were subjected to 8 h of forced activity

Objectively measured physical activity of hospital shift workers.

NARCIS (Netherlands)

Loef, Bette; van der Beek, Allard J; Holtermann, Andreas; Hulsegge, Gerben; van Baarle, Debbie; Proper, Karin I

2018-01-01

Objectives Shift work may alter workers' leisure-time and occupational physical activity (PA) levels, which might be one of the potential underlying mechanisms of the negative health effects of shift work. Therefore, we compared objectively measured PA levels between hospital shift and non-shift

Evaluating the traditional day and night shift in an acute care surgery fellowship: Is the swing shift a better choice?

Science.gov (United States)

Chestovich, Paul J; McNicoll, Christopher F; Ingalls, Nichole K; Kuhls, Deborah A; Fraser, Douglas R; Morrissey, Shawna L; Fildes, John J

2018-01-01

Fellowship trainees in acute care surgery require experience in the management of complex and operative trauma cases. Trauma center staffing usually follows standard 12-hour or 24-hour shifts, with resident and fellow trainees following a similar schedule. Although trauma admissions can be generally unpredictable, we analyzed temporal trends of trauma patient arrival times to determine the best time frame to maximize trainee experience during each day. We reviewed 10 years (2007-2016) of trauma registry data for blunt and penetrating trauma activations. Hourly volumetric trends were observed, and three specific events were chosen for detailed analysis: (1) trauma activation with Injury Severity Score (ISS) greater than 15, (2) laparotomy for trauma, and (3) thoracotomy for trauma. A retrospective shift log was created, which included day (7:00 AM to 7:00 PM), night (7:00 PM to 7:00 AM), and swing (noon to midnight) shifts. A swing shift was chosen because it captures the peak volume for all three events. Means and 95% confidence intervals were calculated, and comparisons were made between shifts using the Wilcoxon matched-pairs signed rank test with Bonferroni correction, and p less than 0.05 considered significant. During the 10-year study period, 28,287 patients were treated at our trauma center. This included the evaluation and management of 7,874 patients with ISS greater than 15, performance of 1,766 laparotomies, and 392 thoracotomies for trauma. Swing shift was superior to both day and night shifts for ISS greater than 15 (p night shifts were superior to day shift for laparotomies (p day shift (p night shift (p = 0.031). Shifts with the highest yield of ISS greater than 15, laparotomies, and thoracotomies include night and swing shifts on Fridays and Saturdays. Projected experience of acute care surgery fellows in managing complex trauma patients increases with the integration of swing shifts into the schedule. Daily trauma volume follows a temporal pattern

Random coil chemical shift for intrinsically disordered proteins

DEFF Research Database (Denmark)

Kjærgaard, Magnus; Brander, Søren; Poulsen, Flemming Martin

2011-01-01

. Temperature has a non-negligible effect on the (13)C random coil chemical shifts, so temperature coefficients are reported for the random coil chemical shifts to allow extrapolation to other temperatures. The pH dependence of the histidine random coil chemical shifts is investigated in a titration series......, which allows the accurate random coil chemical shifts to be obtained at any pH. By correcting the random coil chemical shifts for the effects of temperature and pH, systematic biases of the secondary chemical shifts are minimized, which will improve the reliability of detection of transient secondary...

Associations between shift schedule characteristics with sleep, need for recovery, health and performance measures for regular (semi-)continuous 3-shift systems.

Science.gov (United States)

van de Ven, Hardy A; Brouwer, Sandra; Koolhaas, Wendy; Goudswaard, Anneke; de Looze, Michiel P; Kecklund, Göran; Almansa, Josue; Bültmann, Ute; van der Klink, Jac J L

2016-09-01

In this cross-sectional study associations were examined between eight shift schedule characteristics with shift-specific sleep complaints and need for recovery and generic health and performance measures. It was hypothesized that shift schedule characteristics meeting ergonomic recommendations are associated with better sleep, need for recovery, health and performance. Questionnaire data were collected from 491 shift workers of 18 companies with 9 regular (semi)-continuous shift schedules. The shift schedule characteristics were analyzed separately and combined using multilevel linear regression models. The hypothesis was largely not confirmed. Relatively few associations were found, of which the majority was in the direction as expected. In particular early starts of morning shifts and many consecutive shifts seem to be avoided. The healthy worker effect, limited variation between included schedules and the cross-sectional design might explain the paucity of significant results. Copyright © 2016 Elsevier Ltd. All rights reserved.

Shift Performance Test and Analysis of Multipurpose Vehicle

Directory of Open Access Journals (Sweden)

Can Yang

2014-08-01

Full Text Available This paper presented an analysis of the gear shifting performances of a multipurpose vehicle transmission in driving condition by Ricardo's Gear Shift Quality Assessment (GSQA system. The performances of the transmission included the travel and effort of the gear shift lever and synchronizing time. The mathematic models of the transmission including the gear shift mechanism and synchronizer were developed in MATLAB. The model of the gear shift mechanism was developed to analyze the travel map of the gear shift lever and the model of the synchronizer was developed to obtain the force-time curve of the synchronizer during the slipping time. The model of the synchronizer was used to investigate the relationship between the performances of the transmission and the variation of parameters during gear shifting. The mathematic models of the gear shift mechanism and the synchronizer provided a rapid design and verification method for the transmission with ring spring.

Study on Inertia as a Gravity Induced Property of Mass, in an Infinite Hubble Expanding Universe

Directory of Open Access Journals (Sweden)

Jeroen van Engelshoven

2013-01-01

Full Text Available Mass is experienced to have two intrinsic properties: inertia (resistance to acceleration and gravity (attraction to other masses. In this paper we evaluate the gravitational effect of all masses of the universe on an accelerated mass, starting from linearized general relativity. The gravitational interaction of all masses in a finite static universe model is shown to create a finite resistance to acceleration, which is inertia. Then, we propose a generalization of the linearized theory and evaluate the Hubble expanding universe. It is shown that the gravitational impact of an infinite expanding universe creates finite inertia, according to . The Friedmann critical mass density is found to be valid. The Mach principle is made explicit. The value and sign of the gravitational constant G are found to be of no consequence on an astronomical scale.

Night shift and rotating shift in association with sleep problems, burnout and minor mental disorder in male and female employees.

Science.gov (United States)

Cheng, Wan-Ju; Cheng, Yawen

2017-07-01

Shift work is associated with adverse physical and psychological health outcomes. However, the independent health effects of night work and rotating shift on workers' sleep and mental health risks and the potential gender differences have not been fully evaluated. We used data from a nationwide survey of representative employees of Taiwan in 2013, consisting of 16 440 employees. Participants reported their work shift patterns 1 week prior to the survey, which were classified into the four following shift types: fixed day, rotating day, fixed night and rotating night shifts. Also obtained were self-reported sleep duration, presence of insomnia, burnout and mental disorder assessed by the Brief Symptom Rating Scale. Among all shift types, workers with fixed night shifts were found to have the shortest duration of sleep, highest level of burnout score, and highest prevalence of insomnia and minor mental disorders. Gender-stratified regression analyses with adjustment of age, education and psychosocial work conditions showed that both in male and female workers, fixed night shifts were associated with greater risks for short sleep duration (night shifts were also associated with increased risks for burnout and mental disorders, but after adjusting for insomnia, the associations between fixed night shifts and poor mental health were no longer significant. The findings of this study suggested that a fixed night shift was associated with greater risks for sleep and mental health problems, and the associations might be mediated by sleep disturbance. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Validity of self-reported exposure to shift work.

Science.gov (United States)

Härmä, Mikko; Koskinen, Aki; Ropponen, Annina; Puttonen, Sampsa; Karhula, Kati; Vahtera, Jussi; Kivimäki, Mika

2017-03-01

To evaluate the validity of widely used questionnaire items on work schedule using objective registry data as reference. A cohort study of hospital employees who responded to a self-administered questionnaire on work schedule in 2008, 2012 and 2014 and were linked to individual-level pay-roll-based records on work shifts. For predictive validity, leisure-time fatigue was assessed. According to the survey data in 2014 (n=8896), 55% of the day workers had at least 1 year of earlier shift work experience. 8% of the night shift workers changed to day work during the follow-up. Using pay-roll data as reference, questions on 'shift work with night shifts' and 'permanent night work' showed high sensitivity (96% and 90%) and specificity (92% and 97%). Self-reported 'regular day work' showed moderate sensitivity (73%), but high specificity (99%) and 'shift work without night shifts' showed low sensitivity (62%) and moderate specificity (87%). In multivariate logistic regression analysis, the age-adjusted, sex-adjusted and baseline fatigue-adjusted association between 'shift work without night shifts' and leisure-time fatigue was lower for self-reported compared with objective assessment (1.30, 95% CI 0.94 to 1.82, n=1707 vs 1.89, 95% CI 1.06 to 3.39, n=1627). In contrast, shift work with night shifts, compared with permanent day work, was similarly associated with fatigue in the two assessments (2.04, 95% CI 1.62 to 2.57, n=2311 vs 1.82, 95% CI 1.28 to 2.58, n=1804). The validity of self-reported assessment of shift work varies between work schedules. Exposure misclassification in self-reported data may contribute to bias towards the null in shift work without night shifts. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

5 CFR 532.505 - Night shift differentials.

Science.gov (United States)

2010-01-01

... 5 Administrative Personnel 1 2010-01-01 2010-01-01 false Night shift differentials. 532.505... PREVAILING RATE SYSTEMS Premium Pay and Differentials § 532.505 Night shift differentials. (a) Employees shall be entitled to receive night shift differentials in accordance with section 5343 of title 5...

Shifting Cultivation : Promoting Innovative Policy and Development ...

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

Shifting Cultivation : Promoting Innovative Policy and Development Options in the Eastern Himalayas. Shifting ... pressure and market forces. The idea is to share good policies and practices related to shifting cultivation and alternative options through regional exchange. ... Les chaînes de valeur comme leviers stratégiques.

Paradigm Shifts in Ophthalmic Diagnostics.

Science.gov (United States)

Sebag, J; Sadun, Alfredo A; Pierce, Eric A

2016-08-01

Future advances in ophthalmology will see a paradigm shift in diagnostics from a focus on dysfunction and disease to better measures of psychophysical function and health. Practical methods to define genotypes will be increasingly important and non-invasive nanotechnologies are needed to detect molecular changes that predate histopathology. This is not a review nor meant to be comprehensive. Specific topics have been selected to illustrate the principles of important paradigm shifts that will influence the future of ophthalmic diagnostics. It is our impression that future evaluation of vision will go beyond visual acuity to assess ocular health in terms of psychophysical function. The definition of disease will incorporate genotype into what has historically been a phenotype-centric discipline. Non-invasive nanotechnologies will enable a paradigm shift from disease detection on a cellular level to a sub-cellular molecular level. Vision can be evaluated beyond visual acuity by measuring contrast sensitivity, color vision, and macular function, as these provide better insights into the impact of aging and disease. Distortions can be quantified and the psychophysical basis of vision can be better evaluated than in the past by designing tests that assess particular macular cell function(s). Advances in our understanding of the genetic basis of eye diseases will enable better characterization of ocular health and disease. Non-invasive nanotechnologies can assess molecular changes in the lens, vitreous, and macula that predate visible pathology. Oxygen metabolism and circulatory physiology are measurable indices of ocular health that can detect variations of physiology and early disease. This overview of paradigm shifts in ophthalmology suggests that the future will see significant improvements in ophthalmic diagnostics. The selected topics illustrate the principles of these paradigm shifts and should serve as a guide to further research and development. Indeed

The UDF05 Follow-Up of the Hubble Ultra Deep Field. II. Constraints on Reionization from Z-Dropout Galaxies

Science.gov (United States)

Oesch, P. A.; Carollo, C. M.; Stiavelli, M.; Trenti, M.; Bergeron, L. E.; Koekemoer, A. M.; Lucas, R. A.; Pavlovsky, C. M.; Beckwith, S. V. W.; Dahlen, T.; Ferguson, H. C.; Gardner, Jonathan P.; Lilly, S. J.; Mobasher, B.; Panagia, N.

2009-01-01

We detect three (plus one less certain) z 850-dropout sources in two separate fields (Hubble Ultra Deep Field and NICP34) of our UDF05 Hubble Space Telescope Near-Infrared Camera and Multi-Object Spectrometer images. These z ~ 7 Lyman-break Galaxy (LBG) candidates allow us to constrain the Luminosity Function (LF) of the star-forming galaxy population at those epochs. By assuming a change in only M * and adopting a linear evolution in redshift, anchored to the measured values at z ~ 6, the best-fit evolution coefficient is found to be 0.43 ± 0.19 mag per unit redshift (0.36 ± 0.18, if including all four candidates), which provides a value of M *(z = 7.2) = -19.7 ± 0.3. This implies a drop in the luminosity density in LBGs by a factor of ~2-2.5 over the ~ 170 Myr that separate z ~ 6 and z ~ 7, and a steady evolution for the LBG LF out to z ~ 7, at the same rate that is observed throughout the z ~ 3-6 period. This puts a strong constraint on the star-formation histories of z ~ 6 galaxies, whose ensemble star-formation rate (SFR) density must be lower by a factor of 2 at ~ 170 Myr before the epoch at which they are observed. In particular, a large fraction of stars in the z ~ 6 LBG population must form at redshifts well above z ~ 7. The rate of ionizing photons produced by the LBG population consistently decreases with the decrease in the cosmic SFR density. Extrapolating this steady evolution of the LF out to higher redshifts, we estimate that galaxies would be able to reionize the universe by z ~ 6, provided that the faint-end slope of the z > 7 LF steepens to α ~ -1.9 and that faint galaxies with luminosities below the current detection limits contribute a substantial fraction of the required ionizing photons. This scenario, however, gives an integrated optical depth to electron scattering that is ~2σ below the Wilkinson Microwave Anisotropy Probe-5 measurement. Therefore, altogether, our results indicate that, should galaxies be the primary contributors to

Solvent Effects on Oxygen-17 Chemical Shifts in Amides. Quantitative Linear Solvation Shift Relationships

Science.gov (United States)

Díez, Ernesto; Fabián, Jesús San; Gerothanassis, Ioannis P.; Esteban, Angel L.; Abboud, José-Luis M.; Contreras, Ruben H.; de Kowalewski, Dora G.

1997-01-01

A multiple-linear-regression analysis (MLRA) has been carried out using the Kamlet-Abboud-Taft (KAT) solvatochromic parameters in order to elucidate and quantify the solvent effects on the17O chemical shifts ofN-methylformamide (NMF),N,N-dimethylformamide (DMF),N-methylacetamide (NMA), andN,N-dimethylacetamide (DMA). The chemical shifts of the four molecules show the same dependence (in ppm) on the solvent polarity-polarizability, i.e., -22π*. The influence of the solvent hydrogen-bond-donor (HBD) acidities is slightly larger for the acetamides NMA and DMA, i.e., -48α, than for the formamides NMF and DMF, i.e., -42α. The influence of the solvent hydrogen-bond-acceptor (HBA) basicities is negligible for the nonprotic molecules DMF and DMA but significant for the protic molecules NMF and NMA, i.e., -9β. The effect of substituting the N-H hydrogen by a methyl group amounts to -5.9 ppm in NMF and 5.4 ppm in NMA. The effect of substituting the O=C-H hydrogen amounts to 5.5 ppm in NMF and 16.8 ppm in DMF. The model of specific hydration sites of amides by I. P. Gerothanassis and C. Vakka [J. Org. Chem.59,2341 (1994)] is settled in a more quantitative basis and the model by M. I. Burgar, T. E. St. Amour, and D. Fiat [J. Phys. Chem.85,502 (1981)] is critically evaluated.17O hydration shifts have been calculated for formamide (FOR) by the ab initio LORG method at the 6-31G* level. For a formamide surrounded by the four in-plane molecules of water in the first hydration shell, the calculated17O shift change due to the four hydrogen bonds, -83.2 ppm, is smaller than the empirical hydration shift, -100 ppm. The17O shift change from each out-of-plane water molecule hydrogen-bonded to the amide oxygen is -18.0 ppm. These LORG results support the conclusion that no more than four water molecules are hydrogen-bonded to the amide oxygen in formamide.

Identifying Patterns of Participant Shifts in the Psalms

NARCIS (Netherlands)

Erwich, C.M.

