Objectives This study aimed to examine the link between human mobility and the number of coronavirus disease 2019 (COVID-19)–infected people in countries. Study design Our data set covers 144 countries for which complete data are available. To analyze the link between human mobility and COVID-19–infected people, our study focused on the volume of air travel, the number of airports, and the Schengen system. Methods To analyze the variation in COVID-19–infected people in countries, we used negative binomial regression analysis. Results Our findings suggest a positive relationship between higher volume of airline passenger traffic carried in a country and higher numbers of patients with COVID-19. We further found that countries which have a higher number of airports are associated with higher number of COVID-19 cases. Schengen countries, countries which have higher population density, and higher percentage of elderly population are also found to be more likely to have more COVID-19 cases than other countries. Conclusions The article brings a novel insight into the COVID-19 pandemic from a human mobility perspective. Future research should assess the impacts of the scale of sea/bus/car travel on the epidemic. The findings of this article are relevant for public health authorities, community and health service providers, as well as policy-makers.

Objective The video head impulse test (vHIT) is a diagnostic tool to assess the function of the semicircular canals and branches of the vestibular nerve. The aim of this study was to analyze the interexaminer variability of vHIT results in healthy subjects. Materials and Methods A total of 21 healthy participants were included in the study. vHIT responses were collected by four clinicians. Variability of the vHIT results between examiners was analyzed statistically. Results The vestibulo-ocular reflex (VOR) velocity regression values were from 0.99 to 1.09 degrees per second for the lateral canals. For the vertical canals, VOR velocity regression values were from 0.87 to 1.21 degrees per second. According to repeated measures analysis of variance, the normality assumptions for the velocity regression of the left lateral canal (p = 0.002) and the right anterior canal (p < 0.01) were met and the differences were statistically significant. The normality assumptions were not met for 40, 60, and 80 ms median gain of the right lateral canal (p = 0.016, p = 0.038, and p = 0.001, respectively); 40 and 60 ms median gain of the left lateral canal (p < 0.001 and p = 0.008, respectively); and the velocity regression of the left posterior canal (p < 0.00). These differences were found to be statistically significant by using the Friedman test. Conclusion The interexaminer differences of the VOR gain values for the vHIT were statistically significant. Serial vHIT testing should be performed by the same examiner to reduce the effects of interexaminer variability.

OBJECTIVE:The objective of this study was to establish which factor leads to a higher vestibulo-ocular reflex (VOR) gain: the timing of the movement or the direction of the movement. For this purpose, healthy volunteers were examined under three conditions: (1) when they were informed about the timing of the head movement; (2) when they were informed about the direction of the head movement; and (3) when they knew both the timing and the direction of the head movement. MATERIALS and METHODS:This study included data from 19 participants between the ages of 20 and 23 years with no neurological or vestibular ailments. The gains of the video head impulse test (vHIT) were measured under four different conditions and the final control tests. Five subgroups were defined, and the differences in the subgroups were assessed with using several statistical procedures. RESULTS:We found that there were significant differences between all subgroups gains on the right and left head rotations. Nevertheless, nonsignificant differences were found by performing independent samples t-tests and Mann-Whitney U tests between left and right head rotations for the pairwise comparisons of subgroups. Also, analysis of variance (ANOVA) results indicated that vHIT gains for the right and left , respectively). Thus, knowing the timing or direction or both does not affect vHIT gains. CONCLUSION:The results of these experiments revealed that there is no association whatsoever between VOR gain and awareness of the timing or direction of the movement or both.

Identifying key determinants of success plays an important role in efforts of assessing the current state of educational practices and implementing effective actions to improve academic performance. Given how important is accurate identification of these determinants for valid comparisons, the aim of this research was to present extensive comparative results on 8th grade students' science success for 39 countries. To this end, a total number of 229,493 students' information obtained from the last cycle of Trends in International Mathematics and Science Study was handled. Unlike previous studies in which success has been tried to be explained with some factors, this research extended the literature by investigating the effective factors as well as gender-related variability on science success with a holistic view. Using heterogeneous choice models, unobserved heterogeneity caused by gender difference was tested and controlled. The findings showed that gender variability was evident for 10 countries. Furthermore, factors associated with students' future educational goals, home educational resources and confidence were found as the common determinators of science success in all participant countries. Another notable finding was all factors, except time spent on doing homework, tended to differentiate the success status between girls and boys of 22 countries. Keywords: cross-country comparison, gender variability, heterogeneous choice models, science success.