897 research outputs found

    Effects of augmented exercise therapy time after stroke: a meta-analysis

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    <p><b>Background and Purpose:</b> To present a systematic review of studies that addresses the effects of intensity of augmented exercise therapy time (AETT) on activities of daily living (ADL), walking, and dexterity in patients with stroke.</p> <p><b>Summary of Review:</b> A database of articles published from 1966 to November 2003 was compiled from MEDLINE, CINAHL, Cochrane Central Register of Controlled Trials, PEDro, DARE, and PiCarta using combinations of the following key words: stroke, cerebrovascular disorders, physical therapy, physiotherapy, occupational therapy, exercise therapy, rehabilitation, intensity, dose–response relationship, effectiveness, and randomized controlled trial. References presented in relevant publications were examined as well as abstracts in proceedings. Studies that satisfied the following selection criteria were included: (1) patients had a diagnosis of stroke; (2) effects of intensity of exercise training were investigated; and (3) design of the study was a randomized controlled trial (RCT). For each outcome measure, the estimated effect size (ES) and the summary effect size (SES) expressed in standard deviation units (SDU) were calculated for ADL, walking speed, and dexterity using fixed and random effect models. Correlation coefficients were calculated between observed individual effect sizes on ADL of each study, additional time spent on exercise training, and methodological quality. Cumulative meta-analyses (random effects model) adjusted for the difference in treatment intensity in each study was used for the trials evaluating the effects of AETT provided. Twenty of the 31 candidate studies, involving 2686 stroke patients, were included in the synthesis. The methodological quality ranged from 2 to 10 out of the maximum score of 14 points. The meta-analysis resulted in a small but statistically significant SES with regard to ADL measured at the end of the intervention phase. Further analysis showed a significant homogeneous SES for 17 studies that investigated effects of increased exercise intensity within the first 6 months after stroke. No significant SES was observed for the 3 studies conducted in the chronic phase. Cumulative meta-analysis strongly suggests that at least a 16-hour difference in treatment time between experimental and control groups provided in the first 6 months after stroke is needed to obtain significant differences in ADL. A significant SES supporting a higher intensity was also observed for instrumental ADL and walking speed, whereas no significant SES was found for dexterity.</p> <p><b>Conclusion:</b> The results of the present research synthesis support the hypothesis that augmented exercise therapy has a small but favorable effect on ADL, particularly if therapy input is augmented at least 16 hours within the first 6 months after stroke. This meta-analysis also suggests that clinically relevant treatment effects may be achieved on instrumental ADL and gait speed.</p&gt

    Pion-Nucleon Scattering in Kadyshevsky Formalism: I Meson Exchange Sector

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    In a series of two papers we present the theoretical results of πN\pi N/meson-baryon scattering in the Kadyshevsky formalism. In this paper the results are given for meson exchange diagrams. On the formal side we show, by means of an example, how general couplings, i.e. couplings containing multiple derivatives and/or higher spin fields, should be treated. We do this by introducing and applying the Takahashi-Umezawa and the Gross-Jackiw method. For practical purposes we introduce the Pˉ\bar{P} method. We also show how the Takashashi-Umezawa method can be derived using the theory of Bogoliubov and collaborators and the Gross-Jackiw method is also used to study the nn-dependence of the Kadyshevsky integral equation. Last but not least we present the second quantization procedure of the quasi particle in Kadyshevsky formalism.Comment: 29 page

    'Put Your Money Where Your Mouth Is!': Effects of Streaks on Confidence and Betting in a Binary Choice Task.

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    This is the final published version. It first appeared at http://onlinelibrary.wiley.com/doi/10.1002/bdm.1844/abstract.Human choice under uncertainty is influenced by erroneous beliefs about randomness. In simple binary choice tasks, such as red/black predictions in roulette, long outcome runs (e.g. red, red, red) typically increase the tendency to predict the other outcome (i.e. black), an effect labeled the "gambler's fallacy." In these settings, participants may also attend to streaks in their predictive performance. Winning and losing streaks are thought to affect decision confidence, although prior work indicates conflicting directions. Over three laboratory experiments involving red/black predictions in a sequential roulette task, we sought to identify the effects of outcome runs and winning/losing streaks upon color predictions, decision confidence and betting behavior. Experiments 1 (n = 40) and 3 (n = 40) obtained trial-by-trial confidence ratings, with a win/no win payoff and a no loss/loss payoff, respectively. Experiment 2 (n = 39) obtained a trial-by-trial bet amount on an equivalent scale. In each experiment, the gambler's fallacy was observed on choice behavior after color runs and, in experiment 2, on betting behavior after color runs. Feedback streaks exerted no reliable influence on confidence ratings, in either payoff condition. Betting behavior, on the other hand, increased as a function of losing streaks. The increase in betting on losing streaks is interpreted as a manifestation of loss chasing; these data help clarify the psychological mechanisms underlying loss chasing and caution against the use of betting measures ("post-decision wagering") as a straightforward index of decision confidence. © 2014 The Authors. Journal of Behavioral Decision Making published by John Wiley & Sons Ltd

    Easy on that trigger dad: a study of long term family photo retrieval

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    We examine the effects of new technologies for digital photography on people's longer term storage and access to collections of personal photos. We report an empirical study of parents' ability to retrieve photos related to salient family events from more than a year ago. Performance was relatively poor with people failing to find almost 40% of pictures. We analyze participants' organizational and access strategies to identify reasons for this poor performance. Possible reasons for retrieval failure include: storing too many pictures, rudimentary organization, use of multiple storage systems, failure to maintain collections and participants' false beliefs about their ability to access photos. We conclude by exploring the technical and theoretical implications of these findings