2017-01-01

A great challenge of reading the Hebrew poetry of the Psalms is the identification of participants. The major cause of this problem is a continual shift in person, gender and number (so-called PGN-shifts, or participant shifts) in the text. To account for these PGN-shifts, scholars have always used

The Relationship Between Shift Work and Men's Health.

Science.gov (United States)

Deng, Nanfu; Kohn, Taylor P; Lipshultz, Larry I; Pastuszak, Alexander W

2018-01-19

More than 21 million Americans and nearly 20% of the U.S. workforce are shift workers. Non-standard shift work, defined as work that falls outside of 6 am-6 pm, can lead to poor diet, exercise, and sleep habits that lead to decreased productivity, increased workplace accidents, and a variety of negative health outcomes. To investigate the associations between shift work exposure and chronic medical conditions such as metabolic syndromes, cardiovascular disease, gastrointestinal disturbances, and depression as well as urologic complications including hypogonadism, male infertility, lower urinary tract symptoms, and prostate cancer with a focus on the effects of shift work sleep disorder (SWSD) on the severity of these negative health outcomes. We reviewed the literature examining effects of shift work and SWSD on general and urologic health. We produced a summary of effects of shift work on health with focus on the increased risk of negative health outcomes in non-standard shift workers, particularly those with SWSD, when compared to daytime workers or workers without SWSD. Studies have associated non-standard shift work schedules and poor health outcomes, including increased risks of diabetes mellitus, dyslipidemia, hypertension, heart disease, peptic ulcer disease, and depression, in shift workers. However, few studies have focused on the role that shift work plays in men's urologic health. Current evidence supports associations between non-standard shift work and increased hypogonadal symptoms, poor semen parameters, decreased fertility, lower urinary tract symptoms, and prostate cancer. These associations are strengthened by the presence of SWSD, which affects up to 20% of shift workers. Unfortunately, interventions, such as planned naps, timed light exposure, melatonin, and sedative hypnotics, aimed at alleviating excessive nighttime sleepiness and daytime insomnia in non-standard shift workers experiencing SWSD, are limited and lack strong evidence to support

Shift-Variant Multidimensional Systems.

Science.gov (United States)

1985-05-29

x,y;u,v) is the system response at (x,y) to an unit impulse applied at (u,v). The presence of additive noise in the preceding input-output model of a...space model developed works very effi- ciently to deblur images affected by 2-D linear shift- varying blurs, its use, in presence of noise needs to be...causal linear shift-variant (LSV) system, whose impulse res- ponse is a K-th order degenerate sequence, a K-th order state-space model was obtained

Hubble Space Telescope Imaging of the Mass-losing Supergiant VY Canis Majoris

Science.gov (United States)

Kastner, Joel H.; Weintraub, David A.

1998-04-01

The highly luminous M supergiant VY CMa is a massive star that appears to be in its final death throes, losing mass at high rate en route to exploding as a supernova. Subarcsecond-resolution optical images of VY CMa, obtained with the Faint Object Camera (FOC) aboard the Hubble Space Telescope, vividly demonstrate that mass loss from VY CMa is highly anisotropic. In the FOC images, the optical ``star'' VY CMa constitutes the bright, well-resolved core of an elongated reflection nebula. The imaged nebula is ~3" (~4500 AU) in extent and is clumpy and highly asymmetric. The images indicate that the bright core, which lies near one edge of the nebula, is pure scattered starlight. We conclude that at optical wavelengths VY CMa is obscured from view along our line of sight by its own dusty envelope. The presence of the extended reflection nebula then suggests that this envelope is highly flattened and/or that the star is surrounded by a massive circumstellar disk. Such axisymmetric circumstellar density structure should have profound effects on post-red supergiant mass loss from VY CMa and, ultimately, on the shaping of the remnant of the supernova that will terminate its post-main-sequence evolution.

[Sleep disorders among physicians on shift work].

Science.gov (United States)

Schlafer, O; Wenzel, V; Högl, B

2014-11-01

Sleep disorders in physicians who perform shift work can result in increased risks of health problems that negatively impact performance and patient safety. Even those who cope well with shift work are likely to suffer from sleep disorders. The aim of this manuscript is to discuss possible causes, contributing factors and consequences of sleep disorders in physicians and to identify measures that can improve adaptation to shift work and treatment strategies for shift work-associated sleep disorders. The risk factors that influence the development of sleep disorders in physicians are numerous and include genetic factors (15 % of the population), age (> 50 years), undiagnosed sleep apnea,, alcohol abuse as well as multiple stress factors inherent in clinical duties (including shift work), research, teaching and family obligations. Several studies have reported an increased risk for medical errors in sleep-deprived physicians. Shift workers have an increased risk for psychiatric and cardiovascular diseases and shift work may also be a contributing factor to cancer. A relationship has been reported not only with sleep deprivation and changes in food intake but also with diabetes mellitus, obesity, hypertension and coronary heart disease. Nicotine and alcohol consumption are more frequent among shift workers. Increased sickness and accident rates among physicians when commuting (especially after night shifts) have a socioeconomic impact. In order to reduce fatigue and to improve performance, short naps during shiftwork or naps plus caffeine, have been proposed as coping strategies; however, napping during adverse circadian phases is less effective, if not impossible when unable to fall asleep. Bright and blue light supports alertness during a night shift. After shiftwork, direct sunlight exposure to the retina can be avoided by using dark sunglasses or glasses with orange lenses for commuting home. The home environment for daytime sleeping after a night shift should be

Frequency-shift vs phase-shift characterization of in-liquid quartz crystal microbalance applications

International Nuclear Information System (INIS)

Montagut, Y. J.; Garcia, J. V.; Jimenez, Y.; Arnau, A.; March, C.; Montoya, A.

2011-01-01

The improvement of sensitivity in quartz crystal microbalance (QCM) applications has been addressed in the last decades by increasing the sensor fundamental frequency, following the increment of the frequency/mass sensitivity with the square of frequency predicted by Sauerbrey. However, this sensitivity improvement has not been completely transferred in terms of resolution. The decrease of frequency stability due to the increase of the phase noise, particularly in oscillators, made impossible to reach the expected resolution. A new concept of sensor characterization at constant frequency has been recently proposed. The validation of the new concept is presented in this work. An immunosensor application for the detection of a low molecular weight contaminant, the insecticide carbaryl, has been chosen for the validation. An, in principle, improved version of a balanced-bridge oscillator is validated for its use in liquids, and applied for the frequency shift characterization of the QCM immunosensor application. The classical frequency shift characterization is compared with the new phase-shift characterization concept and system proposed.

Determination and characterization of the Hubble Space Telescope pointing stability

Science.gov (United States)

Bradley, A. J.; Connor, C. T.; del Toro, Y.; Andersen, G. C.; Bely, Pierre Y.; Decker, J.; Franz, O. G.; Wasserman, L. H.; van Altena, William F.

The Hubble Space Telescope (HST) was designed to maintian a pointing stability (jitter) of 0.007 arc seconds rms throughout every observing period, which can last from a few seconds to several orbits. On-orbit measurements indicate that the hardware excitation induced by the reaction wheels. gyros, high gain antennae, science instrument mechanisms and tape recorders are well within specifications. Unexpectedly, the solar arrays because the dominant source of jitter. Every passage through an orbital terminator produces vibrations which emanate from the solar arrays due to thermal effects, which affect the relative positional stability. Broadband frequencies centered about 0.11 and 0.65 Hz were detected in the frequency content of the vehicle jitter. On-board modifications to the control law have attenuated the disturbance torques and reduced the vehicle jitter close to specification. Replacement of the solar arrays in December, 1993, should eliminate the torque distubances. Astrometric science observations are extremely susceptible to corruption from vehicle jitter. The removal of vehicle jitter from astrometric Transfer function scans of binary stars is explained in detail. A binary star separation of 16 milli-seconds of arc has been achieved, a separation resolution of 10 to 12 milli-seconds of arc appears feasible, with a binary star magnitude of 9 m(sub V). The achievement of this resolution is in part due to vehicle jitter removal. Comparison of vehicle jitter measurements from the position path of the vehicle control law, or from the guiding Fine Guidance Sensors (FGS), are shown to be equivalent to approximately 0.001 arc second.

Does workplace health promotion reach shift workers?

DEFF Research Database (Denmark)

Nabe-Nielsen, Kirsten; Garde, Anne Helene; Clausen, Thomas

2015-01-01

OBJECTIVES: One reason for health disparities between shift and day workers may be that workplace health promotion does not reach shift workers to the same extent as it reaches day workers. This study aimed to investigate the association between shift work and the availability of and participation...... in workplace health promotion. METHODS: We used cross-sectional questionnaire data from a large representative sample of all employed people in Denmark. We obtained information on the availability of and participation in six types of workplace health promotion. We also obtained information on working hours, ie......). RESULTS: In the general working population, fixed evening and fixed night workers, and employees working variable shifts including night work reported a higher availability of health promotion, while employees working variable shifts without night work reported a lower availability of health promotion...

Lung function studies before and after a work shift

Energy Technology Data Exchange (ETDEWEB)

Love, R G

1983-05-01

The lung function of 23 underground coal workers and eight surface workers at a Scottish colliery was measured immediately before and after a work shift. Changes in lung function were assessed in relation to the measured respirable dust exposure and the time of day in which the shift was worked. Large, and statistically significant, decrements of lung function during the shift were found in night-shift workers compared with workers on other shifts. Measurements derived from the forced expiratory manoeuvre, particularly FEV1, Vmax50, and Vmax25, after three vital capacity breaths of an 80% He/20% O2 mixture, showed large reductions in night-shift men, smaller reductions in afternoon-shift men, and small increases or decreases in morning-shift underground and surface workers. Within-shift changes for other tests, such as closing volume, N2 index, and volume of isoflow, did not differ significantly between shifts. No significant relationship was found between dust exposure and functional changes during a shift for any test. Lung function changes in a control group of 25 female workers not exposed to dust (hospital nurses) did not show the same large variations between day and night shifts. Examination of a further control group of 16 office workers did not show any difference in diurnal changes between smokers and non-smokers. It is concluded that these coal miners, even on permanent shift patterns, had widely different changes in their lung function cycle depending on which shift they were working. These changes did not appear to be related to dust exposure or cigarette smoking and were not consistent with other biological adaptations known to result from regular night-shift working.

DISCOVERY OF z ∼ 8 GALAXIES IN THE HUBBLE ULTRA DEEP FIELD FROM ULTRA-DEEP WFC3/IR OBSERVATIONS

International Nuclear Information System (INIS)

Bouwens, R. J.; Illingworth, G. D.; Magee, D.; Gonzalez, V.; Oesch, P. A.; Carollo, C. M.; Stiavelli, M.; Van Dokkum, P.; Trenti, M.; Labbe, I.; Franx, M.

2010-01-01

We utilize the newly acquired, ultra-deep WFC3/IR observations over the Hubble Ultra Deep Field (HUDF) to search for star-forming galaxies at z ∼ 8-8.5, only 600 million years from recombination, using a Y 105 -dropout selection. The new 4.7 arcmin 2 WFC3/IR observations reach to ∼28.8 AB mag (5σ) in the Y 105 J 125 H 160 bands. These remarkable data reach ∼1.5 AB mag deeper than the previous data over the HUDF, and now are an excellent match to the HUDF optical ACS data. For our search criteria, we use a two-color Lyman break selection technique to identify z ∼ 8-8.5Y 105 -dropouts. We find five likely z ∼ 8-8.5 candidates. The sources have H 160 -band magnitudes of ∼28.3 AB mag and very blue UV-continuum slopes, with a median estimated β of ∼ λ ∝ λ β ). This suggests that z ∼ 8 galaxies are not only essentially dust free but also may have very young ages or low metallicities. The observed number of Y 105 -dropout candidates is smaller than the 20 ± 6 sources expected assuming no evolution from z ∼ 6, but is consistent with the five expected extrapolating the Bouwens et al. luminosity function (LF) results to z ∼ 8. These results provide evidence that the evolution in the LF seen from z ∼ 7 to z ∼ 3 continues to z ∼ 8. The remarkable improvement in the sensitivity of WFC3/IR has enabled Hubble Space Telescope to cross a threshold, revealing star-forming galaxies at z∼ 8-9.

THE UDF05 FOLLOW-UP OF THE HUBBLE ULTRA DEEP FIELD. III. THE LUMINOSITY FUNCTION AT z ∼ 6

International Nuclear Information System (INIS)

Su Jian; Stiavelli, Massimo; Bergeron, Eddie; Bradley, Larry; Dahlen, Tomas; Ferguson, Henry C.; Koekemoer, Anton; Lucas, Ray A.; Panagia, Nino; Pavlovsky, Cheryl; Oesch, Pascal; Carollo, Marcella; Lilly, Simon; Trenti, Michele; Giavalisco, Mauro; Mobasher, Bahram

2011-01-01

In this paper, we present a derivation of the rest-frame 1400 A luminosity function (LF) at redshift six from a new application of the maximum likelihood method by exploring the five deepest Hubble Space Telescope/Advanced Camera for Surveys (HST/ACS) fields, i.e., the Hubble Ultra Deep Field, two UDF05 fields, and two Great Observatories Origins Deep Survey fields. We work on the latest improved data products, which makes our results more robust than those of previous studies. We use unbinned data and thereby make optimal use of the information contained in the data set. We focus on the analysis to a magnitude limit where the completeness is larger than 50% to avoid possibly large errors in the faint end slope that are difficult to quantify. We also take into account scattering in and out of the dropout sample due to photometric errors by defining for each object a probability that it belongs to the dropout sample. We find the best-fit Schechter parameters to the z ∼ 6 LF are α = 1.87 ± 0.14, M * = -20.25 ± 0.23, and φ * = 1.77 +0.62 -0.49 x 10 -3 Mpc -3 . Such a steep slope suggests that galaxies, especially the faint ones, are possibly the main sources of ionizing photons in the universe at redshift six. We also combine results from all studies at z ∼ 6 to reach an agreement in the 95% confidence level that -20.45 * < -20.05 and -1.90 < α < -1.55. The luminosity density has been found not to evolve significantly between z ∼ 6 and z ∼ 5, but considerable evolution is detected from z ∼ 6 to z ∼ 3.

Health consequences of shift work and insufficient sleep.

Science.gov (United States)

Kecklund, Göran; Axelsson, John

2016-11-01

This review summarises the literature on shift work and its relation to insufficient sleep, chronic diseases, and accidents. It is based on 38 meta-analyses and 24 systematic reviews, with additional narrative reviews and articles used for outlining possible mechanisms by which shift work may cause accidents and adverse health. Evidence shows that the effect of shift work on sleep mainly concerns acute sleep loss in connection with night shifts and early morning shifts. A link also exists between shift work and accidents, type 2 diabetes (relative risk range 1.09-1.40), weight gain, coronary heart disease (relative risk 1.23), stroke (relative risk 1.05), and cancer (relative risk range 1.01-1.32), although the original studies showed mixed results. The relations of shift work to cardiometabolic diseases and accidents mimic those with insufficient sleep. Laboratory studies indicate that cardiometabolic stress and cognitive impairments are increased by shift work, as well as by sleep loss. Given that the health and safety consequences of shift work and insufficient sleep are very similar, they are likely to share common mechanisms. However, additional research is needed to determine whether insufficient sleep is a causal pathway for the adverse health effects associated with shift work. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

SOLAR-LIKE OSCILLATIONS IN A METAL-POOR GLOBULAR CLUSTER WITH THE HUBBLE SPACE TELESCOPE

International Nuclear Information System (INIS)

Stello, Dennis; Gilliland, Ronald L.

2009-01-01

We present analyses of variability in the red giant stars in the metal-poor globular cluster NGC 6397, based on data obtained with the Hubble Space Telescope. We use a nonstandard data reduction approach to turn a 23 day observing run originally aimed at imaging the white dwarf population, into time-series photometry of the cluster's highly saturated red giant stars. With this technique we obtain noise levels in the final power spectra down to 50 parts per million, which allows us to search for low-amplitude solar-like oscillations. We compare the observed excess power seen in the power spectra with estimates of the typical frequency range, frequency spacing, and amplitude from scaling the solar oscillations. We see evidence that the detected variability is consistent with solar-like oscillations in at least one and perhaps up to four stars. With metallicities 2 orders of magnitude lower than those of the Sun, these stars present so far the best evidence of solar-like oscillations in such a low-metallicity environment.

