228 research outputs found
Good images, effective messages? Working with students and educators on academic practice understanding
Work at Northumbria University has focussed on activity that extends opportunities for students to engage directly with the skills development necessary for sound academic practice. This has included highly visual campaigns on the "Plagiarism trap", providing access to Turnitin plagiarism detection software, guides and sessions to highlight use of associated referencing tools. Sessions on a variety of topics, such as supporting study skills and reading originality reports, have been provided for students on taught, undergraduate and postgraduate programmes. This provision has included students working on collaborative partners' sites and also those on research programmes. Alongside the activities with students, "designing out" approaches have been embedded in staff development within the educator community at Northumbria. Formative use of Turnitin is integrated throughout programmes and academic practice development is formally recognised within the University Learning and Teaching Strategy's focus on information literacy. This article outlines and reviews these activities in a critical institutional context and evaluates responses from a variety of students and educators to determine how effective these measures have been
Scalar field exact solutions for non-flat FLRW cosmology: A technique from non-linear Schr\"odinger-type formulation
We report a method of solving for canonical scalar field exact solution in a
non-flat FLRW universe with barotropic fluid using non-linear Schr\"{o}dinger
(NLS)-type formulation in comparison to the method in the standard Friedmann
framework. We consider phantom and non-phantom scalar field cases with
exponential and power-law accelerating expansion. Analysis on effective
equation of state to both cases of expansion is also performed. We speculate
and comment on some advantage and disadvantage of using the NLS formulation in
solving for the exact solution.Comment: 12 pages, GERG format, Reference added. accepted by Gen. Relativ. and
Gra
Attractor Solutions in f(T) Cosmology
In this paper, we explore the cosmological implications of interacting dark
energy model in a torsion based gravity namely . Assuming dark energy
interacts with dark matter and radiation components, we examine the stability
of this model by choosing different forms of interaction terms. We consider
three different forms of dark energy: cosmological constant, quintessence and
phantom energy. We then obtain several attractor solutions for each dark energy
model interacting with other components. This model successfully explains the
coincidence problem via the interacting dark energy scenario.Comment: 10 pages, 23 figures, version accepted for publication in European
Physical Journal C (2012
Predicting substance use behavior among South African adolescents: The role of leisure experiences across time
Using seven waves of data, collected twice a year from the 8th through the 11th grades in a low-resource community in Cape Town, South Africa, we aimed to describe the developmental trends in three specific leisure experiences (leisure boredom, new leisure interests, and healthy leisure) and substance use (cigarettes, alcohol, and marijuana) behaviors and to investigate the ways in which changes in leisure experiences predict changes in substance use behaviors over time. Results indicated that adolescents’ substance use increased significantly across adolescence, but that leisure experiences remained fairly stable over time. We also found that adolescent leisure experiences predicted baseline substance use and that changes in leisure experiences predicted changes in substance use behaviors over time, with leisure boredom emerging as the most consistent and strongest predictor of alcohol, cigarette, and marijuana use. Implications for interventions that target time use and leisure experiences are discussed.Web of Scienc
The Influence of Free Quintessence on Gravitational Frequency Shift and Deflection of Light with 4D momentum
Based on the 4D momentum, the influence of quintessence on the gravitational
frequency shift and the deflection of light are examined in modified
Schwarzschild space. We find that the frequency of photon depends on the state
parameter of quintessence : the frequency increases for and
decreases for . Meanwhile, we adopt an integral power number
() to solve the orbital equation of photon. The photon's
potentials become higher with the decrease of . The behavior of
bending light depends on the state parameter sensitively. In
particular, for the case of , there is no influence on the
deflection of light by quintessence. Else, according to the H-masers of GP-A
redshift experiment and the long-baseline interferometry, the constraints on
the quintessence field in Solar system are presented here.Comment: 12 pages, 2 figures, 4 tables. European Physical Journal C in pres
Potential for Supernova Neutrino Detection in MiniBooNE
The MiniBooNE detector at Fermilab is designed to search for oscillation appearance at and to make a
decisive test of the LSND signal. The main detector (inside a veto shield) is a
spherical volume containing 0.680 ktons of mineral oil. This inner volume,
