1,221 research outputs found

    Differences in virulence of Diplocarpon earlianum isolates on selected strawberry cultivars

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    Huit isolats de Diplocarpon earlianum ont été évalués sur 18 cultivars de fraisiers (Fragaria x ananassa) pour leur virulence, laquelle a été mesurée par leur capacité de causer un pourcentage de surface foliaire portant des symptômes. Des différences significatives ont été observées entre les isolats et les cultivars, ainsi que pour l'interaction isolat x cultivar. Quatre des huit isolats, sur la moyenne des 18 cultivars de fraisiers, avaient une surface foliaire portant des symptômes de 6,7-9,6 % et ils ont été classifiés dans le groupe defaible virulence. Les quatre autres isolats avaient une surface portant des symptômes variant de 25,9-45,8 % et formaient un groupe de forte virulence. Parmi les cultivars testés, 'Vibrant' était résistant et 'Micmac' était susceptible à tous les isolats dans les deux groupes de virulence; 'Honeyoye', 'Redcoat', 'Scotland', 'St. Clair' et 'Vantage' étaient résistants au groupe de faible virulence, mais ils présentaient des interactions différentielles envers les isolats du groupe de forte virulence, les 11 autres cultivars étaient sensibles au groupe de forte virulence mais ils démontraient des interactions différentielles envers les isolats du groupe de faible virulence. Il est suggéré que plusieurs isolats de l'agent pathogène soient requis pour tester des génotypes de fraisiers pour leur résistance à la tache pourpre. Une méthode d'essai utilisant des disques foliaires a été développée et elle peut être utilisée pour évaluer la susceptibilité de génotypes de fraisiers au D. earlianum en laboratoire.Eight isolates of Diplocarpon earlianum were evaluated for virulence, measured as the ability to produce percent leaf area with symptoms (LAS), on 18 cultivars of strawberry (Fragaria x ananassa). Significant differences were observed from isolate and cultivar effects, and isolate x cultivar interaction. Four of the eight isolates, on the average of 18 strawberry cultivars, had LAS ranging from 6.7-9.6%, and were classified as a group of low virulence. The remaining four isolates had LAS ranging from 25.9-45.8% and formed a high virulence group. Of the cultivars tested, 'Vibrant' was resistant and 'Micmac' was susceptible to all isolates in both virulence groups; 'Honeoye', 'Redcoat', 'Scotland', 'St. Clair' and 'Vantage' were resistant to the low virulence group, but had differential interactions to isolates in the high virulence group; the remaining 11 cultivars were susceptible to the high virulence group, but had differential interactions to isolates in the low virulence group. It is suggested that a number of different pathogen isolates are required to test strawberry genotypes for leaf scorch resistance. A leaf disk assay was developed in this study and can be used for laboratory evaluations of strawberry genotypes for susceptibility to D. earlianum

    Perception of simple stimuli using sparse data from a tactile whisker array

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    We introduce a new multi-element sensory array built from tactile whiskers and modelled on the mammalian whisker sensory system. The new array adds, over previous designs, an actuated degree of freedom corresponding approximately to the mobility of the mystacial pad of the animal. We also report on its performance in a preliminary test of simultaneous identification and localisation of simple stimuli (spheres and a plane). The sensory processing system uses prior knowledge of the set of possible stimuli to generate percepts of the form and location of extensive stimuli from sparse and highly localised sensory data. Our results suggest that the additional degree of freedom has the potential to offer a benefit to perception accuracy for this type of sensor. © 2013 Springer-Verlag Berlin Heidelberg

    Brain-inspired Bayesian perception for biomimetic robot touch

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    Studies of decision making in animals suggest a neural mechanism of evidence accumulation for competing percepts according to Bayesian sequential analysis. This model of perception is embodied here in a biomimetic tactile sensing robot based on the rodent whisker system. We implement simultaneous perception of object shape and location using two psychological test paradigms: first, a free-response paradigm in which the agent decides when to respond, implemented with Bayesian sequential analysis; and second an interrogative paradigm in which the agent responds after a fixed interval, implemented with maximum likelihood estimation. A benefit of free-response Bayesian perception is that it allows tuning of reaction speed against accuracy. In addition, we find that large gains in decision performance are achieved with unforced responses that allow null decisions on ambiguous data. Therefore free-response Bayesian perception offers benefits for artificial systems that make them more animal-like in behavior

    Holography in the EPRL Model

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    In this research announcement, we propose a new interpretation of the EPR quantization of the BC model using a functor we call the time functor, which is the first example of a CLa-ren functor. Under the hypothesis that the universe is in the Kodama state, we construct a holographic version of the model. Generalisations to other CLa-ren functors and connections to model category theory are considered.Comment: research announcement. Latex fil

    The learning experiences of health and social care paraprofessionals on a foundation degree

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    Foundation degrees have been developed in the UK as a means of meeting the learning needs of paraprofessionals in health and social care and the services within which they work in a cost-effective fashion. Workplace learning is an intrinsic component to these degrees. Taking a socio-cultural perspective, this paper examines how the students' workplaces, life circumstances and sense of career trajectory shaped their learning experience and motivation. A small-scale evaluation study, using semi-structured interviews, focused on the learning experiences of a group of paraprofessionals enrolled in a foundation degree in health and social care. Data revealed fragmented employment patterns, underpinned by consistent vocational drives. While the study resonated with vocation, participants were ambivalent or lacked information about career progression. Workplace conditions, relationships and limited time shaped learning and coping strategies. A strategic and focused approach to student learning is required and includes attention to career pathways, workforce development strategy, the requirements of a range of stakeholders, workplace supervision and support for learning

    Actinide Complexation Kinetics: Rate and Mechanism of Dioxoneptunium(V) Reaction with Chlorophosphonazo III

