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As the COVID-19 pandemic has strongly disrupted people's daily work and life, a great amount of scientific research has been conducted to understand the key characteristics of this new epidemic. In this manuscript, we focus on four crucial epidemic metrics with regard to the COVID-19, namely the basic reproduction number, the incubation period, the serial interval and the epidemic doubling time. We collect relevant studies based on the COVID-19 data in China and conduct a meta-analysis to obtain pooled estimates on the four metrics. From the summary results, we conclude that the COVID-19 has stronger transmissibility than SARS, implying that stringent public health strategies are necessary. [ABSTRACT FROM AUTHOR]

Objective: We tested 2 hypotheses regarding age at onset within familial epilepsies: (1) family members with epilepsy tend to have similar ages at onset, independent of epilepsy syndrome; and (2) age at onset is younger in successive generations after controlling for sampling bias.Methods: We analyzed clinical data collected by the Epi4K Consortium (303 multiplex families, 1,120 individuals). To test hypothesis 1, we used both linear mixed models commonly used for heritability analysis and Cox regression models with frailty terms to assess clustering of onset within families after controlling for other predictors. To test hypothesis 2, we used mixed effects models, pairwise analyses, and survival analysis to address sampling-related bias that may mimic anticipation.Results: Regarding hypothesis 1, age at seizure onset was significantly heritable (intraclass correlation coefficient = 0.17, p < 0.001) after adjusting for epilepsy type, sex, site, history of febrile seizure, and age at last observation. This finding remained significant after adjusting for epilepsy syndromes, and was robust across statistical methods in all families and in generalized families. Regarding hypothesis 2, the mean age at onset decreased in successive generations (p < 0.001). After adjusting for age at last observation, this effect was not significant in mixed effects models (p = 0.14), but remained significant in pairwise (p = 0.0003) and survival analyses (p = 0.02).Interpretation: Age at seizure onset is an independent familial trait, and may have genetic determinants distinct from the determinants of particular epilepsy syndromes. Younger onsets in successive generations can be explained in part by sampling bias, but the presence of genetic anticipation cannot be excluded. ANN NEUROL 2019. [ABSTRACT FROM AUTHOR]

Objective The current study establishes normative Sniffin' Sticks Odor Identification Test (SS-OIT) scores for cognitively intact older adults. Method Two hundred and twenty-six cognitively normal older adults were identified as eligible for the current study (Mean Age = 70.49 years; 71.7% female). Important demographic covariates were identified using step-wise regression, and a normative regression equation was developed. Results Analyses of the effects of demographic variables (including age, education, and sex) on SS-OIT performance revealed that age was the only significant predictor, b = −0.07, SE b =.01, p <.01. A final regression equation was determined and normative data are reported in 5-year increments for a number of percentile ranks. Conclusions Normative performance on the SS-OIT for adults over the age of 50 was established in a large and demographically diverse sample. These data are needed in order for clinicians to be able to include olfactory testing, a sensitive marker of neurodegeneration, in their assessment armamentarium. [ABSTRACT FROM AUTHOR]

To evaluate whether occupational attainment influences the trajectory of longitudinal cognitive decline in behavioral variant frontotemporal degeneration (bvFTD). Single-center, retrospective, longitudinal study. Sixty-three patients meeting consensus criteria for bvFTD underwent evaluation at the University of Pennsylvania Frontotemporal Degeneration Center. All patients were studied longitudinally on letter-guided fluency, category-naming fluency and Boston Naming Test (BNT). Occupational attainment was defined categorically by assigning each individual's occupation to a professional or non-professional category. Linear mixed-effects models evaluated the interaction of neuropsychological performance change with occupational status. Regression analyses were used to relate longitudinal decline in executive function to baseline MRI grey matter atrophy. Higher occupational status was associated with a more severe slope of cognitive decline on letter-guided fluency and category-naming fluency, but not BNT. Faster rates of longitudinal decline on letter-guided and category-naming fluency were associated with more severe baseline grey matter atrophy in right dorsolateral and inferior frontal regions. Our longitudinal findings suggest that bvFTD individuals with higher lifetime cognitive experience demonstrate more rapid decline on measures of executive function. This finding converges with cross-sectional evidence suggesting that lifetime cognitive experiences contribute to heterogeneity in clinical progression in bvFTD. [ABSTRACT FROM AUTHOR]