    Isotope shift in the electron affinity of chlorine

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    The specific mass shift in the electron affinity between ^{35}Cl and ^{37}Cl has been determined by tunable laser photodetachment spectroscopy to be -0.51(14) GHz. The isotope shift was observed as a difference in the onset of the photodetachment process for the two isotopes. In addition, the electron affinity of Cl was found to be 29138.59(22) cm^{-1}, giving a factor of 2 improvement in the accuracy over earlier measurements. Many-body calculations including lowest-order correlation effects demonstrates the sensitivity of the specific mass shift and show that the inclusion of higher-order correlation effects would be necessary for a quantitative description.Comment: 16 pages, 6 figures, LaTeX2e, amsmat

    Enacting Resilience: A Performative Account of Governing for Urban Resilience

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    Resilience is an increasingly important urban policy discourse that has been taken up at a rapid pace. Yet there is an apparent gap between the advocacy of social-ecological resilience in scientific literature and its take-up in policy discourse on the one hand, and the demonstrated capacity to govern for resilience in practice on the other. This paper explores this gap by developing a performative account of how social-ecological resilience is dealt with in practice through case study analysis of how protection of biodiversity was negotiated in response to Melbourne’s recent metropolitan planning initiative. It is suggested that a performative account expands the possible opportunities for governing for social-ecological resilience beyond the concept’s use as a metaphor, measurement, cognitive frame or programmatic statement of adaptive management/co-management and has the potential to emerge through what has been called the everyday ‘mangle of practice’ in response to social-ecological feedback inherent to policy processes

    Shaping Embodied Neural Networks for Adaptive Goal-directed Behavior

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    The acts of learning and memory are thought to emerge from the modifications of synaptic connections between neurons, as guided by sensory feedback during behavior. However, much is unknown about how such synaptic processes can sculpt and are sculpted by neuronal population dynamics and an interaction with the environment. Here, we embodied a simulated network, inspired by dissociated cortical neuronal cultures, with an artificial animal (an animat) through a sensory-motor loop consisting of structured stimuli, detailed activity metrics incorporating spatial information, and an adaptive training algorithm that takes advantage of spike timing dependent plasticity. By using our design, we demonstrated that the network was capable of learning associations between multiple sensory inputs and motor outputs, and the animat was able to adapt to a new sensory mapping to restore its goal behavior: move toward and stay within a user-defined area. We further showed that successful learning required proper selections of stimuli to encode sensory inputs and a variety of training stimuli with adaptive selection contingent on the animat's behavior. We also found that an individual network had the flexibility to achieve different multi-task goals, and the same goal behavior could be exhibited with different sets of network synaptic strengths. While lacking the characteristic layered structure of in vivo cortical tissue, the biologically inspired simulated networks could tune their activity in behaviorally relevant manners, demonstrating that leaky integrate-and-fire neural networks have an innate ability to process information. This closed-loop hybrid system is a useful tool to study the network properties intermediating synaptic plasticity and behavioral adaptation. The training algorithm provides a stepping stone towards designing future control systems, whether with artificial neural networks or biological animats themselves

    Coordination between arm and leg movements during locomotion

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    To evaluate the contrasting dynamical and biomechanical interpretations of the 2:1 frequency coordination between arm and leg movements that occurs at low walking velocities and the 1:1 frequency coordination that occurs at higher walking velocities, the authors conducted an experiment in which they quantified the effect of walking velocity on the stability of the frequency and phase coordination between the individual limb movements. Spectral analyses revealed the presence of 2:1 frequency coordination as a consistent feature of the data in only 3 out of 8 participants at walking velocities ranging from 1.0 to 2.0 km/h, in spite of the fact that the eigenfrequencies of the arms were rather similar across participants. The degree of interlimb coupling, as indexed by weighted coherence and variability of relative phase, was lower for the arm movements and for ipsilateral and diagonal combinations of arm and leg movements than for the leg movements. Furthermore, the coupling between all pairs of limb movements was found to increase with walking velocity, whereas no clear signs were observed that the switches from 2:1 to 1:1 frequency coordination and vice versa were preceded by loss of stability. Therefore, neither a purely biomechanical nor a purely dynamical model is optimally suited to explain these results. Instead, an integrative model involving elements of both approaches seems to be required

    P300 and uncertainty reduction in a concept identification task.

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    The relationship between the amplitude of P300, the mean amplitude of the Slow Wave, and uncertainty reduction after (dis)confirmation of hypotheses was studied in a Concept-Identification task. The subjects had to categorize stimuli according to a conceptual rule (joint denial or exclusion) and to rate the confidence that their classification was correct. Three types of feedback were distinguished: confirming (subject's categorization was correct), disconfirming (subject's categorization was incorrect), and non-informative feedback. The EEG was averaged separately according to the three types of feedback and the two confidence ratings (low, high). The data showed the predicted interaction between type of feedback and confidence level. A larger P300 amplitude turned up after confirming feedback when the subject was less confident, than when he was more confident. The reverse was found after disconfirming feedback. The P300 amplitude after non-informative feedback was not influenced by confidence. The mean amplitude of the Slow Wave showed approximately the same interaction pattern. The results were interpreted in terms of changes in the probability of hypotheses which subjects use to categorize stimuli in a Concept-Identification task
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