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    Rates of complex formation and dissociation in NpO{sub 2}{sup +}- Chlorophosphonazo III (2,7-bis(4-chloro-2-phosphonobenzeneazo)-1,8- dihydroxynapthalene-3,6-disulfonic acid)(CLIII) were investigated by stopped-flow spectrophotometry. Also, limited studies were made of the rates of reaction of La{sup 3+}, Eu{sup 3+}, Dy{sup 3+}, and Fe{sup 3+} with CLIII. Rate determining step in each system is an intramolecular process, the NpO{sub 2}{sup +}-CLIII reaction proceeding by a first order approach to equilibrium in the acid range from 0.1 to 1.0 M. Complex formation occurs independent of acidity, while both acid dependent and independent dissociation pathways are observed. Activation parameters for the complex formation reaction are {Delta}H=46.2{+-}0.3 kJ/m and {Delta}S=7{+-} J/mK (I=1.0 M); these for the acid dependent and independent dissociation pathways are {Delta}H=38.8{+-}0.6 kJ/m, {Delta}S=-96{+-}18 J/mK, {Delta}H=70.0{+-} kJ/m, and {Delta}S=17{+-}1 J/mK, respectively. An isokinetic relationship is observed between the activation parameters for CLIII complex formation with NpO{sub 2}{sup +}, UO{sub 2}{sup 2+}, Th{sup 4+}, and Zr{sup 4+}. Rates of CLIII complex formation reactions for Fe{sup 3+}, Zr{sup 4+}, NpO{sub 2}{sup +}, UO{sub 2}{sup 2+}, Th{sup 4+}, La{sup 3+}, Eu{sup 3+}, and Dy{sup 3+} correlate with cation radius rather than charge/radius ratio

    The robot vibrissal system: Understanding mammalian sensorimotor co-ordination through biomimetics

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    Chapter 10 The Robot Vibrissal System: Understanding Mammalian Sensorimotor Co-ordination Through Biomimetics Tony J. Prescott, Ben Mitchinson, Nathan F. Lepora, Stuart P. Wilson, Sean R. Anderson, John Porrill, Paul Dean, Charles ..

    Smartphone Apps for Measuring Human Health and Climate Change Co-Benefits: A Comparison and Quality Rating of Available Apps.

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    BACKGROUND: Climate change and the burden of noncommunicable diseases are major global challenges. Opportunities exist to investigate health and climate change co-benefits through a shift from motorized to active transport (walking and cycling) and a shift in dietary patterns away from a globalized diet to reduced consumption of meat and energy dense foods. Given the ubiquitous use and proliferation of smartphone apps, an opportunity exists to use this technology to capture individual travel and dietary behavior and the associated impact on the environment and health. OBJECTIVE: The objective of the study is to identify, describe the features, and rate the quality of existing smartphone apps which capture personal travel and dietary behavior and simultaneously estimate the carbon cost and potential health consequences of these actions. METHODS: The Google Play and Apple App Stores were searched between October 19 and November 6, 2015, and a secondary Google search using the apps filter was conducted between August 8 and September 18, 2016. Eligible apps were required to estimate the carbon cost of personal behaviors with the potential to include features to maximize health outcomes. The quality of included apps was assessed by 2 researchers using the Mobile Application Rating Scale (MARS). RESULTS: Out of 7213 results, 40 apps were identified and rated. Multiple travel-related apps were identified, however no apps solely focused on the carbon impact or health consequences of dietary behavior. None of the rated apps provided sufficient information on the health consequences of travel and dietary behavior. Some apps included features to maximize participant engagement and encourage behavior change towards reduced greenhouse gas emissions. Most apps were rated as acceptable quality as determined by the MARS; 1 was of poor quality and 10 apps were of good quality. Interrater reliability of the 2 evaluators was excellent (ICC=0.94, 95% CI 0.87-0.97). CONCLUSIONS: Existing apps capturing travel and dietary behavior and the associated health and environmental impact are of mixed quality. Most apps do not include all desirable features or provide sufficient health information. Further research is needed to determine the potential of smartphone apps to evoke behavior change resulting in climate change and health co-benefits

    PTF11iqb: cool supergiant mass-loss that bridges the gap between Type IIn and normal supernovae

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    The supernova (SN) PTF11iqb was initially classified as a Type IIn event caught very early after explosion. It showed narrow Wolf–Rayet (WR) spectral features on day 2 (as in SN 1998S and SN 2013cu), but the narrow emission weakened quickly and the spectrum morphed to resemble Types II-L and II-P. At late times, H? exhibited a complex, multipeaked profile reminiscent of SN 1998S. In terms of spectroscopic evolution, we find that PTF11iqb was a near twin of SN 1998S, although with somewhat weaker interaction with circumstellar material (CSM) at early times, and stronger interaction at late times. We interpret the spectral changes as caused by early interaction with asymmetric CSM that is quickly (by day 20) enveloped by the expanding SN ejecta photosphere, but then revealed again after the end of the plateau when the photosphere recedes. The light curve can be matched with a simple model for CSM interaction (with a mass-loss rate of roughly 10?4 M? yr?1) added to the light curve of a normal SN II-P. The underlying plateau requires a progenitor with an extended hydrogen envelope like a red supergiant at the moment of explosion, consistent with the slow wind speed (<80?km?s?1) inferred from narrow H? emission. The cool supergiant progenitor is significant because PTF11iqb showed WR features in its early spectrum – meaning that the presence of such WR features does not necessarily indicate a WR-like progenitor. Overall, PTF11iqb bridges SNe IIn with weaker pre-SN mass-loss seen in SNe II-L and II-P, implying a continuum between these types
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