173 research outputs found

    A comparison of the effects of the colour and size of coloured overlays on young children’s reading

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    This study compared the effects of the colour and size of overlays on reading time, reading errors and on the clarity of text with young primary school children. The sample comprised a non-clinical, typical, sample from an East London primary school. One hundred and six children aged between four and seven years were asked to read 11 short passages of text (60 words) either with full page overlays or smaller reading rulers (53 in each group). This sample included younger children than has often been tested before. The 11 short passages allowed an assessment of baseline reading performance (no reading aid) and performance while reading with each of a set of ten coloured reading aids. Two different, yet beneficial, colours were determined: the most effective and the clearest/most comfortable. Both of these measures are not usually recorded. All but four children had reduced reading times with one of the reading aids and all but one reported their aid improved the perceived visual clarity of the text: the size of the reading aid did not affect reading time or visual clarity significantly. The numbers of skipped words and errors/mis-read words also decreased when reading with the most effective and most comfortable reading aid. Near visual acuity was assessed with and without each child’s most effective coloured aid. The most effective aid improved acuity in over a third of the children. Acuity has not been assessed in previous studies. As reported previously, different colours helped different children. In conclusion, coloured reading overlays reduced reading times on the reading test employed here and the size of the reading aid was not crucial to facilitate performance. The largest reductions occurred for the youngest readers, suggesting these aids may be particularly effective for early readers

    Genetic diversity of clinical isolates of Bacillus cereus using multilocus sequence typing

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    <p>Abstract</p> <p>Background</p> <p><it>Bacillus cereus </it>is most commonly associated with foodborne illness (diarrheal and emetic) but is also an opportunistic pathogen that can cause severe and fatal infections. Several multilocus sequence typing (MLST) schemes have recently been developed to genotype <it>B. cereus </it>and analysis has suggested a clonal or weakly clonal population structure for <it>B. cereus </it>and its close relatives <it>B. anthracis </it>and <it>B. thuringiensis</it>. In this study we used MLST to determine if <it>B. cereus </it>isolates associated with illnesses of varying severity (e.g., severe, systemic vs. gastrointestinal (GI) illness) were clonal or formed clonal complexes.</p> <p>Results</p> <p>A retrospective analysis of 55 clinical <it>B. cereus </it>isolates submitted to the Centers for Disease Control and Prevention between 1954 and 2004 was conducted. Clinical isolates from severe infections (n = 27), gastrointestinal (GI) illness (n = 18), and associated isolates from food (n = 10) were selected for analysis using MLST. The 55 isolates were diverse and comprised 38 sequence types (ST) in two distinct clades. Of the 27 isolates associated with serious illness, 13 clustered in clade 1 while 14 were in clade 2. Isolates associated with GI illness were also found throughout clades 1 and 2, while no isolates in this study belonged to clade 3. All the isolates from this study belonging to the clade 1/cereus III lineage were associated with severe disease while isolates belonging to clade1/cereus II contained isolates primarily associated with severe disease and emetic illness. Only three STs were observed more than once for epidemiologically distinct isolates.</p> <p>Conclusion</p> <p>STs of clinical <it>B. cereus </it>isolates were phylogenetically diverse and distributed among two of three previously described clades. Greater numbers of strains will need to be analyzed to confirm if specific lineages or clonal complexes are more likely to contain clinical isolates or be associated with specific illness, similar to <it>B. anthracis </it>and emetic <it>B. cereus </it>isolates.</p

