490 research outputs found

    Effects of Heartwood Inhabiting Fungi on Thujaplicin Content and Decay Resistance of Western Redcedar (Thuja Plicata Donn.)

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    Western redcedar (Thuja plicata Donn.) outer heartwood blocks from a mature and an immature tree, inoculated with fungi commonly isolated from stained heartwood, had a thujaplicin content of less than 6% and a hot water solubility of about one-half that of controls after 10 weeks of exposure. Decay resistance of blocks from the mature tree was greatly reduced following exposure to the staining fungi. Naturally stained heartwood also had low thujaplicin content, but its decay resistance remained high in the same test

    Attentional processes of high-skilled soccer players with congenital hemiparesis: Differences related to the side of the hemispheric lesion

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    Contains fulltext : 72909.pdf (publisher's version ) (Closed access)We investigated attentional processes that support the performance of high-skilled soccer players with hemiparetic cerebral palsy. Participants (N = 10) dribbled a slalom course as quickly and accurately as possible under two attentional-focus manipulation conditions. In the task-relevant focus condition, they attended to the foot that was in contact with the ball, whereas in the task-irrelevant focus condition, they monitored a series of words played on a tape. The time taken to complete the slalom course was registered. Performances of individuals with left and right hemiparesis were compared to explore differential effects of hemispheric lesion. The high-skilled players with congenital hemiparesis showed similar attentional-focus effects as those previously reported in the literature for high-skilled players without neurological disorders (Beilock et al., 2002; Ford et al., 2005). Task-relevant focus increased dribbling time, whereas a task-irrelevant focus did not result in a significant change in dribbling time. These findings generalized to each of the five participants with left hemiparesis (i.e., damage to the right hemisphere). By contrast, the effects of a task-relevant focus were less consistent for participants with right hemiparesis (i.e., left-hemisphere damage). This corroborates suggestions that the reinvestment of procedural knowledge is a left-lateralized function. The implications for the training of individuals with congenital brain damage are discussed

    Involutivity of integrals for sine-Gordon, modified KdV and potential KdV maps

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    Closed form expressions in terms of multi-sums of products have been given in \cite{Tranclosedform, KRQ} of integrals of sine-Gordon, modified Korteweg-de Vries and potential Korteweg-de Vries maps obtained as so-called (p,−1)(p,-1)-traveling wave reductions of the corresponding partial difference equations. We prove the involutivity of these integrals with respect to recently found symplectic structures for those maps. The proof is based on explicit formulae for the Poisson brackets between multi-sums of products.Comment: 24 page

    The staircase method: integrals for periodic reductions of integrable lattice equations

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    We show, in full generality, that the staircase method provides integrals for mappings, and correspondences, obtained as traveling wave reductions of (systems of) integrable partial difference equations. We apply the staircase method to a variety of equations, including the Korteweg-De Vries equation, the five-point Bruschi-Calogero-Droghei equation, the QD-algorithm, and the Boussinesq system. We show that, in all these cases, if the staircase method provides r integrals for an n-dimensional mapping, with 2r<n, then one can introduce q<= 2r variables, which reduce the dimension of the mapping from n to q. These dimension-reducing variables are obtained as joint invariants of k-symmetries of the mappings. Our results support the idea that often the staircase method provides sufficiently many integrals for the periodic reductions of integrable lattice equations to be completely integrable. We also study reductions on other quad-graphs than the regular 2D lattice, and we prove linear growth of the multi-valuedness of iterates of high-dimensional correspondences obtained as reductions of the QD-algorithm.Comment: 40 pages, 23 Figure

    The structure of the protoplanetary disk surrounding three young intermediate mass stars. II. Spatially resolved dust and gas distribution

