COVID-19 Due to Wild-Type SARS-CoV-2 More Prevalent in Adolescents and Youth than in Older Adults Based on 19 US States in Fall 2020 Prior to Vaccine Availability

PURPOSE: In a prior study, we examined data from six US states during Summer 2020, and found that prevalence of COVID-19 for adolescents and youth was significantly greater than for older adults (p<.00001) as was a prevalence-related measure: Number of cases observed ÷ Number of cases expected (p<.005). We now extended our study to more states in Fall 2020 to confirm the prevalence relationships we found previously. Vaccines were still not available as of Fall 2020. Presumably, the SARS-CoV-2 strain circulating at the time was the wild-type lineage since no variants were reported in the US until the end of December 2020. METHODS: We examined data from 19 U.S. states experiencing surges in cases to determine prevalence of COVID-19, and a prevalence-related measure: [Number of cases observed in a given age group] ÷ [Number of cases expected in the age group based on population demographics]. RESULTS: In 16 of the 19 states, we found that: (1) prevalence of COVID-19 for adolescents and youth was significantly greater than for older adults (p-values ranged from p<0.00001 to p = 0.0175; (2) the ratio of cases observed to cases expected was significantly greater in adolescents and youth than in older adults (p-values ranging from p< 0.00001 to p = 0.004). CONCLUSIONS: Our results are consistent with our previous study in Summer 2020. The finding of lower prevalence in older adults cannot be attributed to access to vaccination since our data are from Fall 2020 when vaccinations were not yet available. Our findings with the SARS-CoV-2 wild-type strain are consistent with the findings currently being reported in the UK for the delta variant. In both studies, prevalence in adolescents and youth exceeded that in older adults. The UK findings are more pronounced perhaps because that study transpired following months of vaccinations of older adults whereas ours occurred before vaccinations were available.

No Evidence That Cognitive and Physical Activities Are Related to Changes in EEG Markers of Cognition in Older Adults at Risk of Dementia

An active lifestyle as well as cognitive and physical training (PT) may benefit cognition by increasing cognitive reserve, but the underlying neurobiological mechanisms of this reserve capacity are not well understood. To investigate these mechanisms of cognitive reserve, we focused on electrophysiological correlates of cognitive performance, namely on an event-related measure of auditory memory and on a measure of global coherence. Both measures have shown to be sensitive markers for cognition and might therefore be suitable to investigate potential training- and lifestyle-related changes. Here, we report on the results of an electrophysiological sub-study that correspond to previously published behavioral findings. Altogether, 65 older adults with subjective or objective cognitive impairment and aged 60–88 years were assigned to a 10-week cognitive (n = 19) or a 10-week PT (n = 21) or to a passive control group (n = 25). In addition, self-reported lifestyle was assessed at baseline. We did not find an effect of both training groups on electroencephalography (EEG) measures of auditory memory decay or global coherence (ps ≥ 0.29) and a more active lifestyle was not associated with improved global coherence (p = 0.38). Results suggest that a 10-week unimodal cognitive or PT and an active lifestyle in older adults at risk for dementia are not strongly related to improvements in electrophysiological correlates of cognition.

Estimates for Operators Related to the Sub-Laplacian with Drift in Heisenberg Groups

In the Heisenberg group of dimension $$2n+1$$ 2 n + 1 , we consider the sub-Laplacian with a drift in the horizontal coordinates. There is a related measure for which this operator is symmetric. The corresponding Riesz transforms are known to be $$L^p$$ L p bounded with respect to this measure. We prove that the Riesz transforms of order 1 are also of weak type (1, 1), and that this is false for order 3 and above. Further, we consider the related maximal Littlewood–Paley–Stein operators and prove the weak type (1, 1) for those of order 1 and disprove it for higher orders.

Brief Morning Light Exposure, Visuomotor Performance, and Biochemistry in Sport Shooters

Context:Demands on concentrative and cognitive performance are high in sport shooting and vary in a circadian pattern, aroused by internal and external stimuli. The most prominent external stimulus is light. Bright light (BL) has been shown to have a certain impact on cognitive and physical performance.Purpose:To evaluate the impact of a single half hour of BL exposure in the morning hours on physical and cognitive performance in 15 sport shooters. In addition, courses of sulfateoxymelatonin (aMT6s), tryptophan (TRP), and kynurenine (KYN) were monitored.Methods:In a crossover design, 15 sport shooters were exposed to 30 min of BL and dim light (DL) in the early-morning hours. Shooting performance, balance, visuomotor performance, and courses of aMT6s, TRP, and KYN were evaluated.Results:Shooting performance was 365.4 (349.7–381.0) and 368.5 (353.9–383.1), identical in both light setups. Numbers of right reactions (sustained attention) and deviations from the horizontal plane (balance-related measure) were higher after BL. TRP concentrations decreased from 77.5 (73.5–81.4) to 66.9 (60.7–67.0) in the DL setup only.Conclusions:The 2 light conditions generated heterogeneous visuomotor and physiological effects in sport shooters. The authors therefore suggest that a single half hour of BL exposure is effective in improving cognitive aspects of performance, but not physical performance. Further research is needed to evaluate BL’s impact on biochemical parameters.