Crystal structures of the human Dysferlin inner DysF domain

Background: Mutations in dysferlin, the first protein linked with the cell membrane repair mechanism, causes a group of muscular dystrophies called dysferlinopathies. Dysferlin is a type two-anchored membrane protein, with a single C terminal trans-membrane helix, and most of the protein lying in cytoplasm. Dysferlin contains several C2 domains and two DysF domains which are nested one inside the other. Many pathogenic point mutations fall in the DysF domain region. Results: We describe the crystal structure of the human dysferlin inner DysF domain with a resolution of 1.9 Angstroms. Most of the pathogenic mutations are part of aromatic/arginine stacks that hold the domain in a folded conformation. The high resolution of the structure show that these interactions are a mixture of parallel ring/guanadinium stacking, perpendicular H bond stacking and aliphatic chain packing. Conclusions: The high resolution structure of the Dysferlin DysF domain gives a template on which to interpret in detail the pathogenic mutations that lead to disease

Sales and Operations Planning: A Performance Framework

Despite a robust body of practitioner-oriented literature focused on the importance of balancing customer demand with product supply within companies, there is very little empirical research suggesting how to achieve it. Sales and Operations planning (S&OP) is a tactical approach meant to help firms accomplish demand and supply balance at aggregate levels. While guidebooks authored by consultants suggest best practices that lead to S&OP success, many experts agree that companies have fallen short of achieving the anticipated benefits. Carried out by cross-functional teams, S&OP entails getting people from different thought worlds to work toward a common goal, a challenging task for any company. Academia is still in the early stages of developing empirical pathways predictive of S&OP performance. The purpose of this study is to test a model of S&OP performance grounded in group effectiveness theory. Using a survey-based approach, perspectives were captured from S&OP team members across a wide cross-section of industries representing sales and operations functions. The results of statistical analysis indicate that managers should focus on helping their teams to achieve a superordinate identity. This allows team members to overcome functional biases and constructively engage in S&OP planning which in turn drives S&OP performance. Also of paramount importance are having team-based rewards and incentives that fully support overarching S&OP goals. These findings provide empirically-based guidance for managers seeking to determine which internal team and contextual support factors are most important for S&OP success. Moreover, grounding S&OP in principles of group effectiveness theory within a broad framework will help support future academic study of S&OP and related efforts by firms to achieve demand and supply harmony

The effect of a semester unit of study on ethical issues in nursing on a group of practising registered nurses

This study explored the effect an educational unit on ethical issues in nursing had on the ethical reasoning of practising registered nurses. The educational unit was conducted at a university school of nursing as part of a baccalaureate degree programme for already registered and practising nurses. A quasi-experimental posttest design utilising stratified random samples compared subjects from one group who had undertaken the unit (n=53) with subjects from another group who had not (n=61). Ethical reasoning was measured using Grisham\u27s Nursing Dilemma Test and a researcher designed demographic data sheet provided information on additional variables for analysis.The group which had undertaken the unit had a significantly higher principled thinking score at n=.05. There were no other significant findings for other variables. The result is discussed in relation to other research findings, various extraneous variables and theoretical and measurement issues

Serfati solutions to the 2D Euler equations on exterior domains

We prove existence and uniqueness of a weak solution to the incompressible 2D Euler equations in the exterior of a bounded smooth obstacle when the initial data is a bounded divergence-free velocity field having bounded scalar curl. This work completes and extends the ideas outlined by P. Serfati for the same problem in the whole-plane case. With non-decaying vorticity, the Biot-Savart integral does not converge, and thus velocity cannot be reconstructed from vorticity in a straightforward way. The key to circumventing this difficulty is the use of the Serfati identity, which is based on the Biot-Savart integral, but holds in more general settings.Comment: 50 page

Melting of hexagonal skyrmion states in chiral magnets

Skyrmions are spiral structures observed in thin films of certain magnetic materials (Uchida et al 2006 Science 311 359–61). Of the phases allowed by the crystalline symmetries of these materials (Yi et al 2009 Phys. Rev. B 80 054416), only the hexagonally packed phases (SCh) have been observed. Here the melting of the SCh phase is investigated using Monte Carlo simulations. In addition to the usual measure of skyrmion density, chiral charge, a morphological measure is considered. In doing so it is shown that the low-temperature reduction in chiral charge is associated with a change in skyrmion profiles rather than skyrmion destruction. At higher temperatures, the loss of six-fold symmetry is associated with the appearance of elongated skyrmions that disrupt the hexagonal packing