Formation and switching of defect dipoles in acceptor doped lead titanate: A kinetic model based on first-principles calculations

The formation and field-induced switching of defect dipoles in acceptor doped lead titanate is described by a kinetic model representing an extension of the well established Arlt-Neumann model [Ferroelectrics {\bf 76}, 303 (1987)]. Energy barriers for defect association and reorientation of oxygen vacancy-dopant (Cu and Fe) complexes are obtained from first-principles calculations and serve as input data for the kinetic coefficients in the rate equation model. The numerical solution of the model describes the time evolution of the oxygen vacancy distribution at different temperatures and dopant concentrations in the presence or absence of an alternating external field. We predict the characteristic time scale for the alignment of all defect dipoles with the spontanenous polarization of the surrounding matrix. In this state the defect dipoles act as obstacles for domain wall motion and contribute to the experimentally observed aging. Under cycling conditions the fully aligned configuration is perturbed and a dynamic equilibrium is established with defect dipoles in parallel and anti-parallel orientation relative to the spontaneous polarization. This process can be related to the deaging behavior of piezoelectric ceramics.Comment: 10 pages, 7 figure

Utilitarian resource assignment

This paper studies a resource allocation problem introduced by Koutsoupias and Papadimitriou. The scenario is modelled as a multiple-player game in which each player selects one of a finite number of known resources. The cost to the player is the total weight of all players who choose that resource, multiplied by the ``delay'' of that resource. Recent papers have studied the Nash equilibria and social optima of this game in terms of the $L_\infty$ cost metric, in which the social cost is taken to be the maximum cost to any player. We study the $L_1$ variant of this game, in which the social cost is taken to be the sum of the costs to the individual players, rather than the maximum of these costs. We give bounds on the size of the coordination ratio, which is the ratio between the social cost incurred by selfish behavior and the optimal social cost; we also study the algorithmic problem of finding optimal (lowest-cost) assignments and Nash Equilibria. Additionally, we obtain bounds on the ratio between alternative Nash equilibria for some special cases of the problem.Comment: 19 page

Staging innovation projects : (when) does it pay off?

Building on real options literature, this study shows that the use of a staged approach for the management of innovation projects affects the innovation output of firms differently depending on firm characteristics and ambitions. In particular, while staged project management increases the effect of inno- vation expenditures on new product sales for firms envisaging incremental or continuous innovations, this moderating effect is absent for firms aspiring radical innovations. In addition, while staged project management has a pos- itive moderating effect in firms with resource slack, this is not the case when firms are resource-constrained. We further investigate the underlying mecha- nisms to this latter finding by demonstrating that in resource-abundant firms staged project organization is associated with delaying projects until more information becomes available. Thereby these firms reap the waiting value inherent to real options reasoning. By contrast, resource-constrained firms using staged project management are shown to abandon a larger share of their innovation projects and to concentrate resources on fewer projects. It appears, however, that, due to budgetary pressure, they make the decision to abandon at a too early stage where uncertainty is insufficiently resolved. This can explain why there is no effect of staged project management on the sales of resource-constrained firms from new products. The paper contributes to theory development on when and why the staging of innovation projects affects the innovation output of firms and to the literature on real options reasoning in general

Reversible phase transformation and doubly-charged anions at the surface of simple cubic RbC60

The simple cubic phase of a RbC60 thin film has been studied using photoelectron spectroscopy. The simple cubic-to-dimer transition is found to be reversible at the film surface. A sharp Fermi edge is observed and a lower limit of 0.5 eV is found for the surface Hubbard U, pointing to a strongly-correlated metallic character of thin-film simple cubic RbC60. A molecular charge state is identified in the valence band and core level photoemission spectra which arises from C602- anions and contributes to the spectral intensity at the Fermi level.Comment: 13 pages, 3 figure

Australian nurses' knowledge of pressure injury prevention and management: A cross-sectional survey

