3,113 research outputs found

    Elastic turbulence in two-dimensional Taylor-Couette flows

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    We report the onset of elastic turbulence in a two-dimensional Taylor-Couette geometry using numerical solutions of the Oldroyd-B model, also performed at high Weissenberg numbers with the program OpenFOAM. Beyond a critical Weissenberg number, an elastic instability causes a supercritical transition from the laminar Taylor-Couette to a turbulent flow. The order parameter, the time average of secondary-flow strength, follows the scaling law Φ(WiWic)γ\Phi \propto (\mathrm{Wi} -\mathrm{Wi}_c)^{\gamma} with Wic=10\mathrm{Wi}_c=10 and γ=0.45\gamma = 0.45. The power spectrum of the velocity fluctuations shows a power-law decay with a characteristic exponent, which strongly depends on the radial position. It is greater than two, which we relate to the dimension of the geometry

    The frequency of vestibular disorders in developmentally delayed preschoolers with otitis media.

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    This study investigated the frequency of vestibular disorders in developmentally disabled preschoolers who did and who did not have a history of otitis media. Fifteen children with a history of otitis media and fifteen children with no history of otitis media were given two tests for vestibular functioning: the Southern California Postrotary Nystagmus Test (SCPNT) and the Lateral Labyrinthine Righting Reaction (LLRR), acting on the head. The scores on these tests were dichotomized, and a correlation between these two tests as measures of vestibular function was obtained. Because this correlation did not reach a satisfactory level, two a satisfactory level, two separate chi-square analyses were performed to examine the frequency of vestibular disorders with otitis media. Both tests showed a statistically significant difference in the incidence of vestibular disorders between the two groups of children; the group having otitis media demonstrated more vestibular disorders. The SCPNT demonstrated more striking results than did LLRR. This finding is related to the two tests measuring different aspects of vestibular functioning; the separate chi-square analyses were performed to examine the frequency of vestibular disorders with otitis media. Both tests showed a statistically significant difference in the incidence of vestibular disorders between the two groups of children; the group having otitis media demonstrated more vestibular disorders. The SCPNT demonstrated more striking results than did LLRR. This finding is related to the two tests measuring different aspects of vestibular functioning; the SCPNT reflects semicircular canal functioning, and the LLRR reflects utricular and saccular functioning. The criteria used for LLRR (four seconds) also may have influenced the results obtained using this test

    AutoEFT: Constructing and exploring on-shell bases of effective field theories

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    Effective Field Theories (EFTs) provide a framework for capturing the effects of yet unseen heavy degrees of freedom in a model-independent manner. However, constructing a complete and minimal set of operators, especially at higher mass dimensions, is challenging. We present AutoEFT, an implementation of an algorithm that systematically handles redundancies among operators due to equations of motion, integration-by-parts identities, Fierz identities, and repeated fields. This algorithm enables the construction of on-shell bases for a broad range of EFTs. Additionally, it facilitates the exploration of various aspects within this field, such as investigating higher mass dimensions or the relationship between different operator bases. AutoEFT can be applied to phenomenologically relevant theories like the Standard Model and its extensions, including new light particles or additional symmetry groups.Comment: 7 pages, 1 figure; contribution to the proceedings of the European Physical Society Conference on High Energy Physics (EPS-HEP2023), 21-25 August 2023, Hamburg, German

    Play behavior and occupational therapy.

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    The effectiveness of treatment methods on a person\u27s ability to carry out occupational roles competently is of interest to occupational therapists. This case study demonstrated how play, as an occupational role of childhood and as a measure of competence, can be used to evaluate the effectiveness of occupational therapy that uses a sensory integrative approach. The positive changes in C.C.\u27s play behavior support the basic philosophy of sensory integration, which states that an increase in sensory integrative functions will improve competence (in this study, competence is defined as play), that is, that a person will have the ability to carry out occupational roles in an adaptive and competent manner. In addition, improvements in other areas, such as the organization and execution of self-care skills and improvements in gross and fine motor skills, provide further support to sensory integrative philosophy. Further exploration of these concepts would add to a growing body of knowledge aimed at the documentation of the effectiveness and efficacy of occupational therapy interventions

    Outcomes of an Evidence-Based, Data Driven-Model Fieldwork Experience for Occupational Therapy Students

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    Over the past decade, there has been an increased emphasis on evidence-based practice (EBP) and the use of outcome measurement in clinical practice, however, the implementation of evidence into practice remains challenging and irregular. During fieldwork, students often experience a disconnect between the emphasis on EBP in the classroom and lack of use in the clinic. Recognizing the need to develop high-quality, evidence-based and data-driven models of practice for student training, we partnered with local fieldwork educators to develop an innovative program that guides students and simultaneously trains fieldwork educators (FWE) in the use of a systematic data driven decision making (DDDM) process to infuse evidence into practice. Using a pre-post quasi-experimental design, we evaluated the impact of this program on students’ perceived knowledge and skills in use of EBP and DDDM. A focus group with participating fieldwork educators captured their knowledge and attitudes in the use of EBP and DDDM in their clinical sites. Eleven FWEs and twenty four students participated. Results revealed significant change in students’ knowledge and skill in use of EBP and DDDM. FWEs reported the program clarified the role of occupational therapy, enhanced communication, and validated the value of occupational therapy in their clinical site. This program serves as a model for training students to implement evidence and data driven approaches in clinical practice, thus bridging the gap between classroom and clinic

    Influence of Hydrodynamic Interactions on the Kinetics of Colloidal Particle's Adsorption

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    The kinetics of irreversible adsorption of spherical particles onto a flat surface is theoretically studied. Previous models, in which hydrodynamic interactions were disregarded, predicted a power-law behavior t2/3t^{-2/3} for the time dependence of the coverage of the surface near saturation. Experiments, however, are in agreement with a power-law behavior of the form t1/2t^{-1/2}. We outline that, when hydrodynamic interactions are considered, the assymptotic behavior is found to be compatible with the experimental results in a wide region near saturation.Comment: 4 pages, 1 figures, Phys. Rev. Lett. (in press

    Occupational therapy using a sensory integrative approach: a case study of effectiveness.

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    OBJECTIVE: This article presents a case report of a child with poor sensory processing and describes the disorders impact on the child\u27s occupational behavior and the changes in occupational performance during 10 months of occupational therapy using a sensory integrative approach (OT-SI). METHOD: Retrospective chart review of assessment data and analysis of parent interview data are reviewed. Progress toward goals and objectives is measured using goal attainment scaling. Themes from parent interview regarding past and present occupational challenges are presented. RESULTS: Notable improvements in occupational performance are noted on goal attainment scales, and these are consistent with improvements in behavior. Parent interview data indicate noteworthy progress in the child\u27s ability to participate in home, school, and family activities. CONCLUSION: This case report demonstrates a model for OT-SI. The findings support the theoretical underpinnings of sensory integration theory: that improvement in the ability to process and integrate sensory input will influence adaptive behavior and occupational performance. Although these findings cannot be generalized, they provide preliminary evidence supporting the theory and the effectiveness of this approach

    Evolution of the sensory integration frame of reference.

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