THE PECULIAR EXTINCTION LAW OF SN 2014J MEASURED WITH THE HUBBLE SPACE TELESCOPE

Energy Technology Data Exchange (ETDEWEB)

Amanullah, R.; Goobar, A.; Johansson, J.; Petrushevska, T. [Oskar Klein Centre, Physics Department, Stockholm University, SE-106 91 Stockholm (Sweden); Banerjee, D. P. K.; Venkataraman, V.; Joshi, V.; Ashok, N. M. [Physical Research Laboratory, Ahmedabad 380009 (India); Cao, Y.; Kulkarni, S. R. [Cahill Center for Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Kasliwal, M. M. [Observatories of the Carnegie Institution for Science, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Nugent, P. E. [Department of Astronomy, University of California Berkeley, B-20 Hearst Field, Annex # 3411, Berkeley, CA 94720-3411 (United States); Stanishev, V., E-mail: rahman@fysik.su.se [CENTRA—Centro Multidisciplinar de Astrofísica, Instituto Superior Técnico, Av. Rovisco Pais 1, 1049-001 Lisbon (Portugal)

2014-06-20

The wavelength dependence of the extinction of Type Ia SN 2014J in the nearby galaxy M82 has been measured using UV to near-IR photometry obtained with the Hubble Space Telescope, the Nordic Optical Telescope, and the Mount Abu Infrared Telescope. This is the first time that the reddening of an SN Ia is characterized over the full wavelength range of 0.2-2 μm. A total-to-selective extinction, R{sub V} ≥ 3.1, is ruled out with high significance. The best fit at maximum using a Galactic type extinction law yields R{sub V} = 1.4 ± 0.1. The observed reddening of SN 2014J is also compatible with a power-law extinction, A {sub λ}/A{sub V} = (λ/λ {sub V}) {sup p} as expected from multiple scattering of light, with p = –2.1 ± 0.1. After correcting for differences in reddening, SN 2014J appears to be very similar to SN 2011fe over the 14 broadband filter light curves used in our study.

Work shifts in Emergency Medicine

Directory of Open Access Journals (Sweden)

Roberto Recupero

2007-06-01

Full Text Available Emergency Medicine is known as a high stress specialty. The adverse effect of constantly rotating shifts is the single most important reason given for premature attrition from the field. In this work problems tied with night shift work will be taken into account and some solutions to reduce the impact of night work on the emergency physicians will be proposed.

Binaries discovered by the SPY project V. GD 687 - a massive double degenerate binary progenitor that will merge within a Hubble time

OpenAIRE

Geier, S.; Heber, U.; Kupfer, T.; Napiwotzki, R.

2010-01-01

Aims. The ESO SN Ia Progenitor Survey (SPY) aims at finding merging double degenerate binaries as candidates for supernova type Ia (SN Ia) explosions. A white dwarf merger has also been suggested to explain the formation of rare types of stars like R CrB, extreme helium or He sdO stars. Here we present the hot subdwarf B binary GD 687, which will merge in less than a Hubble time. Methods. The orbital parameters of the close binary have been determined from time resolved spectroscopy. Since GD...

Glucose metabolism during rotational shift-work in healthcare workers.

Science.gov (United States)

Sharma, Anu; Laurenti, Marcello C; Dalla Man, Chiara; Varghese, Ron T; Cobelli, Claudio; Rizza, Robert A; Matveyenko, Aleksey; Vella, Adrian

2017-08-01

Shift-work is associated with circadian rhythm disruption and an increased risk of obesity and type 2 diabetes. We sought to determine the effect of rotational shift-work on glucose metabolism in humans. We studied 12 otherwise healthy nurses performing rotational shift-work using a randomised crossover study design. On each occasion, participants underwent an isotope-labelled mixed meal test during a simulated day shift and a simulated night shift, enabling simultaneous measurement of glucose flux and beta cell function using the oral minimal model. We sought to determine differences in fasting and postprandial glucose metabolism during the day shift vs the night shift. Postprandial glycaemic excursion was higher during the night shift (381±33 vs 580±48 mmol/l per 5 h, pshift. While insulin action did not differ between study days, the beta cell responsivity to glucose (59±5 vs 44±4 × 10 -9  min -1 ; pshift. Impaired beta cell function during the night shift may result from normal circadian variation, the effect of rotational shift-work or a combination of both. As a consequence, higher postprandial glucose concentrations are observed during the night shift.

Market shifting

Energy Technology Data Exchange (ETDEWEB)

Forst, Michael

2013-11-01

After years of oversupply and artificially low module pricing, market analysts believe that the solar industry will begin to stabilize by 2017. While the market activities are shifting from Europe to the Asia Pacific region and the United States, the solar shakeout continues to be in full swing including solar cell and module manufacturing. (orig.)

Tough Shift

DEFF Research Database (Denmark)

Brewer, Robert S.; Verdezoto, Nervo; Holst, Thomas

2015-01-01

people to change their behavior at home. Leveraging prior research on encouraging reductions in residential energy use through game play, we introduce ShareBuddy: a casual mobile game intended to encourage players not only to reduce, but also to shift their electricity use. We conducted two field studies...... real-world resource use into a game....

Lateral shifting in one dimensional chiral photonic crystal

Energy Technology Data Exchange (ETDEWEB)

You Yuan, E-mail: yctcyouyuan@163.com [School of Physics and Electronics, Yancheng Teachers University, Yancheng, 224002 Jiangsu (China); Chen Changyuan [School of Physics and Electronics, Yancheng Teachers University, Yancheng, 224002 Jiangsu (China)

2012-07-01

We report the lateral shifts of the transmitted waves in a one dimensional chiral photonic crystal by using the stationary-phase approach. It is revealed that two kinds of lateral shifts are observed due to the existence of cross coupling in chiral materials, which is different from what has been observed in previous non-chiral photonic crystals. Unlike the chiral slab, the positions of lateral shift peaks are closely related to the band edges of band gap characteristics of periodic structure and lateral shifts can be positive as well as negative. Besides, the lateral shifts show a strong dependence on the chiral factor, which varies the lateral shift peaks in both magnitudes and positions. These features are desirable for future device applications.

Lateral shifting in one dimensional chiral photonic crystal

International Nuclear Information System (INIS)

You Yuan; Chen Changyuan

2012-01-01

We report the lateral shifts of the transmitted waves in a one dimensional chiral photonic crystal by using the stationary-phase approach. It is revealed that two kinds of lateral shifts are observed due to the existence of cross coupling in chiral materials, which is different from what has been observed in previous non-chiral photonic crystals. Unlike the chiral slab, the positions of lateral shift peaks are closely related to the band edges of band gap characteristics of periodic structure and lateral shifts can be positive as well as negative. Besides, the lateral shifts show a strong dependence on the chiral factor, which varies the lateral shift peaks in both magnitudes and positions. These features are desirable for future device applications.

Proper Motions of Dwarf Spheroidal Galaxies from Hubble Space Telescope Imaging. III. Measurement for Ursa Minor

Science.gov (United States)

Piatek, Slawomir; Pryor, Carlton; Bristow, Paul; Olszewski, Edward W.; Harris, Hugh C.; Mateo, Mario; Minniti, Dante; Tinney, Christopher G.

2005-07-01

This article presents a measurement of the proper motion of the Ursa Minor dwarf spheroidal galaxy determined from images taken with the Hubble Space Telescope in two distinct fields. Each field contains a quasi-stellar object that serves as the ``reference point.'' The measured proper motion for Ursa Minor, expressed in the equatorial coordinate system, is (μα,μδ)=(-50+/-17,22+/-16) mas century-1. Removing the contributions of the solar motion and the motion of the local standard of rest yields the proper motion in the Galactic rest frame: (μGrfα,μGrfδ)=(-8+/-17,38+/-16) mas century-1. The implied space velocity with respect to the Galactic center has a radial component of Vr=-75+/-44 km s-1 and a tangential component of Vt=144+/-50 km s-1. Integrating the motion of Ursa Minor in a realistic potential for the Milky Way produces orbital elements. The perigalacticon and apogalacticon are 40 (10, 76) and 89 (78, 160) kpc, respectively, where the values in the parentheses represent the 95% confidence intervals derived from Monte Carlo experiments. The eccentricity of the orbit is 0.39 (0.09, 0.79), and the orbital period is 1.5 (1.1, 2.7) Gyr. The orbit is retrograde and inclined by 124° (94°, 136°) to the Galactic plane. Ursa Minor is not a likely member of a proposed stream of galaxies on similar orbits around the Milky Way, nor is the plane of its orbit coincident with a recently proposed planar alignment of galaxies around the Milky Way. Comparing the orbits of Ursa Minor and Carina shows no reason for the different star formation histories of these two galaxies. Ursa Minor must contain dark matter to have a high probability of having survived disruption by the Galactic tidal force until the present. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

Choice Shift in Opinion Network Dynamics

Science.gov (United States)

Gabbay, Michael

Choice shift is a phenomenon associated with small group dynamics whereby group discussion causes group members to shift their opinions in a more extreme direction so that the mean post-discussion opinion exceeds the mean pre-discussion opinion. Also known as group polarization, choice shift is a robust experimental phenomenon and has been well-studied within social psychology. In opinion network models, shifts toward extremism are typically produced by the presence of stubborn agents at the extremes of the opinion axis, whose opinions are much more resistant to change than moderate agents. However, we present a model in which choice shift can arise without the assumption of stubborn agents; the model evolves member opinions and uncertainties using coupled nonlinear differential equations. In addition, we briefly describe the results of a recent experiment conducted involving online group discussion concerning the outcome of National Football League games are described. The model predictions concerning the effects of network structure, disagreement level, and team choice (favorite or underdog) are in accord with the experimental results. This research was funded by the Office of Naval Research and the Defense Threat Reduction Agency.

Cosmological models - in which universe do we live

International Nuclear Information System (INIS)

Hartvigsen, Y.

1976-01-01

A general discussion of the present state of cosmological models is introduced with a brief presentation of the expanding universe theory, the red shift and Hubble's Law. Hubble's Constant lies between 30 and 105 km/sec/Mpc, and a value of 55 km/sec/Mpc is assumed in this article. The arguments for the big bang and steady state theories are presented and the reasons for the present acceptance of the former given. Friedmann models are briefly discussed and 'universe density', rho, and 'space curvature',k, and the 'cosmological constant', Λ, are presented. These are shown on the Stabell-Refsdal diagram and the density parameter, sigma 0 , and the retardation parameter, q 0 , are related to Hubble's Constant. These parameters are then discussed and their values restricted such that the part of the Stabell-Refsdal diagram which is of interest may be defined. (JIW)

Rapid Hydrogen Shift Reactions in Acyl Peroxy Radicals

DEFF Research Database (Denmark)

Knap, Hasse Christian; Jørgensen, Solvejg

2017-01-01

-shift with X = 6, 7, 8, or 9) in the hydroperoxy acyl peroxy radicals, this H-shift is a reversible reaction and it scrambles between two peroxides, hydroperoxy acyl peroxy and peroxy peroxoic acid radicals. The forward reaction rate constants of the 1,X-OOH H-shift reactions are estimated to be above 103 s–1...... with transition state theory corrected with Eckart quantum tunnelling correction. The ratio between the forward and reverse reaction rate constant of the 1,X-OOH H-shift reactions is around ∼105. Therefore, the equilibrium is pushed toward the production of peroxy peroxoic acid radicals. These very fast 1,X-OOH H......We have used quantum mechanical chemical calculations (CCSD(T)-F12a/cc-pVDZ-F12//M06-2X/aug-cc-pVTZ) to investigate the hydrogen shift (H-shift) reactions in acyl peroxy and hydroperoxy acyl peroxy radicals. We have focused on the H-shift reactions from a hydroperoxy group (OOH) (1,X-OOH H...

Giant Lamb shift in photonic crystals

International Nuclear Information System (INIS)

Wang Xuehua; Kivshar, Yuri S.; Gu Benyuan

2004-01-01

We obtain a general result for the Lamb shift of excited states of multilevel atoms in inhomogeneous electromagnetic structures and apply it to study atomic hydrogen in inverse-opal photonic crystals. We find that the photonic-crystal environment can lead to very large values of the Lamb shift, as compared to the case of vacuum. We also suggest that the position-dependent Lamb shift should extend from a single level to a miniband for an assembly of atoms with random distribution in space, similar to the velocity-dependent Doppler effect in atomic/molecular gases

Origins of Stokes shift in PbS nanocrystals

KAUST Repository

Voznyy, Oleksandr

2017-10-27

Stokes shift, an energy difference between the excitonic absorption and emission, is a property of colloidal quantum dots (CQDs) typically ascribed to splitting between dark and bright excitons. In some materials, e.g., PbS, CuInS2, CdHgTe, a Stokes shift of up to 200 meV is observed, substantially larger than the estimates of dark-bright state splitting or vibronic relaxations. The shift origin remains highly debated, as contradictory signatures of both surface and bulk character were reported for the Stokes-shifted electronic state. Here we show that the energy transfer among CQDs in a polydispersed ensemble in solution suffices to explain the excess Stokes shift. This energy transfer is primarily due to CQD aggregation, and can be substantially eliminated by extreme dilution, higher-viscosity solvent, or better-dispersed colloids. Our findings highlight that ensemble polydispersity remains the primary source of the Stokes shift in CQDs in solution, propagating into the Stokes shift in films and the open-circuit voltage deficit in CQD solar cells. Improved synthetic control can bring notable advancements in CQD photovoltaics, and the Stokes shift continues to provide a sensitive and significant metric to monitor ensemble size distribution.

The androgen receptor malignancy shift in prostate cancer.

Science.gov (United States)

Copeland, Ben T; Pal, Sumanta K; Bolton, Eric C; Jones, Jeremy O

2018-05-01

Androgens and the androgen receptor (AR) are necessary for the development, function, and homeostatic growth regulation of the prostate gland. However, once prostate cells are transformed, the AR is necessary for the proliferation and survival of the malignant cells. This change in AR function appears to occur in nearly every prostate cancer. We have termed this the AR malignancy shift. In this review, we summarize the current knowledge of the AR malignancy shift, including the DNA-binding patterns that define the shift, the transcriptome changes associated with the shift, the putative drivers of the shift, and its clinical implications. In benign prostate epithelial cells, the AR primarily binds consensus AR binding sites. In carcinoma cells, the AR cistrome is dramatically altered, as the AR associates with FOXA1 and HOXB13 motifs, among others. This shift leads to the transcription of genes associated with a malignant phenotype. In model systems, some mutations commonly found in localized prostate cancer can alter the AR cistrome, consistent with the AR malignancy shift. Current evidence suggests that the AR malignancy shift is necessary but not sufficient for transformation of prostate epithelial cells. Reinterpretation of prostate cancer genomic classification systems in light of the AR malignancy shift may improve our ability to predict clinical outcomes and treat patients appropriately. Identifying and targeting the molecular factors that contribute to the AR malignancy shift is not trivial but by doing so, we may be able to develop new strategies for the treatment or prevention of prostate cancer. © 2018 Wiley Periodicals, Inc.

Shift work disorder, depression, and anxiety in the transition to rotating shifts: the role of sleep reactivity.

Science.gov (United States)

Kalmbach, David A; Pillai, Vivek; Cheng, Philip; Arnedt, J Todd; Drake, Christopher L

2015-12-01

The aim of this study is to investigate premorbid sleep reactivity as a vulnerability to incident shift work disorder (SWD), and related changes in depression as well as anxiety following a transition to a rotating shifts work schedule. This is a longitudinal study with two waves of data collection. The community-based sample included normal sleeping non-shift workers (N = 96; 62.5% female; 47.9 ± 13.3 years) without a lifetime history of insomnia or baseline excessive daytime sleepiness who transitioned to rotating shift work one year later. Participants reported demographic characteristics, trait sleep reactivity on the Ford Insomnia Response to Stress Test, depression symptoms on the Quick Inventory of Depression Symptomatology, and anxiety symptoms on the Beck Anxiety Inventory. SWD was determined based on significant sleep disturbance and/or excessive sleepiness in the context of working in a rotating-shift schedule. Analyses revealed that the odds were over five times greater for highly sleep-reactive individuals to develop SWD after transitioning to rotating shifts (OR = 5.59, p = 0.04). Nearly 90% of participants who suffered from SWD were accurately identified as high risk at one year before disease onset. Furthermore, individuals who developed SWD reported greater increases in symptoms of depression and anxiety. Finally, analyses revealed significant indirect effects wherein high sleep reactivity increased risk for SWD, which led to greater severity of anxiety and depression symptoms. The Ford Insomnia Response to Stress Test (FIRST) accurately identifies a focused target population in which the premorbid psychobiological processes complicit in SWD onset and progression, as well as shift work-related depression and anxiety changes, can be better investigated, thus improving future preventative efforts. Copyright © 2015 Elsevier B.V. All rights reserved.