    Discovery of soft and hard X-ray time lags in low-mass AGNs

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    The scaling relations between the black hole (BH) mass and soft lag properties for both active galactic nuclei (AGNs) and BH X-ray binaries (BHXRBs) suggest the same underlying physical mechanism at work in accreting BH systems spanning a broad range of mass. However, the low-mass end of AGNs has never been explored in detail. In this work, we extend the existing scaling relations to lower-mass AGNs, which serve as anchors between the normal-mass AGNs and BHXRBs. For this purpose, we construct a sample of low-mass AGNs (MBH<3×106MM_{\rm BH}<3\times 10^{6} M_{\rm \odot}) from the XMM-Newton archive and measure frequency-resolved time delays between the soft (0.3-1 keV) and hard (1-4 keV) X-ray emissions. We report that the soft band lags behind the hard band emission at high frequencies [1.32.6]×103\sim[1.3-2.6]\times 10^{-3} Hz, which is interpreted as a sign of reverberation from the inner accretion disc in response to the direct coronal emission. At low frequencies ([38]×104\sim[3-8]\times 10^{-4} Hz), the hard band lags behind the soft band variations, which we explain in the context of the inward propagation of luminosity fluctuations through the corona. Assuming a lamppost geometry for the corona, we find that the X-ray source of the sample extends at an average height and radius of 10rg\sim 10r_{\rm g} and 6rg\sim 6r_{\rm g}, respectively. Our results confirm that the scaling relations between the BH mass and soft lag amplitude/frequency derived for higher-mass AGNs can safely extrapolate to lower-mass AGNs, and the accretion process is indeed independent of the BH mass.Comment: 11 pages, 5 figures, 4 tables, Published in MNRA

    Investigations into the photophysical and electronic properties of pnictoles and Their pnictenium counterparts

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    The reaction of phosphole/arsole starting materials with a series of halide abstraction reagents afforded their respective phosphenium/arsenium complexes. UV–vis absorption and luminescence studies on these cations showed interesting emission profiles, which were found to be dependent upon counterion choice. The addition of a reductant to the phosphole reagent garnered a dimeric species with a central P–P bond, which when heated was found to undergo homolytic bond cleavage to produce an 11π radical complex. Electron paramagnetic resonance (EPR), supported by density functional theory (DFT) calculations, was used to characterize this radical species

    Low-Frequency Heroin Injection among Out-of-Treatment, Street-Recruited Injection Drug Users

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    In this paper, we explore the understudied phenomenon of "low-frequency" heroin injection in a sample of street-recruited heroin injectors not in drug treatment. We conducted a cross-sectional study of 2,410 active injection drug users (IDUs) recruited in San Francisco, California from 2000 to 2005. We compare the sociodemographic characteristics and injection risk behaviors of low-frequency heroin injectors (low-FHI; one to 10 self-reported heroin injections in the past 30 days) to high-frequency heroin injectors (high-FHI; 30 or more self-reported heroin injections in the past 30 days). Fifteen percent of the sample met criteria for low-FHI. African American race, men who have sex with men (MSM) behavior, and injection and noninjection methamphetamine use were independently associated with low-FHI. Compared to high-FHI, low-FHI were less likely to report syringe sharing and nonfatal heroin overdose. A small but significant proportion of heroin injectors inject heroin 10 or less times per month. Additional research is needed to qualitatively examine low-frequency heroin injection and its relationship to drug use trajectories

    Comparison of two multiple-locus variable-number tandem-repeat analysis methods for molecular strain typing of human Brucella melitensis isolates from the Middle East

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    Brucella species are highly monomorphic, with minimal genetic variation among species, hindering the development of reliable subtyping tools for epidemiologic and phylogenetic analyses. Our objective was to compare two distinct multiple-locus variable-number tandem-repeat analysis (MLVA) subtyping methods on a collection of 101 Brucella melitensis isolates from sporadic human cases of brucellosis in Egypt (n = 83), Qatar (n = 17), and Libya (n = 1). A gel-based MLVA technique, MLVA-15IGM, was compared to an automated capillary electrophoresis-based method, MLVA-15NAU, with each MLVA scheme examining a unique set of variable-number tandem repeats. Both the MLVAIGM and MLVANAU methods were highly discriminatory, resolving 99 and 101 distinct genotypes, respectively, and were able to largely separate genotypes from Egypt and Qatar. The MLVA-15NAU scheme presented higher strain-to-strain diversity in our test population than that observed with the MLVA-15IGM assay. Both schemes were able to genetically correlate some strains originating from the same hospital or region within a country. In addition to comparing the genotyping abilities of these two schemes, we also compared the usability, limitations, and advantages of the two MLVA systems and their applications in the epidemiological genotyping of human B. melitensis strains

    Vive la radiorésistance!: converging research in radiobiology and biogerontology to enhance human radioresistance for deep space exploration and colonization.

