Tag: PNAS

How Benjamin Franklin Helped Foil Early American Money Counterfeiters

Mary Pat Campbell

Link: https://www.wsj.com/articles/how-benjamin-franklin-helped-foil-early-american-money-counterfeiters-bf51f8c7

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Franklin, who was a printer, among his other roles, was known for marking his early paper money with images of intricately veined leaves that were nearly impossible for counterfeiters to copy, using a variety of fonts, some available only to him, and intentionally lacing the text with misspellings.

But scientists say Franklin took things a step further to stave off fraudsters. Other distinguishing characteristics of Franklin’s money—the new research revealed through advanced atomic-level imaging methods—were more subtle. He used a unique black ink. His paper glimmered. Blue threads decorated the surface, and finer fibers were woven throughout. 

Researchers detailed the innovations in a paper published Monday in the journal Proceedings of the National Academy of Sciences. The findings describe previously unknown methods Franklin developed to safeguard printed money notes against counterfeiting.

Author(s): Jo Craven McGinty

Publication Date: 17 July 2023

Publication Site: WSJ

Asymptomatic SARS-CoV-2 infection: A systematic review and meta-analysis

Mary Pat Campbell

Link: https://www.pnas.org/content/118/34/e2109229118

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Asymptomatic infections have been widely reported for COVID-19. However, many studies do not distinguish between the presymptomatic stage and truly asymptomatic infections. We conducted a systematic review and meta-analysis of COVID-19 literature reporting laboratory-confirmed infections to determine the burden of asymptomatic infections and removed index cases from our calculations to avoid conflation. By analyzing over 350 papers, we estimated that more than one-third of infections are truly asymptomatic. We found evidence of greater asymptomaticity in children compared with the elderly, and lower asymptomaticity among cases with comorbidities compared to cases with no underlying medical conditions. Greater asymptomaticity at younger ages suggests that heightened vigilance is needed among these individuals, to prevent spillover into the broader community.

Author(s): Pratha Sah, Meagan C. Fitzpatrick, Charlotte F. Zimmer, Elaheh Abdollahi, Lyndon Juden-Kelly, Seyed M. Moghadas, Burton H. Singer, Alison P. Galvani

Publication Date: 24 August 2021

Publication Site: PNAS

Death rates at specific life stages mold the sex gap in life expectancy

Mary Pat Campbell

Link: https://www.pnas.org/content/118/20/e2010588118

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Female life expectancy exceeds male life expectancy. Males at ages 15 to 40 die at rates that are often three times female levels, but this excess mortality is not the main cause of the life expectancy gap. Few deaths occur at younger adult ages compared with mortality after age 60 or, historically, among newborns. Our demographic analysis shows that, up through the early decades of the 20th century, the life expectancy gap largely resulted from excess deaths of infant boys. Afterward, higher mortality among men 60+ became crucial. The higher mortality of males at ages 15 to 40 has played a modest role.

Author(s): Virginia Zarulli, Ilya Kashnitsky, James W. Vaupel

Supplementary online material: https://www.pnas.org/content/pnas/suppl/2021/05/06/2010588118.DCSupplemental/pnas.2010588118.sapp.pdf

Github: https://github.com/CPop-SDU/sex-gap-e0-pnas

Publication Date: 18 May 2021

Publication Site: PNAS

Reductions in 2020 US life expectancy due to COVID-19 and the disproportionate impact on the Black and Latino populations

Mary Pat Campbell

Link: https://www.pnas.org/content/118/5/e2014746118

Abstract: COVID-19 has resulted in a staggering death toll in the United States: over 215,000 by mid-October 2020, according to the Centers for Disease Control and Prevention. Black and Latino Americans have experienced a disproportionate burden of COVID-19 morbidity and mortality, reflecting persistent structural inequalities that increase risk of exposure to COVID-19 and mortality risk for those infected. We estimate life expectancy at birth and at age 65 y for 2020, for the total US population and by race and ethnicity, using four scenarios of deaths—one in which the COVID-19 pandemic had not occurred and three including COVID-19 mortality projections produced by the Institute for Health Metrics and Evaluation. Our medium estimate indicates a reduction in US life expectancy at birth of 1.13 y to 77.48 y, lower than any year since 2003. We also project a 0.87-y reduction in life expectancy at age 65 y. The Black and Latino populations are estimated to experience declines in life expectancy at birth of 2.10 and 3.05 y, respectively, both of which are several times the 0.68-y reduction for Whites. These projections imply an increase of nearly 40% in the Black−White life expectancy gap, from 3.6 y to over 5 y, thereby eliminating progress made in reducing this differential since 2006. Latinos, who have consistently experienced lower mortality than Whites (a phenomenon known as the Latino or Hispanic paradox), would see their more than 3-y survival advantage reduced to less than 1 y.

Authors: Theresa Andrasfay and Noreen Goldman

Reference: PNAS February 2, 2021 118 (5) e2014746118; https://doi.org/10.1073/pnas.2014746118

Publication Date: 2 February 2021

Publication Site: PNAS