366 research outputs found

    Visual Bias Predicts Gait Adaptability in Novel Sensory Discordant Conditions

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    We designed a gait training study that presented combinations of visual flow and support-surface manipulations to investigate the response of healthy adults to novel discordant sensorimotor conditions. We aimed to determine whether a relationship existed between subjects visual dependence and their postural stability and cognitive performance in a new discordant environment presented at the conclusion of training (Transfer Test). Our training system comprised a treadmill placed on a motion base facing a virtual visual scene that provided a variety of sensory challenges. Ten healthy adults completed 3 training sessions during which they walked on a treadmill at 1.1 m/s while receiving discordant support-surface and visual manipulations. At the first visit, in an analysis of normalized torso translation measured in a scene-movement-only condition, 3 of 10 subjects were classified as visually dependent. During the Transfer Test, all participants received a 2-minute novel exposure. In a combined measure of stride frequency and reaction time, the non-visually dependent subjects showed improved adaptation on the Transfer Test compared to their visually dependent counterparts. This finding suggests that individual differences in the ability to adapt to new sensorimotor conditions may be explained by individuals innate sensory biases. An accurate preflight assessment of crewmembers biases for visual dependence could be used to predict their propensities to adapt to novel sensory conditions. It may also facilitate the development of customized training regimens that could expedite adaptation to alternate gravitational environments

    Short- and long-term effects of rote rehearsal on ESL learners’ processing of L2 collocations

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    Worldwide there is thought to be around 750 million people who speak English as a foreign language (Crystal, 2003, p. 69). For these speakers the difference between make a picture and take a picture may seem arbitrary. However, use of the former is likely to influence how their second language (L2) performance is perceived (Boers, Eyckmans, Kappel, Stengers, & Demecheleer, 2006). Consequently, L2 speakers' use of collocations (“fixed, identifiable, non-idiomatic phrases and constructions”; Benson, Benson, & Ilson, 1997, p. xv) and other formulaic sequences is an important aspect of L2 competence (Wray, 2002). Several factors appear to influence the acquisition and use of L2 collocations. One of them is L1–L2 collocational congruency. Research has demonstrated that word-for-word translation equivalents (congruent collocations) are processed more efficiently than incongruent collocations (Wolter & Gyllstad, 2011; Yamashita & Jiang, 2010). Moreover, research has demonstrated that collocational frequency, and the frequency of formulaic sequences more generally, influences processing, with more frequent combinations being processed more quickly (Siyanova-Chanturia, Conklin, & van Heuven, 2011; Wolter & Gyllstad, 2013). Researchers have also explored the role of different L2 input conditions on the processing of collocations. Sonbul and Schmitt (2013) compared the effects of three treatments (enriched, enhanced, and decontextualized input) on the collocational competence of learners of English as a second language (ESL). For explicit knowledge, they observed an improvement in both receptive and productive tests for all treatment conditions, but for implicit knowledge no gains were found. Peters (2012) examined L2-German learners' acquisition of words and formulaic sequences as dependent on an instructional method (directing learners' attention through instructions) and input enhancement (bolding and underlining). In a form recall test, input enhancement led to gains in learners' knowledge, whereas the instructional method did not seem to affect their results. The present study brings together a number of questions that have been prominent in the literature by examining the short- and long-term effects of two different input conditions on ESL learners' processing of L2 collocations, as well as exploring the influence of frequency and collocational congruency

