Blocked-braid Groups

We introduce and study a family of groups $\mathbf{BB}_n$, called the blocked-braid groups, which are quotients of Artin's braid groups $\mathbf{B}_n$, and have the corresponding symmetric groups $\Sigma_n$ as quotients. They are defined by adding a certain class of geometrical modifications to braids. They arise in the study of commutative Frobenius algebras and tangle algebras in braided strict monoidal categories. A fundamental equation true in $\mathbf{BB}_n$ is Dirac's Belt Trick; that torsion through $4\pi$ is equal to the identity. We show that $\mathbf{BB}_n$ is finite for $n=1,2$ and 3 but infinite for $n>3$

Red-Cockaded Woodpecker Recovery: An Integrated Strategy

Populations of the red-cockaded woodpecker (Picoides borealis) have experienced massive declines since European colonization of North America. This is due to extensive habitat loss and alteration. Logging of old-growth pine forests and alteration of the fire regime throughout the historic range of the species were the primary causes of population decline. Listing of the red-cockaded woodpecker under the Endangered Species Act of 1973, as amended, and increased emphasis on management of non-game species have resulted in efforts to recover remnant populations of the red-cockaded woodpecker in many parts of its historic range. Due to extensive research and adaptive management initiatives much is now known about the elements required for both short- and long-term management of viable populations of red-cockaded woodpeckers. A short-term strategy is crucial because currently available habitat, in nearly all populations, is poor in 1 or more critical respects. Consequently, almost all populations require immediate attention in the short term, to insure suitable midstory and understory conditions, adequate availability of suitable cavities, and restoration of demographic viability through improvements in number and distribution of breeding groups. Management techniques including artificial cavities, cavity entrance restrictors, translocation of birds, prescribed fire, and mechanical and chemical control of woody vegetation are available to achieve these needs. In the long term, cost-effective management of red-cockaded woodpecker populations requires a timber management program and prescribed fire regime that will produce and maintain the stand structure characteristic of high quality nesting and foraging habitat, so that additional intensive management specific to the woodpeckers is no longer necessary. Timber management that achieves this goal and still allows substantial timber harvest is feasible. The implementation of a red-cockaded woodpecker management strategy, as outlined above, represents appropriate ecosystem management in the fire-maintained pine ecosystems of the southeastern United States and will ultimately benefit a great number of additional species of plants and animals adapted to this ecosystem

Experiences of advance care planning in Parkinson’s disease and atypical Parkinsonian disorders: a mixed methods systematic review

Background and purpose: Advance care planning allows people to plan for their future care needs and can include medical, psychological and social aspects. However, little is known on the use, experience of and attitudes towards advance care planning in patients with parkinsonian disorders, their family carers and healthcare professionals. Methods: A systematic search of online databases was conducted in April 2019 using a narrative synthesis approach with thematic analysis and tabulation to synthesize the findings. Results: In all, 507 articles were identified and 27 were included. There were five overarching themes: (i) what is involved in advance care planning discussions, (ii) when and how advance care planning discussions are initiated, (iii) barriers to advance care planning, (iv) the role of healthcare professionals and (v) the role of the family carer. This evidence was used to highlight eight effective components to support optimal advance care planning in parkinsonian disorders: advance care planning discussions should be individualized in content, timing and approach; patients should be invited to discuss advance care planning early and regularly; palliative care services should be introduced early; a skilled professional should deliver advance care planning; support to family carers should be offered in the advance care planning process; healthcare professionals should be educated on parkinsonian disorders and palliative care; advance care planning should be clearly documented and shared with relevant services; and healthcare professionals should be enabled to conduct effective advance care planning. Conclusions: These components can inform best practice in advance care planning in patients with parkinsonian disorders

Transients in Power Systems

Power system engineering largely focuses on steady state analysis. The main areas of power system engineering are power flow studies and fault studies - both steady state technologies. But the world is largely transient, and power systems are always subject to time varying and short lived signals. This technical report concerns several important topics in transient analyses of power systems. The leading chapter deals with a new analytical tool-wavelets-for power system transients. Flicker and electric are furnace transients are discussed in Chapters I1 and IV. Chapter 111 deals with transients from shunt capacitor switching. The concluding chapters deal with transformer inrush current and non simultaneous pole closures of circuit breakers. This report was prepared by the students in EE532 at Purdue University. When I first came to Purdue in 1965, Professor El-Abiad was asking for student term projects which were turned into technical reports. I have \u27borrowed\u27 this idea and for many years we have produced technical reports from the power systems courses. The students get practice in writing reports, and the reader is able to get an idea of the coverage of our courses. I think that the students have done a good job on the subject of transients in power systems

Mixed-precision arithmetic in the ENDGame dynamical core of the Unified model, a numerical weather prediction and climate model code

The Met Office's weather and climate simulation code the Unified Model is used for both operational Numerical Weather Prediction and Climate modelling. The computational performance of the model running on parallel supercomputers is a key consideration. A Krylov sub-space solver is employed to solve the equations of the dynamical core of the model, known as ENDGame. These describe the evolution of the Earth's atmosphere. Typically, 64-bit precision is used throughout weather and climate applications. This work presents a mixed-precision implementation of the solver, the beneficial effect on run-time and the impact on solver convergence. The complex interplay of errors arising from accumulated round-off in floating-point arithmetic and other numerical effects is discussed. A careful analysis is required. The mixed-precision solver is now employed in the operational forecast to satisfy run-time constraints without compromising the accuracy of the solution

