740 research outputs found
Envisioning future parenthood among bisexual, lesbian, and heterosexual women
For many individuals, becoming a parent is an important milestone. The current study examined attitudes and beliefs about parenting among a sample of 196 self-identified bisexual, lesbian, and heterosexual women. Results showed no differences by sexual orientation for women’s desires and intentions to have children, their idealization of parenthood, and perceptions of their parental self-efficacy (i.e., their ability to care for a child). In contrast, differences did emerge by sexual orientation in aspects such as partner expectations as well as professional intentions (i.e., wanting a permanent position before becoming a parent). Bisexual women tended to anticipate lower partner support compared to heterosexual women. Lesbian women, however, had a greater preference to work full-time during parenthood and wanted a permanent position before becoming a parent compared to both bisexual and heterosexual women. Implications are discussed of how bisexual women’s perceptions of parenthood are both similar to and distinct from lesbian and heterosexual women
Dobrushin states in the \phi^4_1 model
We consider the van der Waals free energy functional in a bounded interval
with inhomogeneous Dirichlet boundary conditions imposing the two stable phases
at the endpoints. We compute the asymptotic free energy cost, as the length of
the interval diverges, of shifting the interface from the midpoint. We then
discuss the effect of thermal fluctuations by analyzing the \phi^4_1-measure
with Dobrushin boundary conditions. In particular, we obtain a nontrivial limit
in a suitable scaling in which the length of the interval diverges and the
temperature vanishes. The limiting state is not translation invariant and
describes a localized interface. This result can be seen as the probabilistic
counterpart of the variational convergence of the associated excess free
energy.Comment: 34 page
Fourier Acceleration of Langevin Molecular Dynamics
Fourier acceleration has been successfully applied to the simulation of
lattice field theories for more than a decade. In this paper, we extend the
method to the dynamics of discrete particles moving in continuum. Although our
method is based on a mapping of the particles' dynamics to a regular grid so
that discrete Fourier transforms may be taken, it should be emphasized that the
introduction of the grid is a purely algorithmic device and that no smoothing,
coarse-graining or mean-field approximations are made. The method thus can be
applied to the equations of motion of molecular dynamics (MD), or its Langevin
or Brownian variants. For example, in Langevin MD simulations our acceleration
technique permits a straightforward spectral decomposition of forces so that
the long-wavelength modes are integrated with a longer time step, thereby
reducing the time required to reach equilibrium or to decorrelate the system in
equilibrium. Speedup factors of up to 30 are observed relative to pure
(unaccelerated) Langevin MD. As with acceleration of critical lattice models,
even further gains relative to the unaccelerated method are expected for larger
systems. Preliminary results for Fourier-accelerated molecular dynamics are
presented in order to illustrate the basic concepts. Possible extensions of the
method and further lines of research are discussed.Comment: 11 pages, two illustrations included using graphic
Raising the participation age in historical perspective : Policy learning from the past?
The raising of the participation age (RPA) to 17 in 2013 and 18 in 2015 marks a historic expansion of compulsory education. Despite the tendency of New Labour governments to eschew historical understanding and explanation, RPA was conceived with the benefit of an analysis of previous attempts to extend compulsion in schooling. This paper assesses the value of a historical understanding of education policy. The period from inception to the projected implementation of RPA is an extended one which has crossed over the change of government, from Labour to Coalition, in 2010. The shifting emphases and meanings of RPA are not simply technical issues but connect to profound historical and social changes. An analysis of the history of the raising of the school leaving age reveals many points of comparison with the contemporary situation. In a number of key areas it is possible to gain insights into the ways in which the study of the past can help to comprehend the present: the role of human capital, the structures of education, in curriculum development and in terms of preparations for change
The Effects of Atmospheric Dispersion on High-Resolution Solar Spectroscopy
We investigate the effects of atmospheric dispersion on observations of the
Sun at the ever-higher spatial resolutions afforded by increased apertures and
improved techniques. The problems induced by atmospheric refraction are
particularly significant for solar physics because the Sun is often best
observed at low elevations, and the effect of the image displacement is not
merely a loss of efficiency, but the mixing of information originating from
different points on the solar surface. We calculate the magnitude of the
atmospheric dispersion for the Sun during the year and examine the problems
produced by this dispersion in both spectrographic and filter observations. We
describe an observing technique for scanning spectrograph observations that
minimizes the effects of the atmospheric dispersion while maintaining a regular
scanning geometry. Such an approach could be useful for the new class of
high-resolution solar spectrographs, such as SPINOR, POLIS, TRIPPEL, and ViSP
Spin fluctuations in the quasi-two dimensional Heisenberg ferromagnet GdI_2 studied by Electron Spin Resonance
The spin dynamics of GdI_2 have been investigated by ESR spectroscopy. The
temperature dependences of the resonance field and ESR intensity are well
described by the model for the spin susceptibility proposed by Eremin et al.
[Phys. Rev. B 64, 064425 (2001)]. The temperature dependence of the resonance
linewidth shows a maximum similar to the electrical resistance and is discussed
in terms of scattering processes between conduction electrons and localized
spins.Comment: to be published in PR
Anisotropic transport in unidirectional lateral superlattice around half-filling of the second Landau level
We have observed marked transport anisotropy in short period (a=92 nm)
unidirectional lateral superlattices around filling factors nu=5/2 and 7/2:
magnetoresistance shows a sharp peak for current along the modulation grating
while a dip appears for current across the grating. By altering the ratio a/l
(with l=sqrt{hbar/eB_perp} the magnetic length) via changing the electron
density n_e, it is shown that the nu=5/2 anisotropic features appear in the
range 6.6 alt a/l alt 7.2 varying their intensities, becoming most conspicuous
at a/l simeq 6.7. The peak/dip broadens with temperature roughly preserving its
height/depth up to 250 mK. Tilt experiments reveal that the structures are
slightly enhanced by an in-plane magnetic field B_| perpendicular to the
grating but are almost completely destroyed by B_| parallel to the grating. The
observations suggest the stabilization of a unidirectional charge-density-wave
or stripe phase by weak external periodic modulation at the second Landau
level.Comment: REVTeX, 5 pages, 3 figures, Some minor revisions, Added notes and
reference
Thinking about growth : a cognitive mapping approach to understanding small business development
School of Managemen
Observational Constraints on the Modified Gravity Model (MOG) Proposed by Moffat: Using the Magellanic System
A simple model for the dynamics of the Magellanic Stream (MS), in the
framework of modified gravity models is investigated. We assume that the galaxy
is made up of baryonic matter out of context of dark matter scenario. The model
we used here is named Modified Gravity (MOG) proposed by Moffat (2005). In
order to examine the compatibility of the overall properties of the MS under
the MOG theory, the observational radial velocity profile of the MS is compared
with the numerical results using the fit method. In order to obtain
the best model parameters, a maximum likelihood analysis is performed. We also
compare the results of this model with the Cold Dark Matter (CDM) halo model
and the other alternative gravity model that proposed by Bekenstein (2004), so
called TeVeS. We show that by selecting the appropriate values for the free
parameters, the MOG theory seems to be plausible to explain the dynamics of the
MS as well as the CDM and the TeVeS models.Comment: 14 pages, 3 Figures, accepted in Int. J. Theor. Phy
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