Lamb shift of Rydberg atoms in a resonator

International Nuclear Information System (INIS)

Belov, A.A.; Lozovik, Yu.E.; Pokrovsky, V.L.

1988-08-01

The Lamb shift of a Rydberg atom in a cavity is shown to be enhanced with the resonance interaction of a virtual atomic transition and cavity modes. The dependence of the Lamb shift on quantum numbers and atomic number changes drastically. Shifting cavity walls and scanning the atomic beam one can vary the Lamb shift. The value of the Lamb shift in a cavity may exceed a typical magnitude of the fine structure energy. For a rough resonance tuning the Coulumb multiplet occurs to be strongly mixed and a novel classification is necessary. (author). 8 refs, 2 figs

The calculation of proton chemical shifts in hydrocarbons

Energy Technology Data Exchange (ETDEWEB)

Abraham, Raymond J [Liverpool Univ. (United Kingdom). Dept. of Chemistry

1994-12-31

Novel extension of the CHARGE3 semi-empirical calculation of the partial atomic charges in molecules are described which allow the accurate calculation of the proton chemical shifts of a variety of acyclic alkanes. This simple scheme predicts the proton chemical shifts of all the simple alkanes, cyclohexane and methyl cyclohexanes, norbornane, trans-decalin and trans perhydrophenanthrene, comprising a range of chemical shifts from 0.3 to 2.2 {delta} with the known substituent chemical shifts of other functional groups this could allow the general prediction of proton chemical shifts in a simple and useful format. (author) 13 refs., 2 figs.

Does the ARFIMA really shift?

DEFF Research Database (Denmark)

Monache, Davide Delle; Grassi, Stefano; Santucci de Magistris, Paolo

Short memory models contaminated by level shifts have long-memory features similar to those associated to processes generated under fractional integration. In this paper, we propose a robust testing procedure, based on an encompassing parametric specification, that allows to disentangle the level...... the highest power compared to other existing tests for spurious long-memory. Finally, we illustrate the usefulness of the proposed approach on the daily series of bipower variation and share turnover and on the monthly inflation series of G7 countries....... shift term from the ARFIMA component. The estimation is carried out via a state-space methodology and it leads to a robust estimate of the fractional integration parameter also in presence of level shifts.The Monte Carlo simulations show that this approach produces unbiased estimates of the fractional...

Differences in cortisol profiles and circadian adjustment time between nurses working night shifts and regular day shifts: A prospective longitudinal study.

Science.gov (United States)

Niu, Shu-Fen; Chung, Min-Huey; Chu, Hsin; Tsai, Jui-Chen; Lin, Chun-Chieh; Liao, Yuan-Mei; Ou, Keng-Liang; O'Brien, Anthony Paul; Chou, Kuei-Ru

2015-07-01

This study explored the differences in the circadian salivary cortisol profiles between nurses working night shifts and regular day shifts following a slow rotating shift schedule to assess the number of days required for adjusting the circadian rhythm of salivary cortisol levels in nurses working consecutive night shifts and the number of days off required to restore the diurnal circadian rhythm of salivary cortisol levels. This was a prospective, longitudinal, parallel-group comparative study. The participants were randomly assigned to night and day-shift groups, and saliva samples were collected to measure their cortisol levels and circadian secretion patterns. Significant differences were observed in the overall salivary cortisol pattern parameters (cortisol awakening response, changes in cortisol profiles between 6 and 12h after awakening, and changes in cortisol profiles between 30 min and 12 h after awakening) from Days 2 to 4 of the workdays between both groups. However, on Day 2 of the days off, both groups exhibited similar cortisol profiles and the cortisol profiles in the night-shift group were restored. Nurses working night shifts require at least 4 days to adjust their circadian rhythms of cortisol secretions. Moreover, on changing from night shift to other shifts, nurses must be allowed more than 2 days off work. Copyright © 2015 Elsevier Ltd. All rights reserved.

Isotope shift studies in gadolinium spectra

International Nuclear Information System (INIS)

Ahmad, S.A.; Saksena, G.D.; Venugopalan, A.

1976-01-01

Isotope shift studies have been carried out in the gadolinium spectrum using a recording Fabry-Perot spectrometer and gadolinium samples enriched in 156 Gd and 160 Gd isotopes. Isotope shifts Δsigma(156-160) have been recorded in 134 lines in the region 3930-4140 A. Some of these lines involve the recently identified even configuration 4f 8 5d6s of Gd I and the newly classified transition 4f 8 6s-4f 8 6p of Gd II. From the isotope shift measurements of lines involving the 4f 8 6s-4f 8 6p transition in Gd II, the isotope shift, ΔT(156-160)=87 mK, has been obtained for the 4f 8 6s configuration. Electronic configurations have been suggested for a number of energy levels and configuration mixing has been pointed out in certain cases. (Auth.)

Pramana – Journal of Physics | Indian Academy of Sciences

Indian Academy of Sciences (India)

Emergent Universe (EU) model is investigated here using the recent observational data of thebackground tests. The background test data comprise observed Hubble data, baryon acoustic oscillation data, cosmic microwave background shift data and Union compilation(2.1) data. The flat EU model obtained by Mukherjee e t ...

Association between exposure to rotating night shift versus day shift using levels of 6-sulfatoxymelatonin and cortisol and other sex hormones in women.

Science.gov (United States)

Gómez-Acebo, Inés; Dierssen-Sotos, Trinidad; Papantoniou, Kyriaki; García-Unzueta, María Teresa; Santos-Benito, María Francisca; Llorca, Javier

2015-02-01

The present study aims to compare 6-sulfatoxymelatonin (aMT6s) secretion patterns and levels of cortisol and sex hormones (estradiol, progesterone, DHEA, DHEAS, and testosterone) among rotating night-shift workers and day-shift workers. We performed a cross-sectional study in Cantabria (northern Spain) including 136 women (73 day-shift workers and 63 rotating night-shift workers). Blood and urine samples were obtained after two consecutive working days. Differences in means were estimated using ANCOVA, stratified by menopausal status, ovulation phase, and adjusted for season, age, body mass index, consumption of cigarettes in the last 24 h. aMT6s circadian rhythm was analyzed using the cosinor analysis. The present study showed that rotating night-shift workers had lower excretion of aMT6s than day-shift workers (mesor = 50.26 ng aMT6s/mg creatinine in women with rotating night shift versus 88.79 ng aMT6s/mg creatinine in women with day shift), lower fluctuation (amplitude = 45.24 ng aMT6s/mg creatinine in rotating night-shift workers versus 79.71 ng aMT6s/mg creatinine in day-shift workers), and a later acrophase (aMT6s peak time: 08:31 in rotating night-shift workers versus 07:13 h in day-shift workers). Additionally, women with rotating night shift had higher estradiol and progesterone levels, compared to day workers, especially in the follicular phase on the menstrual cycle.

3D-HST: A Wide-field Grism Spectroscopic Survey with the Hubble Space Telescope

Science.gov (United States)

Brammer, Gabriel B.; van Dokkum, Pieter G.; Franx, Marijn; Fumagalli, Mattia; Patel, Shannon; Rix, Hans-Walter; Skelton, Rosalind E.; Kriek, Mariska; Nelson, Erica; Schmidt, Kasper B.; Bezanson, Rachel; da Cunha, Elisabete; Erb, Dawn K.; Fan, Xiaohui; Förster Schreiber, Natascha; Illingworth, Garth D.; Labbé, Ivo; Leja, Joel; Lundgren, Britt; Magee, Dan; Marchesini, Danilo; McCarthy, Patrick; Momcheva, Ivelina; Muzzin, Adam; Quadri, Ryan; Steidel, Charles C.; Tal, Tomer; Wake, David; Whitaker, Katherine E.; Williams, Anna

2012-06-01

We present 3D-HST, a near-infrared spectroscopic Treasury program with the Hubble Space Telescope for studying the physical processes that shape galaxies in the distant universe. 3D-HST provides rest-frame optical spectra for a sample of ~7000 galaxies at 1 < z < 3.5, the epoch when ~60% of all star formation took place, the number density of quasars peaked, the first galaxies stopped forming stars, and the structural regularity that we see in galaxies today must have emerged. 3D-HST will cover three quarters (625 arcmin2) of the CANDELS Treasury survey area with two orbits of primary WFC3/G141 grism coverage and two to four orbits with the ACS/G800L grism in parallel. In the IR, these exposure times yield a continuum signal-to-noise ratio of ~5 per resolution element at H 140 ~ 23.1 and a 5σ emission-line sensitivity of ~5 × 10-17 erg s-1 cm-2 for typical objects, improving by a factor of ~2 for compact sources in images with low sky background levels. The WFC3/G141 spectra provide continuous wavelength coverage from 1.1 to 1.6 μm at a spatial resolution of ~0farcs13, which, combined with their depth, makes them a unique resource for studying galaxy evolution. We present an overview of the preliminary reduction and analysis of the grism observations, including emission-line and redshift measurements from combined fits to the extracted grism spectra and photometry from ancillary multi-wavelength catalogs. The present analysis yields redshift estimates with a precision of σ(z) = 0.0034(1 + z), or σ(v) ≈ 1000 km s-1. We illustrate how the generalized nature of the survey yields near-infrared spectra of remarkable quality for many different types of objects, including a quasar at z = 4.7, quiescent galaxies at z ~ 2, and the most distant T-type brown dwarf star known. The combination of the CANDELS and 3D-HST surveys will provide the definitive imaging and spectroscopic data set for studies of the 1 < z < 3.5 universe until the launch of the James Webb Space

Validation of archived chemical shifts through atomic coordinates

Science.gov (United States)

Rieping, Wolfgang; Vranken, Wim F

2010-01-01

The public archives containing protein information in the form of NMR chemical shift data at the BioMagResBank (BMRB) and of 3D structure coordinates at the Protein Data Bank are continuously expanding. The quality of the data contained in these archives, however, varies. The main issue for chemical shift values is that they are determined relative to a reference frequency. When this reference frequency is set incorrectly, all related chemical shift values are systematically offset. Such wrongly referenced chemical shift values, as well as other problems such as chemical shift values that are assigned to the wrong atom, are not easily distinguished from correct values and effectively reduce the usefulness of the archive. We describe a new method to correct and validate protein chemical shift values in relation to their 3D structure coordinates. This method classifies atoms using two parameters: the per-atom solvent accessible surface area (as calculated from the coordinates) and the secondary structure of the parent amino acid. Through the use of Gaussian statistics based on a large database of 3220 BMRB entries, we obtain per-entry chemical shift corrections as well as Z scores for the individual chemical shift values. In addition, information on the error of the correction value itself is available, and the method can retain only dependable correction values. We provide an online resource with chemical shift, atom exposure, and secondary structure information for all relevant BMRB entries (http://www.ebi.ac.uk/pdbe/nmr/vasco) and hope this data will aid the development of new chemical shift-based methods in NMR. Proteins 2010. © 2010 Wiley-Liss, Inc. PMID:20602353

Nurse perceptions of workplace environment: differences across shifts.

Science.gov (United States)

Teclaw, Robert; Osatuke, Katerine

2015-11-01

To evaluate whether nurse work shift affected workplace perceptions. Although the importance of work schedule in shaping work attitudes, generally (and specifically for nurses) is well accepted, much work remains in characterising how and why nurses' perceptions might differ across shifts. Using an exploratory study of observational data, we examined whether shift influenced non-supervisory nurses' job perceptions in the Veterans Health Administration All Employee Survey (n = 14057; years 2008, 2010, 2012). The size of differences in item means (95% C.I.) across shifts was evaluated graphically. Using ordinal logistic regression, we accounted for the ordinal outcome variables and controlled for the demographic and survey year effects. Nurses' perceptions of workplace climate differed across shifts. Items with the greatest differences, consistent across years and analytic methods, involved supervisors and fairness. Night and weekend shift nurse ratings were more negative than for weekday shift nurses. Off-shift nurses are less satisfied with work/life balance, their supervisors and especially fairness. Overall satisfaction and turnover intention are not affected to the same extent. These results indicate several specific areas that nurse managers can address through workforce support and communication. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

Soft theorems for shift-symmetric cosmologies

Science.gov (United States)

Finelli, Bernardo; Goon, Garrett; Pajer, Enrico; Santoni, Luca

2018-03-01

We derive soft theorems for single-clock cosmologies that enjoy a shift symmetry. These so-called consistency conditions arise from a combination of a large diffeomorphism and the internal shift symmetry and fix the squeezed limit of all correlators with a soft scalar mode. As an application, we show that our results reproduce the squeezed bispectrum for ultra-slow-roll inflation, a particular shift-symmetric, nonattractor model which is known to violate Maldacena's consistency relation. Similar results have been previously obtained by Mooij and Palma using background-wave methods. Our results shed new light on the infrared structure of single-clock cosmological spacetimes.

Type-Ia Supernova Rates to Redshift 2.4 from Clash: The Cluster Lensing and Supernova Survey with Hubble

Science.gov (United States)

Graur, O.; Rodney, S. A.; Maoz, D.; Riess, A. G.; Jha, S. W.; Postman, M.; Dahlen, T.; Holoien, T. W.-S.; McCully, C.; Patel, B.;

Anthropometric changes and fluid shifts

Science.gov (United States)

Thornton, W. E.; Hoffler, G. W.; Rummel, J. A.

1974-01-01

Several observations of body size, shape, posture, and configuration were made to document changes resulting from direct effects of weightlessness during the Skylab 4 mission. After the crewmen were placed in orbit, a number of anatomical and anthropometric changes occurred including a straightening of the thoracolumbar spine, a general decrease in truncal girth, and an increase in height. By the time of the earliest in-flight measurement on mission day 3, all crewmen had lost more than two liters of extravascular fluid from the calf and thigh. The puffy facies, the bird legs effect, the engorgement of upper body veins, and the reduced volume of lower body veins were all documented with photographs. Center-of-mass measurements confirmed a fluid shift cephalad. This shift remained throughout the mission until recovery, when a sharp reversal occurred; a major portion of the reversal was completed in a few hours. The anatomical changes are of considerable scientific interest and of import to the human factors design engineer, but the shifts of blood and extravascular fluid are of more consequence. It is hypothesized that the driving force for the fluid shift is the intrinsic and unopposed lower limb elasticity that forces venous blood and then other fluid cephalad.

Associations between shift schedule characteristics with sleep, need for recovery, health and performance measures for regular (semi-) continuous 3-shift systems

NARCIS (Netherlands)

van de Ven, Hardy A.; Brouwer, Sandra; Koolhaas, Wendy; Goudswaard, Anneke; de Looze, Michiel P.; Kecklund, Goran; Almansa, Josue; Bultmann, Ute; van der Klink, Jac J. L.

In this cross-sectional study associations were examined between eight shift schedule characteristics with shift-specific sleep complaints and need for recovery and generic health and performance measures. It was hypothesized that shift schedule characteristics meeting ergonomic recommendations are

Associations between shift schedule characteristics with sleep, need for recovery, health and performance measures for regular (semi-)continuous 3-shift systems

NARCIS (Netherlands)

van de Ven, Hardy A.; Brouwer, Sandra; Koolhaas, Wendy; Goudswaard, Anneke; de Looze, Michiel P.; Kecklund, Göran; Almansa, Josue; Bültmann, Ute; van der Klink, Jac J L

2016-01-01

In this cross-sectional study associations were examined between eight shift schedule characteristics with shift-specific sleep complaints and need for recovery and generic health and performance measures. It was hypothesized that shift schedule characteristics meeting ergonomic recommendations are

Dietary habits among persons hired on shift work

OpenAIRE

Joanna Strzemecka; Iwona Bojar; Ewa Strzemecka; Alfred Owoc

2014-01-01

Introduction. Shift-work determinates irregular nutrition habits. The quality as well as the quantity of meals consumed by shift-workers can significantly affects their health. Objective. The aim of this study was to evaluate the dietary habits of people performing shift work in the Bogdanka mine. Material and Methods. The study was carried out in the Bogdanka mine in Leczna. The questionnaire, which was designed by the author of this dissertation, was conducted among 700 shift-workers,...

