34,756 research outputs found

    Using interactive whiteboards to enrich the teaching of mathematics

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    Reassessment of the invasion history of two species of Cakile (Brassicaceae) in Australia

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    In this paper we revisit the invasion history of two species of Cakile in Australia. Cakile edentula subsp. edentula arrived in the mid 19th Century and spread into coastal strandline habitat from the southeast towards the west and to the north; Cakile maritima arrived in the late 19th Century and has replaced Cakile edentula over much of the range. While Cakile edentula is morphologically quite uniform, the great variation within Cakile maritima has confused field ecologists. Using herbarium records we update previous accounts of the spread of the species and report on field surveys that determined their current geographic overlap in Tasmania and in northern New South Wales/southern Queensland. We examine regional morphological variation within Cakile maritima using the national herbaria collections and variation within new population samples. We support previous interpretations that Cakile maritima has been introduced on more than one occasion from morphologically distinct races, resulting in regional variation within Australia and high variability within populations in the south-east. Western Australian populations appear distinct and probably did not initiate those in the east; we consider that eastern populations are likely to be a mix of Cakile maritima subsp. maritima from the Mediterranean and Cakile maritima subsp. integrifolia from Atlantic Europe. Although introgression from Cakile edentula into Cakile maritima cannot be discounted from our results, it is not required to explain the levels of variation in the latter species observed in Australia. Cakile maritima continues to spread southwards in Tasmania and northwards in NSW; in Queenland, a recent occurrence has proliferated in Moreton Bay, spreading slowly to the north but not appreciably southwards

    Digital Heritage

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    Case study: visualisers

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    Development and testing of Parabolic Dish Concentrator No. 1

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    Parabolic Dish Concentrator No. 1 (PDC-1) is a 12-m-diameter prototype concentrator with low life-cycle costs for use with thermal-to-electric energy conversion devices. The concentrator assembly features panels made of a resin transfer molded balsa core/fiberglass sandwich with plastic reflective film as the reflective surface and a ribbed framework to hold the panels in place. The concentrator assembly tracks in azimuth and elevation on a base frame riding on a circular track. It is shown that the panels do not exhibit the proper parabolic contour. However, thermal gradients were discovered in the panels with daily temperature changes. The PDC-1 has sufficient optical quality to operate satisfactorily in a dish-electric system. The PDC-1 development provides the impetus for creating innovative optical testing methods and valuable information for use in designing and fabricating concentrators of future dish-electric systems

    Design considerations for delivering e-learning to surgical trainees

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    Copyright © 2011, IGI Global. Distributed with permission.Challenges remain in leveraging e-health technologies for continuous medical education/professional development. This study examines the interface design and learning process features related to the use of multimedia in providing effective support for the knowledge and practice of surgical skills. Twenty-one surgical trainees evaluated surgical content on a CD-ROM format based on 14 interface design and 11 learning process features using a questionnaire adapted from an established tool created to assess educational multimedia. Significant Spearman’s correlations were found for seven of the 14 interface design features – ‘Navigation’, ‘Learning demands’, ‘Videos’, ‘Media integration’, ‘Level of material’, ‘Information presentation’ and ‘Overall functionality’, explaining ratings of the learning process. The interplay of interface design and learning process features of educational multimedia highlight key design considerations in e-learning. An understanding of these features is relevant to the delivery of surgical training, reflecting the current state of the art in transferring static CD-ROM content to the dynamic web or creating CD/web hybrid models of education

    FOSTA: A Hostile Law with a Human Cost

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    The Allow States and Victims to Fight Online Sex Trafficking Act of 2017 (“FOSTA”) rescinded legal immunity for websites that intentionally host user-generated advertisements for sex trafficking. However, Congress’s mechanism of choice to protect sex-trafficking victims has faced critique and backlash from advocates for those involved in commercial sex, who argue that FOSTA’s broad legislative language does far more to harm sex workers—a group distinct from sex-trafficking victims—than it does to end sex trafficking, chilling significant protected speech in the process. These critics posit that FOSTA’s results toward eradicating sex trafficking have been negligible and that its chief outcome has been to eliminate digital screening and security protections that consensual sex workers rely upon, thereby forcing the industry back into a far more dangerous street-based model. By eliminating protections for consensual sex workers, however, FOSTA endangers trafficking victims as well, and without online advertisements serving as a “smoking gun,” law enforcement has struggled to find trafficked individuals. This Note explores FOSTA’s effects on consensual sex workers in the United States from two angles. First, it analyzes how FOSTA’s chill on speech that advocates for sex workers’ health, safety, and right to work in their industry contributes to the law’s unconstitutional overbreadth. Second, it compares FOSTA’s practical effects that are in line with its stated goals with the harmful consequences the law has inflicted upon the sex work community and beyond. While this Note proposes amended language to improve FOSTA, it ultimately advocates for FOSTA’s repeal and suggests that if sex work were decriminalized and more pragmatic legislation were implemented to better inculpate traffickers, mitigate harm to trafficking survivors, and reduce future victimization, FOSTA’s stated goals could be realized

    The structure and petrology of the Cnoc nan Cuilean Intrusion, Loch Loyal Syenite Complex, NW Scotland

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    In NW Scotland, several alkaline intrusive complexes of Silurian age intrude the Caledonian orogenic front. The most northerly is the Loch Loyal Syenite Complex, which is divided into three separate intrusions (Ben Loyal, Beinn Stumanadh and Cnoc nan Cuilean). Mapping of the Cnoc nan Cuilean intrusion shows two main zones: a Mixed Syenite Zone (MZ) and a Massive Leucosyenite Zone (LZ), with a gradational contact. The MZ forms a lopolith, with multiple syenitic lithologies, including early basic melasyenites and later felsic leucosyenites. Leucosyenite melts mixed and mingled with melasyenites, resulting in extreme heterogeneity within the MZ. Continued felsic magmatism resulted in formation of the relatively homogeneous LZ, invading western parts of the MZ and now forming the topographically highest terrane. The identification of pegmatites, microgranitic veins and unusual biotite-magnetite veins demonstrates the intrusion's complex petrogenesis. Cross-sections have been used to create a novel 3D GoCad™ model contributing to our understanding of the intrusion. The Loch Loyal Syenite Complex is known to have relatively high concentrations of rare earth elements (REEs), and thus the area has potential economic and strategic value. At Cnoc nan Cuilean, abundant REE-bearing allanite is present within melasyenites of the MZ. Extensive hydrothermal alteration of melasyenites here formed steeply dipping biotite-magnetite veins, most enriched in allanite and other REE-bearing accessories. This study has thus identified the area of greatest importance for further study of REE enrichment processes in the Cnoc nan Cuilean intrusion
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