The mobility gap: estimating mobility levels required to control Canada’s winter COVID-19 surge

BackgroundNon-pharmaceutical interventions remain a primary means of suppressing COVID-19 until vaccination coverage is sufficient to achieve herd immunity. We used anonymized smartphone mobility measures in seven Canadian provinces to quantify the mobility level needed to suppress COVID-19 (mobility threshold), and the difference relative to current mobility levels (mobility gap).MethodsWe conducted a longitudinal study of weekly COVID-19 incidence from March 15, 2020 to January 16, 2021, among provinces with 20 COVID-19 cases in at least 10 weeks. The outcome was weekly growth rate defined as the ratio of current cases compared to the previous week. We examined the effects of average time spent outside the home (non-residential mobility) in the prior three weeks using a lognormal regression model accounting for province, season, and mean temperature. We calculated the COVID-19 mobility threshold and gap.ResultsAcross the 44-week study period, a total of 704,294 persons were infected with COVID-19. Non-residential mobility dropped rapidly in the spring and reached a median of 36% (IQR: 31,40) in April 2020. After adjustment, each 5% increase in non-residential mobility was associated with a 9% increase in the COVID-19 weekly growth rate (ratio=1.09, 95%CI: 1.07,1.12). The mobility gap increased through the fall months, which was associated with increasing case growth.InterpretationMobility strongly and consistently predicts weekly case growth, and low levels of mobility are needed to control COVID-19 through winter 2021. Mobility measures from anonymized smartphone data can be used to guide the provincial and regional implementation and loosening of physical distancing measures.

The Individual Transport Mobility Gap (ITMG) as an Obstacle on the Road to Higher Rates of Public Transport Use

Research purpose. The call for higher rates of public transport usage seems reasonable and understandable, given the growing impact of climate change and the high burden of heavy traffic, especially on urban transport structures. A course of Bachelor’s degree students in Logistics explored the issue of satisfaction with individual transport mobility, formulating the hypothesis that there must be a striking difference in the quality behind the use of a private car versus the use of public transport. The hypothesised difference in perceived quality between the two modes of transport was called the individual transport mobility gap (ITMG).Design/Methodology/Approach. The ITMG was considered from the perspective of people who mainly use a car (car users) and who mainly use public transport (public transport users). Both groups were asked how they rate their preferred means of transport and how they rate the alternative mode of transport using an online questionnaire. The survey can be accessed online at: https://fhludwigshafen.eu.qualtrics.com/jfe/form/SV_6JOoxNvlSVxsdDv.Findings. The results of the study confirmed the hypothesis that there is a substantial perceived gap with an ITMG value of 4.0 between using a car versus using public transport for people who primarily use a car. In contrast, the ITMG value for public transport users was only 0.8.Originality/Relevance/Practical Implications. The originality of this approach lies in surveying satisfaction with a mode of transport at a highly aggregated level rather than at the level of individual quality factors, such as punctuality or flexibility. ITMG is defined in this study as a valuable metric that provides a basis for comparison. This quantitative metric can in turn be used to determine the effectiveness of measures to increase usage rates of public transport. The study also provides practical findings by making available its database to other researchers for further evaluation purposes. The study also contributes to scholarly and public discourse on how to effectively reduce the satisfaction gap in the use of private cars versus public transport, thus resulting in improved outcomes for the environment and society.

Structural and optical investigations of CdO-Na2CO3-H3BO3 glasses

Glasses with composition xCdO-(40-x) Na2CO3-60H3BO3; x = 10, 20, 30 and 40 mol% were prepared by conventional melt-quenching technique and checked by XRD technique for their amorphous nature. An increase in density and refractive index of the samples with an increase in content of CdO has been observed and discussed. The optical absorption spectra of the glasses were recorded in the range 200–1100 nm and was used to find optical mobility gap, Urbach energy, and cut-off wavelength for each sample. The decrease in optical mobility gap with increase in CdO points towards the compactness of the structure with the addition of CdO. FTIR spectroscopy reveals the presence of trigonal and tetrahedral borate units, and the results indicate the conversion of BO3 to BO4 units with the increase in CdO content.