Shift work and burnout among health care workers.

Science.gov (United States)

Wisetborisut, A; Angkurawaranon, C; Jiraporncharoen, W; Uaphanthasath, R; Wiwatanadate, P

2014-06-01

Burnout, defined as a syndrome derived from prolonged exposure to stressors at work, is often seen in health care workers. Shift work is considered one of the occupational risks for burnout in health care workers. To identify and describe the association between shift work and burnout among health care workers. A cross-sectional study of health care workers in Chiang Mai University Hospital, Thailand. Data were collected via an online self-answered questionnaire and included details of shift work and burnout. Burnout was measured by the Maslach Burnout Inventory (MBI). Two thousand seven hundred and seventy two health care workers participated, a 52% response rate. Burnout was found more frequently among shift workers than those who did not work shifts (adjusted odds ratio [aOR] 1.4, 95% confidence interval [CI]: 1.0-1.9). Among shift workers, over 10 years of being a shift worker was associated with increasing burnout (aOR 1.7, 95% CI: 1.2-2.6) and having 6-8 sleeping hours per day was associated with having less burnout (aOR 0.7, 95% CI: 0.5-0.9). Nurses who had at least 8 days off per month had lower odds of burnout compared with those with fewer than 8 days off (aOR 0.6, 95% CI: 0.5-0.8). Shift work was associated with burnout in this sample. Increased years of work as a shift worker were associated with more frequent burnout. Adequate sleeping hours and days off were found to be possible protective factors. Policies on shift work should take into account the potential of such work for contributing towards increasing burnout. © The Author 2014. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

HUBBLE TARANTULA TREASURY PROJECT. III. PHOTOMETRIC CATALOG AND RESULTING CONSTRAINTS ON THE PROGRESSION OF STAR FORMATION IN THE 30 DORADUS REGION

Energy Technology Data Exchange (ETDEWEB)

Sabbi, E.; Anderson, J.; Cignoni, M.; Marel, R. P. van der; Panagia, N.; Sana, H.; Aloisi, A.; Arab, H.; Gordon, K. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD, 21218 (United States); Lennon, D. J. [ESA—European Space Astronomy Center, Apdo. de Correo 78, E-28691 Associate Villanueva de la Cañada, Madrid (Spain); Zaritsky, D. [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Marchi, G. De [Space Science Department, European Space Agency, Keplerlaan 1, 2200 AG Noordwijk (Netherlands); Gouliermis, D. A. [Zentrum für Astronomie der Universität Heidelberg, Institut für Theoretische Astrophysik, Albert-Ueberle-Str. 2, D-69120 Heidelberg (Germany); Grebel, E. K. [Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg, Mönchhofstr. 12-14, D-69120 Heidelberg (Germany); III, J. S. Gallagher [Department of Astronomy, University of Wisconsin, 475 North Charter Street, Madison, WI 53706 (United States); Smith, L. J. [ESA/STScI, 3700 San Martin Drive, Baltimore, MD, 21218 (United States); Tosi, M. [Istituto Nazionale di Astrofisica, Osservatorio Astronomico di Bologna, Via Ranzani 1, I-40127 Bologna (Italy); Evans, C. J. [UK Astronomy Technology Center, Royal Observatory Edinburgh, Blackford Hill, Edinburgh, EH9 3HJ (United Kingdom); Boyer, M. [Observational Cosmology Lab, Code 665, NASA, Goddard Space Flight Center, Greenbelt, MD, 20771 (United States); Mink, S. E. de, E-mail: sabbi@stsci.edu [Astronomical Institute “Anton Pannekoek,”University of Amsterdam, P.O. Box 94249, NL-1090 GE Amsterdam (Netherlands); and others

2016-01-15

We present and describe the astro-photometric catalog of more than 800,000 sources found in the Hubble Tarantula Treasury Project (HTTP). HTTP is a Hubble Space Telescope Treasury program designed to image the entire 30 Doradus region down to the sub-solar (∼0.5 M{sub ⊙}) mass regime using the Wide Field Camera 3 and the Advanced Camera for Surveys. We observed 30 Doradus in the near-ultraviolet (F275W, F336W), optical (F555W, F658N, F775W), and near-infrared (F110W, F160W) wavelengths. The stellar photometry was measured using point-spread function fitting across all bands simultaneously. The relative astrometric accuracy of the catalog is 0.4 mas. The astro-photometric catalog, results from artificial star experiments, and the mosaics for all the filters are available for download. Color–magnitude diagrams are presented showing the spatial distributions and ages of stars within 30 Dor as well as in the surrounding fields. HTTP provides the first rich and statistically significant sample of intermediate- and low-mass pre-main sequence candidates and allows us to trace how star formation has been developing through the region. The depth and high spatial resolution of our analysis highlight the dual role of stellar feedback in quenching and triggering star formation on the giant H ii region scale. Our results are consistent with stellar sub-clustering in a partially filled gaseous nebula that is offset toward our side of the Large Magellanic Cloud.

Machiavellianism, Discussion Time, and Group Shift

Science.gov (United States)

Lamm, Helmut; Myers, David G.

1976-01-01

Social-emotional and rational-cognitive explanations of group risky shift on choice dilemmas (hypothetical life situations) were evaluated by comparing shift in groups of low Mach (emotional) and high Mach (non-emotional) subjects. Effects of Machiavellian beliefs on social functioning are examined. Group composition was not observed to affect…

Multiscale regime shifts and planetary boundaries

NARCIS (Netherlands)

Hughes, T.P.; Carpenter, S.; Rockstrom, J.; Scheffer, M.; Walker, B.

2013-01-01

Life on Earth has repeatedly displayed abrupt and massive changes in the past, and there is no reason to expect that comparable planetary-scale regime shifts will not continue in the future. Different lines of evidence indicate that regime shifts occur when the climate or biosphere transgresses a

TOWARD A NEW GEOMETRIC DISTANCE TO THE ACTIVE GALAXY NGC 4258. III. FINAL RESULTS AND THE HUBBLE CONSTANT

International Nuclear Information System (INIS)

Humphreys, E. M. L.; Reid, M. J.; Moran, J. M.; Greenhill, L. J.; Argon, A. L.

2013-01-01

We report a new geometric maser distance estimate to the active galaxy NGC 4258. The data for the new model are maser line-of-sight (LOS) velocities and sky positions from 18 epochs of very long baseline interferometry observations, and LOS accelerations measured from a 10 yr monitoring program of the 22 GHz maser emission of NGC 4258. The new model includes both disk warping and confocal elliptical maser orbits with differential precession. The distance to NGC 4258 is 7.60 ± 0.17 ± 0.15 Mpc, a 3% uncertainty including formal fitting and systematic terms. The resulting Hubble constant, based on the use of the Cepheid variables in NGC 4258 to recalibrate the Cepheid distance scale, is H 0 = 72.0 ± 3.0 km s –1 Mpc –1

Environmental tax shifting in Canada : theory and application

International Nuclear Information System (INIS)

Taylor, A.; Hornung, R.; Cairns, S.

2003-03-01

Canada's leading energy and resource companies along with the Pembina Institute for Appropriate Development have collaborated in the Triple E Tax Shift Research Collaborative which examines the use of environmental tax shifting in Canada. The objective is to design, evaluate and advance federal and provincial environmental tax shifts that will influence individual behaviour and decisions to improve ecological integrity through measurable reductions in materials and energy throughput, and to maintain or increase economic competitiveness through the creation of a tax framework that would encourage businesses to improve energy efficiency. Another objective is to increase employment and social benefits through more employment opportunities and improved quality of life. Environmental tax shifting means shifting a portion of a government's tax base onto goods, services and activities associated with harmful environmental impacts that add to societal costs. Tax shifting can be implemented by offering rebates to consumers of environmental significant goods, or by adjustments to existing taxes so that environmentally sensitive goods are taxed at a lower rate than environmentally harmful goods and services. Environmental tax shifting can also be implemented by reducing existing environmental taxes and introducing a carbon dioxide emissions tax. This report is the first product of the collaboration and is intended to promote public dialogue on the subject and identify ways to implement environmental tax shifting. tabs., figs

PANCHROMATIC HUBBLE ANDROMEDA TREASURY. XII. MAPPING STELLAR METALLICITY DISTRIBUTIONS IN M31

Energy Technology Data Exchange (ETDEWEB)

Gregersen, Dylan; Seth, Anil C. [Department of Physics and Astronomy, University of Utah, Salt Lake City, UT 84112 (United States); Williams, Benjamin F.; Dalcanton, Julianne J.; Johnson, L. C.; Lewis, Alexia R. [Department of Astronomy, Box 351580, University of Washington, Seattle, WA 98195 (United States); Lang, Dustin [McWilliams Center for Cosmology, Department of Physics, Carnegie Mellon University, Pittsburgh, PA 15213 (United States); Girardi, Leó [Osservatorio Astronomico di Padova—INAF, Vicolo dell’Osservatori 5, I-35122 Padova (Italy); Skillman, Evan D. [Minnesota Institute for Astrophysics, University of Minnesota, Minneapolis, MN 55455 (United States); Bell, Eric [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States); Dolphin, Andrew E. [Raytheon, 1151 E. Hermans Road, Tucson, AZ 85706 (United States); Fouesneau, Morgan [MPIA, Koenigstuhl 17, D-69117 Heidelberg (Germany); Guhathakurta, Puragra; Hamren, Katherine M. [UCO/Lick Observatory, University of California at Santa Cruz, 1156 High Street, Santa Cruz, CA 95064 (United States); Kalirai, Jason [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Monachesi, Antonela [MPA, Garching (Germany); Olsen, Knut, E-mail: dylan.gregersen@utah.edu, E-mail: aseth@astro.utah.edu [NOAO, Tucson, AZ 85719 (United States)

2015-12-15

We present a study of spatial variations in the metallicity of old red giant branch stars in the Andromeda galaxy. Photometric metallicity estimates are derived by interpolating isochrones for over seven million stars in the Panchromatic Hubble Andromeda Treasury (PHAT) survey. This is the first systematic study of stellar metallicities over the inner 20 kpc of Andromeda’s galactic disk. We see a clear metallicity gradient of −0.020 ± 0.004 dex kpc{sup −1} from ∼4–20 kpc assuming a constant red giant branch age. This metallicity gradient is derived after correcting for the effects of photometric bias and completeness and dust extinction, and is quite insensitive to these effects. The unknown age gradient in M31's disk creates the dominant systematic uncertainty in our derived metallicity gradient. However, spectroscopic analyses of galaxies similar to M31 show that they typically have small age gradients that make this systematic error comparable to the 1σ error on our metallicity gradient measurement. In addition to the metallicity gradient, we observe an asymmetric local enhancement in metallicity at radii of 3–6 kpc that appears to be associated with Andromeda’s elongated bar. This same region also appears to have an enhanced stellar density and velocity dispersion.

FOMALHAUT b: INDEPENDENT ANALYSIS OF THE HUBBLE SPACE TELESCOPE PUBLIC ARCHIVE DATA

International Nuclear Information System (INIS)

Galicher, Raphaël; Marois, Christian; Zuckerman, B.; Macintosh, Bruce

2013-01-01

The nature and even the existence of a putative planet-mass companion ( F omalhaut b ) to Fomalhaut has been debated since 2008. In the present paper, we reanalyze the multi-epoch ACS/STIS/WFC3 Hubble Space Telescope (HST) optical/near-infrared images on which the discovery and some other claims were based. We confirm that the HST images do reveal an object in orbit around Fomalhaut, but the detailed results from our analysis differ in some ways from previous discussions. In particular, we do not confirm flux variability over a two-year interval at 0.6 μm wavelength and we detect Fomalhaut b for the first time at the short wavelength of 0.43 μm. We find that the HST image of Fomalhaut b at 0.8 μm may be extended beyond the point-spread function. We cannot determine from our astrometry if Fomalhaut b will cross or not the dust ring. The optical through mid-infrared spectral energy distribution (SED) of Fomalhaut b cannot be explained as due to direct or scattered radiation from a massive planet. We consider two models to explain the SED: (1) a large circumplanetary disk around an unseen planet and (2) the aftermath of a collision during the past 50-150 yr of two Kuiper-Belt-like objects of radii ∼50 km.

Health and Occupational Outcomes Among Injured, Nonstandard Shift Workers.

Science.gov (United States)

Wong, Imelda S; Smith, Peter M; Mustard, Cameron A; Gignac, Monique A M

2015-11-01

This study compares health and occupational outcomes following a work-related injury for nonstandard and day-shift workers. National Population Health Survey data were used to explore outcomes 2 years post-work injury. Retrospective-matched cohort analyses examined main effects and interactions of shift schedule and work injury with changes in health, shift schedule, and labor force status. Models were adjusted for respondent characteristics, baseline health status, and occupational strength requirements. Injured nonstandard shift workers reported lower health utility index scores, compared with uninjured and injured daytime workers and uninjured nonstandard-shift workers. No significant interactions between shift and injury were found with schedule change and leaving the labor force. Injured nonstandard-shift workers are as likely to remain employed as other groups, but may be vulnerable in terms of diminished health.

TIPS (trigger an IIF paradigm shift)

Energy Technology Data Exchange (ETDEWEB)

Kilcup, P.E. Glen [Intel Corporation, MS: F9-016, 4100 Sara Road, Rio Rancho, NM 87124 (United States)]. E-mail: glen.w.kilcup@intel.com; Hickox, Dick [Intel Corporation, MS: F9-016, 4100 Sara Road, Rio Rancho, NM 87124 (United States); Reynaga, Adolfo [Intel Corporation, MS: F9-016, 4100 Sara Road, Rio Rancho, NM 87124 (United States)

2007-04-11

Challenge: New Mexico Corporate Services (NMCS) recordable injuries have been averaging 2-4 per year for the last 5 years with no statistical improvement. However, we believe all NM employees must go home incident and injury free every day and just as healthy as they came to work. In addition, we have received feedback from several sources, that indicates some employees are reluctant to report injuries. These indicators showed us that continuing our current strategies, making incremental improvement and changes, would not give us the improvement desired. We needed a paradigm shift to get everyone completely engaged in the IIF (Incident and Injury Free) culture, in order to achieve true IIF results. Methods/Strategies: We formed a small (3-person) taskforce consisting of safety representatives from EHS, Site Services and CS Operations. We reviewed 5 years worth of data to determine what was injuring our people. We also decided to review all injuries, not simply those classified as recordable by OSHA standards. First we identified the types of injury information needed to get a true picture of our safety issues. We analyzed IRB (Incident Review Board) data showing us the following factors and whether any of them contributed to the injury: - Date - Incident Description - Severity - Root Cause - Type of Injury - Season - Work Group/Shift - Area - Improper evaluation of hazard - Inadequate work procedures - Incorrect Mental Model - Inadequate PPE Requirement - Failure to Follow or Unaware of PPE Requirement - Shortcut or Schedule Pressure - Last or First Day of Shift or Adjacent to Holiday - OT - Aggravate Existing Condition - Inadequate Training or Passdown - Experience in Task - Corrective Action Taken - Overall Quality of Response. Once this information was collected for all injuries in an Excel file, we graphed it several ways to help reveal trends: - Shift 7 had double the injuries of shift 5 - Night shift injuries were relatively high but lower than Shift 7 -Shift

TIPS (trigger an IIF paradigm shift)

International Nuclear Information System (INIS)

Kilcup, P.E. Glen; Hickox, Dick; Reynaga, Adolfo

2007-01-01

Challenge: New Mexico Corporate Services (NMCS) recordable injuries have been averaging 2-4 per year for the last 5 years with no statistical improvement. However, we believe all NM employees must go home incident and injury free every day and just as healthy as they came to work. In addition, we have received feedback from several sources, that indicates some employees are reluctant to report injuries. These indicators showed us that continuing our current strategies, making incremental improvement and changes, would not give us the improvement desired. We needed a paradigm shift to get everyone completely engaged in the IIF (Incident and Injury Free) culture, in order to achieve true IIF results. Methods/Strategies: We formed a small (3-person) taskforce consisting of safety representatives from EHS, Site Services and CS Operations. We reviewed 5 years worth of data to determine what was injuring our people. We also decided to review all injuries, not simply those classified as recordable by OSHA standards. First we identified the types of injury information needed to get a true picture of our safety issues. We analyzed IRB (Incident Review Board) data showing us the following factors and whether any of them contributed to the injury: - Date - Incident Description - Severity - Root Cause - Type of Injury - Season - Work Group/Shift - Area - Improper evaluation of hazard - Inadequate work procedures - Incorrect Mental Model - Inadequate PPE Requirement - Failure to Follow or Unaware of PPE Requirement - Shortcut or Schedule Pressure - Last or First Day of Shift or Adjacent to Holiday - OT - Aggravate Existing Condition - Inadequate Training or Passdown - Experience in Task - Corrective Action Taken - Overall Quality of Response. Once this information was collected for all injuries in an Excel file, we graphed it several ways to help reveal trends: - Shift 7 had double the injuries of shift 5 - Night shift injuries were relatively high but lower than Shift 7 -Shift

TIPS (trigger an IIF paradigm shift).