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    While many efforts have been made to pave the way toward human space colonization, little consideration has been given to the methods of protecting spacefarers against harsh cosmic and local radioactive environments and the high costs associated with protection from the deleterious physiological effects of exposure to high-Linear energy transfer (high-LET) radiation. Herein, we lay the foundations of a roadmap toward enhancing human radioresistance for the purposes of deep space colonization and exploration. We outline future research directions toward the goal of enhancing human radioresistance, including upregulation of endogenous repair and radioprotective mechanisms, possible leeways into gene therapy in order to enhance radioresistance via the translation of exogenous and engineered DNA repair and radioprotective mechanisms, the substitution of organic molecules with fortified isoforms, and methods of slowing metabolic activity while preserving cognitive function. We conclude by presenting the known associations between radioresistance and longevity, and articulating the position that enhancing human radioresistance is likely to extend the healthspan of human spacefarers as well

    Thriving Nebraska: Key Drivers for Community Economic Vitality

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    Thriving Nebraska: Key Drivers for Community Economic Vitality When we think about community vitality, we consider the factors that influence the quality of life and the prosperity of life for people in those communities. We have a responsibility in our research and discovery agenda to push the bounds and discover new information. Then, we put this new information to work in our state

    Crop Updates - 2003 Weeds

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    This session covers Thirty four papers from different authors INTRODUCTION INTEGRATED WEED MANAGEMENT IWM system studies/demonstration sites Six years of IWM investigation – what does it tell us? Bill Roy, Agricultural Consulting and Research Services Pty Ltd Long term herbicide resistance site, the final chapter, Peter Newman and Glen Adam, Department of Agriculture Management of skeleton weed (chondrilla juncea) in a cropping rotation in Western Australia, J. R. Peirce and B. J. Rayner, Department of Agriculture WEED BIOLOGY AND COMPETITION Annual ryegrass seedbanks: The good, the bad and the ugly, Kathryn J. Steadman1, Amanda J. Ellery2 and Sally C. Peltzer3 , 1WA Herbicide Resistance Initiative, UWA, 2CSIRO Plant Industry, 3 Department of Agriculture Annual ryegrass seeds after-ripen faster during a hot summer, Kathryn J. Steadman1, Gavin P. Bignell1 and Amanda J. Ellery2, 1WA Herbicide Resistance Initiative, UWA, 2CSIRO Plant Industry Predicting annual ryegrass dormancy from climatic variables, Amanda Ellery, Andrew Moore, Sandy Nedelkos, Ross Chapman, CSIRO Plant Industry Removing dormancy in annual ryegrass seeds for early herbicide resistance testing, Kathryn J. Steadman and Mechelle J. Owen, WA Herbicide Resistance Initiative, UWA Annual ryegrass germination responds to nitrogen, Amanda Ellery1, Simone Dudley1 and Robert Gallagher2, 1CSIRO Plant Industry, 2Washington State University The agro-ecology of Malva parviflora (small flowered mallow), Pippa J. Michael, Kathryn J. Steadman and Julie A. Plummer, Western Australia Herbicide Resistance Initiative, School of Plant Biology, University of Western Australia The looming threat of wild radish, Peter Newman, Department of Agriculture IWM TOOLS Double knock, how close can we go? Peter Newman and Glen Adam, Department of Agriculture Double knock herbicide effect on annual ryegrass, Catherine