1,617 research outputs found

    Examining the effects of Referent Power on Intrinsic Motivation in organisations: a self-concept based approach

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    Using a self-concept based approach we examine the literature for evidence of effects, induced by referent power, on the intrinsic motivation of employees. We propose that the subject of a referent power relationship will be intrinsically motivated to affirm, or enhance their self-concept, in relation to characteristics of a referent agent. Hypotheses were developed and tested using data from 311 employees of a large consulting firm. We found empirical support for the view that referent motivation leads to behaviour in individuals that is in accord with characteristics of a referent agent, with this behaviour resulting in affirmation or enhancement of their self-concept

    Impact of Technology on Meat Safety

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    Innovations and new technologies tend to create apprehension among consumers who are not familiar with the technologies and their mode of action. This case currently exists regarding the use of hormones, antibiotics and other feed additives in livestock production. The purpose of this fact sheet is to familiarize consumers with some of the products of technology that are currently utilized in the production of meat animals and to provide an evaluation of how these products impact the safety of meat and meat products

    The Compton hump and variable blue wing in the extreme low-flux NuSTAR observations of 1H0707-495

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    The Narrow-line Seyfert I galaxy, 1H0707-495, has been well observed in the 0.3-10 keV band, revealing a dramatic drop in flux in the iron K alpha band, a strong soft excess, and short timescale reverberation lags associated with these spectral features. In this paper, we present the first results of a deep 250 ks NuSTAR observation of 1H0707-495, which includes the first sensitive observations above 10 keV. Even though the NuSTAR observations caught the source in an extreme low-flux state, the Compton hump is still significantly detected. NuSTAR, with its high effective area above 7 keV, clearly detects the drop in flux in the iron K alpha band, and by comparing these observations with archival XMM-Newton observations, we find that the energy of this drop increases with increasing flux. We discuss possible explanations for this, the most likely of which is that the drop in flux is the blue wing of the relativistically broadened iron K alpha emission line. When the flux is low, the coronal source height is low, thus enhancing the most gravitationally redshifted emission.Comment: Submitted to MNRAS, comments are welcome. 9 pages, 5 figure

    Effects of Growth Pattern on Muscle Growth, Nuclei Number, Protein Accretion, and Body Composition in Heifers

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    The effects of compensatory growth on accretion of muscle mass, protein mass, and nuclei number of the supraspinatus and semitendinosus muscles were evaluated using seven serial slaughter groups of Angus x Limousin heifer calves (n = 28, BW 270 2 9.5 kg). Fractional growth rates of carcass protein and fat were also evaluated. To achieve compensatory growth, energy intake was restricted for 88 days (Phase 1) followed by adlibitum feeding of a high energy diet (Phase2) [LH]. Controls were allowed continuous ad libitum access to the high energy diet (HH). Muscle weights, body composition samples, and muscle biopsies were collected at various weight (465 vs 500 kg) or age (88 vs 186 days) constants. Phase 1 energy restriction limited body weight, carcass weight, carcass protein mass, and carcass fat mass (P\u3c.05). This was the result of the limited tissue fractional growth rates. The fractional growth rate of protein for heifers exhibiting compensatory growth was not increased but was maintained until maximum carcass protein mass was attained. Maximum carcass protein mass was attained by a weight of 465 kg. Any further increase in carcass weight was primarily attributed to an increase of carcass fat mass regardless of previous management. Energy restriction limited muscle, protein, and nuclei accretion rates. Heifers exhibiting compensatory growth sustained a linear growth potential until maximum muscle mass occurred at an end point similar to cattle not exhibiting compensatory growth. Muscle nuclei maintained a constant relationship to muscle mass independent of nutritional treatment, muscle type (supraspinatus vs semitendinosus), or days on feed. These data indicate compensatory growth alters the growth curve without affecting the mechanisms of growth

    Effects of Energy Restriction and Realimentation on the Development of Carcass Traits of Yearling Heifers

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    Feedlot performance and carcass development were compared between heifers fed a low energy diet for an 88-day backgrounding period before receiving a high energy diet (LE) and heifers receiving a high energy diet throughout the trial (HE). The LE heifers were delayed in carcass and muscle growth (P\u3c.10) when compared to HE heifers on day 89. At an 1100 1b weight constant, LE and HE carcasses had similar dissected muscle weights, rib fat measurements and marbling scores. Carcass dressing percentage was only affected by time (P\u3c.10) on an energy dense diet at 1030 Ib. During the initial 88-day background period, HE heifers had higher ADG (P\u3c.001) and lower Feed/gain requirements (P\u3c.001). During realimentation, compensatory growth was exhibited through increased ADG (P\u3c .lo) and improved feed/gain (P\u3c.05) for LE heifers. From day 0 until slaughter, the cumulative ADG for HE heifers was greater (P\u3c.05) and the cumulative feed conversion was lower for HE heifers (P\u3c.10)

    Generation of Arbitrary Frequency Chirps with a Fiber-Based Phase Modulator and Self-Injection-Locked Diode Laser

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    We present a novel technique for producing pulses of laser light whose frequency is arbitrarily chirped. The output from a diode laser is sent through a fiber-optical delay line containing a fiber-based electro-optical phase modulator. Upon emerging from the fiber, the phase-modulated pulse is used to injection-lock the laser and the process is repeated. Large phase modulations are realized by multiple passes through the loop while the high optical power is maintained by self-injection-locking after each pass. Arbitrary chirps are produced by driving the modulator with an arbitrary waveform generator

