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What motivates academic dishonesty in students? A reinforcement sensitivity theory explanation
BACKGROUND: Academic dishonesty (AD) is an increasing challenge for universities worldwide. The rise of the Internet has further increased opportunities for students to cheat.
AIMS: In this study, we investigate the role of personality traits defined within Reinforcement Sensitivity Theory (RST) as potential determinants of AD. RST defines behaviour as resulting from approach (Reward Interest/reactivity, goal-drive, and Impulsivity) and avoidance (behavioural inhibition and Fight-Flight-Freeze) motivations. We further consider the role of deep, surface, or achieving study motivations in mediating/moderating the relationship between personality and AD.
SAMPLE: A sample of UK undergraduates (NÂ =Â 240).
METHOD: All participants completed the RST Personality Questionnaire, a short-form version of the study process questionnaire and a measure of engagement in AD, its perceived prevalence, and seriousness.
RESULTS: Results showed that RST traits account for additional variance in AD. Mediation analysis suggested that GDP predicted dishonesty indirectly via a surface study approach while the indirect effect via deep study processes suggested dishonesty was not likely. Likelihood of engagement in AD was positively associated with personality traits reflecting Impulsivity and Fight-Flight-Freeze behaviours. Surface study motivation moderated the Impulsivity effect and achieving motivation the FFFS effect such that cheating was even more likely when high levels of these processes were used.
CONCLUSIONS: The findings suggest that motivational personality traits defined within RST can explain variance in the likelihood of engaging in dishonest academic behaviours
Large Torque Variations in Two Soft Gamma Repeaters
We have monitored the pulse frequencies of the two soft gamma repeaters SGR
1806-20 and SGR 1900+14 through the beginning of year 2001 using primarily
Rossi X-ray Timing Explorer Proportional Counter Array observations. In both
sources, we observe large changes in the spin-down torque up to a factor of ~4,
which persist for several months. Using long baseline phase-connected timing
solutions as well as the overall frequency histories, we construct torque noise
power spectra for each SGR. The power spectrum of each source is very red
(power-law slope ~-3.5). The torque noise power levels are consistent with some
accreting systems on time scales of ~1 year, yet the full power spectrum is
much steeper in frequency than any known accreting source. To the best of our
knowledge, torque noise power spectra with a comparably steep frequency
dependence have only been seen in young, glitching radio pulsars (e.g. Vela).
The observed changes in spin-down rate do not correlate with burst activity,
therefore, the physical mechanisms behind each phenomenon are also likely
unrelated. Within the context of the magnetar model, seismic activity cannot
account for both the bursts and the long-term torque changes unless the
seismically active regions are decoupled from one another.Comment: 26 pages, 11 figures included, accepted for publication in ApJ,
analysis of torque noise power density spectra is revised from previous
version and minor text changes were mad
Transcriptional and Proteomic Analysis of a Ferric Uptake Regulator (Fur) Mutant of Shewanella oneidensis: Possible Involvement of Fur in Energy Metabolism, Transcriptional Regulation, and Oxidative Stress
The iron-directed, coordinate regulation of genes depends on the fur (ferric uptake regulator) gene product, which acts as an iron-responsive, transcriptional repressor protein. To investigate the biological function of a fur homolog in the dissimilatory metal-reducing bacterium Shewanella oneidensis MR-1, a fur knockout strain (FUR1) was generated by suicide plasmid integration into this gene and characterized using phenotype assays, DNA microarrays containing 691 arrayed genes, and two-dimensional polyacrylamide gel electrophoresis. Physiological studies indicated that FUR1 was similar to the wild-type strain when they were compared for anaerobic growth and reduction of various electron acceptors. Transcription profiling, however, revealed that genes with predicted functions in electron transport, energy metabolism, transcriptional regulation, and oxidative stress protection were either repressed (ccoNQ, etrA, cytochrome b and c maturation-encoding genes, qor, yiaY, sodB, rpoH, phoB, and chvI) or induced (yggW, pdhC, prpC, aceE, fdhD, and ppc) in the fur mutant. Disruption of fur also resulted in derepression of genes (hxuC, alcC, fhuA, hemR, irgA, and ompW) putatively