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Archive - Jun 29, 2019

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New, Low-Cost OCT Retinal Scanner Could Help Prevent Blindness Worldwide; Duke-Led Effort Creates Portable, Much Cheaper Device Nearly As Accurate As Current Very Costly Standard-of-Care OCT Instruments

Biomedical engineers at Duke University in North Carolina have developed a low-cost, portable optical coherence tomography (OCT) scanner that promises to bring the vision-saving technology to underserved regions throughout the United States and abroad. Thanks to a redesigned, 3D-printed spectrometer, the scanner is 15 times lighter and smaller than current commercial systems (image shows example of a typically bulky current commercial system) and is made from parts costing less than a tenth the retail price of commercial systems -- all without sacrificing imaging quality. In its first clinical trial, the new OCT scanner produced images of 120 retinas that were 95 percent as sharp as those taken by current commercial systems, which was sufficient for accurate clinical diagnosis. The results were published online on June 28, 2019 in Translational Vision Science & Technology, an ARVO journal. The open-access article is titled “First Clinical Application of Low-Cost OCT." In use since the 1990s, OCT imaging has become the standard of care for the diagnosis of many retinal diseases, including macular degeneration and diabetic retinopathy, as well as for glaucoma. However, OCT is rarely included as part of a standard screening exam because machines can cost more than $100,000 -- meaning that usually only larger eye centers have them. "Once you have lost vision, it's very difficult to get it back, so the key to preventing blindness is early detection," said Adam Wax, PhD, Professor of Biomedical Engineering at Duke. "Our goal is to make OCT drastically less expensive so more clinics can afford the devices, especially in global health settings." OCT is the optical analogue of ultrasound, which works by sending sound waves into tissues and measuring how long the waves take to come back.

Archaeological Mystery Solved with Modern Genetics -- Y Chromosomes Reveal Population Boom and Bust in Ancient Japan

Researchers at the University of Tokyo conducted a census of the Japanese population of approximately 2,500 years ago using the Y chromosomes of men living on the main islands of modern-day Japan. This is the first time that analysis of modern genomes has estimated the size of an ancient human population before they were met by a separate ancient population. The research was published online on June 17, 2019 in Scientific Reports. The open-access article is titled “Analysis of Whole Y-Chromosome Sequences Reveals the Japanese Population History in the Jomon Period.” "Evidence at archaeological dig sites has been used to estimate the size of ancient human populations, but the difficulty and unpredictability of finding those sites is a big limitation. Now we have a method that uses a large amount of modern data," said Associate Professor Jun Ohashi, PhD, an expert in human evolutionary genetics and leader of the research team that performed the analysis. The current theory on human migrations into Japan is that the original inhabitants, the Jomon people, were met about 2,500 years ago by a separate group coming mainly from the Korean Peninsula, the Yayoi people. Archaeologists have identified fewer Jomon sites from the Late Jomon Period, the era immediately before the Yayoi arrival. Global temperatures and sea levels dropped during that period, which could have made life more difficult for the hunter-gatherer Jomon people. When the Yayoi people arrived, they brought wet rice farming to Japan, which would have led to a more stable food supply for the remaining Jomon people living with the new Yayoi migrants. The lesser amount of archaeological remains from the Late Jomon Period could be evidence of an actual population decline, or just that the archaeological dig sites have not yet been found. Dr.