    Progress in Lunar Laser Ranging Tests of Relativistic Gravity

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    Analyses of laser ranges to the Moon provide increasingly stringent limits on any violation of the Equivalence Principle (EP); they also enable several very accurate tests of relativistic gravity. We report the results of our recent analysis of Lunar Laser Ranging (LLR) data giving an EP test of \Delta (M_G/M_I)_{EP} =(-1.0 +/- 1.4) x 10^{-13}. This result yields a Strong Equivalence Principle (SEP) test of \Delta (M_G/M_I)_{SEP} =(-2.0 +/- 2.0) x 10^{-13}. Also, the corresponding SEP violation parameter \eta is (4.4 +/- 4.5) x 10^{-4}, where \eta=4\beta-\gamma-3 and both \beta and \gamma are parametrized post-Newtonian (PPN) parameters. Using the recent Cassini result for the parameter \gamma, PPN parameter \beta is determined to be \beta-1=(1.2 +/- 1.1) x 10^{-4}. The geodetic precession test, expressed as a relative deviation from general relativity, is K_{gp}=-0.0019 +/- 0.0064. The search for a time variation in the gravitational constant results in \dot G/G=(4 +/- 9) x 10^{-13} yr^{-1}, consequently there is no evidence for local (~1AU) scale expansion of the solar system.Comment: 4 pages, revtex4, minor changes made for publicatio

    The broad band spectral variability of MCG-6-30-15 observed by NuSTAR and XMM-Newton

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    MCG-6-30-15, at a distance of 37 Mpc (z=0.008), is the archetypical Seyfert 1 galaxy showing very broad Fe Kα\alpha emission. We present results from a joint NuSTAR and XMM-Newton observational campaign that, for the first time, allows a sensitive, time-resolved spectral analysis from 0.35 keV up to 80 keV. The strong variability of the source is best explained in terms of intrinsic X-ray flux variations and in the context of the light bending model: the primary, variable emission is reprocessed by the accretion disk, which produces secondary, less variable, reflected emission. The broad Fe Kα\alpha profile is, as usual for this source, well explained by relativistic effects occurring in the innermost regions of the accretion disk around a rapidly rotating black hole. We also discuss the alternative model in which the broadening of the Fe Kα\alpha is due to the complex nature of the circumnuclear absorbing structure. Even if this model cannot be ruled out, it is disfavored on statistical grounds. We also detected an occultation event likely caused by BLR clouds crossing the line of sight.Comment: 19 pages, 16 figures, accepted for publication on Ap

    New Constraints on the Black Hole Low/Hard State Inner Accretion Flow with NuSTAR

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    We report on an observation of the Galactic black hole candidate GRS 1739-278 during its 2014 outburst, obtained with NuSTAR. The source was captured at the peak of a rising "low/hard" state, at a flux of ~0.3 Crab. A broad, skewed iron line and disk reflection spectrum are revealed. Fits to the sensitive NuSTAR spectra with a number of relativistically blurred disk reflection models yield strong geometrical constraints on the disk and hard X-ray "corona". Two models that explicitly assume a "lamppost" corona find its base to have a vertical height above the black hole of h = 5 (+7, -2) GM/c^2 and h = 18 +/-4 GM/c^2 (90% confidence errors); models that do not assume a "lamppost" return emissivity profiles that are broadly consistent with coronae of this size. Given that X-ray microlensing studies of quasars and reverberation lags in Seyferts find similarly compact coronae, observations may now signal that compact coronae are fundamental across the black hole mass scale. All of the models fit to GRS 1739-278 find that the accretion disk extends very close to the black hole - the least stringent constraint is r = 5 (+3,-4) GM/c^2. Only two of the models deliver meaningful spin constraints, but a = 0.8 +/-0.2 is consistent with all of the fits. Overall, the data provide especially compelling evidence of an association between compact hard X-ray coronae and the base of relativistic radio jets in black holes.Comment: Accepted for publication in ApJ Letter

    Observations of the Prompt Gamma-Ray Emission of GRB 070125

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    The long, bright gamma-ray burst GRB 070125 was localized by the Interplanetary Network. We present light curves of the prompt gamma-ray emission as observed by Konus-WIND, RHESSI, Suzaku-WAM, and \textit{Swift}-BAT. We detail the results of joint spectral fits with Konus and RHESSI data. The burst shows moderate hard-to-soft evolution in its multi-peaked emission over a period of about one minute. The total burst fluence as observed by Konus is 1.79×1041.79 \times 10^{-4} erg/cm2^2 (20 keV--10 MeV). Using the spectroscopic redshift z=1.548z=1.548, we find that the burst is consistent with the ``Amati'' Epeak,iEisoE_{peak,i}-E_{iso} correlation. Assuming a jet opening angle derived from broadband modeling of the burst afterglow, GRB 070125 is a significant outlier to the ``Ghirlanda'' Epeak,iEγE_{peak,i}-E_\gamma correlation. Its collimation-corrected energy release Eγ=2.5×1052E_\gamma = 2.5 \times 10^{52} ergs is the largest yet observed.Comment: 25 pages, 6 figures; accepted for publication in ApJ. Improved spectral fits and energetics estimate
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