The Genetic Architecture of Methotrexate Toxicity Is Similar in Drosophila melanogaster and Humans

The severity of the toxic side effects of chemotherapy varies among patients, and much of this variation is likely genetically based. Here, we use the model system Drosophila melanogaster to genetically dissect the toxicity of methotrexate (MTX), a drug used primarily to treat childhood acute lymphoblastic leukemia and rheumatoid arthritis. We use the Drosophila Synthetic Population Resource, a panel of recombinant inbred lines derived from a multiparent advanced intercross, and quantify MTX toxicity as a reduction in female fecundity. We identify three quantitative trait loci (QTL) affecting MTX toxicity; two colocalize with the fly orthologs of human genes believed to mediate MTX toxicity and one is a novel MTX toxicity gene with a human ortholog. A fourth suggestive QTL spans a centromere. Local single-marker association scans of candidate gene exons fail to implicate amino acid variants as the causative single-nucleotide polymorphisms, and we therefore hypothesize the causative variation is regulatory. In addition, the effects at our mapped QTL do not conform to a simple biallelic pattern, suggesting multiple causative factors underlie the QTL mapping results. Consistent with this observation, no single single-nucleotide polymorphism located in or near a candidate gene can explain the QTL mapping signal. Overall, our results validate D. melanogaster as a model for uncovering the genetic basis of chemotoxicity and suggest the genetic basis of MTX toxicity is due to a handful of genes each harboring multiple segregating regulatory factors

Plate-impact loading of cellular structures formed by selective laser melting

Porous materials are of great interest because of improved energy absorption over their solid counterparts. Their properties, however, have been difficult to optimize. Additive manufacturing has emerged as a potential technique to closely define the structure and properties of porous components, i.e. density, strut width and pore size; however, the behaviour of these materials at very high impact energies remains largely unexplored. We describe an initial study of the dynamic compression response of lattice materials fabricated through additive manufacturing. Lattices consisting of an array of intersecting stainless steel rods were fabricated into discs using selective laser melting. The resulting discs were impacted against solid stainless steel targets at velocities ranging from 300 to 700 m s-1 using a gas gun. Continuum CTH simulations were performed to identify key features in the measured wave profiles, while 3D simulations, in which the individual cells were modelled, revealed details of microscale deformation during collapse of the lattice structure. The validated computer models have been used to provide an understanding of the deformation processes in the cellular samples. The study supports the optimization of cellular structures for application as energy absorbers. © 2014 IOP Publishing Ltd

Universities and community-based research in developing countries: community voice and educational provision in rural Tanzania

The main focus of recent research on the community engagement role of universities has been in developed countries, generally in towns and cities and usually conducted from the perspectives of universities rather than the communities with which they engage. The purpose of this paper is to investigate the community engagement role of universities in the rural areas of developing countries, and its potential for strengthening the voice of rural communities. The particular focus is on the provision of primary and secondary education. The paper is based on the assumption that in order for community members to have both the capacity and the confidence to engage in political discourse for improving educational capacity and quality, they need the opportunity to become involved and well-versed in the options available, beyond their own experience. Particular attention is given in the paper to community-based research (CBR). CBR is explored from the perspectives of community members and local leaders in the government-community partnerships which have responsibility for the provision of primary and secondary education in rural Tanzania. The historical and policy background of the partnerships, together with findings from two case studies, provide the context for the paper

Target Personification Influences the Positive Emotional Link Between Generating and Implementing Malevolently Creative Ideas

Research on malevolent creativity has rarely linked the generation of harmful ideas with their implementation (i.e., malevolent innovation). To explain why people might act upon their malevolently creative ideas, we drew on affective events theory. Specifically, given evidence that aggressive and creative thought events can elicit positive emotions, we argued that generating new and harmful ideas can evoke positive emotional states that make malevolent innovation a more desirable course of action. We first tested our mediational pathway in two studies with different malevolent creativity tasks. Finding only partial support for our predictions in Study 1 (N = 126), but full support in Study 2 (N = 296), we reflected on our study tasks and suspected that our mixed results may have occurred because the target of ideas in Study 2 embodied more human qualities than in Study 1. Thus, we integrated theory on target personification to see if assigning personhood to a target moderated the malevolent creativity-innovation pathway. We tested our updated model in Study 3 (N = 214) and found that the indirect effect of malevolent creativity on the desire to implement ideas (through positive emotions) was indeed conditional upon individuals’ personification of a target. Plain Language Summary Little research has examined why and when people might act upon their malevolently creative (i.e., new and harmful) ideas. Given evidence that aggression and creativity can both arouse positive emotional states, it may be possible that forming malevolently creative ideas can make people feel more positively about implementing them later on. However, our research findings paint a more nuanced picture, suggesting that the emotional link between generating and implementing malevolently creative ideas only occurs when people see their targets as more human-like (i.e., they can assign personhood to their targets)