6,168 research outputs found
Female reproductive strategy predicts preferences for sexual dimorphism in male faces
The aim of the current studies was to test an assumption that variation in female preferences for sexually dimorphic male facial characteristics reflects strategic optimisation of investment in offspring. A negative relationship was predicted between ideal number of children and preferences for masculine male face shapes, as the benefits of securing paternal investment should outweigh the benefits of securing good genes as the costs of raising offspring increase. In Study 1 desired number of children and preferences for masculine face shapes were compared in a sample of female students. In study 2, the prediction was tested in a sample with a wider age profile while controlling for relationship status. Preferences for explicit partner characteristics were also assessed. The prediction was supported: women who desired a higher number of children preferred more feminine male face shapes and ranked cues to investment of parental care over cues to immunocompetence in a partner more highly than those who desired fewer children. Results indicate that female mate preferences vary with reproductive strategy and support assumptions that preferences for feminine male faces reflect preferences for “good dads”
Orbital magnetoelectric coupling in band insulators
Magnetoelectric responses are a fundamental characteristic of materials that
break time-reversal and inversion symmetries (notably multiferroics) and,
remarkably, of "topological insulators" in which those symmetries are unbroken.
Previous work has shown how to compute spin and lattice contributions to the
magnetoelectric tensor. Here we solve the problem of orbital contributions by
computing the frozen-lattice electronic polarization induced by a magnetic
field. One part of this response (the "Chern-Simons term") can appear even in
time-reversal-symmetric materials and has been previously shown to be quantized
in topological insulators. In general materials there are additional orbital
contributions to all parts of the magnetoelectric tensor; these vanish in
topological insulators by symmetry and also vanish in several simplified models
without time-reversal and inversion those magnetoelectric couplings were
studied before. We give two derivations of the response formula, one based on a
uniform magnetic field and one based on extrapolation of a long-wavelength
magnetic field, and discuss some of the consequences of this formula.Comment: 13 page
Dynamical model of the dielectric screening of conjugated polymers
A dynamical model of the dielectric screening of conjugated polymers is
introduced and solved using the density matrix renormalization group method.
The model consists of a line of quantized dipoles interacting with a polymer
chain. The polymer is modelled by the Pariser-Parr-Pople (P-P-P) model. It is
found that: (1) Compared to isolated, unscreened single chains, the screened
1Bu- exciton binding energy is typically reduced by ca. 1 eV to just over 1 eV;
(2) Covalent (magnon and bi-magnon) states are very weakly screened compared to
ionic (exciton) states; (3) Screening of the 1Bu- exciton is closer to the
dispersion than solvation limit.Comment: 12 pages, 2 figure
Continuum Annulus Amplitude from the Two-Matrix Model
An explicit expression for continuum annulus amplitudes having boundary
lengths and is obtained from the two-matrix model for the
case of the unitary series; . In the limit of vanishing
cosmological constant, we find an integral representation of these amplitudes
which is reproduced, for the cases of the and the , by a continuum approach consisting of quantum mechanics of loops
and a matter system integrated over the modular parameter of the annulus. We
comment on a possible relation to the unconventional branch of the Liouville
gravity.Comment: 9 pages, OU-HET 190, revised version. A part of the conclusions has
been corrected. A new result on integral representation of the annulus
amplitudes has been adde
A Generalization of Martin's Axiom
We define the chain condition. The corresponding forcing axiom
is a generalization of Martin's Axiom and implies certain uniform failures of
club--guessing on that don't seem to have been considered in the
literature before.Comment: 36 page
First principles theory of fluctuations in vortex liquids and solids
Consistent perturbation theory for thermodynamical quantities in type II
superconductors in magnetic field at low temperatures is developed. It is
complementary to the existing expansion valid at high temperatures.
Magnetization and specific heat are calculated to two loop order and compare
well to existing Monte Carlo simulations and experiments.Comment: 3 .ps fig. In press Phys. Rev.
Outcomes important to patients with non-infectious posterior segment-involving uveitis:a qualitative study
Objective: Uveitis, a group of disorders characterised by intraocular inflammation, causes 10–15% of total blindness in the developed world. The most sight-threatening forms of non-infectious uveitis are those affecting the posterior segment of the eye, collectively known as posterior-segment involving uveitis (PSIU). Numerous different clinical outcomes have been used in trials evaluating treatments for PSIU but these may not represent patients’ and carers’ concerns. Therefore, the aims of this study were to understand the impact of PSIU on adult patients’ and carers’ lives, and to explore what outcomes of treatment are important to them.Methods: Four focus group discussions were undertaken to understand the perspectives of adult patients (n=18) and carers (n=10) with PSIU. Participants were grouped according to whether or not their uveitis was complicated by the sight-threatening condition uveitic macular oedema (UMO). Discussions were audio recorded, transcribed and analysed using the framework analytical approach. Outcomes were identified and grouped into outcome domains. Results: Eleven core domains were identified as important to patients and carers undergoing treatment for PSIU comprising: (1) visual function, (2) symptoms, (3) functional ability, (4) impact on relationships, (5) financial impact, (6) psychological morbidity and emotional well-being (7) psychosocial adjustment to uveitis, (8) doctor/patient/interprofessional relationships and access to health care, (9) treatment burden, (10) treatment side effects, (11) disease control.Conclusion: The domains identified represent patients and carers experience and perspectives and can be used to reflect on outcomes assessed in PSIU. They will directly inform the development of a core outcome set for PSIU clinical trials.Ethical approval: Ethical approval was obtained from the United Kingdom National Research Ethics Service (Reference 17-WM-0111).<br/
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