7,296 research outputs found

    Does Micro-CT scanning damage DNA in museum specimens?

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    X-ray micro-computed tomography and DNA sequencing are useful and increasingly common tools in taxonomy and collections research. Whilst the benefits of each method are continually evaluated and debated individually, how the methods impact each other requires more attention. We compared DNA fragment length and the barcode sequence CO1 in samples throughout a CT-scanning protocol, for a range of X-ray exposures and energies. We found no evidence of DNA damage, but advise caution when using precious or archival material, highlighting the need for further investigations and considering potential areas for research.NatSCA supports open access publication as part of its mission is to promote and support natural science collections. NatSCA uses the Creative Commons Attribution License (CCAL) http://creativecommons.org/licenses/by/2.5/ for all works we publish. Under CCAL authors retain ownership of the copyright for their article, but authors allow anyone to download, reuse, reprint, modify, distribute, and/or copy articles in NatSCA publications, so long as the original authors and source are cited. The attached file is the published version of the article

    Kertesz on Fat Graphs?

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    The identification of phase transition points, beta_c, with the percolation thresholds of suitably defined clusters of spins has proved immensely fruitful in many areas of statistical mechanics. Some time ago Kertesz suggested that such percolation thresholds for models defined in field might also have measurable physical consequences for regions of the phase diagram below beta_c, giving rise to a ``Kertesz line'' running between beta_c and the bond percolation threshold, beta_p, in the M, beta plane. Although no thermodynamic singularities were associated with this line it could still be divined by looking for a change in the behaviour of high-field series for quantities such as the free energy or magnetisation. Adler and Stauffer did precisely this with some pre-existing series for the regular square lattice and simple cubic lattice Ising models and did, indeed, find evidence for such a change in high-field series around beta_p. Since there is a general dearth of high-field series there has been no other work along these lines. In this paper we use the solution of the Ising model in field on planar random graphs by Boulatov and Kazakov to carry out a similar exercise for the Ising model on random graphs (i.e. coupled to 2D quantum gravity). We generate a high-field series for the Ising model on Ί4\Phi^4 random graphs and examine its behaviour for evidence of a Kertesz line

    Robust degradation and enhancement of robot mission behaviour in unpredictable environments

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    © 2015 ACM.Temporal logic based approaches that automatically generate controllers have been shown to be useful for mission level planning of motion, surveillance and navigation, among others. These approaches critically rely on the validity of the environment models used for synthesis. Yet simplifying assumptions are inevitable to reduce complexity and provide mission-level guarantees; no plan can guarantee results in a model of a world in which everything can go wrong. In this paper, we show how our approach, which reduces reliance on a single model by introducing a stack of models, can endow systems with incremental guarantees based on increasingly strengthened assumptions, supporting graceful degradation when the environment does not behave as expected, and progressive enhancement when it does

    Quality of DNA extracted from formalin-fixed, paraffin-embedded canine tissues.

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    Veterinary pathology tissue banks are valuable resources for genetic studies. However, limited data exist as to whether quality DNA can be extracted from these tissues for use in canine genotyping studies. We extracted DNA from 44 formalin-fixed, paraffin-embedded (FFPE) tissue blocks from dogs; 9 of these dogs had DNA available from whole blood samples that had been banked. We genotyped DNA from 30 of 44 tissue blocks and 9 whole blood samples on the Illumina CanineHD BeadChip; DNA quality was insufficient in 14 of 44 samples from tissue blocks. There was significant correlation between the 260/280 ratio and single-nucleotide variation (SNV) call rate (p = 0.0276; r2 = 0.162); 23 of 30 samples from FFPE were genotyped with > 65% call rates. Median pairwise identical-by-state (IBS) analysis was 0.99 in 8 pairs of dogs with call rates > 65%. Neither age of tissue block nor specific tissue types were associated with significant differences in DNA concentration, 260/280 ratio, or SNV call rate. DNA extracted from tissue blocks can have variable quality, although comparable levels of homozygosity suggest that extracts from FFPE with call rates > 65% might provide similar results to samples from whole blood when analyzed on the Illumina CanineHD BeadChip

    NASA space materials research

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    The effect of the space environment on: (1) thermal control coatings and thin polymer films; (2) radiation stability of 250 F and 350 F cured graphite/epoxy composites; and (3) the thermal mechanical stability of graphite/epoxy, graphite/glass composites are considered. Degradation in mechanical properties due to combined radiation and thermal cycling is highlighted. Damage mechanisms are presented and chemistry modifications to improve stability are suggested. The dimensional instabilities in graphite/epoxy composites associated with microcracking during thermal cycling is examined as well as the thermal strain hysteresis found in metal-matrix composites

    Studies in the Interaction of Heavy Charged Particles With Matter.