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    [Abridged] We present the first direct comparison of the distribution of the gas, as traced by the [OI] 6300 AA emission, and the dust, as traced by the 10 micron emission, in the protoplanetary disk around three intermediate-mass stars: HD 101412, HD 135344 B and HD 179218. N-band visibilities were obtained with VLTI/MIDI. Simple geometrical models are used to compare the dust emission to high-resolution optical spectra in the 6300 AA [OI] line of the same targets. The disks around HD 101412 and HD 135344 B appear strongly flared in the gas, but self-shadowed in the dust beyond ~ 2 AU. In both systems, the 10 micron emission is rather compact (< 2 AU) while the [OI] brightness profile shows a double peaked structure. The inner peak is strongest and is consistent with the location of the dust, the outer peak is fainter and is located at 5-10 AU. Spatially extended PAH emission is found in both disks. The disk around HD 179218 is flared in the dust. The 10 micron emission emerges from a double ring-like structure with the first ring peaking at ~ 1 AU and the second at ~ 20 AU. No dust emission is detected between ~ 3 -- 15 AU. The oxygen emission seems also to come from a flared structure, however, the bulk of this emission is produced between ~ 1 -- 10 AU. This could indicate a lack of gas in the outer disk or could be due to chemical effects which reduce the abundance of OH -- the parent molecule of the observed [OI] emission -- further away from the star. The three systems, HD 179218, HD 135344 B and HD 101412, may form an evolutionary sequence: the disk initially flared becomes flat under the combined action of gas-dust decoupling, grain growth and dust settling.Comment: Accepted for publication in A&

    First results of the Herschel Key Program 'Dust, Ice and Gas in Time': Dust and Gas Spectroscopy of HD 100546

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    We present far-infrared spectroscopic observations, taken with the Photodetector Array Camera and Spectrometer (PACS) on the Herschel Space Observatory, of the protoplanetary disk around the pre-main-sequence star HD 100546. These observations are the first within the DIGIT Herschel key program, which aims to follow the evolution of dust, ice, and gas from young stellar objects still embedded in their parental molecular cloud core, through the final pre-main-sequence phases when the circumstellar disks are dissipated. Our aim is to improve the constraints on temperature and chemical composition of the crystalline olivines in the disk of HD 100546 and to give an inventory of the gas lines present in its far-infrared spectrum. The 69 \mu\m feature is analyzed in terms of position and shape to derive the dust temperature and composition. Furthermore, we detected 32 emission lines from five gaseous species and measured their line fluxes. The 69 \mu\m emission comes either from dust grains with ~70 K at radii larger than 50 AU, as suggested by blackbody fitting, or it arises from ~200 K dust at ~13 AU, close to the midplane, as supported by radiative transfer models. We also conclude that the forsterite crystals have few defects and contain at most a few percent iron by mass. Forbidden line emission from [CII] at 157 \mu\m and [OI] at 63 and 145 \mu\m, most likely due to photodissociation by stellar photons, is detected. Furthermore, five H2O and several OH lines are detected. We also found high-J rotational transition lines of CO, with rotational temperatures of ~300 K for the transitions up to J=22-21 and T~800 K for higher transitions

    Cultivating compliance: governance of North Indian organic basmati smallholders in a global value chain

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    Focusing on a global value chain (GVC) for organic basmati rice, we study how farmers’ practices are governed through product and process standards, organic certification protocols, and contracts with buyer firms. We analyze how farmers’ entry into the GVC reconfigures their agencements (defined as heterogeneous arrangements of human and nonhuman agencies which are associated with each other). These reconfigurations entail the severance of some associations among procedural and material elements of the agencements and the formation of new associations, in order to produce cultivation practices that are accurately described by the GVC’s standards and protocols. Based on ethnography of two farmers in Uttarakhand, North India, we find that the same standards were enacted differently on the two farmers’ fields, producing variable degrees of (selective) compliance with the ‘official’ GVC standards. We argue that the disjuncture between the ‘official’ scripts of the standards and actual cultivation practices must be nurtured to allow farmers’ agencements to align their practices with local sociotechnical relations and farm ecology. Furthermore, we find that compliance and disjuncture were facilitated by many practices and associations that were officially ungoverned by the GVC
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