The development of vocabulary exercises to accompany social studies textbooks in the intermediate grades.

Thesis (Ed.M.)--Boston Universit

Chain‐Growth Polymerization of Aryl Grignards Initiated by a Stabilized NHC‐Pd Precatalyst

An N‐heterocyclic carbene‐ligated palladium catalyst was discovered to mediate living, chain‐growth polymerizations of both phenylene‐ and thiophene‐based monomers. Polymerization of a fluorene‐based monomer, on the other hand, did not proceed through a living, chain‐growth pathway. Excitingly, block copolymerizations of phenylene and thiophene proceeded via a chain‐growth pathway, regardless of the order of monomer addition. Although some chain termination was observed during these copolymerizations, this pathway could be minimized when the second monomer was added shortly after consumption of the first monomer. These results suggest that the catalyst resting‐state at the end of polymerization is unstable. As a result, modifications to the NHC‐scaffold or the 3‐chloropyridine ligand will be necessary to generate an improved catalyst. A Pd catalyst that can mediate a living, chain‐growth polymerization of π‐conjugated monomers is reported. Using (IPr)Pd(3‐chloropyridine)Cl 2 as a precatalyst, both homopolymers and block copolymers of phenylene‐ and thiophene‐based monomers were prepared. Although a living, chain‐growth mechanism is observed during polymerization, the catalyst resting state is somewhat unstable after the monomer is consumed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/92031/1/marc_201200096_sm_suppl.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/92031/2/842_ftp.pd

A study of macro-, meso- and micro-barriers and enablers affecting extended scopes of practice: The case of rural nurse practitioners in Australia

© 2019 The Author(s). Background: Shortages of skills needed to deliver optimal health care in rural and remote locations raises questions about using extended scopes of practice or advanced practice models in a range of health professions. The nurse practitioner (NP) model was introduced to address health service gaps; however, its sustainability has been questioned, while other extended scope of practice roles have not progressed in Australia. This study aimed to explore the experiences and perceptions of NPs and their colleagues about barriers to and enablers of extended scope of practice and consider the relevance of the findings to other health professions. Methods: Semi-structured, in-depth interviews were conducted with primary, nurse practitioner informants, who were also invited to nominate up to two colleagues, as secondary informants. Data analysis was guided by a multi-level, socio-institutional lens of macro-, meso- and micro-perspectives. Results: Fifteen primary informants and five colleagues were interviewed from various rural and remote locations. There was a fairly even distribution of informants across primary, aged, chronic and emergency or critical care roles. Key barriers and enablers at each level of analysis were identified. At the macro-level were legal, regulatory, and economic barriers and enablers, as well as job availability. The meso-level concerned local health service and community factors, such as attitudes and support from managers and patients. The micro-level relates to day-to-day practice. Role clarity was of considerable importance, along with embedded professional hierarchies and traditional role expectations influencing interactions with individual colleagues. Given a lack of understanding of NP scope of practice, NPs often had to expend effort promoting and advocating for their roles. Conclusions: For communities to benefit from extended scope of practice models of health service delivery, energy needs to be directed towards addressing legislative and regulatory barriers. To be successful, extended scope of practice roles must be promoted with managers and decision-makers, who may have limited understanding of the clinical importance. Support is also important from other members of the interprofessional health care team

Understanding all-terrain vehicle user behaviour: the human dimensions of ATV use in Northeastern New Brunswick, Canada

This study examined all-terrain vehicle (ATV) users in northeastern New Brunswick, Canada, providing a human dimensions approach to understanding the activity and inform future management decisions. A methodological comparison between self-classification and multivariate applications of Bryan's (1977) recreation specialization framework was conducted to assess variation in participant engagement within the activity. The impact of activity consumption on levels of recreation specialization was also examined to investigate how differences in ATV use affects user engagement. Self-administered questionnaires were randomly distributed to three New Brunswick communities (n = 144). Results suggest that both applications of the recreation specialization framework did not similarly classify participants as expected. Specialization levels were found to differ across three activity consumption sub-groups, suggesting different types of ATV use may impact user engagement. Resource managers should consider differences in user recreation specialization and activity consumption when designing strategies to manage the heterogeneous activity

