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

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

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

Is it pointing to grasping or grasping pointing?

The Smeets and Brenner view on grasping is simple: grasping is in fact pointing. In our comments we examine the model beyond the reach-to-grasp task namely, by grasping (without reaching) of moving objects and eating. The model fits the data of both tasks. Although generalization of a model to different tasks usually strengthens its acceptance, in the present case it reveals its shortcomings, namely, both tasks include a clear grasping component that is hard to accept as pointing.</jats:p

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

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

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

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 $(p,-1)$-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

Motor skill learning in groups: Some proposals for applying implicit learning and self-controlled feedback

Contrary to researchers' current focus on individual motor skill learning, in institutional settings such as physical education and sports motor skill learning is often taught in groups. In these settings, there is not only the interaction between teacher and learner (analogous to research), but also the many interactions between the learners in the group. In this paper, we discuss the pitfalls of applying research findings without taking into account the different dynamics that the interactions between group members bring about. To this end, we especially discuss implicit motor learning and self-controlled feedback, as these have recently been hailed as being particularly effective for increasing motor skill and self-efficacy. Proposals are provided to adopt these methods for motor skill learning in groups. This is not only relevant for practitioners in physical education and sports, but also establishes an agenda for research

The effect of the "Rod-and-frame" Illusion on grip planning in a sequential object manipulation task

We investigated the effect of visual context (i.e., a visual illusion) on the planning of a sequential object manipulation task. Participants (n = 13) had to grasp a rod embedded in a "rod-and-frame" illusion and insert the rod-end into a tight hole in a pre-defined way. The grip type (defined by start posture, either pronated or supinated; and end posture, either comfortable or uncomfortable) used to grasp the rod was registered as a macroscopic variable of motor planning. Different rod orientations forced the participants to switch between grip types. As expected, most participants switched between pronated and supinated start postures, such that they ended the movement with a comfortable end posture. As it has been argued that planning is dependent on visual context information, we hypothesized that the visual illusion would affect the specific rod orientation at which participants would switch into a different grip type. This hypothesis was confirmed. More specifically, the illusion affected the critical spatial information that is used for action planning. Collectively, these findings are the first to show an effect of an illusion on motor planning in a sequential object manipulation task. © 2007 Springer-Verlag

Exploring the merits of perceptual anticipation in the soccer penalty kick

This study investigated whether soccer penalty-takers can exploit predictive information from the goalkeeper’s actions. Eight low- and seven high-skilled participants kicked balls in a penalty task with the goalkeeper’s action displayed on a large screen. The goalkeeper initiated his dive either before, at or after the ball was struck. The percentage of balls shot to the empty half of the goal was not above chance when the participants could only rely on predictive information. Gaze patterns suggested that the need to fixate the target location to maintain aiming accuracy hindered perceptual anticipation. It is argued that penalty-takers should select a target location in advance of the run-up to the ball and disregard the goalkeeper’s actions.</jats:p

Exploring the thresholds of vision for perception and action

Based upon evidence that vision for action has quicker access to visual information than vision for perception, we hypothesized that the two systems may have differentiated visual thresholds. There is also evidence that, unlike vision for perception, vision for action is insensitive to cognitive dual-task interference. Using visual masking, we determined the visual thresholds of 15 participants in a perception task, an action task and an action plus concurrent cognitive secondary task. There was no difference in threshold between the perception task and the action task, but the action plus concurrent secondary task was accompanied by a greater visual threshold than both the perception task and the action task alone, indicating dual-task interference. The action task was thus most likely informed by vision for perception. The implications of these results are reviewed in the context of recent discussions of the two visual systems model. © 2012 Human Kinetics, Inc.published_or_final_versio