11,416 research outputs found
Changing times of feminism and higher education: From community to employability
This article discusses the creation of space and time for feminist approaches in higher education in the context of shifting community and employment relations and the restructuring of higher education space-time. It draws on the reflections of three feminist academics concerning aspects of their work biographies in two very different higher education settings. It explores the shift from working in an academic department concerned with community studies to one concerned with education and related employment. The article focuses on the attempt to sustain feminist practices through these changing times and settings and is informed by the work on time and space by Barbara Adam, Henri Lefebvre and Doreen Massey. © 2011 Taylor & Francis
High accuracy results for the energy levels of the molecular ions H2+, D2+ and HD+, up to J=2
We present a nonrelativistic calculation of the rotation-vibration levels of
the molecular ions H2+, D2+ and HD+, relying on the diagonalization of the
exact three-body Hamiltonian. The J=2 levels are obtained with a very high
accuracy of 10^{-14} a.u. (for most levels) representing an improvement by five
orders of magnitude over previous calculations. The accuracy is also improved
for the J=1 levels of H2+ and D2+ with respect to earlier works. Moreover, we
have computed the sensitivities of the energy levels with respect to the mass
ratios, allowing these levels to be used for metrological purposes.Comment: 11 page
A Possible Resolution of the Black Hole Information Puzzle
The problem of information loss is considered under the assumption that the
process of black hole evaporation terminates in the decay of the black hole
interior into a baby universe. We show that such theories can be decomposed
into superselection sectors labeled by eigenvalues of the third-quantized baby
universe field operator, and that scattering is unitary within each
superselection sector. This result relies crucially on the quantum-mechanical
variability of the decay time. It is further argued that the decay rate in the
black hole rest frame is necessarily proportional to , where
is the total entropy produced during the evaporation process,
entailing a very long-lived remnant.Comment: 15 pages, 3 uuencoded figures. Revised version contains some
notational simplification
Cosmological Constraints on Dissipative Models of Inflation
(Abridged) We study dissipative inflation in the regime where the dissipative
term takes a specific form, \Gamma=\Gamma(\phi), analyzing two models in the
weak and strong dissipative regimes with a SUSY breaking potential. After
developing intuition about the predictions from these models through analytic
approximations, we compute the predicted cosmological observables through full
numerical evolution of the equations of motion, relating the mass scale and
scale of dissipation to the characteristic amplitude and shape of the
primordial power spectrum. We then use Markov Chain Monte Carlo techniques to
constrain a subset of the models with cosmological data from the cosmic
microwave background (WMAP three-year data) and large scale structure (SDSS
Luminous Red Galaxy power spectrum). We find that the posterior distributions
of the dissipative parameters are highly non-Gaussian and their allowed ranges
agree well with the expectations obtained using analytic approximations. In the
weak regime, only the mass scale is tightly constrained; conversely, in the
strong regime, only the dissipative coefficient is tightly constrained. A lower
limit is seen on the inflation scale: a sub-Planckian inflaton is disfavoured
by the data. In both weak and strong regimes, we reconstruct the limits on the
primordial power spectrum and show that these models prefer a {\it red}
spectrum, with no significant running of the index. We calculate the reheat
temperature and show that the gravitino problem can be overcome with large
dissipation, which in turn leads to large levels of non-Gaussianity: if
dissipative inflation is to evade the gravitino problem, the predicted level of
non-Gaussianity might be seen by the Planck satellite.Comment: 14 pages, 9 figures, Accepted by JCAP without text changes,
References adde
Comparison of Allen Carr's Easyway programme with a specialist behavioural and pharmacological smoking cessation support service: a randomized controlled trial.