involved in iron uptake. This agreed with the finding that the fur mutant produced threefold-higher levels of siderophore than the wild-type strain under conditions of sufficient iron. Analysis of a subset of the FUR1 proteome (i.e., primarily soluble cytoplasmic and periplasmic proteins) indicated that 11 major protein species reproducibly showed significant (P < 0.05) differences in abundance relative to the wild type. Protein identification using mass spectrometry indicated that the expression of two of these proteins (SodB and AlcC) correlated with the microarray data. These results suggest a possible regulatory role of S. oneidensis MR-1 Fur in energy metabolism that extends the traditional model of Fur as a negative regulator of iron acquisition systems
The Role of Galactic Winds on Molecular Gas Emission from Galaxy Mergers
We assess the impact of starburst and AGN feedback-driven winds on the CO
emission from galaxy mergers, and, in particular, search for signatures of
these winds in the simulated CO morphologies and emission line profiles. We do
so by combining a 3D non-LTE molecular line radiative transfer code with
smoothed particle hydrodynamics (SPH) simulations of galaxy mergers that
include prescriptions for star formation, black hole growth, a multiphase
interstellar medium (ISM), and the winds associated with star formation and
black hole growth. Our main results are: (1) Galactic winds can drive outflows
of masses ~10^8-10^9 Msun which may be imaged via CO emission line mapping. (2)
AGN feedback-driven winds are able to drive imageable CO outflows for longer
periods of time than starburst-driven winds owing to the greater amount of
energy imparted to the ISM by AGN feedback compared to star formation. (3)
Galactic winds can control the spatial extent of the CO emission in post-merger
galaxies, and may serve as a physical motivation for the sub-kiloparsec scale
CO emission radii observed in local advanced mergers. (4) Secondary emission
peaks at velocities greater than the circular velocity are seen in the CO
emission lines in all models. In models with winds, these high velocity peaks
are seen to preferentially correspond to outflowing gas entrained in winds,
which is not the case in the model without winds. The high velocity peaks seen
in models without winds are typically confined to velocity offsets (from the
systemic) < 1.7 times the circular velocity, whereas the models with AGN
feedback-driven winds can drive high velocity peaks to ~2.5 times the circular
velocity.Comment: Accepted by ApJ; Minor revisions; Resolution tests include
Elite male Flat jockeys display lower bone density and lower resting metabolic rate than their female counterparts: implications for athlete welfare
To test the hypothesis that daily weight-making is more problematic to health in male compared with female jockeys, we compared the bone-density and resting metabolic rate (RMR) in weight-matched male and female Flat-jockeys. RMR (kcal.kg-1 lean mass) was lower in males compared with females as well as lower bone-density Z-scores at the hip and lumbar spine. Data suggest the lifestyle of male jockeysâ compromise health more severely than females, possibly due to making-weight more frequently
Ocean processes at the Antarctic continental slope
The Antarctic continental shelves and slopes occupy relatively small areas, but, nevertheless, are important for global climate, biogeochemical cycling and ecosystem functioning. Processes of water mass transformation through sea ice formation/melting and ocean-atmosphere interaction are key to the formation of deep and bottom waters as well as determining the heat flux beneath ice shelves. Climate models, however, struggle to capture these physical processes and are unable to reproduce water mass properties of the region. Dynamics at the continental slope are key for correctly modelling climate, yet their small spatial scale presents challenges both for ocean modelling and for observational studies. Cross-slope exchange processes are also vital for the flux of nutrients such as iron from the continental shelf into the mixed layer of the Southern Ocean. An © 2014 The Authors
Quadrilateral-octagon coordinates for almost normal surfaces
Normal and almost normal surfaces are essential tools for algorithmic
3-manifold topology, but to use them requires exponentially slow enumeration
algorithms in a high-dimensional vector space. The quadrilateral coordinates of
Tollefson alleviate this problem considerably for normal surfaces, by reducing
the dimension of this vector space from 7n to 3n (where n is the complexity of
the underlying triangulation). Here we develop an analogous theory for
octagonal almost normal surfaces, using quadrilateral and octagon coordinates
