Atomistic modelling of large-scale metal film growth fronts

We present simulations of metallization morphologies under ionized sputter deposition conditions, obtained by a new theoretical approach. By means of molecular dynamics simulations using a carefully designed interaction potential, we analyze the surface adsorption, reflection, and etching reactions taking place during Al physical vapor deposition, and calculate their relative probability. These probabilities are then employed in a feature-scale cellular-automaton simulator, which produces calculated film morphologies in excellent agreement with scanning-electron-microscopy data on ionized sputter deposition.Comment: RevTeX 4 pages, 2 figure

Implications of teacher life-work histories for conceptualisations of ‘care’: narratives from rural Zimbabwe

Schools are increasingly seen as key sites for support to HIV-affected and other vulnerable children, and teachers are assigned the critical role of identifying and providing psychosocial support. Drawing on the life-work history narratives of twelve teachers in Zimbabwe, this paper explores the psychosocial processes underpinning teachers’ conceptualisations of these caring roles. The influence of prolonged adversity, formative relationships, and broader patterns of social and institutional change in teacher identity formation processes speak to the complex and embodied nature of understandings of ‘care’. In such extreme settings teachers prioritise the material and disciplinary aspects of ‘care’ that they see as essential for supporting children to overcome hardship. This focus not only means that emotional support as envisaged in international policy is commonly overlooked, but also exposes a wider ideological clash about childrearing. This tension together with an overall ambivalence surrounding teacher identities puts further strain on teacher-student relationships. We propose the current trainings on providing emotional support are insufficient and that more active focus needs to be directed at support to teachers in relation with their students

Optimizing end-labeled free-solution electrophoresis by increasing the hydrodynamic friction of the drag-tag

We study the electrophoretic separation of polyelectrolytes of varying lengths by means of end-labeled free-solution electrophoresis (ELFSE). A coarse-grained molecular dynamics simulation model, using full electrostatic interactions and a mesoscopic Lattice Boltzmann fluid to account for hydrodynamic interactions, is used to characterize the drag coefficients of different label types: linear and branched polymeric labels, as well as transiently bound micelles. It is specifically shown that the label's drag coefficient is determined by its hydrodynamic size, and that the drag per label monomer is largest for linear labels. However, the addition of side chains to a linear label offers the possibility to increase the hydrodynamic size, and therefore the label efficiency, without having to increase the linear length of the label, thereby simplifying synthesis. The third class of labels investigated, transiently bound micelles, seems very promising for the usage in ELFSE, as they provide a significant higher hydrodynamic drag than the other label types. The results are compared to theoretical predictions, and we investigate how the efficiency of the ELFSE method can be improved by using smartly designed drag-tags.Comment: 32 pages, 11 figures, submitted to Macromolecule

Predicting Left Ventricular Assist Device Outcomes Utilizing the Stanford Integrated Psychosocial Assessment for Transplant Measure

Objective: Durable mechanical circulatory support is a proven therapy to extend survival for patients with end-stage heart failure (HF). The International Society for Heart and Lung Transplantation guidelines recommend a detailed psychosocial assessment when selecting candidates for durable mechanical circulatory support. Currently, there are no formally validated psychosocial evaluation tools for left ventricular assist device (LVAD) candidacy. The Stanford Integrated Psychosocial Assessment for Transplantation (SIPAT) uses a multidisciplinary algorithm to evaluate the impact of pre-transplant risk factors on post-transplant outcomes. Emerging literature suggests that the SIPAT might be useful for assessing psychosocial risk factors for LVAD outcomes. Methods: A total of 268 consecutive patients (median age 66 years, 84.6% male) with terminal HF were evaluated before LVAD implantation with a SIPAT assessment. Key outcomes included readmission and mortality rates at 30 days and two years. Results: After screening, 234 subjects met the inclusion criteria and were analyzed. The Patient Readiness subscale of the SIPAT was statistically significant in predicting two-year mortality (B = .167, P \u3c .001; Nagelkerke r2 = .106). Scores on the SIPAT did not correlate to 30-day readmission, 30-day mortality, or two-year readmission rates. Discussion: In this study, only the Patient Readiness score was associated with mortality at two-years post-implantation. This research elucidates the potential longer-term impact of psychosocial factors on LVAD outcomes and the SIPAT’s utility in evaluating LVAD candidacy