Relationship between the Romberg Test and the Wii Basic Balance Test and Cognition in Athletes with Concussion

Background: Approximately 30% of individuals with a sport-related concussion present with postural instability. Multiple clinical balance tests exist to diagnose postural instability; yet little is known about the potential relationship between these type of postural assessments and cognition post-concussion. Aim: The purpose of the current study was to assess the relationship between the Romberg test, the Wii Fit basic balance test (WBBT), and the composite scores on the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) test in a sample of athletes with concussions. Methods: 55 post-concussed athletes (40 male) completed the Romberg Test (RT) (−/+), the WBBT, and ImPACT test. Wii Fit basic balance test performance was operationalized as the number of successfully completed trials (of 5 trials of increasing difficulty) within 30 seconds. Pearson’s and point-biserial correlations examined univariate associations among the variables. Results: The RT and WBBT were not significantly related (r = −0.029, p = 0.832). The RT weakly correlated with ImPACT impairment scores (r= 0.26, p= 0.041), whereas WBBT the number of trials did not (r = − 0.20, p = 0.155). Romberg Test scores were significantly correlated with ImPACT Visual Processing Speed Score (r = 0.27, p = 0.036) and Reaction Time score (r = 0.34, p = 0.006). In contrast, WBBT trials were significantly correlated with the ImPACT Visual Memory Score (r = − 0.41, p = 0.003). Conclusions: These results suggest that the WBBT and RT assess unique aspects of postural control. The RT may relate directly to single sensory cognitive and motor processing, while the WBBT may relate to multi-sensory visually driven cognitive and motor processing. Relevance for patients: Clinical balance tests could point to different cognitive impairments post-concussion

Magnetospectroscopy of symmetric and anti-symmetric states in double quantum wells

The experimental results obtained for the magneto-transport in the InGaAs/InAlAs double quantum wells (DQW) structures of two different shapes of wells are reported. The beating-effect occurred in the Shubnikov-de Haas (SdH) oscillations was observed for both types of the structures at low temperatures in the parallel transport when magnetic field was perpendicular to the layers. An approach to the calculation of the Landau levels energies for DQW structures was developed and then applied to the analysis and interpretation of the experimental data related to the beating-effect. We also argue that in order to account for the observed magneto-transport phenomena (SdH and Integer Quantum Hall effect), one should introduce two different quasi-Fermi levels characterizing two electron sub-systems regarding symmetry properties of their states, symmetric and anti-symmetric ones which are not mixed by electron-electron interaction.Comment: 20 pages, 20 figure

Parallel magnetotransport in multiple quantum well structures

The results of investigations of parallel magnetotransport in AlGaAs/GaAs and InGaAs/InAlAs/InP multiple quantum wells structures (MQW’s) are presented in this paper. The MQW’s were obtained by metalorganic vapour phase epitaxy with different shapes of QW, numbers of QW and levels of doping. The magnetotransport measurements were performed in wide region of temperatures (0.5–300 K) and at high magnetic fields up to 30 T (B is perpendicular and current is parallel to the plane of the QW). Three types of observed effects are analyzed: quantum Hall effect and Shubnikov—de Haas oscillations at low temperatures (0.5–6 K) as well as magnetophonon resonance at higher temperatures (77–300 K)

The Cortisol Response to Anticipated Intergroup Interactions Predicts Self-Reported Prejudice

Objectives: While prejudice has often been shown to be rooted in experiences of threat, the biological underpinnings of this threat–prejudice association have received less research attention. The present experiment aims to test whether activations of the hypothalamus-pituitary-adrenal (HPA) axis, due to anticipated interactions with out-group members, predict self-reported prejudice. Moreover, we explore potential moderators of this relationship (i.e., interpersonal similarity; subtle vs. blatant prejudice). Methodology/Principal findings: Participants anticipated an interaction with an out-group member who was similar or dissimilar to the self. To index HPA activation, cortisol responses to this event were measured. Then, subtle and blatant prejudices were measured via questionnaires. Findings indicated that only when people anticipated an interaction with an out-group member who was dissimilar to the self, their cortisol response to this event significantly predicted subtle (r =.50) and blatant (r =.53) prejudice. Conclusions: These findings indicate that prejudicial attitudes are linked to HPA-axis activity. Furthermore, when intergroup interactions are interpreted to be about individuals (and not so much about groups), experienced threat (or its biological substrate) is less likely to relate to prejudice. This conclusion is discussed in terms of recent insights from social neuroscience

Role of the Thermal Stress on the Magnetophonon Peak Structure in the Parallel Transport of the GaAs/AlGaAs Multiple Quantum Wells

The magnetophonon resonance in parallel transport of two types multiple quantum wells was studied. The transverse magnetoresistance was measured in pulsed magnetic fields up to 30 T (within temperature region from 77 to 340 K). A fine structure of magnetophonon resonance peaks which depends on temperature and does not depend on the type of multiple quantum wells, was observed. This effect could be attributed to two phenomena: contribution of barrier phonons and influence of thermostresses