    A Comparison of Tandem Walk Performance Between Bed Rest Subjects and Astronauts

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    Astronauts experience a microgravity environment during spaceflight, which results in a central reinterpretation of both vestibular and body axial-loading information by the sensorimotor system. Subjects in bed rest studies lie at 6deg head-down in strict bed rest to simulate the fluid shift and gravity-unloading of the microgravity environment. However, bed rest subjects still sense gravity in the vestibular organs. Therefore, bed rest isolates the axial-unloading component, thus allowing for the direct study of its effects. The Tandem Walk is a standard sensorimotor test of dynamic postural stability. In a previous abstract, we compared performance on a Tandem Walk test between bed rest control subjects, and short- and long-duration astronauts both before and after flight/bed rest using a composite index of performance, called the Tandem Walk Parameter (TWP), that takes into account speed, accuracy, and balance control. This new study extends the previous data set to include bed rest subjects who performed exercise countermeasures. The purpose of this study was to compare performance during the Tandem Walk test between bed rest subjects (with and without exercise), short-duration (Space Shuttle) crewmembers, and long-duration International Space Station (ISS) crewmembers at various time points during their recovery from bed rest or spaceflight

    Impact of rhinitis on asthma severity in school-age children.

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    BACKGROUND: In a population-based sample of school-age children, we investigated factors associated with rhinitis, and differences between allergic and nonallergic rhinitis. Amongst children with asthma, we explored the association between rhinitis and asthma severity. METHODS: Children participating in a birth cohort study (n = 906) were reviewed at age 8 years. Asthma was defined as at least two of the following three features: physician-diagnosed asthma, currently using asthma medication and current wheeze. We measured lung function (plethysmography and spirometry) and airway hyper-reactivity (AHR; methacholine challenge). RESULTS: In the analysis adjusted for the presence of asthma, children with rhinitis had significantly higher AHR (P = 0.001). Maternal smoking and absence of breastfeeding were stronger predictors of nonallergic rhinitis, whereas current wheeze and eczema were stronger predictors of allergic rhinitis. Amongst asthmatics (n = 159), when compared to 76 children without rhinitis, those with rhinitis (n = 83) were 2.89-fold (95% CI 1.41-5.91) more likely to experience frequent attacks of wheezing, 3.44-fold (1.19-9.94) more likely to experience severe attacks of wheezing limiting speech, 10.14-fold (1.27-81.21) more likely to have frequent visits to their doctor because of asthma and nine-fold (1.11-72.83) more likely to miss school. Reported use of intranasal corticosteroids resulted in a numerically small, but consistent reduction in risk, rendering the associations between rhinitis and asthma severity nonsignificant. CONCLUSION: We observed differences in risk factors and severity between allergic and nonallergic rhinitis. In children with asthma, rhinitis had adverse impact on asthma severity. The use of intranasal corticosteroids resulted in a small, but consistent reduction in the risk

    Clinical profile, outcomes and improvement in symptoms and productivity in rhinitic patients in Karachi, Pakistan

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    <p>Abstract</p> <p>Background</p> <p>Rhinitis can cause a heavy toll on patients because of its bothersome effects on productivity. This retrospective study was conducted to explore the clinical profile, outcomes and improvement in the symptoms and productivity resulting from treatment of allergic rhinitis in Pakistan.</p> <p>Methods</p> <p>We carried out a retrospective file review of all allergic rhinitis patients who presented to the Ear, Nose, Throat Consulting Clinic from January, 2006 to June, 2008 using a structured proforma especially designed for this purpose. Data was entered and analyzed using SPSS v. 16.0.</p> <p>Results</p> <p>The charts of 169 patients were reviewed. The mean age of the patients was 35.2 ± 9.1 years. Sixty percent patients were male. Ninety eight patients (58%) reported allergy symptoms to be present at both home and work. One hundred and two patients (60.4%) had symptoms severe enough to cause absence from work or academic activities. Up to seventy one percent patients were spending between 1000 - 3000 Pakistani Rupees (1 US$= 83.3 Pakistani rupees) on the treatment of allergic rhinitis per year. One hundred and fifty one patients (89.3%) reported an improvement in rhinitic symptoms and productivity while 18 patients (10.7%) didn't. This improvement was significantly associated with satisfaction with treatment (p < 0.001).</p> <p>Conclusion</p> <p>Allergic rhinitis, a ubiquitous disease, was seen to cause a strain on patients in the form of recurrent treatment-related expenses as well as absenteeism from work or other daily activities. Symptoms and productivity improved significantly after treatment.</p
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