7,495 research outputs found
Addressing Ethical Issues in Studying Men’s Traumatic Stress
Like many human experiences, traumatic stress is highly gendered. Over the past several decades, a sub-stantial number of empirical studies have explored ethical issues in traumatic stress research. However, these studies have typically reported female samples or failed to account for the influence of gender in their analyses of mixed-sex samples. By extension, ethical issues that are relevant to male participants in traumatic stress research are poorly understood. After briefly exploring why the vulnerabilities of male participants are under-explored in traumatic stress research, this article highlights many ethical issues that are important to address when men participate in traumatic stress research, concluding with some sugges-tions for how these might be taken up to advance the field
Bipolar diathermy for the outpatient control of posterior epistaxis
LetterThe original publication is available at http://www.samj.org.za[No abstract available
How linear features alter predator movement and the functional\ud response
In areas of oil and gas exploration, seismic lines have been reported to alter the movement patterns of wolves (Canis lupus). We developed a mechanistic first passage time model, based on an anisotropic elliptic partial differential equation, and used this to explore how wolf movement responses to seismic lines influence the encounter rate of the wolves with their prey. The model was parametrized using 5 min GPS location data. These data showed that wolves travelled faster on seismic lines and had a higher probability of staying on a seismic line once they were on it. We simulated wolf movement on a range of seismic line densities and drew implications for the rate of predator–prey interactions as described by the functional response. The functional response exhibited a more than linear increase with respect to prey density (type III) as well as interactions with seismic line density. Encounter rates were significantly higher in landscapes with high seismic line density and were most pronounced at low prey densities. This suggests that prey at low population densities are at higher risk in environments with a high seismic line density unless they learn to avoid them
Comparison of the phase diagram of the half-filled layered organic superconductors with the phase diagram of the RVB theory of the Hubbard-Heisenberg model
We present an resonating valence bond (RVB) theory of superconductivity for
the Hubbard--Heisenberg model on an anisotropic triangular lattice. We show
that these calculations are consistent with the observed phase diagram of the
half-filled layered organic superconductors, such as the beta, beta', kappa and
lambda phases of (BEDT-TTF)_2X [bis(ethylenedithio)tetrathiafulvalene] and
(BETS)_2X [bis(ethylenedithio)tetraselenafulvalene]. We find a first order
transition from a Mott insulator to a d_{x^2-y^2} superconductor with a small
superfluid stiffness and a pseudogap with d_{x^2-y^2} symmetry. The
Mott--Hubbard transition can be driven either by increasing the on-site Coulomb
repulsion, U, or by changing the anisotropy of the two hopping integrals, t'/t.
Our results suggest that the ratio t'/t plays an important role in determining
the phase diagram of the organic superconductors.Comment: 4 pages, 3 figur
Critical Behaviour of One-particle Spectral Weights in the Transverse Ising Model
We investigate the critical behaviour of the spectral weight of a single
quasiparticle, one of the key observables in experiment, for the particular
case of the transverse Ising model.Series expansions are calculated for the
linear chain and the square and simple cubic lattices. For the chain model, a
conjectured exact result is discovered. For the square and simple cubic
lattices, series analyses are used to estimate the critical exponents. The
results agree with the general predictions of Sachdev.Comment: 4 pages, 3 figure
Detergent Extraction of a Presumptive Gating Component from the Voltage-Dependent Sodium Channel
A physiologically characterized radiolabeled neurotoxin complex obtained from venom of the scorpion Leiurus quinquestriatus has been used to identify detergent-solubilized presumptive sodium channel components in sucrose gradients. This toxin-binding component is found in extracts prepared from three sources of excitable membrane but appears to be absent from similar extracts prepared from nonexcitable membrane or from Torpedo californica membrane. Procedures that destroy the physiological activity of the Leiurus neurotoxin lead to a corresponding loss of toxin binding to the putative sodium channel component. The major component recognized by the Leiurus toxin sediments at 6.5 S. Scatchard analysis of quantitative binding experiments carried out in sucrose gradients shows approximately linear plots and indicates that the toxin recognizes a relatively small number of sites with a dissociation constant near 10 nM. Once formed, the channel element--toxin complex is quite stable. Experiments show diphasic dissociation kinetics with half-times near 70 hr and greater than 200 hr
Axillary nodal metastasis at primary presentation of an oropharyngeal primary carcinoma: a case report and review of the literature
<p>Abstract</p> <p>Introduction</p> <p>Axillary nodal metastasis is very rare in head and neck squamous cell carcinoma. The few cases reported in the literature all involve patients who have previously undergone either neck dissection alone, or neck dissection and radiotherapy to the neck, and subsequently develop delayed recurrences of disease, with axillary nodal involvement.</p> <p>Case presentation</p> <p>We present the case of a 62-year-old man of Cape Malay ethnicity, who presented with an oropharyngeal squamous cell carcinoma, and cervical and axillary nodal metastasis at primary presentation.</p> <p>Conclusion</p> <p>Whilst previous reports in the literature suggest routine examination of the axilla is advisable in patients with previously treated neck cancer and recurrence of head and neck cancer, we propose that the axilla should be routinely examined in new cases, particularly when there is involvement of the level 5 nodes.</p
Comment on "Plasma ionization by annularly bounded helicon waves" [Phys . Plasmas 13, 063501 (2006)]
The neoclassical calculation of the helicon wave theory contains a
fundamental flaw. Use is made of a proportional relationship between the
magnetic field and its curl to derive the Helmholtz equation describing helicon
wave propagation; however, by the fundamental theorem of Stokes, the curl of
the magnetic field must be perpendicular to that portion of the field
contributing to the local curl. Reexamination of the equations of motion
indicates that only electromagnetic waves propagate through a stationary region
of constant pressure in a fully ionized, neutral medium.Comment: 7 pages, 1 figure, to be published in Phys. Plasmas,
http://link.aip.org/link/?PHPAEN/16/054701/
Temperature dependence of the interlayer magnetoresistance of quasi-one-dimensional Fermi liquids at the magic angles
The interlayer magnetoresistance of a quasi-one-dimensional Fermi liquid is
considered for the case of a magnetic field that is rotated within the plane
perpendicular to the most-conducting direction. Within semi-classical transport
theory dips in the magnetoresistance occur at integer amgic angles only when
the electronic dispersion parallel to the chains is nonlinear. If the field
direction is fixed at one of the magic angles and the temperature is varied the
resulting variation of the scattering rate can lead to a non-monotonic
variation of the interlayer magnetoresistance with temperature. Although the
model considered here gives a good description of some of the properties of the
Bechgaard salts, (TMTSF)2PF6 for pressures less than 8kbar and (TMTSF)2ClO4 it
gives a poor description of their properties when the field is parallel to the
layers and of the intralayer transport.Comment: 10pages, RevTeX + epsf, 3 figure
Evidence from satellite altimetry for small-scale convection in the mantle
Small scale convection can be defined as that part of the mantle circulation in which upwellings and downwellings can occur beneath the lithosphere within the interiors of plates, in contrast to the large scale flow associated with plate motions where upwellings and downwellings occur at ridges and trenches. The two scales of convection will interact so that the form of the small scale convection will depend on how it arises within the large scale flow. Observations based on GEOS-3 and SEASAT altimetry suggest that small scale convection occurs in at least two different ways
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