This study aims to design and pilot an empirically based mobile application (ActiviDaily) to increase daily activity in persons with apathy and ADRD and test its feasibility and preliminary efficacy. ActiviDaily was developed to address impairments in goal-directed behaviour, including difficulty with initiation, planning, and motivation that contribute to apathy. Participants included patients with apathy and MCI, mild bvFTD, or mild AD and their caregivers. In Phase I, 6 patient-caregiver dyads participated in 1-week pilot testing and focus groups. In Phase II, 24 dyads completed 4 weeks of at-home ActiviDaily use. Baseline and follow-up visits included assessments of app usability, goal attainment, global cognition and functioning, apathy, and psychological symptoms. App use did not differ across diagnostic groups and was not associated with age, sex, education, global functioning or neuropsychiatric symptoms. Patients and care-partners reported high levels of satisfaction and usability, and care-partner usability rating predicted app use. At follow-up, participants showed significant improvement in goal achievement for all goal types combined. Participant goal-directed behaviour increased after 4 weeks of ActiviDaily use. Patients and caregivers reported good usability and user satisfaction. Our findings support the feasibility and efficacy of mobile-health applications to increase goal-directed behaviour in ADRD. [ABSTRACT FROM AUTHOR]

Background: Racial disparities in many aging‐related health outcomes are persistent and pervasive among older Americans. There are well‐documented inequities in the social determinants of health for older adults, including the social and physical environment, due to structural and environmental racism, but there is little understanding of the biological intermediates by which social determinants affect disparate health outcomes. Biological aging measured by DNA methylation (DNAm) is robustly associated with worse age‐related outcomes and higher social adversity. We hypothesize that individual social determinants, the social environment, and air pollution exposures interact to contribute to racial disparities in DNAm aging according to GrimAge and Dunedin Pace of Aging methylation (DPoAm). Method: We performed retrospective cross‐sectional analyses among 3250 non‐Hispanic participants (80.3% white, 19.7% Black) in the Health and Retirement Study whose 2016 epigenetic age is linked to survey responses and geographic data. DNAm aging is defined as the residual after regressing epigenetic age on chronological age. Measures of the neighborhood social environment include the Social Deprivation Index and perceived social stress. Air pollution exposures include particulate matter (PM2.5), nitrogen dioxide (NO2), and ozone. Individual‐level determinants include socioeconomic status, healthcare access, health status, and health behaviors. We implemented multivariable linear regression models to identify significant associations, interactions, and mediators in the relationship between each DNAm aging measure and the social and environmental determinants. Result: We found on average Black individuals have significantly accelerated DNAm aging compared to white individuals (599% and 498%) according to GrimAge and DPoAm, respectively. Individual‐level factors evaluated account for approximately 43% of the disparity in GrimAge and 34% in DPoAm. Further results suggest that associations between neighborhood social environment and DNAm aging are significant and mediated by individual‐level factors. PM2.5 may be associated with DPoAm acceleration in certain sub‐populations. NO2 and ozone are not significantly associated with DNAm aging. We are investigating individual‐level factors that mediate social environmental exposures and increase vulnerability to PM2.5. Conclusion: DNAm aging may play a role in social determinants "getting under the skin" and contributing to age‐related health disparities between Black and white Americans. Work is ongoing to determine the environmental and individual factors that contribute to these disparities. [ABSTRACT FROM AUTHOR]

The diagnosis of Alzheimer’s disease (AD) in the oldest-old is complicated by the increasing prevalence of age-related neurofibrillary tangles, plaques and non-AD pathologies such as cerebrovascular disease (CVD), hippocampal sclerosis (HS), aging-related tau astrogliopathy (ARTAG), as well as TDP-43 and Lewy pathology. The contribution of these non-AD pathologies to dementia and cognitive resilience is unclear. We assessed the level of AD neuropathologic change (ADNPC) and non-AD pathology in 185 participants enrolled in The 90+ Study with available cognitive assessments and brain tissue. Logistic regression models—adjusting for age, sex and education—determined the association between each pathology and dementia or between subgroups. 53% had dementia, primarily AD or mixed AD; 23% had cognitive impairment without dementia (CIND); 23% were not impaired. Both AD and non-AD pathology was prevalent. 100% had tangles, 81% had plaques, and both tangles and plaques associated with dementia. ARTAG distributed across limbic (70%), brainstem (39%) and cortical regions (24%). 49% had possible CVD and 26% had definite CVD, while HS was noted in 15%. Cortical ARTAG, CVD and HS were each associated with dementia, but limbic and brainstem ARTAGs were not. TDP-43 and Lewy pathologies were found in 36 and 17% and both associated with dementia. No pathology distinguished CIND and the not impaired. By NIA-AA criteria and dementia status, the cohort was subdivided into four groups: those with minimal ADNPC included the not dementia (ND) and Not AD dementia groups; and those with significant ADNPC included the Resilient without dementia and AD dementia groups. Compared to the ND group, the Not AD dementia group had more HS, cortical ARTAG, TDP-43, and Lewy pathology. Compared to the AD dementia group, the Resilient group had less CVD, no HS and less cortical ARTAG, TDP-43 and Lewy pathology. Our findings imply that reductions in non-AD pathologies including CVD contribute to cognitive resilience in the oldest-old. [ABSTRACT FROM AUTHOR]