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    In recent years the technology of thin film preparation and the fabrication of gold surface barrier detectors and their associated electronics have become highly developed. This has enabled improved energy loss measurements to be made more conveniently for a large range of absorbers and charged particles. The basic interaction processes of heavy charged particles with matter have been investigated by analysing the energy spectra of charged particles before and after passing through absorbers. Results concerning the variation in energy loss, stopping power and energy straggling are given for alpha particles and fission fragments in various absorbers. Experimental studies of energy straggling have been carried out for Am-241 alpha particles using surface barrier detectors to observe the energy dispersion following transmission through solid absorbers. Energy straggling of the emitted alpha particles increased with increasing absorber thickness in accordance with theory, until the energy spectra of the helium ions entered the capture and loss region, when the trend is reversed and straggling began to decrease with increasing absorber thickness. An explanation of the phenomenon is given by reference to the stopping power of alpha particles as a function of their energy. Similarly measurements have been made of the energy straggling of Cf-252 fission fragments through air and solid films using a heavy ion surface barrier detector. Analysis of the energy spectra of the heavy and light fragments show a decreasing energy straggling with increasing absorber thickness. Again this and other spectra parameters are explained by reference to stopping power data for fission fragments

    Health Information Exchanges in The Community Pharmacy Setting

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    The landscape of health care is shifting as new payment models and mandates for health information technology (HIT) rise. There is an unprecedented demand to meet our nation’s health care challenges of access, safety, quality, and cost. To meet these demands, the health care industry has recognized a team-based care model which can introduce the collaborative power through health information exchanges (HIEs). Providers like pharmacists, can detect and resolve medication errors, duplications, and omissions by using HIEs. HIEs give pharmacists the entire view of the patient from the bed-side of the hospital to the community pharmacy. However, the implementation of HIE is currently lacking some community pharmacies. With this being said, pharmacy staff has realized the need for HIE, and hopefully, with timely implementation, pharmacists can move from the traditional filling prescriptions role to the clinical services role

    MA

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    thesisThis thesis is a variationist study of a reputed "Third Dialect" of American English; - the variety of English; spoken in the Salt Lake Valley. Wendy Morkel's dialectological study revealed that the Southern monophthongal (ai) is present in Utah. Morkel's study follows the study of Di Paolo and Faber predicting the Southern Rotation in Utah. This thesis is a sociophonetic assessment of these claims. Sociolinguistic interviews of seven young adults in Utah were analyzed acoustically. Results of the acoustic analysis indicated that glide-weakening in (ai) is present in Utah English; and is conditioned by the voicing of the following consonant, consistent with Southern patterns. Glides tend to be weaker before voiced obstruents, nasals, and in open syllables. However, this thesis found that the front-upgliding word classes are inconsistent with Southern patterns. The analysis also revealed that gender plays an important role, with men weakening glides significantly more than women. This thesis frames the results of the analysis within sociolinguistic theory and will show how the evidence presented can inform sociolinguistic research both linguistically and socially

    Trends in Pulse and Oilseed Crops in Winter Cereal Rotations in NSW

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    The key aims in this study are to assess the current level of importance of pulse and oilseed (broadleaf) crops in winter cereal rotations in NSW, and to identify recent trends. The production of broadleaf crops has increased in each region of NSW, but different crops have been favoured. Canola has played a key role in southern regions, and chickpea in the northern regions. In many areas, pulse crops have been grown more because of rotational benefits than their direct gross margins. If recent trends continue, the role of broadleaf crops will increase to 25% of the area sown to field crops in NSW by 2020. However, that will only be achieved with a focussed effort in both research and extension activities.broadleaf crop, oilseed, pulse, production, rotation, NSW, Agribusiness, Crop Production/Industries, Production Economics, Research and Development/Tech Change/Emerging Technologies, Q160,
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