BACKGROUND AND AIMS: A combination of behavioural and pharmacological support is judged to be the optimal approach for assisting smoking cessation. Allen Carr's Easyway (ACE) is a single-session pharmacotherapy-free programme that has been in operation internationally for 38Â years. We compared the effectiveness of ACE with specialist behavioural and pharmacological support delivered to the national standard in England. DESIGN: A two-arm, parallel-group, single-blind, randomized controlled trial. SETTING: London, UK, between February 2017 and May 2018. PARTICIPANTS: A total of 620 participants (310 in ACE and 310 in the combined behavioural and pharmacological support condition) were included in the analysis. Adult (â„ 18Â years) smokers wanting to quit were randomized in a 1Â :Â 1 ratio. Mean age for the total sample was 40.8Â years, with 53.4% being male. Participant baseline characteristics (ethnicity, educational level, number of previous quit attempts, nicotine dependence) were evenly balanced between treatment groups. INTERVENTION AND COMPARATOR: The intervention was the ACE method of stopping smoking. This centres on a 4.5-6-hour session of group-based support, alongside subsequent text messages and top-up sessions if needed. It aims to make it easy to stop smoking by convincing smokers that smoking provides no benefits for them. The comparator was a specialist stop smoking service (SSS) providing behavioural and pharmacological support in accordance with national standards. MEASUREMENTS: The primary outcome was self-reported continuous abstinence for 26Â weeks from the quit/quit re-set date verified by exhaled breath carbon monoxide measurement <Â 10Â parts per million (p.p.m.). Primary analysis was by intention to treat. Secondary outcomes were: use of pharmacotherapy, adverse events and continuous abstinence up to 4 and 12Â weeks. FINDINGS: A total of 468 participants attended treatment (255 ACE versus 213 SSS, PÂ <Â 0.05). Of those who did attend treatment, 100 completed 6-month measures (23.7% ACE versus 20.7% SSS). Continuous abstinence to 26Â weeks was 19.4% (60 of 310) in the ACE intervention and 14.8% (46 of 310) in the SSS intervention [risk difference for ACE versus SSS 4.5% (95% confidence interval (CI) =Â -1.4 to 10.4%, odds ratio (OR)Â =Â 1.38)]. The Bayes factor for superiority of the ACE condition was 1.24. CONCLUSION: There was no clear evidence of a difference in the efficacies of the Allen Carr's Easyway (ACE) and specialist smoking cessation support involving behavioural support and pharmacotherapy
Spherical Formulation for Diagramatic Evaluations on a Manifold with Boundary
The mathematical formalism necessary for the diagramatic evaluation of
quantum corrections to a conformally invariant field theory for a
self-interacting scalar field on a curved manifold with boundary is considered.
The evaluation of quantum corrections to the effective action past one-loop
necessitates diagramatic techniques. Diagramatic evaluations and higher
loop-order renormalisation can be best accomplished on a Riemannian manifold of
constant curvature accommodating a boundary of constant extrinsic curvature. In
such a context the stated evaluations can be accomplished through a consistent
interpretation of the Feynman rules within the spherical formulation of the
theory for which the method of images allows. To this effect, the mathematical
consequences of such an interpretation are analyzed and the spherical
formulation of the Feynman rules on the bounded manifold is, as a result,
developed.Comment: 12 pages, references added. To appear in Classical and Quantum
Gravit
Chemical signatures of the Anthropocene in the Clyde Estuary, UK: sediment hosted Pb, 207/206 Pb, Total Petroleum Hydrocarbons (TPH), Polyaromatic Hydrocarbon (PAH) and Polychlorinated Bipheny (PCB) pollution records
The sediment concentrations of total petroleum hydrocarbons (TPHs), polyaromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), Pb and 207/206Pb isotope ratios were measured in seven cores from the middle Clyde estuary (Scotland, UK) with an aim of tracking the late Anthropocene. Concentrations of TPHs ranged from 34 to 4386âmgâkgâ1, total PAHs from 19 to 16â163âÎŒgâkgâ1 and total PCBs between less than 4.3 to 1217âÎŒgâkgâ1. Inventories, distributions and isomeric ratios of the organic pollutants were used to reconstruct pollutant histories. Pre-Industrial Revolution and modern non-polluted sediments were characterized by low TPH and PAH values as well as high relative abundance of biogenic-sourced phenanthrene and naphthalene. The increasing industrialization of the Clyde gave rise to elevated PAH concentrations and PAH isomeric ratios characteristic of both grass/wood/coal and petroleum and combustion (specifically petroleum combustion). Overall, PAHs had the longest history of any of the organic contaminants. Increasing TPH concentrations and a concomitant decline in PAHs mirrored the lessening of coal use and increasing reliance on petroleum fuels from about the 1950s. Thereafter, declining hydrocarbon pollution was followed by the onset (1950s), peak (1965â1977) and decline (post-1980s) in total PCB concentrations. Lead concentrations ranged from 6 to 631âmgâkgâ1, while 207/206Pb isotope ratios spanned 0.838â0.876, indicative of various proportions of âbackgroundâ, British ore/coal and Broken Hill type petrol/industrial lead. A chronology was established using published Pb isotope data for aerosol-derived Pb and applied to the cores
Effective Actions for Heterotic M-Theory
We discuss the moduli space approximation for heterotic M-theory, both for
the minimal case of two boundary branes only, and when a bulk brane is
included. The resulting effective actions may be used to describe the
cosmological dynamics in the regime where the branes are moving slowly, away
from singularities. We make use of the recently derived colliding branes
solution to determine the global structure of moduli space, finding a boundary
at which the trajectories undergo a hard wall reflection. This has important
consequences for the allowed moduli space trajectories, and for the behaviour
of cosmological perturbations in the model.Comment: 21 pages, 4 figures. References added and some discussions clarifie
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