Reconfiguration of Polygonal Subdivisions via Recombination

Motivated by the problem of redistricting, we study area-preserving reconfigurations of connected subdivisions of a simple polygon. A connected subdivision of a polygon ?, called a district map, is a set of interior disjoint connected polygons called districts whose union equals ?. We consider the recombination as the reconfiguration move which takes a subdivision and produces another by merging two adjacent districts, and by splitting them into two connected polygons of the same area as the original districts. The complexity of a map is the number of vertices in the boundaries of its districts. Given two maps with k districts, with complexity O(n), and a perfect matching between districts of the same area in the two maps, we show constructively that (log n)^O(log k) recombination moves are sufficient to reconfigure one into the other. We also show that ?(log n) recombination moves are sometimes necessary even when k = 3, thus providing a tight bound when k = 3

Situating Computer Simulation Professional Development: Does It Promote Inquiry-Based Simulation Use?

This mixed-methods study sought to identify professional development implementation variables that may influence participant (a) adoption of simulations, and (b) use for inquiry-based science instruction. Two groups (Cohort 1, N = 52; Cohort 2, N = 104) received different professional development. Cohort 1 was focused on Web site use mechanics. Cohort 2 was situated in nature and provided three additional elements: (a) modeling simulation use within inquiry-based instruction; (b) collaboration; and (c) provision of content-relevant lesson planning time. There was no difference in the extent of simulation use between cohorts, χ2(1) = 0.878, p = .349, φ = −0.075. Results were inconclusive for a difference in observed inquiry instruction as Fisher\u27s Exact Test was insignificant but had a medium effect size, p = .228, φ = 0.283. Computer-based standardized tests emerged as a novel technology integration barrier. These findings have implications for school policy, professional development, and future research

Elementary science teachers’ integration of engineering design into science instruction: results from a randomised controlled trial

This randomised controlled trial used a mixed-methods approach to investigate the frequency and how elementary teachers integrated engineering design (ED) principles into their science instruction following professional development (PD). The ED components of the PD were aligned with Cunningham and Carlsen’s [(2014). Teaching engineering practices. Journal of Science Teacher Education, 25, 197–210] guidelines for ED PD and promoted inclusion of ED within science teaching. The treatment group included 219 teachers from 83 schools. Participants in the control group included 145 teachers from 60 schools in a mid-Atlantic state. Data sources, including lesson overviews and videotaped classroom observations, were analysed quantitatively to determine the frequency of ED integration and qualitatively to describe how teachers incorporated ED into instruction after attending the PD. Results indicated more participants who attended the PD (55%) incorporated ED into instruction compared with the control participants (24%), χ2(1, n = 401) = 33.225, p \u3c .001,  = 0.308. Treatment and control teachers taught similar science content (p’s \u3e .05) through ED lessons. In ED lessons, students typically conducted research and created and tested initial designs. The results suggest the PD supported teachers in implementing ED into their science instruction and support the efficacy of using Cunningham and Carlsen’s (2014) guidelines to inform ED PD design

Characterizing Universal Reconfigurability of Modular Pivoting Robots

We give both efficient algorithms and hardness results for reconfiguring between two connected configurations of modules in the hexagonal grid. The reconfiguration moves that we consider are "pivots", where a hexagonal module rotates around a vertex shared with another module. Following prior work on modular robots, we define two natural sets of hexagon pivoting moves of increasing power: restricted and monkey moves. When we allow both moves, we present the first universal reconfiguration algorithm, which transforms between any two connected configurations using $O(n^3)$ monkey moves. This result strongly contrasts the analogous problem for squares, where there are rigid examples that do not have a single pivoting move preserving connectivity. On the other hand, if we only allow restricted moves, we prove that the reconfiguration problem becomes PSPACE-complete. Moreover, we show that, in contrast to hexagons, the reconfiguration problem for pivoting squares is PSPACE-complete regardless of the set of pivoting moves allowed. In the process, we strengthen the reduction framework of Demaine et al. [FUN'18] that we consider of independent interest

The performance of Remicade (R)-optimized quantification assays in the assessment of Flixabi (R) levels