viewed by 1280 phototubes, is primarily a \v{C}erenkov medium, as the
scintillation yield is low. The entire detector is under a 3 m earth
overburden. Though the detector is not optimized for low-energy (tens of MeV)
events, and the cosmic-ray muon rate is high (10 kHz), we show that MiniBooNE
can function as a useful supernova neutrino detector. Simple trigger-level cuts
can greatly reduce the backgrounds due to cosmic-ray muons. For a canonical
Galactic supernova at 10 kpc, about 190 supernova
events would be detected. By adding MiniBooNE to the international network of
supernova detectors, the possibility of a supernova being missed would be
reduced. Additionally, the paths of the supernova neutrinos through Earth will
be different for MiniBooNE and other detectors, thus allowing tests of
matter-affected mixing effects on the neutrino signal.Comment: Added references, version to appear in PR
Cosmological expansion and local systems: a Lema\^{i}tre-Tolman-Bondi model
We propose a Lema\^{i}tre-Tolman-Bondi system mimicking a two-body system to
address the problem of the cosmological expansion versus local dynamics. This
system is strongly bound but participates in the cosmic expansion and is
exactly comoving with the cosmic substratum
Entropy and universality of Cardy-Verlinde formula in dark energy universe
We study the entropy of a FRW universe filled with dark energy (cosmological
constant, quintessence or phantom). For general or time-dependent equation of
state the entropy is expressed in terms of energy, Casimir energy,
and . The correspondent expression reminds one about 2d CFT entropy only for
conformal matter. At the same time, the cosmological Cardy-Verlinde formula
relating three typical FRW universe entropies remains to be universal for any
type of matter. The same conclusions hold in modified gravity which represents
gravitational alternative for dark energy and which contains terms growing at
low curvature. It is interesting that BHs in modified gravity are more entropic
than in Einstein gravity. Finally, some hydrodynamical examples testing new
shear viscosity bound, which is expected to be the consequence of the
holographic entropy bound, are presented for the early universe in the plasma
era and for the Kasner metric. It seems that the Kasner metric provides a
counterexample to the new shear viscosity bound.Comment: LaTeX file, 39 pages, references are adde
Molecular characterization of slow leaf-rusting resistance in wheat
Slow leaf-rusting resistance in wheat (Triticum aestivum L) is gaining acceptance as a breeding objective because of its durability in comparison with race-specific resistance. CI 13227 was previously reported to provide the highest level of slow leaf-rusting resistance. The objective of this study was to characterize the slow leaf-rusting resistance conferred by CI 13227 using molecular markers. A population of recombinant inbred lines (RILs) derived from CI 13227/Suwon 92 was evaluated for final severity (FS), area under disease progress curve (AUDPC), infection rate (IR), and infection duration (ID) of leaf rust. Four hundred fifty-nine amplified fragment length polymorphism (AFLP) markers and 28 simple sequence repeat (SSR) markers were analyzed in the population. Two quantitative trait loci (QTL), designated as QLr.osu-2B and QLr.osu-7BL, were consistently associated with AUDPC, FS, and IR of leaf rust, caused by Puccinia triticina (previously P. recondita Rob. Ex Desm. f. sp. tritici). The percentages of phenotypic variance explained by each QTL varied with experiments and traits, ranging from 13.4 to 18.8% for AUDPC, 12.5 to 20.8% for FS, and 12.9 to 16.1% for IR. The third QTL for leaf rust ID, designated as QLrid.osu-2DS, was located on chromo- some 2DS and explained 26.4 and 21.47% of the phenotypic variance in 1994 and 1995, respectively. Both the QTL and correlation analysis indicate reasonable progress in leaf-rusting resistance by selecting for final severity. SSR markers closely associated with QLr.osu-2B or QLr.osu-7BL have potential to be used in marker-assisted selection (MAS) for durable leaf rust resistant cultivars.Peer reviewedPlant and Soil SciencesEntomology and Plant Patholog
Neutrino oscillation constraints on neutrinoless double beta decay
We have studied the constraints imposed by the results of neutrino
oscillation experiments on the effective Majorana mass || that characterizes
the contribution of Majorana neutrino masses to the matrix element of
neutrinoless double-beta decay. We have shown that in a general scheme with
three Majorana neutrinos and a hierarchy of neutrino masses (which can be
explained by the see-saw mechanism), the results of neutrino oscillation
experiments imply rather strong constraints on the parameter ||. From the
results of the first reactor long-baseline experiment CHOOZ and the Bugey
experiment it follows that || < 3x10^{-2} eV if the largest mass-squared
difference is smaller than 2 eV^2. Hence, we conclude that the observation of
neutrinoless double-beta decay with a probability that corresponds to || >
10^{-1} eV would be a signal for a non-hierarchical neutrino mass spectrum
and/or non-standard mechanisms of lepton number violation.Comment: 20 pages, including 4 figure
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