Science.gov (United States)

Kilcup P E, Glen; Hickox, Dick; Reynaga, Adolfo

2007-04-11

New Mexico Corporate Services (NMCS) recordable injuries have been averaging 2-4 per year for the last 5 years with no statistical improvement. However, we believe all NM employees must go home incident and injury free every day and just as healthy as they came to work. In addition, we have received feedback from several sources, that indicates some employees are reluctant to report injuries. These indicators showed us that continuing our current strategies, making incremental improvement and changes, would not give us the improvement desired. We needed a paradigm shift to get everyone completely engaged in the IIF (Incident & Injury Free) culture, in order to achieve true IIF results. We formed a small (3-person) taskforce consisting of safety representatives from EHS, Site Services and CS Operations. We reviewed 5 years worth of data to determine what was injuring our people. We also decided to review all injuries, not simply those classified as recordable by OSHA standards. First we identified the types of injury information needed to get a true picture of our safety issues. We analyzed IRB (Incident Review Board) data showing us the following factors and whether any of them contributed to the injury: - Date - Incident Description - Severity - Root Cause - Type of Injury - Season - Work Group/Shift - Area - Improper evaluation of hazard - Inadequate work procedures - Incorrect Mental Model - Inadequate PPE Requirement - Failure to Follow or Unaware of PPE Requirement - Shortcut or Schedule Pressure - Last or First Day of Shift or Adjacent to Holiday - OT - Aggravate Existing Condition - Inadequate Training or Passdown - Experience in Task - Corrective Action Taken - Overall Quality of Response. Once this information was collected for all injuries in an Excel file, we graphed it several ways to help reveal trends: Shift 7 had double the injuries of shift 5. Night shift injuries were relatively high but lower than Shift 7. Shift 5 had no severe (recordable

UPPER LIMITS ON THE MASSES OF 105 SUPERMASSIVE BLACK HOLES FROM HUBBLE SPACE TELESCOPE/SPACE TELESCOPE IMAGING SPECTROGRAPH ARCHIVAL DATA

International Nuclear Information System (INIS)

Beifiori, A.; Corsini, E. M.; Bonta, E. Dalla; Pizzella, A.; Coccato, L.; Bertola, F.; Sarzi, M.

2009-01-01

Based on the modeling of the central emission-line width measured over subarcsecond apertures with the Hubble Space Telescope, we present stringent upper bounds on the mass of the central supermassive black hole, M . , for a sample of 105 nearby galaxies (D c (58-419 km s -1 ). For the vast majority of the objects, the derived M . upper limits run parallel and above the well-known M . -σ c relation independently of the galaxy distance, suggesting that our nebular line-width measurements trace rather well the nuclear gravitational potential. For values of σ c between 90 and 220 km s -1 , 68% of our upper limits falls immediately above the M . -σ c relation without exceeding the expected M . values by more than a factor 4.1. No systematic trends or offsets are observed in this σ c range as a function of the galaxy Hubble type or with respect to the presence of a bar. For 6 of our 12 M . upper limits with σ c -1 , our line-width measurements are more sensitive to the stellar contribution to the gravitational potential, either due to the presence of a nuclear stellar cluster or because of a greater distance compared to the other galaxies at the low-σ c end of the M . -σ c relation. Conversely, our M . upper bounds appear to lie closer to the expected M . in the most massive elliptical galaxies with values of σ c above 220 km s -1 . Such a flattening of the M . -σ c relation at its high-σ c end would appear consistent with a coevolution of supermassive black holes and galaxies driven by dry mergers, although better and more consistent measurements for σ c and K-band luminosity are needed for these kinds of objects before systematic effects can be ruled out.

Time Zones, Shift Working and International Outsourcing

OpenAIRE

Matsuoka, Yuji; Fukushima, Marcelo

2009-01-01

We build a trade model with two identical countries located in different time zones and a monopolistically competitive sector of which production requires differentiated goods produced in two successive stages. We introduce shift working disutility and allow consumers to choose between day and night shifts. Shift working disutility raises the cost of night production and firms can reduce costs by “virtually” outsourcing foreign labor. We found that firms only outsource if relat...

Forecasting interest rates with shifting endpoints

DEFF Research Database (Denmark)

Van Dijk, Dick; Koopman, Siem Jan; Wel, Michel van der

2014-01-01

We consider forecasting the term structure of interest rates with the assumption that factors driving the yield curve are stationary around a slowly time-varying mean or ‘shifting endpoint’. The shifting endpoints are captured using either (i) time series methods (exponential smoothing) or (ii......) long-range survey forecasts of either interest rates or inflation and output growth, or (iii) exponentially smoothed realizations of these macro variables. Allowing for shifting endpoints in yield curve factors provides substantial and significant gains in out-of-sample predictive accuracy, relative...... to stationary and random walk benchmarks. Forecast improvements are largest for long-maturity interest rates and for long-horizon forecasts....

Beta-shifts, their languages and computability

DEFF Research Database (Denmark)

Simonsen, Jakob Grue

2011-01-01

they give into the dynamics of the underlying system. We prove that the language of the ß-shift is recursive iff ß is a computable real number. That fact yields a precise characterization of the reals: The real numbers ß for which we can compute arbitrarily good approximations—hence in particular......For every real number ß >1, the ß-shift is a dynamical system describing iterations of the map x ¿ ßx mod 1 and is studied intensively in number theory. Each ß-shift has an associated language of finite strings of characters; properties of this language are studied for the additional insight...

Lamb Shift in Nonrelativistic Quantum Electrodynamics.

Science.gov (United States)

Grotch, Howard

1981-01-01

The bound electron self-energy or Lamb shift is calculated in nonrelativistic quantum electrodynamics. Retardation is retained and also an interaction previously dropped in other nonrelativistic approaches is kept. Results are finite without introducing a cutoff and lead to a Lamb shift in hydrogen of 1030.9 MHz. (Author/JN)

Gear shift map design methodology for automotive transmissions

NARCIS (Netherlands)

Ngo, Viet Dac; Hofman, Theo; Steinbuch, Maarten; Serrarens, Alex

In this paper, a design methodology is developed to condtruct the gear shift map for the automotive transmissions used in conventional and hybrid electric vehicles. The methodology utilizes an optimal gear shift strategy to derive the optimal gear shift patterns over a wide range of driving

Uniqueness and zeros of q-shift difference polynomials

Indian Academy of Sciences (India)

In this paper, we consider the zero distributions of -shift difference polynomials of meromorphic functions with zero order, and obtain two theorems that extend the classical Hayman results on the zeros of differential polynomials to -shift difference polynomials. We also investigate the uniqueness problem of -shift ...

The impact of chronotype on melatonin levels among shift workers.

Science.gov (United States)

Bhatti, Parveen; Mirick, Dana K; Davis, Scott

2014-03-01

The association between shift work and cancer, which is thought to be mediated by effects on circulating melatonin levels, may be modified by chronotype (ie, the inherent preference for activity in the morning or the evening); however, few studies have examined the potential impact of chronotype on the carcinogenic effects of shift work. The authors analysed the impact of chronotype on previously reported differences in melatonin levels among healthcare workers that exclusively worked night or day shifts. The cross-sectional study included 664 men and women (310 day shift and 354 night shift workers) from which urine samples were collected throughout work and sleep periods and were assayed for 6-sulfatoxymelatonin. Participants also completed the Composite Scale of Morningness, a questionnaire used to assess chronotype. Among both morning and evening-type night shift workers, 6-sulfatoxymelatonin levels were constitutively lower during daytime sleep, night-time sleep and night work compared with day shift workers during night-time sleep. However, morning-type night shift workers consistently showed 6-sulfatoxymelatonin levels that were closer to levels in day shift workers than did evening-type night shift workers. Differences in 6-sulfatoxymelatonin levels between morning-type and evening-type night shift workers relative to day shift workers were statistically significant in every instance (pnight shift workers may be better able to maintain a 'normal' circadian pattern of melatonin production as compared with evening-type night shift workers. The impact of this chronotype effect on cancer risk among shift workers requires further study.

Written Language Shift among Norwegian Youth

Directory of Open Access Journals (Sweden)

Kamil ÖZERK

2013-07-01

Full Text Available In Norway there are two written Norwegian languages, Bokmål and Nynorsk. Of these two written languages Bokmål is being used by the majority of the people, and Bokmål has the highest prestige in the society. This article is about the shift of written language from Nynorsk to Bokmål among young people in a traditional Nynorsk district in the country. Drawing on empirical data we conclude that many adolescents are experiencing written language shift. We discuss various reasons for this phenomenon in the linguistic landscape of Norway. In our discussions we emphasize the importance of the school with regard to language maintenance and language revitalization. We call for a new language policy in the educational system that can prevent language shift. Having several dialects and two officially written forms of Norwegian in the country, creates a special linguistic landscape in Norway. Despite the fact that the Norwegian language situation is in several ways unique, it’s done very little research on how the existing policy works in practice. Our research reveals that the existing language policy and practice in the school system is not powerful enough to prevent language shift and language decay among the youngsters. The school system functions like a fabric for language shift.

Task Shifting in Dermatology: A Call to Action.

Science.gov (United States)

Brown, Danielle N; Langan, Sinéad M; Freeman, Esther E

2017-11-01

Can task shifting be used to improve the delivery of dermatologic care in resource-poor settings worldwide? Task shifting is a means of redistributing available resources, whereby highly trained individuals train an available workforce to provide necessary care in low-resource settings. Limited evidence exists for task shifting in dermatology; however, studies from psychiatry demonstrate its efficacy. In the field of dermatology there is a need for high-quality evidence including randomized clinical trials to validate the implementation of task shifting in low-resource settings globally.

Relationship between thyroid stimulating hormone and night shift work.

Science.gov (United States)

Moon, So-Hyun; Lee, Bum-Joon; Kim, Seong-Jin; Kim, Hwan-Cheol

2016-01-01

Night shift work has well-known adverse effects on health. However, few studies have investigated the relationship between thyroid diseases and night shift work. This study aimed to examine night shift workers and their changes in thyroid stimulating hormones (TSH) levels over time. Medical check-up data (2011-2015) were obtained from 967 female workers at a university hospital in Incheon, Korea. Data regarding TSH levels were extracted from the records, and 2015 was used as a reference point to determine night shift work status. The relationships between TSH levels and night shift work in each year were analyzed using the general linear model (GLM). The generalized estimating equation (GEE) was used to evaluate the repeated measurements over the 5-year period. The GEE analysis revealed that from 2011 to 2015, night shift workers had TSH levels that were 0.303 mIU/L higher than the levels of non-night shift workers (95 % CI: 0.087-0.519 mIU/L, p  = 0.006) after adjusting for age and department. When we used TSH levels of 4.5 ≥ mIU/L to identify subclinical hypothyroidism, night shift workers exhibited a 1.399 fold higher risk of subclinical hypothyroidism (95 % CI: 1.050-1.863, p  = 0.022), compared to their non-night shift counterparts. This result of this study suggests that night shift workers may have an increased risk of thyroid diseases, compared to non-night shift workers.

Impacts of shift work on sleep and circadian rhythms.

Science.gov (United States)

Boivin, D B; Boudreau, P

2014-10-01

Shift work comprises work schedules that extend beyond the typical "nine-to-five" workday, wherein schedules often comprise early work start, compressed work weeks with 12-hour shifts, and night work. According to recent American and European surveys, between 15 and 30% of adult workers are engaged in some type of shift work, with 19% of the European population reportedly working at least 2 hours between 22:00 and 05:00. The 2005 International Classification of Sleep Disorders estimates that a shift work sleep disorder can be found in 2-5% of workers. This disorder is characterized by excessive sleepiness and/or sleep disruption for at least one month in relation with the atypical work schedule. Individual tolerance to shift work remains a complex problem that is affected by the number of consecutive work hours and shifts, the rest periods, and the predictability of work schedules. Sleepiness usually occurs during night shifts and is maximal at the end of the night. Impaired vigilance and performance occur around times of increased sleepiness and can seriously compromise workers' health and safety. Indeed, workers suffering from a shift work sleep-wake disorder can fall asleep involuntarily at work or while driving back home after a night shift. Working on atypical shifts has important socioeconomic impacts as it leads to an increased risk of accidents, workers' impairment and danger to public safety, especially at night. The aim of the present review is to review the circadian and sleep-wake disturbances associated with shift work as well as their medical impacts. Copyright © 2014. Published by Elsevier SAS.

On the energy shift the ECC cusp. Does the shift really exist?

International Nuclear Information System (INIS)

Sarkadi, L.; Barrachina, R.O.

2004-01-01

The cusplike 'electron capture to the continuum' (ECC) peak appearing in the spectrum of the forward emitted electrons in ion-atom collisions are generally thought to be a divergence. Recently Shah et al., however, claimed that 'the ECC cusp is indeed a cusp, and not a divergence smoothed by the experiment'. These authors measured the ECC cusp for collisions of 10- and 20-keV protons with H 2 and He, and found that the peak was shifted to lower velocity than its expected position. We also carried out CTMC calculations (for the case of 20-keV protons on He) by which we demonstrated that the shift really exists but its value depends on the angular window of the electron detection. (K.A.)

Stochastic dynamical models for ecological regime shifts

DEFF Research Database (Denmark)

Møller, Jan Kloppenborg; Carstensen, Jacob; Madsen, Henrik

the physical and biological knowledge of the system, and nonlinearities introduced here can generate regime shifts or enhance the probability of regime shifts in the case of stochastic models, typically characterized by a threshold value for the known driver. A simple model for light competition between...... definition and stability of regimes become less subtle. Ecological regime shifts and their modeling must be viewed in a probabilistic manner, particularly if such model results are to be used in ecosystem management....

Comparison of second-order impact line shifts

International Nuclear Information System (INIS)

Griem, H.R.; Iglesias, C.A.; Boercker, D.B.

1991-01-01

The second-order impact shifts in hydrogen obtained from the Baranger formalism are compared with those from a kinetic theory approach. The resulting Δn=0 contributions to the shift from the two theories are shown to be identical, except for the neglect of electron-electron correlations in the Baranger formalism. It is also shown that some care is required in taking the classical limit for the perturbing electrons, or else the shift from Δn=0 interactions vanishes

Shift versus no-shift in local regularization of Chern-Simons theory

International Nuclear Information System (INIS)

Giavarini, G.; Parma Univ.; Martin, C.P.; Ruiz Ruiz, F.

1994-01-01

We consider a family of local BRS-invariant higher covariant derivative regularizations of SU(N) Chern-Simons theory that do not shift the value of the Chern-Simons parameter k to k + sign(k) c v at one loop. (orig.)

