Breast Self-Examination Teaching for Women in Chemical Dependency Programs

Fifty-two women from 5 chemical dependency programs participated in a 1 hour health education program teaching breast self-examination using breast models. Tactile skills and general information about breast cancer and breast self-examination were presented. The program was evaluated for its ability to teach this high risk population. Nine true/false questions and lump detection skills were evaluated using_a pretest/posttest non-experimental design. A level of significance for the true/false questions was set at .01, and for lump detection skills it was set at .05. Dependent t tests was used to statistically analyze the data. Participants improved their general knowledge about breast cancer and self-examination as a result of this program (p \u3c.01). Lump detection skills also improved (p \u3c.05). This study indicates health education programs are of value and can potentially decrease the survival discrepancy for breast cancer for a specific high risk population

Resistance spikes and domain wall loops in Ising quantum Hall ferromagnets

We explain the recent observation of resistance spikes and hysteretic transport properties in Ising quantum Hall ferromagnets in terms of the unique physics of their domain walls. Self-consistent RPA/Hartree-Fock theory is applied to microscopically determine properties of the ground state and domain-wall excitations. In these systems domain wall loops support one-dimensional electron systems with an effective mass comparable to the bare electron mass and may carry charge. Our theory is able to account quantitatively for the experimental Ising critical temperature and to explain characteristics of the resistive hysteresis loops.Comment: 4 pages, 3 figure

Co-planar spin-polarized light emitting diode

Studies of spin manipulation in semiconductors has benefited from the possibility to grow these materials in high quality on top of optically active III-V systems. The induced electroluminescence in these layered semiconductor heterostructures has been used for a reliable spin detection. In semiconductors with strong spin-orbit interaction, the sensitivity of vertical devices may be insufficient, however, because of the sepration of the spin aligner part and the spin detection region by one or more heterointerfaces and becuse of the short spin coherence length. Here we demostrate that higly sensitive spin detection can be achieved using a lateral arrangement of the spin polarized and optically active regions. Using our co-planar spin-polarized light emitting diodes we detect electrical field induced spin generation in a semiconductor heterojunction two-dimensional hole gas. The polarization results from spin asymmetric recombination of injected electrons with strongly SO coupled two-dimensional holes. The possibility to detect magnetized Co particles deposited on the co-planar diode structure is also demonstrated.Comment: 8 pages, 3 figure

Quantum dynamics following electron photodetachment in the I-Ar2 complex: How Good Are New Separable and Non-Separable Simulation Methods?

The process of electron photodetachment in the I-Ar2 cluster is chosen for testing new approximate quantum dynamical methods - the Classical Separable Potential (CSP) approach and its Configuration Interaction (CI-CSP) extension. The results are encouraging in the sense of a quantitative agreement between the CSP and the established Time-Dependent Self-Consistent Field schemes, and in the fact that inclusion of correlations via the CI-CSP approach brings the results significantly closer to numerically exact ones. These findings justify applying the new methods to fast dynamical processes in moderately quantal large polyatomic systems, where other approaches become computationally extremely demanding or unfeasible

Experimental observation of the spin-Hall effect in a two dimensional spin-orbit coupled semiconductor system

We report the experimental observation of the spin-Hall effect in a two-dimensional (2D) hole system with Rashba spin-orbit coupling. The 2D hole layer is a part of a p-n junction light-emitting diode with a specially designed co-planar geometry which allows an angle-resolved polarization detection at opposite edges of the 2D hole system. In equilibrium the angular momenta of the Rashba split heavy hole states lie in the plane of the 2D layer. When an electric field is applied across the hole channel a non zero out-of-plane component of the angular momentum is detected whose sign depends on the sign of the electric field and is opposite for the two edges. Microscopic quantum transport calculations show only a weak effect of disorder suggesting that the clean limit spin-Hall conductance description (intrinsic spin-Hall effect) might apply to our system.Comment: 4 pages, 3 figures, paper based on work presented at the Gordon Research Conference on Magnetic Nano-structures (August 2004) and Oxford Kobe Seminar on Spintronics (September 2004); accepted for publication in Physical Review Letters December 200

