First-year composition and transfer: a quantitative study

The present study investigated the effect of writing pedagogy on transfer by examining the effect of pedagogical orientation (WAC/WID or ‘traditional’) on content-area grades. Participants were 1,052 undergraduates from 17 schools throughout the United States. Hypothesis was that the WAC/WID orientation would lead to higher transfer levels as measured by participants’ higher content-area performance. Composition grades were collected in year one; content-area grades where collected in year two. Propensity scores were calculated to stratify the groups and minimize selection bias of writing-class assignment, thereby allowing quasi-causal inference. An ANOVA was performed on the resulting 2-by-5 stratified data. Results indicated that students who completed the WAC/WID composition classes received significantly higher content grades than those in the ‘traditional’ writing classes. The results confirmed the hypothesis

Equivalence between two-dimensional alternating/random Ising model and the ground state of one-dimensional alternating/random XY chain

It is derived that the two-dimensional Ising model with alternating/random interactions and with periodic/free boundary conditions is equivalent to the ground state of the one-dimensional alternating/random XY model with the corresponding periodic/free boundary conditions. This provides an exact equivalence between a random rectangular Ising model, in which the Griffiths-McCoy phase appears, and a random XY chain.Comment: 10 page

Theory of multiwave mixing and decoherence control in qubit array system

We develop a theory to analyze the decoherence effect in a charged qubit array system with photon echo signals in the multiwave mixing configuration. We present how the decoherence suppression effect by the {\it bang-bang} control with the $\pi$ pulses can be demonstrated in laboratory by using a bulk ensemble of exciton qubits and optical pulses whose pulse area is even smaller than $\pi$. Analysis is made on the time-integated multiwave mixing signals diffracted into certain phase matching directions from a bulk ensemble. Depending on the pulse interval conditions, the cross over from the decoherence acceleration regime to the decoherence suppression regime, which is a peculiar feature of the coherent interaction between a qubit and the reservoir bosons, may be observed in the time-integated multiwave mixing signals in the realistic case including inhomogeneous broadening effect. Our analysis will successfully be applied to precise estimation of the reservoir parameters from experimental data of the direction resolved signal intensities obtained in the multiwave mixing technique.Comment: 19 pages, 11 figure

Phase transition in compressible Ising systems at fixed volume

Using a Ginzburg-Landau model, we study the phase transition behavior of compressible Ising systems at constant volume by varying the temperature $T$ and the applied magnetic field $h$. We show that two phases can coexist macroscopically in equilibrium within a closed region in the $T$-$h$ plane. It occurence is favored near tricriticality. We find a field-induced critical point, where the correlation length diverges, the difference of the coexisting two phases and the surface tension vanish, but the isothermal magnetic susceptibility does not diverge in the mean field theory. We also investigate phase ordering numerically.Comment: 13 figure

The repulsion between localization centers in the Anderson model

In this note we show that, a simple combination of deep results in the theory of random Schr\"odinger operators yields a quantitative estimate of the fact that the localization centers become far apart, as corresponding energies are close together

Spin-1/2 Ising-Heisenberg model with the pair XYZ Heisenberg interaction and quartic Ising interactions as the exactly soluble zero-field eight-vertex model

The spin-1/2 Ising-Heisenberg model with the pair XYZ Heisenberg interaction and quartic Ising interactions is exactly solved by establishing a precise mapping relationship with the corresponding zero-field (symmetric) eight-vertex model. It is shown that the Ising-Heisenberg model with the ferromagnetic Heisenberg interaction exhibits a striking critical behavior, which manifests itself through re-entrant phase transitions as well as continuously varying critical exponents. The changes of critical exponents are in accordance with the weak universality hypothesis in spite of a peculiar singular behavior to emerge at a quantum critical point of the infinite order, which occurs at the isotropic limit of the Heisenberg interaction. On the other hand, the Ising-Heisenberg model with the antiferromagnetic Heisenberg interaction surprisingly exhibits less significant changes of both critical temperatures as well as critical exponents upon varying a strength of the exchange anisotropy in the Heisenberg interaction.Comment: 11 pages, 9 figure

Multimodality Treatment for Early-Stage Hepatocellular Carcinoma: A Bridging Therapy for Liver Transplantation

Purpose: To evaluate the efficiency of a multimodality approach consisting of transcatheter arterial chemoembolization (TACE) and radiofrequency ablation (RFA) as bridging therapy for patients with hepatocellular carcinoma (HCC) awaiting orthotopic liver transplantation (OLT) and to evaluate the histopathological response in explant specimens. Materials and Methods: Between April 2001 and November 2011, 36 patients with 50 HCC nodules (1.4-5.0 cm, median 2.8 cm) on the waiting list for liver transplantation were treated by TACE and RFA. The drop-out rate during the follow-up period was recorded. The local efficacy was evaluated by histopathological examination of the explanted livers. Results: During a median follow-up time of 29 (4.0-95.3) months the cumulative drop-out rate for the patients on the waiting list was 0, 2.8, 5.5, 11.0, 13.9 and 16.7% at 3, 6, 12, 24, 36 and 48 months, respectively. 16 patients (with 26 HCC lesions) out of 36(44.4%) were transplanted by the end of study with a median waiting list time of 13.7 (2.5-37.8) months. The histopathological examination of the explanted specimens revealed a complete necrosis in 20 of 26 HCCs (76.9%), whereas 6 (23.1%) nodules showed viable residual tumor tissue. All transplanted patients are alive at a median time of 29.9 months. Imaging correlation showed 100% specificity and 66.7% sensitivity for the depiction of residual or recurrent tumor. Conclusion: We conclude that TACE.combined with RFA could provide an effective treatment to decrease the drop-out rate from the OLT waiting list for HCC patients. Furthermore, this combination therapy results in high rates of complete tumor necrosis as evaluated in the histopathological analysis of the explanted livers. Further randomized trials are needed to demonstrate if there is a benefit in comparison with a single-treatment approach. copyright (C) 2012 S. Karger AG, Base

ARSENIC REMOVAL FROM GROUNDWATER USING INDIGENOUS IRON AND MANGANESE OXDIZING BACTERIA

Joint Research on Environmental Science and Technology for the Eart

Sheared Solid Materials

We present a time-dependent Ginzburg-Landau model of nonlinear elasticity in solid materials. We assume that the elastic energy density is a periodic function of the shear and tetragonal strains owing to the underlying lattice structure. With this new ingredient, solving the equations yields formation of dislocation dipoles or slips. In plastic flow high-density dislocations emerge at large strains to accumulate and grow into shear bands where the strains are localized. In addition to the elastic displacement, we also introduce the local free volume {\it m}. For very small $m$ the defect structures are metastable and long-lived where the dislocations are pinned by the Peierls potential barrier. However, if the shear modulus decreases with increasing {\it m}, accumulation of {\it m} around dislocation cores eventually breaks the Peierls potential leading to slow relaxations in the stress and the free energy (aging). As another application of our scheme, we also study dislocation formation in two-phase alloys (coherency loss) under shear strains, where dislocations glide preferentially in the softer regions and are trapped at the interfaces.Comment: 16pages, 11figure