Testing backreaction effects with observational Hubble parameter data

Science.gov (United States)

Cao, Shu-Lei; Teng, Huan-Yu; Wan, Hao-Yi; Yu, Hao-Ran; Zhang, Tong-Jie

2018-02-01

The spatially averaged inhomogeneous Universe includes a kinematical backreaction term Q_{D} that is relate to the averaged spatial Ricci scalar _{D} in the framework of general relativity. Under the assumption that Q_{D} and _{D} obey the scaling laws of the volume scale factor a_{D}, a direct coupling between them with a scaling index n is remarkable. In order to explore the generic properties of a backreaction model for explaining the accelerated expansion of the Universe, we exploit two metrics to describe the late time Universe. Since the standard FLRW metric cannot precisely describe the late time Universe on small scales, the template metric with an evolving curvature parameter κ _{D}(t) is employed. However, we doubt the validity of the prescription for κ _{D}, which motivates us apply observational Hubble parameter data (OHD) to constrain parameters in dust cosmology. First, for FLRW metric, by getting best-fit constraints of Ω^{D_0}_m = 0.25^{+0.03}_{-0.03}, n = 0.02^{+0.69}_{-0.66}, and H_{D_0} = 70.54^{+4.24}_{-3.97} km s^{-1 Mpc^{-1}}, the evolutions of parameters are explored. Second, in template metric context, by marginalizing over H_{D_0} as a prior of uniform distribution, we obtain the best-fit values of n=-1.22^{+0.68}_{-0.41} and Ωm^{D0}=0.12^{+0.04}_{-0.02}. Moreover, we utilize three different Gaussian priors of H_{D_0}, which result in different best-fits of n, but almost the same best-fit value of Ωm^{D0}˜ 0.12. Also, the absolute constraints without marginalization of parameter are obtained: n=-1.1^{+0.58}_{-0.50} and Ωm^{D0}=0.13± 0.03. With these constraints, the evolutions of the effective deceleration parameter q^{D} indicate that the backreaction can account for the accelerated expansion of the Universe without involving extra dark energy component in the scaling solution context. Nevertheless, the results also verify that the prescription of κ _{D} is insufficient and should be improved.

[Shift and night work and mental health].

Science.gov (United States)

Sancini, Angela; Ciarrocca, Manuela; Capozzella, Assunta; Corbosiero, Paola; Fiaschetti, Maria; Caciari, Tiziana; Cetica, Carlotta; Scimitto, Lara; Ponticiello, Barnaba Giuseppina; Tasciotti, Zaira; Schifano, Maria Pia; Andreozzit, Giorgia; Tomei, Francesco; Tomei, Gianfranco

2012-01-01

Aim of our study was to evaluate the influence that shift work and night work could have on mental health. A review of literary articles from 1990 to 2011 on shift work and night work was carried out. The results of this review confirmed that the shift work and night work affect mental health with the onset of neuropsychological disorders such as mood disorders, anxiety, nervousness, depressive anxiety syndromes, chronic fatigue and chronic insomnia irritability, sleep disturbances, reduction in levels of attention, cognitive impairments, alteration of circadian rhythm. Night work and shift work cause severe desynchronization of the cronobiological rhythms and a disruption of social life with negative effects on performance at work, on health and on social relationships. In the light of these results and recognizing shift work and night work as risk factors for the health of workers is necessary to implement preventive and periodic health checks by the occupational doctor to ensure the health and safety of workers taking account of the different environmental and individual factors.

Dietary habits among persons hired on shift work.

Science.gov (United States)

Strzemecka, Joanna; Bojar, Iwona; Strzemecka, Ewa; Owoc, Alfred

2014-01-01

Shift-work determinates irregular nutrition habits. The quality as well as the quantity of meals consumed by shift-workers can significantly affects their health. The aim of this study was to evaluate the dietary habits of people performing shift work in the Bogdanka mine. The study was carried out in the Bogdanka mine in Leczna. The questionnaire, which was designed by the author of this dissertation, was conducted among 700 shift-workers, working underground. The results were subjected to statistical analysis based on STATISTICA v. 7.1 (StatSoft, Poland) software. Nearly half of respondents reported regular consumption of meals (40.0%) Interviewees admitted having warm meals during the day (81.4%). The most frequently consumed meal during the day was the hot one (50.9%), three meals and more were consumed the least frequently (8.1%). Almost half of respondents considered their eating habits as inappropriate (46.3%). Among those, nearly half (68.2%) stated that shift - work is the reason for their nutrition habits. More than half of respondents (66.0%) admitted that shift work hampers regular consumption of meals. Shift work makes nourishment and regular consumption difficult. It contributes to the limited amount of warm meals eaten during the day. In order to maintain preventive health care and the improvement of quality of life, shift workers should be provided with an easier access to meals (including warm one) at specified times of the day.

Metabolic syndrome in fixed-shift workers.

Science.gov (United States)

Canuto, Raquel; Pattussi, Marcos Pascoal; Macagnan, Jamile Block Araldi; Henn, Ruth Liane; Olinto, Maria Teresa Anselmo

2015-01-01

OBJECTIVE To analyze if metabolic syndrome and its altered components are associated with demographic, socioeconomic and behavioral factors in fixed-shift workers. METHODS A cross-sectional study was conducted on a sample of 902 shift workers of both sexes in a poultry processing plant in Southern Brazil in 2010. The diagnosis of metabolic syndrome was determined according to the recommendations from Harmonizing the Metabolic Syndrome. Its frequency was evaluated according to the demographic (sex, skin color, age and marital status), socioeconomic (educational level, income and work shift), and behavioral characteristics (smoking, alcohol intake, leisure time physical activity, number of meals and sleep duration) of the sample. The multivariate analysis followed a theoretical framework for identifying metabolic syndrome in fixed-shift workers. RESULTS The prevalence of metabolic syndrome in the sample was 9.3% (95%CI 7.4;11.2). The most frequently altered component was waist circumference (PR 48.4%; 95%CI 45.5;51.2), followed by high-density lipoprotein. Work shift was not associated with metabolic syndrome and its altered components. After adjustment, the prevalence of metabolic syndrome was positively associated with women (PR 2.16; 95%CI 1.28;3.64), workers aged over 40 years (PR 3.90; 95%CI 1.78;8.93) and those who reported sleeping five hours or less per day (PR 1.70; 95%CI 1.09;2.24). On the other hand, metabolic syndrome was inversely associated with educational level and having more than three meals per day (PR 0.43; 95%CI 0.26;0.73). CONCLUSIONS Being female, older and deprived of sleep are probable risk factors for metabolic syndrome, whereas higher educational level and higher number of meals per day are protective factors for metabolic syndrome in fixed-shift workers.

Shift work in a security environment

International Nuclear Information System (INIS)

Longhouser, G.A. Jr.

1993-01-01

Human beings are diurnal species, normally active by day and asleep by night. Yet over thirty million Americans struggle with work schedules that include an off-normal work effort. The railroads, law enforcement, health services, Department of Defense, factory workers, chemical plants and public services, communications and utility workers must provide some form of around-the-clock effort. Shift work has been around since the advent of recorded history. There has always been a need for some type of off-normal service and assistance. The impact of shift work is replete with tales and factual evidence of an increased personnel error rate; disorders, both personal and family, and of course, increased accident events. In recent memory, the Three Mile Island Nuclear Plant incident, Union Carbide's explosion in Bhopal, and the Chernobyl Nuclear Plant catastrophe all occurred during off-normal working hours. Yet management overall has done little to correct the production-driven twelve hour, seven day week shift mentality of the nineteenth century. Most schedules in use today are nothing more than cosmetic variations of the old production schedules. This could be driven by a management consideration of the worker's response to change coupled with a reluctant buy-in of responsibility for the effects of change. Florida Power Corporation has developed for its nuclear security force, a unique work schedule which attempts to employ the sound principles of circadian rhythms coupled with a comprehensive training program to counter the problems associated with shift work. The results over the last four years have seen a marked reduction in the generic problems of personnel errors, absenteeism, unscheduled overtime and turnover rates. Utilization and understanding of this scheduling process for rotational shift work needs to be assessed to determine if the benefits are site specific or provide an expected response to the problems of shift work

Metabolic syndrome in fixed-shift workers

Directory of Open Access Journals (Sweden)

Raquel Canuto

2015-01-01

Full Text Available OBJECTIVE To analyze if metabolic syndrome and its altered components are associated with demographic, socioeconomic and behavioral factors in fixed-shift workers. METHODS A cross-sectional study was conducted on a sample of 902 shift workers of both sexes in a poultry processing plant in Southern Brazil in 2010. The diagnosis of metabolic syndrome was determined according to the recommendations from Harmonizing the Metabolic Syndrome. Its frequency was evaluated according to the demographic (sex, skin color, age and marital status, socioeconomic (educational level, income and work shift, and behavioral characteristics (smoking, alcohol intake, leisure time physical activity, number of meals and sleep duration of the sample. The multivariate analysis followed a theoretical framework for identifying metabolic syndrome in fixed-shift workers. RESULTS The prevalence of metabolic syndrome in the sample was 9.3% (95%CI 7.4;11.2. The most frequently altered component was waist circumference (PR 48.4%; 95%CI 45.5;51.2, followed by high-density lipoprotein. Work shift was not associated with metabolic syndrome and its altered components. After adjustment, the prevalence of metabolic syndrome was positively associated with women (PR 2.16; 95%CI 1.28;3.64, workers aged over 40 years (PR 3.90; 95%CI 1.78;8.93 and those who reported sleeping five hours or less per day (PR 1.70; 95%CI 1.09;2.24. On the other hand, metabolic syndrome was inversely associated with educational level and having more than three meals per day (PR 0.43; 95%CI 0.26;0.73. CONCLUSIONS Being female, older and deprived of sleep are probable risk factors for metabolic syndrome, whereas higher educational level and higher number of meals per day are protective factors for metabolic syndrome in fixed-shift workers.

Measuring proton shift tensors with ultrafast MAS NMR.

Science.gov (United States)

Miah, Habeeba K; Bennett, David A; Iuga, Dinu; Titman, Jeremy J

2013-10-01

A new proton anisotropic-isotropic shift correlation experiment is described which operates with ultrafast MAS, resulting in good resolution of isotropic proton shifts in the detection dimension. The new experiment makes use of a recoupling sequence designed using symmetry principles which reintroduces the proton chemical shift anisotropy in the indirect dimension. The experiment has been used to measure the proton shift tensor parameters for the OH hydrogen-bonded protons in tyrosine·HCl and citric acid at Larmor frequencies of up to 850 MHz. Copyright © 2013 Elsevier Inc. All rights reserved.

HUBBLE SPACE TELESCOPE EMISSION-LINE GALAXIES AT z ∼ 2: THE MYSTERY OF NEON

International Nuclear Information System (INIS)

Zeimann, Gregory R.; Ciardullo, Robin; Gebhardt, Henry; Gronwall, Caryl; Hagen, Alex; Trump, Jonathan R.; Bridge, Joanna S.; Luo, Bin; Schneider, Donald P.

2015-01-01

We use near-infrared grism spectroscopy from the Hubble Space Telescope to examine the strength of [Ne III] λ3869 relative to Hβ, [O II] λ3727, and [O III] λ5007 in 236 low-mass (7.5 ≲ log (M * /M ☉ ) ≲ 10.5) star-forming galaxies in the redshift range 1.90 < z < 2.35. By stacking the data by stellar mass, we show that the [Ne III]/[O II] ratios of the z ∼ 2 universe are marginally higher than those seen in a comparable set of local Sloan Digital Sky Survey galaxies, and that [Ne III]/[O III] is enhanced by ∼0.2 dex. We consider the possible explanations for this ∼4σ result, including higher oxygen depletion out of the gas phase, denser H II regions, higher production of 22 Ne via Wolf-Rayet stars, and the existence of a larger population of X-ray obscured active galactic nuclei at z ∼ 2 compared to z ∼ 0. None of these simple scenarios, alone, are favored to explain the observed line ratios. We conclude by suggesting several avenues of future observations to further explore the mystery of enhanced [Ne III] emission

Josephson shift register design and layout

International Nuclear Information System (INIS)

Przybysz, J.X.; Buttyan, J.; Blaugher, R.D.

1989-01-01

Integrated circuit chips were designed and fabricated, based on Josephson shift register circuit that simulated operation at 25 GHz using the SPICE program. The 6.25 mm square chip featured a twelve-gate, four-stage shift register fabricated with Nb/AlO/sub x//Nb Josephson junctions with a design value of 2000 A/cm/sup 2/ critical current density. SUPERCOMPACT, a general program for the design of monolithic microwave integrated circuits, was used to model the effects of layout geometry on the uniformity and phase coherence of logic gate bias currents. Gate bias resistors were treated as resistive transmission lines. A layout geometry for the superconductive transmission lines and thin film bias resistors was developed. The original SPICE-designed circuit was modified as a result of these calculations. Modeling indicated that bias current variations could be limited to 3% for all possible logic states of the shift register, and phase coherence of the gates could be maintained to within 2 degrees of 10 Ghz. The fundamental soundness of the circuit design was demonstrated by the proper operation of fabricated shift registers

Scandinavian Object Shift and Optimality Theory

DEFF Research Database (Denmark)

Engels, Eva; Vikner, Sten

This study presents an account of object shift, a word order phenomenon found in most of the Scandinavian languages where an object occurs unexpectedly to the left and not to the right of a sentential adverbial. The book examines object shift across many of the Scandinavian languages and dialects...... and original observations, this book is an important addition to the fields of phonology, optimality theory and theoretical syntax......., and analyses the variation, for example whether object shift is optional or obligatory, whether it applies only to pronouns or other objects as well, and whether it applies to adverbials. The authors show that optimality theory, traditionally used in phonology, is a useful framework for accounting...

Special offer for early shift takers!

CERN Multimedia

Muriel

Peter Jenni, spokesperson of the ATLAS collaboration, just made the following announcement. "Despite the few problems that we are encountering, which of course are unavoidable in such a large project, I am very pleased with the way the ATLAS experiment is taking shape. With the imminence of data taking, I would like to make a special gesture as a thank you to all of you who are working so hard for ATLAS to meet its many deadlines. The first 100 ATLAS members who will sign up for shifts will receive twice the standard OTSMOU credit." You can sign up for shifts as of April 1st by sending an e-mail to Atlas.Shifts@cern.ch.

Profit shifting in the Norwegian and British petroleum industry: Differentiating between the real and shifting response to tax changes

OpenAIRE

Vada, Helene

2016-01-01

In this master’s thesis, I explain the concept of profit shifting within multinational enterprises and investigate whether petroleum companies on the Norwegian and British continental shelves engage in tax motivated profit shifting, by applying ordinary least squares and company fixed effects estimation. To be able to distinguish between traditional tax distortions and profit shifting, I extend the model developed by James R. Hines and Eric M. Rice in their 1994 article “Fiscal Paradise: Fore...

Cost effective shift schedules enhance utility operations

International Nuclear Information System (INIS)

Coleman, R.M.

1995-01-01

This article describes how new shift scheduling concepts can save utility operations millions of dollars every year and yet maintain safety and improve employee morale. The key to scheduling is to define and match the work load. This includes discretionary as well as daily, weekly, and yearly core work loads. In most power plants the overall work load (including maintenance, operations, materials handling, etc.) on day shift is greater than on other shifts, hence an unbalanced schedule would be appropriate

Automated Morphological Classification in Deep Hubble Space Telescope UBVI Fields: Rapidly and Passively Evolving Faint Galaxy Populations

Science.gov (United States)

Odewahn, Stephen C.; Windhorst, Rogier A.; Driver, Simon P.; Keel, William C.

1996-11-01

We analyze deep Hubble Space Telescope Wide Field Planetary Camera 2 (WFPC2) images in U, B, V, I using artificial neural network (ANN) classifiers, which are based on galaxy surface brightness and light profile (but not on color nor on scale length, rhl). The ANN distinguishes quite well between E/S0, Sabc, and Sd/Irr+M galaxies (M for merging systems) for BJ ~ 24 mag. The faint blue galaxy counts in the B band are dominated by Sd/Irr+M galaxies and can be explained by a moderately steep local luminosity function (LF) undergoing strong luminosity evolution. We suggest that these faint late-type objects (24 mag <~ BJ <~ 28 mag) are a combination of low-luminosity lower redshift dwarf galaxies, plus compact star-forming galaxies and merging systems at z ~= 1--3, possibly the building blocks of the luminous early-type galaxies seen today.

Lateral shift in one-dimensional quasiperiodic chiral photonic crystal

Energy Technology Data Exchange (ETDEWEB)

Da, Jian, E-mail: dajian521@sina.com [Department of Information Engineering, Huaian Senior Vocational and Technical School, Feiyao road, Huaian 223005, Jiangsu Province (China); Mo, Qi, E-mail: moqiyueyang@163.com [School of Software, Yunnan University, Cuihu Bai Road, Kunming City, Yunnan Province 650091 (China); Cheng, Yaokun [Department of Information Engineering, Huaian Senior Vocational and Technical School, Feiyao road, Huaian 223005, Jiangsu Province (China); Liu, Taixiang [Taishan Vocational College of Nursing, Shandong Province 271000 (China)

2015-02-01

We investigate the lateral shift of a one-dimensional quasiperiodic photonic crystal consisting of chiral and conventional dielectric materials. The effect of structural irregularity on lateral shift is evaluated by stationary-phase approach. Our results show that the lateral shift can be modulated by varying the structural irregularity in quasiperiodic structure. Besides, the position of peak in lateral shift spectrum stays sensitive to the chiral factor of chiral materials. In comparison with that of periodic structure, quasiperiodic structure provides an extra degree of freedom to manipulate the lateral shift.