Purpose: The aim of this study was to assess nurses' knowledge of pressure injuries in order to gather benchmark data, identify knowledge gaps, and based on results, implement educational strategies to improve practice. Design: Cross-sectional survey. Subjects and setting: The study setting was a large Australian tertiary general hospital employing approximately 2500 nurses in both full-time and part-time roles. A proportional sample (25%) stratified by experience, preparation, and facility-generated categories (nursing grade) was generated. The sample included nursing students and nursing assistants. Three hundred six participants completing the survey. Instrument: The Pieper-Zulkowski Pressure Ulcer Knowledge Test (PZPUKT) version 2, comprising 72 statements, with 3 subscales (prevention/risk, staging, and wound description) was used to measure pressure injury knowledge. Item responses are "True," "False," and "Don't know." For the purpose of analyses, correct responses were scored 1, and incorrect or "don't know" responses were scored 0. Generally accepted ranges of scoring for the original PZPUKT specify less than 70% as unsatisfactory, 70% to 79.9% as satisfactory, 80% to 89.9% as good, and 90% and greater as very good knowledge of pressure injury prevention. Methods: The survey was advertised throughout the hospital by strategically placed posters, computer screen savers within the hospital, and e-mails. Respondents completed paper-based questionnaires and data were manually entered online. Data were collected between September 2015 and October 2016. Descriptive and nonparametric inferential statistical tests (Mann-Whitney U, Kruskal-Wallis H) were used to analyze within sample differences in scores. Results: The overall mean knowledge score was 65%; approximately two-thirds of the sample (68%) scored 60% and greater, reflecting an unsatisfactory knowledge level of pressure injury prevention according to the original PZPUKT scores. The lowest mean scores were found in the "wound description" subscale. Participants who sought pressure injury information via the Internet or had read pressure injury guidelines scored significantly higher than those who did not (P = .001 and P =70%) should be used to indicate an overall satisfactory score. Our results identified deficits in pressure injury knowledge related to seating support and seated individuals and wound dressings as areas where nurses would benefit from focused education strategies

Did Plant Patents Create the American Rose?

The Plant Patent Act of 1930 was the first step towards creating property rights for biological innovation: it introduced patent rights for asexually-propagated plants. This paper uses data on plant patents and registrations of new varieties to examine whether the Act encouraged innovation. Nearly half of all plant patents between 1931 and 1970 were for roses. Large commercial nurseries, which began to build mass hybridization programs in the 1940s, accounted for most of these patents, suggesting that the new intellectual property rights may have helped to encourage the development of a commercial rose breeding industry. Data on registrations of newly-created roses, however, yield no evidence of an increase in innovation: less than 20 percent of new roses were patented, European breeders continued to create most new roses, and there was no increase in the number of new varieties per year after 1931.

Improving family functioning and child outcome in methadone maintained families: the parents under pressure programme

t Societal responses to the existence of substance misuse fluctuate between harm minimisation and prohibition. Both approaches are predominantly downstream reactions to substance misuse that focus on the supply of harmful substances and the containment of misuse through treatment, rehabilitation or punishment. Until recently, little attention has been paid to the upstream individual, family, relationship, community or societal antecedents of substance misuse (which often overlap with those for other adverse life outcomes, such as unemployment, antisocial personality disorder and mental health problems) that have operated during earlier life. A growing body of evidence highlights the overlapping biological and experiential antecedents for substance abuse and other poor outcomes as well as the trajectory-changing protective factors that can prevent risks being translated into destiny. Risk minimisation and protection enhancement embedded in family and social systems are the essential building blocks of a set of early intervention strategies that begin antenatally and continue through the developing years of childhood, adolescence and young adult life, that have been shown to be effective in improving many outcomes in development, health and well-being. Much remains to be done to enable the promise of effective universal and targeted early intervention to be translated into policies, programs and practices that could be life-changing for citizens bogged in the mire of substance misuse and their children. Realistic, timely investment, influenced by the best scientific evidence indicating what works, for whom, under what circumstances, an increased degree of collaboration within and between governments and their agencies to enable "whole of government" responses in partnership with community-based initiatives are essential along with investments in multidisciplinary program evaluation research that will enable evidence-informed policy decisions to be tailored to the needs of individual countries. [Vimpani G. Getting the mix right: family, community and social policy interventions to improve outcomes for young people at risk of substance misuse.Griffith Health, School of Applied PsychologyNo Full Tex