Borger, Abul Hashem and Nerys Wilkins, Department of Agriculture Tactical techniques for managing Annual Ryegrass, Sally Peltzer1, Alex Douglas1, Fran Hoyle1, Paul Matson1 and Michael Walsh2 Department of Agriculture and 2Western Australian Herbicide Resistance Initiative. Weed control through soil inversion, Sally Peltzer, Alex Douglas and Paul Matson, Department of Agriculture The burning issues of annual ryegrass seed control, Darren Chitty and Michael Walsh, Western Australian Herbicide Resistance Initiative, UWA No sign of chaff-cart resistant ryegrass! David Ferris, WA Herbicide Resistance Initiative UWA PACKAGES AND MODELLING Conserving glyphosate susceptibility – modelling past, present and future us. Paul Neve1, Art Diggle2, Patrick Smith3 and Stephen Powles1 ,1Western Australian Herbicide Resistance Initiative, School of Plant Biology, University of Western Australia, 2Department of Agriculture, 3CSIRO Sustainable Ecosystems WEEDEM: A program for predicting weed emergence in Western Australia, Michael Walsh,1 David Archer2, James Eklund2 and Frank Forcella2, 1Western Australia Herbicide Resistance Initiative, UWA, 2USDA-Agricultural Research Service, 803 Iowa Avenue, Morris, MN 56267, USA Weed and herbicide management for long term profit: A workshop, Alister Draper1 and Rick Llewellyn12, 1WA Herbicide Resistance Initiative, 2School of Agricultural and Resource Economics, University of Western Australia HERBICIDE RESISTANCE Alternative herbicides for control of triazine and diflufenican multiple resistant wild radish, Aik Cheam1, Siew Lee1, David Nicholson1 and Mike Clarke2 1Department of Agriculture, Western Australia, 2Bayer CropScience Resistance of wild mustard biotype to ALS-inhibiting herbicides in WA Wheatbelt, Abul Hashem, Department of Agriculture Glyphosate-resistant ryegrass biotypes in the WA wheatbelt, Abul Hashem, Catherine Borger and Nerys Wilkins, Department of Agriculture Implications of herbicide rates for resistance management, Paul Neve, Western Australian Herbicide Resistance Initiative, University of Western Australia Putting a price on herbicide resistance, Rick Llewellyn, School of Agricultural and Resource Economics/WA Herbicide Resistance Initiative, University of Western Australia Herbicide resistance from over the fence: Mobility and management, Debbie Allena, Rick Llewellynb, aUniversity of Western Australia, 4th year student, 2002. Mingenew-Irwin Group, bSchool of Agricultural and Resource Economics/Western Australia Herbicide Resistance Initiative, University of Western Australia HERBICIDE TOLERANCE Herbicide tolerance of new barley varieties, Harmohinder S. Dhammu and Terry Piper, Department of Agriculture Herbicide tolerance of new lupins, Harmohinder S. Dhammu, Terry Piper and David Nicholson, Department of Agriculture Herbicide tolerance of new field pea varieties, Harmohinder S. Dhammu, Terry Piper and David Nicholson, Department of Agriculture Herbicide tolerance of new lentil varieties, H.S. Dhammu, T.J. Piper and L.E. Young, Department of Agriculture HERBICIDES – NEW PRODUCTS/PRODUCT USES; USE Kill half leaf ryegrass with Spray.Seed® at night, Peter Newman and Glenn Adam, Department of Agriculture CLEARFIELD™ wheat to control hard-to-kill weeds, Abul Hashem, Catherine Borger and Nerys Wilkins, Department of Agriculture Diuron, a possible alternative to simazine pre-emergent in lupins, Peter Newman and Glenn Adam, Department of Agriculture Dual Gold® soft on barley, soft on weeds in dry conditions, Peter Newman and Glenn Adam, Department of Agriculture Dual Gold® soft on lupins, soft on ryegrass in dry conditions, Peter Newman and Glenn Adam, Department of Agricultur
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