IMPORTANCE Local variation in the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) across the United States has not been well studied. OBJECTIVE To examine the association of county-level factors with variation in the SARS-CoV-2 reproduction number over time.
Given the absence of statistically significant difference in the FPR and recall rates in comparison with FD, FAST scans can replace FD for screening of breast cancer.
Word Count: 2922All rights reserved. No reuse allowed without permission.(which was not certified by peer review) is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.
Key PointsQuestion: How is the instantaneous reproduction number (R t ) of SARS-CoV-2 influenced by local area effects of social distancing, wet bulb temperature, and population density in counties across the United States?Findings: Social distancing, temperate weather, and lower population density were associated with a decrease in R t . Of these county-specific factors, social distancing appeared to be the most significant in reducing SARS-CoV-2 transmission.Meaning: R t varies significantly across counties. The relationship between R t and countyspecific factors can inform policies to reduce SARS-CoV-2 transmission in selective and heterogeneous communities.
AbstractImportance: The Covid-19 pandemic has been marked by considerable heterogeneity in outbreaks across the United States. Local factors that may be associated with variation in SARS-CoV-2 transmission have not been well studied.Objective: To examine the association of county-level factors with variation in the SARS-CoV-2 reproduction number over time.
Design: Observational studySetting: 211 counties in 46 states and the District of Columbia between February 25, 2020 and April 23, 2020.
Participants: Residents within the counties (55% of the US population)Exposures: Social distancing as measured by percent change in visits to non-essential businesses, population density, lagged daily wet bulb temperatures.
Main Outcomes and Measures:The instantaneous reproduction number (R t ) which is the estimated number of cases generated by one case at a given time during the pandemic.Results: Median case incidence was 1185 cases and fatality rate was 43.7 deaths per 100,000 people for the top decile of 21 counties, nearly ten times the incidence and fatality rate in the lowest density quartile. Average R t in the first two weeks was 5.7 (SD 2.5) in the top decile, compared to 3.1 (SD 1.2) in the lowest quartile. In multivariable analysis, a 50% decrease in visits to non-essential businesses was associated with a 57% decrease in R t (95% confidence interval, 56% to 58%). Cumulative temperature effects over 4 to 10 days prior to case incidence were nonlinear; relative R t decreased as temperatures warmed above 32°F to 53°F, which was the point of minimum R t , then increased between 53°F and 66°F, at which point R t began to decrease. At 55°F, and with a 70% reduction in visits to non-essential business, 96% of counties All rights reserved. No reuse allowed without permission. : medRxiv preprint 5 were estimated to fall below a threshold R t of 1.0, including 86% of counties among the top density decile and 98% of counties in the lowest density quartile.Conclusions and Relevance: Social distancing, lower population density, and temperate weather change were associated with a decreased SARS-Co-V-2 R t in counties across the United States.These relationships can ...
Mitochondria are one of the essential cellular organelles. Apart from being considered as the powerhouse of the cell, mitochondria have been widely known to regulate redox reaction, inflammation, cell survival, cell death, metabolism, etc., and are implicated in the progression of numerous disease conditions including neurodegenerative diseases. Since brain is an energy-demanding organ, mitochondria and their functions are important for maintaining normal brain homeostasis. Alterations in mitochondrial gene expression, mutations, and epigenetic modification contribute to inflammation and neurodegeneration. Dysregulation of reactive oxygen species production by mitochondria and aggregation of proteins in neurons leads to alteration in mitochondria functions which further causes neuronal death and progression of neurodegeneration. Pharmacological studies have prioritized mitochondria as a possible drug target in the regulation of neurodegenerative diseases. Therefore, the present review article has been intended to provide a comprehensive understanding of mitochondrial role in the development and progression of neurodegenerative diseases mainly Alzheimer's, Parkinson's, multiple sclerosis, and amyotrophic lateral sclerosis followed by possible intervention and future treatment strategies to combat mitochondrial-mediated neurodegeneration.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.