A preliminary cross-sectional assessment of postural control responses to continuous platform rotations following a sport-related concussion.

BACKGROUND: Individuals suffering a sport-related concussion typically recover within 1 month; however, persistent post-concussive symptoms are known to occur beyond this period. Clinical guidelines may not be sufficient to determine if dynamic postural control is still impaired at the point of the return to play decision. RESEARCH QUESTION: Do individuals with a previous sport-related concussion who have returned to play show differences in postural control compared to individuals without a previous concussion, in response to continuous platform perturbations? METHODS: Eight previously concussed and eight age- and position-matched participants completed six one-minute trials (three with eyes open/closed) whilst stood on a moving platform that rotated about the pitch axis with a peak-to-peak amplitude of 4° at a frequency of 0.8 Hz. Six trials were also captured during static quiet stance for comparison. Reactive and anticipatory stages of postural control were analysed by determining anteroposterior margins of stability (MoS) as a measure of whole-body postural control and head-to-trunk anchoring index as an indication of the head-trunk segmental coupling strategy. RESULTS: Posterior MoS during platform rotations reduced for both groups during eyes closed trials, but previously concussed participants exhibited a significantly greater reduction (1.97 cm) in comparison to matched-controls (0.34 cm). Participants, regardless of group, showed a preference towards a head-stabilised-to-trunk strategy during platform rotations. There were no differences during static trials. SIGNIFICANCE: This preliminary study suggests previously concussed athletes demonstrate a greater reduction in postural control whilst undergoing continuous platform rotations with eyes closed, which could indicate possible lingering deficits to other sensory systems such as the vestibular system, though participants were not likely to lose their balance.

Non-invasive measurement of lubricating oil viscosity using an ultrasonic continuously repeated chirp shear wave.

The ability to monitor the viscosity of lubricating oils within metallic products is of interest to many industries, these being the automotive, aerospace and food industries to name a few. Acoustic mismatch at the metallic-liquid interface restricts ultrasonic signal transmission and so limits applicability and sensitivity of the technique. In this work, we propose the use of a continuously repeated chirp (CRC) shear wave to amplify the measurable acoustic response to liquid viscosity. The technique enables multiple reflections to superimpose inside the component and form a quasi-static standing wave whose amplitude spectrum depends on the condition at the solid-liquid boundary. Bare element shear ultrasonic transducers of 5 MHz resonant frequency were bonded to the lower surface of an aluminium plate in a pitch-catch arrangement to measure liquid in contact with the upper surface. Transducers were pulsed using a continuously repeated frequency sweep, from 0.5 to 9.5 MHz over 10 ms. The amplitude spectrum of the resulting standing wave was observed for a series of standard viscosity oils, which served as a calibration procedure, from which the standing wave reflection coefficient (S), was obtained. Measurements of 17 blended oils ranging in viscosity from 1080 to 6.7 mPa s were made. The technique was also evaluated with the addition of a polyimide matching layer (ML) between the metallic and liquid interface. Ultrasonic viscosity measurement values were then compared to measurements made using a conventional laboratory viscometer. The CRC method was found to significantly improve the sensitivity of viscosity measurement at a metal-liquid interface when compared to a single frequency burst with the benefit of low cost signal generation and acquisition hardware requirements. The CRC method is also capable of instant rapid response measurements as the signal responds in real time without the need to wait for a returning pulse.

Changing practices in the consent process for nose and throat procedures: a three-year study.

OBJECTIVES: To assess elective surgery consent practices amongst senior house officers from a selection of UK ENT departments, and to compare results with those obtained in a similar survey in 2002. METHODS: A telephone survey of senior house officers in 40 UK ENT departments was carried out to assess departmental consent policies and knowledge of complications of common ENT operations. RESULTS: Over 80 per cent of the senior house officers surveyed remained responsible for obtaining consent for routine surgery. Since 2002, there had been a significant increase in the proportion of departments which: used the Department of Health model consent form; provided patient information leaflets; and had an established informed consent protocol. Senior house officers' knowledge of specific complications remained poor. CONCLUSION: There has been a small change in the practice of obtaining informed consent, in accordance with General Medical Council guidelines. Many senior house officers continue to perform this duty, however, and the majority are poorly trained.

Maternal beliefs about adaptive and maladaptive social behaviors in normal, aggressive, and withdrawn preschoolers.

The purpose of this study was to compare mothers of normal, aggressive, and anxious-withdrawn preschoolers with regard to their beliefs about how socially competent behaviors are learned and their beliefs concerning the origins of two types of maladaptive behaviors--aggression and withdrawal. 121 mothers of 4-year olds were questioned about how they think social skills are acquired. They were also presented with descriptions of hypothetical incidents of peer-directed aggression and social withdrawal and asked what they would do about these behaviors, how they would feel about them, and how they would explain them. Children's social behaviors were observed during free play and rated by their teachers. A norm-based multitargeting procedure was used that resulted in the identification of 10 highly aggressive children, 6 highly withdrawn children, and 60 children who were average in social adaptation. Results indicated that mothers of withdrawn children were more likely than mothers of average children to believe that social skills should best be taught in a directive manner and that maladaptive behaviors should be responded to in a high-powered, coercive fashion. These mothers were also more likely than mothers of average children to indicate that they would feel guilty and embarrassed by displays of maladaptive behavior, and they attributed these behaviors to dispositional factors. Mothers of aggressive children suggested highly directive strategies to teach social skills, but were more laissez-faire than mothers of average and withdrawn children in their reactions to maladaptive behaviors.

Sociability and social withdrawal in childhood: stability and outcomes.

The stability and long-term correlates of both social withdrawal and sociability were investigated in a longitudinal study of normal children in kindergarten through the fifth grade. Both observational and peer assessment indices of withdrawal and sociability were considered; furthermore, a distinction was made between observed active versus passive solitude. Of particular interest was whether social withdrawal in early childhood was predictive of subsequent internalizing problems, as assessed by self-reports of social competence, overall self-worth, loneliness, and depression as well as teacher ratings of shy/anxious behavior, in later childhood. Results indicated a modest degree of stability for observed social withdrawal but not for observed sociability, nor for active or passive forms of solitude. Somewhat higher stability correlations were obtained for peer assessments of both sociability and withdrawal. In terms of predictive outcomes, significant relations were found between early social withdrawal in kindergarten and Grade 2 and subsequent internalizing problems in Grades 4 and 5, although the pattern of results was mixed. These data suggest that social withdrawal in early childhood may be predictive of risk for internalizing difficulties in later childhood.

Comparison of Carr-Price analysis and liquid chromatographic analysis for vitamin A in fortified milk.

The determination of the vitamin A concentration in fortified milk was compared using Carr-Price analysis and liquid chromatography (LC). Carr-Price analysis required saponification of the sample with alcoholic potassium hydroxide, extraction with ether, and colorimetry with antimony trichloride in chloroform. LC analysis required hexane extraction of a 71% alcohol-sample solution and centrifugation at 2000 rpm. A 100 microL aliquot of the extract was analyzed on a LiChrosorb Si-60, 5 micron column, using an ethyl ether-hexane (2 + 98) mobile phase and detection at 313 nm. Each method was statistically evaluated for precision and sample-to-sample reproducibility. The LC extraction procedure was examined for efficiency. Each LC value was divided by the Carr-Price value obtained for the same sample; an average value of 0.975 with a coefficient of variation of 6.90% was obtained. It was concluded that the procedures were statistically equivalent.