Dynamic Characteristics Analysis of Power Shift Control Valve

Directory of Open Access Journals (Sweden)

Feng Ren

2014-07-01

Full Text Available In order to study the influence that dynamic performance of shift control valve has on shifting process of construction machinery, the paper introduces working principle of the shift control valve and sets up the dynamically mathematical model and corresponding simulation model with simulation software LMS Imagine. Lab AMESim. Based on simulation, the paper analyzes the influence of pressure variation characteristics and buffering characteristics acting on vehicle performance during the process of shifting, meanwhile conducting experiments to verify the simulation. The results indicate that the simulation model is accurate and credible; the performance of the valve is satisfactory, which indeed reduces impact during shifting. Furthermore, the valve can meet the demand of other construction machineries in better degree by suitable matching between control spring stiffness and damping holes diameter.

Shift manager workload assessment - A case study

International Nuclear Information System (INIS)

Berntson, K.; Kozak, A.; Malcolm, J. S.

2006-01-01

In early 2003, Bruce Power restarted two of its previously laid up units in the Bruce A generating station, Units 3 and 4. However, due to challenges relating to the availability of personnel with active Shift Manager licenses, an alternate shift structure was proposed to ensure the safe operation of the station. This alternate structure resulted in a redistribution of responsibility, and a need to assess the resulting changes in workload. Atomic Energy of Canada Limited was contracted to perform a workload assessment based on the new shift structure, and to provide recommendations, if necessary, to ensure Shift Managers had sufficient resources available to perform their required duties. This paper discusses the performance of that assessment, and lessons learned as a result of the work performed during the Restart project. (authors)

Lambda shifted photonic crystal cavity laser

DEFF Research Database (Denmark)

Schubert, Martin; Skovgård, Troels Suhr; Ek, Sara

2010-01-01

We propose and demonstrate an alternative type of photonic crystal laser design that shifts all the holes in the lattice by a fixed fraction of the targeted emission wavelength. The structures are realized in InGaAsP =1.15 with InGaAsP quantum wells =1.52 as gain material. Cavities with shifts of...

Shift Work and Cognitive Flexibility: Decomposing Task Performance.

Science.gov (United States)

Cheng, Philip; Tallent, Gabriel; Bender, Thomas John; Tran, Kieulinh Michelle; Drake, Christopher L

2017-04-01

Deficits in cognitive functioning associated with shift work are particularly relevant to occupational performance; however, few studies have examined how cognitive functioning is associated with specific components of shift work. This observational study examined how circadian phase, nocturnal sleepiness, and daytime insomnia in a sample of shift workers ( N = 30) were associated with cognitive flexibility during the night shift. Cognitive flexibility was measured using a computerized task-switching paradigm, which produces 2 indexes of flexibility: switch cost and set inhibition. Switch cost represents the additional cognitive effort required in switching to a different task and can impact performance when multitasking is involved. Set inhibition is the efficiency in returning to previously completed tasks and represents the degree of cognitive perseveration, which can lead to reduced accuracy. Circadian phase was measured via melatonin assays, nocturnal sleepiness was assessed using the Multiple Sleep Latency Test, and daytime insomnia was assessed using the Insomnia Severity Index. Results indicated that those with an earlier circadian phase, insomnia, and sleepiness exhibited reduced cognitive flexibility; however, specific components of cognitive flexibility were differentially associated with circadian phase, insomnia, and sleepiness. Individuals with an earlier circadian phase (thus more misaligned to the night shift) exhibited larger switch costs, which was also associated with reduced task efficiency. Shift workers with more daytime insomnia demonstrated difficulties with cognitive inhibition, whereas nocturnal sleepiness was associated with difficulties in reactivating previous tasks. Deficits in set inhibition were also related to reduced accuracy and increased perseverative errors. Together, this study indicates that task performance deficits in shift work are complex and are variably impacted by different mechanisms. Future research may examine

Night shift decreases cognitive performance of ICU physicians.

Science.gov (United States)

Maltese, François; Adda, Mélanie; Bablon, Amandine; Hraeich, Sami; Guervilly, Christophe; Lehingue, Samuel; Wiramus, Sandrine; Leone, Marc; Martin, Claude; Vialet, Renaud; Thirion, Xavier; Roch, Antoine; Forel, Jean-Marie; Papazian, Laurent

2016-03-01

The relationship between tiredness and the risk of medical errors is now commonly accepted. The main objective of this study was to assess the impact of an intensive care unit (ICU) night shift on the cognitive performance of a group of intensivists. The influence of professional experience and the amount of sleep on cognitive performance was also investigated. A total of 51 intensivists from three ICUs (24 seniors and 27 residents) were included. The study participants were evaluated after a night of rest and after a night shift according to a randomized order. Four cognitive skills were tested according to the Wechsler Adult Intelligence Scale and the Wisconsin Card Sorting Test. All cognitive abilities worsened after a night shift: working memory capacity (11.3 ± 0.3 vs. 9.4 ± 0.3; p night shift. The cognitive abilities of intensivists were significantly altered following a night shift in the ICU, regardless of either the amount of professional experience or the duration of sleep during the shift. The consequences for patients' safety and physicians' health should be further evaluated.

Shift work and its association with metabolic disorders.

Science.gov (United States)

Brum, Maria Carlota Borba; Filho, Fábio Fernandes Dantas; Schnorr, Claudia Carolina; Bottega, Gustavo Borchardt; Rodrigues, Ticiana C

2015-01-01

Although the health burden of shift work has not been extensively studied, evidence suggests that it may affect the metabolic balance and cause obesity and other metabolic disorders. Sleep deprivation, circadian desynchronization and behavioral changes in diet and physical activity are among the most commonly mentioned factors in studies of the association between night work and metabolic disorders. Individual adaptation to night work depends greatly on personal factors such as family and social life, but occupational interventions may also make a positive contribution to the transition to shift work, such as exposure to bright lights during the night shift, melatonin use, shift regularity and clockwise rotation, and dietary adaptations for the metabolic needs of night workers. The evaluation of the impact of night work on health and of the mechanisms underlying this relationship can serve as a basis for intervention strategies to minimize the health burden of shift work. This review aimed to identify highlights regarding therapeutic implications following the association between night and shift work and metabolic disorders, as well as the mechanisms and pathways responsible for these relationships.

Staffing, overtime, and shift scheduling project

International Nuclear Information System (INIS)

Lewis, P.M.

1989-01-01

Recent events at the Peach Bottom nuclear power plant have demonstrated the need to establish a quantifiable basis for assessing the safety significance of long work hours on nuclear power plant operators. The incidents at TMI-2, Chernobyl, and Bhopal, which all occurred during the late evening/night shift, further highlight the importance of the relationship between shift scheduling and performance. The objective of this project is to estimate, using statistical analysis on data from the nuclear industry, the effects on safety of staffing levels, overtime, and shift scheduling for operators and maintenance personnel. Regarding staffing levels, the Nuclear Regulatory Commission (NRC) currently has no explicit regulation concerning the minimum acceptable levels of staffing in a plant that has an operating license. The NRC has no systematic method for collecting data on the number of licensed operators on the operating crews. In 1982 the NRC recommended that plants write into their technical specifications a model policy on overtime. Currently, 77 nuclear power plant units have the model policy or a modification of it written into their technical specifications; 33 units have no policy on overtime. The model policy sets limits on overtime for safety related personnel, although these limits can be exceeded with plant manger approval. The US nuclear power industry has three types of shift schedules: (1) forward-rotating 8-hour/day shift schedules, (2) backward-rotating 8-hour/day schedules, and (3) 12-hour/day schedules

Night Shift Work and Its Health Effects on Nurses.

Science.gov (United States)

Books, Candie; Coody, Leon C; Kauffman, Ryan; Abraham, Sam

The purpose of this research was to study night shift work and its health effects on nurses. This was a quantitative study using descriptive design; it also incorporated three qualitative open-ended questions to complement the study. The data were collected using Survey Monkey, with an Internet-based confidential data collection tool. The population of relevance to this study was nurses employed in hospital settings in the United States. E-mail addresses and Facebook were used to recruit participants. Results indicated that there is an increased risk of sleep deprivation, family stressors, and mood changes because of working the night shift. Rotating shifts were mentioned as a major concern for night shift nurses. Respondents agreed that complaints about fatigue and fatigue-related illnesses in night shift workers were ignored. There was also a general perception among nurses working the night shift that sleep deprivation leads to negative health consequences including obesity; however, they were not as high a concern as rotating shifts or fatigue.

Recurrence phase shift in Fermi-Pasta-Ulam nonlinear dynamics

Energy Technology Data Exchange (ETDEWEB)

Devine, N., E-mail: nnd124@rsphysse.anu.edu.au [Optical Sciences Group, Research School of Physics and Engineering, The Australian National University, Canberra ACT 0200 (Australia); Ankiewicz, A. [Optical Sciences Group, Research School of Physics and Engineering, The Australian National University, Canberra ACT 0200 (Australia); Genty, G. [Tampere University of Technology, Optics Laboratory, FI-33101 Tampere (Finland); Dudley, J.M. [Institut FEMTO-ST UMR 6174 CNRS/Universite de Franche-Comte, Besancon (France); Akhmediev, N. [Optical Sciences Group, Research School of Physics and Engineering, The Australian National University, Canberra ACT 0200 (Australia)

2011-11-07

We show that the dynamics of Fermi-Pasta-Ulam recurrence is associated with a nonlinear phase shift between initial and final states that are otherwise identical, after a full growth-return cycle. The properties of this phase shift are studied for the particular case of the self-focussing nonlinear Schroedinger equation, and we describe the magnitude of the phase shift in terms of the system parameters. This phase shift, accumulated during the nonlinear recurrence cycle, is a previously-unremarked feature of the Fermi-Pasta-Ulam problem, and we anticipate its wide significance as an essential feature of related dynamics in other systems. -- Highlights: → The dynamics of FPU recurrence is associated with a phase shift between initial and final states. → The properties of this phase shift are studied for the self-focussing NLS equation. → This phase shift is a previously-unremarked feature of the FPU growth-return cycle. → We anticipate its wide significance as an essential feature of related dynamics in other systems.

Recurrence phase shift in Fermi-Pasta-Ulam nonlinear dynamics

International Nuclear Information System (INIS)

Devine, N.; Ankiewicz, A.; Genty, G.; Dudley, J.M.; Akhmediev, N.

2011-01-01

We show that the dynamics of Fermi-Pasta-Ulam recurrence is associated with a nonlinear phase shift between initial and final states that are otherwise identical, after a full growth-return cycle. The properties of this phase shift are studied for the particular case of the self-focussing nonlinear Schroedinger equation, and we describe the magnitude of the phase shift in terms of the system parameters. This phase shift, accumulated during the nonlinear recurrence cycle, is a previously-unremarked feature of the Fermi-Pasta-Ulam problem, and we anticipate its wide significance as an essential feature of related dynamics in other systems. -- Highlights: → The dynamics of FPU recurrence is associated with a phase shift between initial and final states. → The properties of this phase shift are studied for the self-focussing NLS equation. → This phase shift is a previously-unremarked feature of the FPU growth-return cycle. → We anticipate its wide significance as an essential feature of related dynamics in other systems.

Passing the Baton: An Experimental Study of Shift Handover

Science.gov (United States)

Parke, Bonny; Hobbs, Alan; Kanki, Barbara

2010-01-01

Shift handovers occur in many safety-critical environments, including aviation maintenance, medicine, air traffic control, and mission control for space shuttle and space station operations. Shift handovers are associated with increased risk of communication failures and human error. In dynamic industries, errors and accidents occur disproportionately after shift handover. Typical shift handovers involve transferring information from an outgoing shift to an incoming shift via written logs, or in some cases, face-to-face briefings. The current study explores the possibility of improving written communication with the support modalities of audio and video recordings, as well as face-to-face briefings. Fifty participants participated in an experimental task which mimicked some of the critical challenges involved in transferring information between shifts in industrial settings. All three support modalities, face-to-face, video, and audio recordings, reduced task errors significantly over written communication alone. The support modality most preferred by participants was face-to-face communication; the least preferred was written communication alone.

Dietary habits among persons hired on shift work

Directory of Open Access Journals (Sweden)

Joanna Strzemecka

2014-03-01

Full Text Available Introduction. Shift-work determinates irregular nutrition habits. The quality as well as the quantity of meals consumed by shift-workers can significantly affects their health. Objective. The aim of this study was to evaluate the dietary habits of people performing shift work in the Bogdanka mine. Material and Methods. The study was carried out in the Bogdanka mine in Leczna. The questionnaire, which was designed by the author of this dissertation, was conducted among 700 shift-workers, working underground. The results were subjected to statistical analysis based on STATISTICA v. 7.1 (StatSoft, Poland software. Results. Nearly half of respondents reported regular consumption of meals (40.0% Interviewees admitted having warm meals during the day (81.4%. The most frequently consumed meal during the day was the hot one (50.9%, three meals and more were consumed the least frequently (8.1%. Almost half of respondents considered their eating habits as inappropriate (46.3%. Among those, nearly half (68.2% stated that shift – work is the reason for their nutrition habits. More than half of respondents (66.0% admitted that shift work hampers regular consumption of meals. Conclusions. Shift work makes nourishment and regular consumption difficult. It contributes to the limited amount of warm meals eaten during the day. In order to maintain preventive health care and the improvement of quality of life, shift workers should be provided with an easier access to meals (including warm one at specified times of the day.

The Prerequisites for a Degrowth Paradigm Shift

DEFF Research Database (Denmark)

Buch-Hansen, Hubert

2018-01-01

What would it take for a degrowth paradigm shift to take place? Drawing on contemporary critical political economy scholarship, this article identifies four prerequisites for socio-economic paradigm shifts: deep crisis, an alternative political project, a comprehensive coalition of social forces...... currently facing humanity. On the other hand, the prospects for a degrowth paradigm shift remain bleak: unlike political projects that became hegemonic in the past, degrowth has neither support from a comprehensive coalition of social forces nor any consent to its agenda among the broader population....

Hubble space telescope servicing mission joint ESA/BAE UK technical press briefing Wednesday 10 March 1993

Science.gov (United States)

1993-02-01

On Wednesday 10 March 1993 astronauts from ESA and NASA will be at British Aerospace Space Systems Limited, Filton, Bristol, UK, training on the replacement set of solar arrays which they are scheduled to fit to the Hubble Space Telescope at year end. You are invited to attend a technical briefing on that day, which will be given by senior representatives of the European Space Agency and British Aerospace. The briefing will include details of the design modifications and status of the solar arrays, together with a brief overview of the scientific results already achieved by the teams of astronomers using the telescope. There will be an opportunity for interviews with the mission specialists in the crew of NASA's Space Shuttle flight STS-61, who will be carrying out the servicing mission for the Hubble Space Telescope in a series of "Extra-Vehicular Activities - EVA' (space-walks). Five astronauts are expected : Story Musgrave, Colonel Tom Akers, Jeffrey A. Hoffman, Kathryn C. Thornton from NASA and Claude Nicollier from ESA. There will also be a chance to view the solar arrays in the British Aerospace clean room area where the astronauts are working on their familiarisation programme. The briefing will take place on Wednesday 10 March 1993 at British Aerospace Space Systems, Filton, Bristol, UK (on the northern outskirts of the city of Bristol). The event will begin at 10h30 a.m. and end with a buffet lunch running from approximately 01h30 p.m. to 02h30 p.m. In order to assists with arrangements for travel to and from bristol, British Aerospace proposes to run a free coach from and to London Victoria Coach Station - if there proves to be sufficient press interest. This coach would depart from London at approximately 07h50 a.m. and arrive back at around 05h30 p.m. Further details will be available on request when numbers are known. In order to gain access to the site and the briefing it is essential that all attendees are expected and their names are provided in

Shifting Sugars and Shifting Paradigms