to reduce this dimension from 10n to 6n. As an application, we show that
quadrilateral-octagon coordinates can be used exclusively in the streamlined
3-sphere recognition algorithm of Jaco, Rubinstein and Thompson, reducing
experimental running times by factors of thousands. We also introduce joint
coordinates, a system with only 3n dimensions for octagonal almost normal
surfaces that has appealing geometric properties.Comment: 34 pages, 20 figures; v2: Simplified the proof of Theorem 4.5 using
cohomology, plus other minor changes; v3: Minor housekeepin
Asymmetric Supernovae, Pulsars, Magnetars, and Gamma-Ray Bursts
We outline the possible physical processes, associated timescales, and
energetics that could lead to the production of pulsars, jets, asymmetric
supernovae, and weak gamma-ray bursts in routine circumstances and to a
magnetar and perhaps stronger gamma-ray burst in more extreme circumstances in
the collapse of the bare core of a massive star. The production of a
LeBlanc-Wilson MHD jet could provide an asymmetric supernova and result in a
weak gamma-ray burst when the jet accelerates down the stellar density gradient
of a hydrogen-poor photosphere. The matter-dominated jet would be formed
promptly, but requires 5 to 10 s to reach the surface of the progenitor of a
Type Ib/c supernova. During this time, the newly-born neutron star could
contract, spin up, and wind up field lines or turn on an alpha-Omega dynamo. In
addition, the light cylinder will contract from a radius large compared to the
Alfven radius to a size comparable to that of the neutron star. This will
disrupt the structure of any organized dipole field and promote the generation
of ultrarelativistic MHD waves (UMHDW) at high density and Large Amplitude
Electromagnetic Waves (LAEMW) at low density. The generation of the these waves
would be delayed by the cooling time of the neutron star about 5 to 10 seconds,
but the propagation time is short so the UMHDW could arrive at the surface at
about the same time as the matter jet. In the density gradient of the star and
the matter jet, the intense flux of UMHDW and LAEMW could drive shocks,
generate pions by proton-proton collision, or create electron/positron pairs
depending on the circumstances. The UMHDW and LAEMW could influence the
dynamics of the explosion and might also tend to flow out the rotation axis to
produce a collimated gamma-ray burst.Comment: 31 pages, LaTeX, revised for referee comments, accepted for ApJ, July
10 issu
Theory of x-ray absorption by laser-aligned symmetric-top molecules
We devise a theory of x-ray absorption by symmetric-top molecules which are
aligned by an intense optical laser. Initially, the density matrix of the
system is composed of the electronic ground state of the molecules and a
thermal ensemble of rigid-rotor eigenstates. We formulate equations of motion
of the two-color (laser plus x rays) rotational-electronic problem. The
interaction with the laser is assumed to be nonresonant; it is described by an
electric dipole polarizability tensor. X-ray absorption is approximated as a
one-photon process. It is shown that the equations can be separated such that
the interaction with the laser can be treated independently of the x rays. The
laser-only density matrix is propagated numerically. After each time step, the
x-ray absorption is calculated. We apply our theory to study adiabatic
alignment of bromine molecules (Br2). The required dynamic polarizabilities are
determined using the ab initio linear response methods coupled-cluster singles
(CCS), second-order approximate coupled-cluster singles and doubles (CC2), and
coupled-cluster singles and doubles (CCSD). For the description of x-ray
absorption on the sigma_g 1s --> sigma_u 4p resonance, a parameter-free
two-level model is used for the electronic structure of the molecules. Our
theory opens up novel perspectives for the quantum control of x-ray radiation.Comment: 14 pages, 4 figures, 1 table, RevTeX4, revise
Anisotropic three-dimentional magnetic fluctuations in heavy fermion CeRhIn5
CeRhIn5 is a heavy fermion antiferromagnet that orders at 3.8 K. The
observation of pressure-induced superconductivity in CeRhIn5 at a very high Tc
of 2.1 K for heavy fermion materials has led to speculations regarding to its
magnetic fluctuation spectrum. Using magnetic neutron scattering, we report
anisotropic three-dimensional antiferromagnetic fluctuations with an energy
scale of less than 1.7 meV for temperatures as high as 3Tc. In addition, the
effect of the magnetic fluctuations on electrical resistivity is well described
by the Born approximation.Comment: 4 pages, 4 figure
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