Quantum Dynamics of the Photodissociation of Hydrogen Halides in Rare Gas Matrices. I. The Initial State

The present study focusses on the rotational motion of HCl molecules embedded in an Ar matrix. Assuming the HCl molecules to occupy substitutional sites in the fcc lattice, rotational wavefunctions for the vibrational and electronic ground state are obtained. Both the energetics and the spatial structures of the wavefunctions are investigated. While the J=0 and the J=1 state show relatively little matrix effects, all levels for J>1 are split by the crystal field. A possible control of the photodissociation dynamics by selection of rotational states of different spatial orientation is discussed

Photolysis of Hydrogen Chloride Embedded in the First Argon Solvation Shell: Rotational Control and Quantum Dynamics of Photofragments

Under standard conditions reaction yields are connected with terms like free energy differences and thermal distributions. However, many modern experimental techniques, such as supersonic beam expansion or matrix isolation, deal with cryogenic temperatures and isolated reactants in inert clusters or solid matrices. Under these conditions the photochemical reaction mechanism is in many cases strongly dependent on the shape of delocalized initial vibrational or rotational wavefunctions of the reactants which can be employed for an efficient reaction yield control. Here, we apply, using quantum molecular dynamics simulations,such a scheme to the rotational control of photolysis of the HCl molecule embedded in an icosahedral Ar12cluster. First, the HCl molecule is preexcited into a specific low lying rotational level. Depending on the rotational state, the hydrogen probability is enhanced in different directions within the cluster. In a second step, the HCl molecule is photolyzed by a UV pulse. The rapidly dissociating hydrogen atom reaches then primarily either the holes in the solvent shell or the argon atoms, depending on the rotational preexcitation. Starting either from the ground or from the first totally symmetric excited rotational states, the direct dissociation and the delayed process accompanied with a temporary trapping of the hydrogen atom have very different relative yields. As a consequence, differences up to a factor of five in the temporary population of the hydrogen atom inside the cluster after the first hydrogen - cage collision are observed. In the energy domain a significant difference in the structure of the kinetic energy distribution spectra, connected with the existence of short-lived vibrational resonances of the hydrogen atom, is predicted

Librational control of photochemical reactions in small clusters

A novel approach to the control of photochemical reaction yield in hydrogen containing clusters is outlined and applied to the process of the Cl2 molecule formation from a UV photolyzed Cl...HCl species. The control mechanism consists in a far-IR preexcitation of the large amplitude hydrogenic bending (librational) mode prior to the HCl photodissociation, leading to more than a factor of two enhancement of the Cl2 yield both in the parent and deuterated cluster

Vibrationally Resolved Spectra from Short Time Quantum Molecular Dynamics by the Filter-Diagonalization Method

The possibility of calculating vibrationally resolved spectra from very short numerically exact and approximate quantum dynamical propagations using the new Filter-Diagonalization method is explored. The benchmark process under study concerns electron photodetachment in the I-Ar2 complex. Comparison with results obtained from long time propagations and with experiment reveals the power of the Filter-Diagonalization scheme. Using the new methodology it now becomes possible to extract positions of spectral peaks for large polyatomic systems from approximate quantum propagations e.g., by means of the recently developed Classical Separable Potential approach

Mn incorporation in as-grown and annealed (Ga,Mn)As layers studied by x-ray diffraction and standing-wave uorescence

A combination of high-resolution x-ray diffraction and a new technique of x-ray standing wave uorescence at grazing incidence is employed to study the structure of (Ga,Mn)As diluted magnetic semiconductor and its changes during post-growth annealing steps. We find that the film is formed by a uniform, single crystallographic phase epilayer covered by a thin surface layer with enhanced Mn concentration due to Mn atoms at random non-crystallographic positions. In the epilayer, Mn incorporated at interstitial position has a dominant effect on lattice expansion as compared to substitutional Mn. The expansion coeffcient of interstitial Mn estimated from our data is consistent with theory predictions. The concentration of interstitial Mn and the corresponding lattice expansion of the epilayer are reduced by annealing, accompanied by an increase of the density of randomly distributed Mn atoms in the disordered surface layer. Substitutional Mn atoms remain stable during the low-temperature annealing.Comment: 9 pages, 9 figure