Background: The advent of Remicade (R) biosimilars, Remsima (R), Inflectra (R) and, more recently, Flixabi (R), has brought along the potential to decrease the costs associated with this therapy, therefore increasing its access to a larger group of patients. However, and in order to assure a soft transition, one must make sure the assays and algorithms previously developed and optimized for Remicade perform equally well with its biosimilars. This study aimed to: (a) validate the utilization of Remicade-optimized therapeutic drug monitoring assays for the quantification of Flixabi; and (b) determine the existence of Remicade, Remsima and Flixabi cross-immunogenicity. Methods: Healthy donors' sera spiked with Remicade, Remsima and Flixabi were quantified using three different Remicade-quantification assays, and the reactivity of anti-Remicade and anti-Remsima sera to Remicade and to its biosimilars was assessed. Results: The results show that all tested Remicade-infliximab-optimized assays measure Flixabi as accurately as they measure Remicade and Remsima: the intraclass correlation coefficients between theoretical and measured concentrations varied from 0.920 to 0.990. Moreover, the interassay agreement values for the same compounds were high (intraclass correlation coefficients varied from 0.936 to 0.995). Finally, the anti-Remicade and anti-Remsima sera reacted to the different drugs in a similar fashion. Conclusions: The tested assays can be used to monitor Flixabi levels. Moreover, Remicade, Remsima and Flixabi were shown to have a high cross-immunogenicity, which supports their high similarity but prevents their switching in nonresponders with antidrug antibodies.Portuguese IBD Group (GEDII, Grupo de Estudo da Doenca Inflamatoria Intestinal

Interaction Between Convection and Pulsation

This article reviews our current understanding of modelling convection dynamics in stars. Several semi-analytical time-dependent convection models have been proposed for pulsating one-dimensional stellar structures with different formulations for how the convective turbulent velocity field couples with the global stellar oscillations. In this review we put emphasis on two, widely used, time-dependent convection formulations for estimating pulsation properties in one-dimensional stellar models. Applications to pulsating stars are presented with results for oscillation properties, such as the effects of convection dynamics on the oscillation frequencies, or the stability of pulsation modes, in classical pulsators and in stars supporting solar-type oscillations.Comment: Invited review article for Living Reviews in Solar Physics. 88 pages, 14 figure

New directions for lifelong learning using network technologies

Please refer only to original source: Koper, R., Tattersall, C. (2004). New directions for lifelong learning using network technologies. British Journal of Educational Technology, 35 (6), 689-700.The requirements placed on learning technologies to support lifelong learning differ considerably from those placed on technologies to support particular fragments of a learning lifetime. The time scales involved in lifelong learning, together with its multi-institutional and episodic nature are not reflected in today’s mainstream learning technologies and their associated architectures. The article presents an integrated model and architecture to serve as the basis for the realization of networked learning technologies serving the specific needs and characteristics of lifelong learners. The integrative model is called a “Learning Network” (LN) and its requirements and architecture are explored, together with the ways in which its application can help in reducing barriers to lifelong learning

The diffusion of policy in contexts of practice : flexible delivery in Australian vocational education and training

Significant changes have occurred over the last decade within the Australian Vocational Education and Training (VET) system. Not least amongst these has been a shift from a predominantly traditional face-to-face classroom model of programme delivery to more flexible models informed by the needs of clients. To lead this revolution, in 1991 the Australian Commonwealth and State Ministers for Training established the Flexible Delivery Working Party. A series of reports followed that sought to develop a policy framework, including a definition of flexible delivery, and its principles and characteristics. Despite these efforts, project funding and national staff development initiatives, several difficulties have been experienced in the ‘take-up’ of flexible delivery; problems that we argue are related to how the dissemination of innovative practice is conceived. Specifically, the literature and research on the diffusion of innovations points to the efficacy of informal social networks ‘in which individuals adopt the new idea as a result of talking with other individuals who have already adopted it’ (Valente, 1995, p. ix). Following a discussion of these issues, the article concludes by arguing the need for research of innovative practice transfer within VET in Australia, using qualitative case study in order to develop an in-depth and rich description of the process, and facilitate greater understanding of how it works in practice