27 research outputs found

    Far-infrared photo-conductivity of electrons in an array of nano-structured antidots

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    We present far-infrared (FIR) photo-conductivity measurements for a two-dimensional electron gas in an array of nano-structured antidots. We detect, resistively and spectrally resolved, both the magnetoplasmon and the edge-magnetoplasmon modes. Temperature-dependent measurements demonstrates that both modes contribute to the photo resistance by heating the electron gas via resonant absorption of the FIR radiation. Influences of spin effect and phonon bands on the collective excitations in the antidot lattice are observed.Comment: 5 pages, 3 figure

    The Trichoptera barcode initiative: a strategy for generating a species-level Tree of Life

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    DNA barcoding was intended as a means to provide species-level identifications through associating DNA sequences from unknown specimens to those from curated reference specimens. Although barcodes were not designed for phylogenetics, they can be beneficial to the completion of the Tree of Life. The barcode database for Trichoptera is relatively comprehensive, with data from every family, approximately two-thirds of the genera, and one-third of the described species. Most Trichoptera, as with most of life’s species, have never been subjected to any formal phylogenetic analysis. Here, we present a phylogeny with over 16 000 unique haplotypes as a working hypothesis that can be updated as our estimates improve. We suggest a strategy of implementing constrained tree searches, which allow larger datasets to dictate the backbone phylogeny, while the barcode data fill out the tips of the tree. We also discuss how this phylogeny could be used to focus taxonomic attention on ambiguous species boundaries and hidden biodiversity. We suggest that systematists continue to differentiate between ‘Barcode Index Numbers’ (BINs) and ‘species’ that have been formally described. Each has utility, but they are not synonyms. We highlight examples of integrative taxonomy, using both barcodes and morphology for species description. This article is part of the themed issue ‘From DNA barcodes to biomes’

    Don’t let up: implementing and sustaining change in a new post-licensure education model for developing extended role practitioners involved in arthritis care

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    Katie Lundon,1,3 Rachel Shupak,1–3 Sonya Canzian,4 Ed Ziesmann,5 Rayfel Schneider,6,71Office of Continuing Professional Development, Faculty of Medicine, University of Toronto, 2Division of Rheumatology, St Michael's Hospital, 3Department of Medicine, University of Toronto, 4Trauma/Neurosurgery and Mobility Programs, St Michael's Hospital, 5Programs and Services, The Arthritis Society, 6Division of Rheumatology, The Hospital for Sick Children, 7Department of Paediatrics, University of Toronto, Toronto, ON, CanadaKey message: Across a 9-year period, the Advanced Clinician Practitioner in Arthritis Care program has achieved a set of short-term “wins” giving direction and momentum to the development of new roles for health care practitioners providing arthritis care.Implications: This is a viable model for post-licensure training offered to multiple allied health professionals to support the development of competent extended role practitioners (extended scope practice). Challenges at this critical juncture include: retain focus, drive, and commitment; develop academic and financial partnerships transferring short-term success to long-term sustainability; advanced, context-driven, system-level evaluation including fiscal outcome; health care policy adaptation to new human health resource development.Supporting evidence: Success includes: completed 2-year health services research evaluating 37 graduates; leadership, innovation, educational excellence, and human health resource benefit awards; influential publications/presentations addressing post-licensure education/outcome, interprofessional collaboration, and improved patient care. Keywords: human health resource development, post-licensure education, arthritis, extended role practitioners, allied health professional

    Antennal contact chemosensilla in Psylliodes chrysocephala responding to cruciferous allelochemicals

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    Sensilla chaetica, which protrude above all other sensilla on the antenna of Psylliodes chrysocephala L., the cabbage stem flea beetle, were investigated ultrastructurally and found to be innervated by five to six sensory neurones. A dendrite from one of these neurones terminates in a tubular body at the shaft base, whereas dendrites from the others run unbranched to a pore at the shaft tip. Such a structure typifies a sensillum with a combined gustatory/mechanosensory function. Electrophysiological recordings using the tip-recording technique confirmed that this sensillum contains one mechanosensory cell and several chemosensory cells. The chemosensory cells were responsive to host plant chemicals. Sensilla chaetica were also found to be responsive to glucosinolates. One of the sensilla chaetica emerges from a domed area of cuticle on antennomere six. This was found to be relatively less responsive to the chemical stimuli tested and more responsive to mechanical stimulation. It is suggested that the sensilla chaetica are contact chemosensilla, that respond to chemicals present in plant surface waxes when P. chrysocephala antennates a leaf
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