Total variation approximation for quasi-equilibrium distributions

Quasi-stationary distributions, as discussed by Darroch & Seneta (1965), have been used in biology to describe the steady state behaviour of population models which, while eventually certain to become extinct, nevertheless maintain an apparent stochastic equilibrium for long periods. These distributions have some drawbacks: they need not exist, nor be unique, and their calculation can present problems. In this paper, we give biologically plausible conditions under which the quasi-stationary distribution is unique, and can be closely approximated by distributions that are simple to compute.Comment: 16 page

An updated description of the FEL simulation code Puffin

Puffin [1] is an unaveraged 3D FEL simulation tool with no Slowly Varying Envelope Approximation (SVEA), no undulator period averaging of the electron motion, and no periodic slicing of the electron beam, enabling simulation of broadband and high resolution FEL phenomena. It is a massively parallel code, written in modern Fortran and MPI, which scales from single core machines to HPC facilities. Its use in a number of projects since its initial description in 2012 has necessitated a number of additions to expand or improve its capability, including new numerical techniques, and the addition of a wide and flexible array of undulator tunings and polarizations along with electron beam optics elements for the undulator line. In the following paper, we provide an updated description of Puffin including an overview of these updates

Molecular weight dependent structure and charge transport in MAPLE‐deposited poly(3‐hexylthiophene) thin films

In this work, poly(3‐hexylthiophene) (P3HT) films prepared using the matrix‐assisted pulsed laser evaporation (MAPLE) technique are shown to possess morphological structures that are dependent on molecular weight (MW). Specifically, the structures of low MW samples of MAPLE‐deposited film are composed of crystallites/aggregates embedded within highly disordered environments, whereas those of high MW samples are composed of aggregated domains connected by long polymer chains. Additionally, the crystallite size along the side‐chain (100) direction decreases, whereas the conjugation length increases with increasing molecular weight. This is qualitatively similar to the structure of spin‐cast films, though the MAPLE‐deposited films are more disordered. In‐plane carrier mobilities in the MAPLE‐deposited samples increase with MW, consistent with the notion that longer chains bridge adjacent aggregated domains thereby facilitating more effective charge transport. The carrier mobilities in the MAPLE‐deposited simples are consistently lower than those in the solvent‐cast samples for all molecular weights, consistent with the shorter conjugation length in samples prepared by this deposition technique. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018, 56, 652–662The structure of MAPLE‐deposited P3HT thin films is shown to possess molecular weight (MW) dependence behavior. The MAPLE films deposited from low MW materials consist of crystallite domains embedded within a highly amorphous environment, whereas those deposited from high MW materials are composed of long polymer chains bridging the aggregate domains. The in‐plane mobility is shown to increase with MW, highlighting the importance of domain connectivity in facilitating charge transport in conjugated polymers.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142537/1/polb24588-sup-0001-suppinfo1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142537/2/polb24588_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142537/3/polb24588.pd

V1647 Orionis: Optical Photometric and Spectroscopic Monitoring Through the 2003-2006 Outburst

We present results from an optical imaging and spectroscopic monitoring campaign on the young, low-mass eruptive variable star V1647 Orionis. The star and associated nebulosity (McNeil's Nebula) were observed over the period February 2004 to February 2006 with observations commencing a few months after the original outburst event occurred. Using the Gemini North telescope, we obtained multi-band optical imaging photometry and medium-resolution long-slit spectroscopy of V1647 Ori on an approximately monthly interval. During this period, V1647 Ori remained at, or close to, peak brightness and then faded by 5 magnitudes to close to its pre-outburst brightness. This implies an outburst timescale of around 27 months. Spectral features seen in both emission and absorption varied considerably during the monitoring period. For example, the Halpha line changed significantly in both intensity and profile. We present and discuss the observed photometric and spectroscopic changes and consider how this eruptive event relates to the early formative stages of low-mass stars.Comment: 59 pages, 22 figure