Preconditioning for Allen-Cahn variational inequalities with non-local constraints

The solution of Allen-Cahn variational inequalities with mass constraints is of interest in many applications. This problem can be solved both in its scalar and vector-valued form as a PDE-constrained optimization problem by means of a primal-dual active set method. At the heart of this method lies the solution of linear systems in saddle point form. In this paper we propose the use of Krylov-subspace solvers and suitable preconditioners for the saddle point systems. Numerical results illustrate the competitiveness of this approach

Explicit isogeny descent on elliptic curves

In this note, we consider an l-isogeny descent on a pair of elliptic curves over Q. We assume that l > 3 is a prime. The main result expresses the relevant Selmer groups as kernels of simple explicit maps between finite- dimensional F_l-vector spaces defined in terms of the splitting fields of the kernels of the two isogenies. We give examples of proving the l-part of the Birch and Swinnerton-Dyer conjectural formula for certain curves of small conductor.Comment: 17 pages, accepted for publication in Mathematics of Computatio

Correlation-induced corrections to the band structure of boron nitride: a wave-function-based approach

We present a systematic study of the correlation-induced corrections to the electronic band structure of zinc-blende BN. Our investigation employs an ab initio wave-function-based local Hamiltonian formalism which offers a rigorous approach to the calculation of the polarization and local charge redistribution effects around an extra electron or hole placed into the conduction or valence bands of semiconducting and insulating materials. Moreover, electron correlations beyond relaxation and polarization can be readily incorporated. The electron correlation treatment is performed on finite clusters. In conducting our study, we make use of localized Wannier functions and embedding potentials derived explicitly from prior periodic Hartree-Fock calculations. The on-site and nearest-neighbor charge relaxation bring corrections of several eV to the Hartree-Fock band gap. Additional corrections are caused by long-range polarization effects. In contrast, the dispersion of the Hartree-Fock bands is marginally affected by electron correlations. Our final result for the fundamental gap of zinc-blende BN compares well with that derived from soft x-ray experiments at the B and N K-edges.Comment: 18 pages, 8 figures; the following article has been submitted to J. Chem. Phy

Five challenges in moving towards evidence-informed practice

An international spotlight is now shining on evidence-informed practice. In a fast-changing world, where diverse groups of pupils need to be prepared for their future rather than their parents’ past, the nature of teacher professionalism has changed. Th is now includes teachers having the confi dence to access and/or create the knowledge they need with colleagues and share it to benefi t others as well as themselves (Schleicher, 2015). Being evidence-informed is therefore at the heart of teacher professionalism. So why doesn’t everyone just get on with it? Here, I pose fi ve challenges that need addressing before this vision can be realised; I offer thoughts on ways to tackle these, and then conclude by raising questions as a stimulus for conversation

Using evidence, learning and the role of professional learning communities

Being able to collaborate to make the best use of evidence to enhance teacher practice is fundamental to successful teaching today. In this chapter, I first describe three evidence sources: student and other data; teacher research or enquiry projects; and external research findings. Next, I consider different perspectives on the social learning that takes place when teachers engage with evidence. I argue that professional learning communities provide the ideal home for evidence-informed practice, and that they are what bring evidence to life. I offer four reasons for this. The chapter concludes with a set of suggestions for leadership of evidence-rich professional learning communities

Nutrient limitation and algal growth above and below the Maple River dam.

Rivers, Lakes & WetlandsIn order to determine limiting nutrient of a lotic system above and below a dam, we created nitrogen, phosphorus, nitrogen and phosphorus, and control agar bioassays. Three sites were chosen, two for both stream branches above the dam and one below. After two weeks of incubation in the river, the bioassays were removed and tested for chlorophyll a amounts. We found that the nitrogen bioassays had the greatest growth in the West branch, but every other nutrient returned the greatest growth in the Main branch. The trends show that the Main and East branches are phosphorus limited, but the West branch is nitrogen limited. This study can be used as preliminary data for future studies, after the Maple River dam is removed.http://deepblue.lib.umich.edu/bitstream/2027.42/116794/1/Stoll_Taine_2015.pd

Recreational Development at Pelican Lake, Minnesota: An Analysis of Factors Affecting Site Selection

In order to better predict those areas whicd\u27 have the po tential to be developed more rapidly than others, research concerning physical land use character isti ;s which determine current lakeshore patterns needs to be implemented. This study is designed to assess which physics . land use/cover characteristics have affected lake home development at Peli can Lake in north central Minnesota. Analysis involves the interpretation of aerial photo graphs from the years 1939, I960, 1969, and 1978 which were used to map location and extent of land use/cover change in the Pelican Lake area. Archival data is utilized in order to determine number and location of recreational homes ex isting on the shoreline of Pelican Lake. Finally, correla tion and regression techniques are used in order to ascer tain relationships between the physical parameters of the watershed and location of lakeshore homes. Length of shoreline is found to be the leading indicator in number of homes in each section bordering Pelican Lake. Distance to nearest improved road also proves to be a sig nificant factor. Of the land use/cover data obtained from aerial photographs, only acres of that land covered by water and.acres in Pelican. Lake are determined to be of signifi cance in location of lakeshore homes

A Quality Improvement Initiative to Enhance Nursing Teamwork: An Element of Excellence

Health care is changing at a rapid pace to meet the needs and expectations of consumers across the United States. The desire for improved quality of care while reducing costs has led to increased attention on team composition, relationships, and culture. There is growing evidence to support the importance of quality workplace relationships and teamwork (Brunetto et al., 2013). Research indicates a positive relationship between a culture of teamwork and quality performance measures in the health care setting (Meterko, Mohr, & Young, 2004). Teamwork in the acute inpatient care nursing team deserves more attention (Kalisch, Lee, & Rochman, 2010). Evidence of the impact of nursing teamwork on staff satisfaction, patient satisfaction, inpatient falls, or staff perceptions of nursing teamwork was lacking at the unit level within a large health care system in the Midwest. A dashboard of unit level nursing teamwork variables was created using nursing teamwork survey (NTS) results along with personal job satisfaction and perceptions of teamwork among nursing team members, patient satisfaction, and patient falls. Dashboard results were used to determine if an intervention to enhance nursing teamwork was needed. The project found that a significant relationship between patient falls and nursing teamwork exists. Fifty percent of nursing units evaluated were not meeting the national benchmark for patient falls and could benefit from an intervention to enhance nursing teamwork. Dashboard results will be disseminated to nursing leadership at the large Midwestern health care system to facilitate recommendation of evidence-based teamwork interventions. Five themes emerged during the analysis of perceptions of teamwork collected through interviews with nursing staff and assisted in the creation of a potential evidence-based intervention. Themes were consistent with The Big Five in Teamwork model by Eduardo Salas and colleagues (Kalisch, Lee, & Salas, 2010; Salas, Sims, & Burke, 2005)