Leadership
Michael Abramoff, MD, PhD
Founder and Executive Chairman
Michael D. Abramoff, MD, PhD, is a fellowship-trained retina specialist, computer scientist and entrepreneur. He is Founder and Executive Chairman of Digital Diagnostics, the first company ever to receive FDA clearance for an autonomous AI diagnostic system. To transform the quality, accessibility, and affordability of global healthcare through the automation of medical diagnosis and treatment.
Dr. Abramoff (gold Fellow ARVO, Fellow IEEE) is the Robert C. Watzke, MD Professor of Ophthalmology and Visual Sciences at the University of Iowa, with a joint appointment in the College of Engineering. Dr. Abramoff is the Founder and Executive Chairman of Digital Diagnostics, the Autonomous AI diagnostics company that was the first in any field of medicine to get FDA clearance for an autonomous AI.
In primary care, the AI system can instantaneously diagnose diabetic retinopathy (including macular edema) at the point-of-care. Dr. Abramoff developed an ethical foundation for autonomous AI that was used during the design and validation, and regulatory and payment pathways for autonomous AI.
As the author of over 400 peer-reviewed publications in this field, he has been cited over 50,000 times, and is the inventor on 25 issued patents and many patent applications. Dr. Abramoff has mentored dozens of engineering graduate students, ophthalmology residents, and retina fellows.
His passion is to use AI to improve the affordability, accessibility and quality of care.
John Bertrand
Co-Founder and Chief Executive Officer
John Bertrand brings over a decade of healthcare technology experience to Digital Diagnostics, previously holding a variety of executive roles at Epic Systems. During his 12-year career with Epic, Bertrand led cross-functional teams in a variety of product, customer success, and business development roles with a focus on growth.
Most recently Bertrand served as Executive in Residence at 8VC, a leading Silicon Valley venture capital firm focused on healthcare technology. His time in this space focused on the application of artificial intelligence and computer vision in healthcare.
Kurt Blasena
Chief Commercial Officer
Kurt Blasena is the Chief Commercial Officer at Digital Diagnostics where he is committed to improving health equity and care quality through technology in medical diagnosis and treatment that is free of racial and ethnic bias.
With a career entirely dedicated to healthcare, Blasena brings a passion for increasing access and quality in healthcare, as well as extensive experience in leading commercial organizations. For more than 20 years, Blasena has led SaaS companies through rapid expansion and building go-to-market strategies. His leadership has focused on digital health and artificial intelligence, with an emphasis on driving revenue growth and building high-performance sales and account teams to accelerate growth.
Blasena believes in fostering a strong company culture and has a proven track record of attracting and developing talented teams focused on growth, with a history of delivering results and scaling revenue from a start-up stage to +$200,000,000.
Blasena graduated from the University of Wisconsin-Eau Claire with a bachelor’s degree in marketing and economics.
Luke Miller
Chief Legal Officer, Chief Compliance Officer, and Corporate Secretary
Luke Miller is the Chief Legal Officer, Chief Compliance Officer, and Corporate Secretary at Digital Diagnostics, bringing with him experience as a startup, mid-size, and public company healthcare executive.
Prior to joining Digital Diagnostics, Miller served as the General Counsel & Chief Strategy Officer of Quidient, a pioneering 3D imaging technology company. Before Quidient, Miller served as the SVP, General Counsel, Chief Compliance Officer & Corporate Secretary of K2M Group Holdings, Inc. (NASDAQ: KTWO), a global medical device company that served spinal surgery patients across 40+ countries. During his 12-year tenure at K2M, Miller managed the company’s majority interest sale to a private equity firm (2010), its subsequent IPO (2014), and its $1.4B sale to Stryker Corp. (2018). Following Stryker’s acquisition of K2M, Miller served as the lead counsel of Stryker Spine.
Miller holds a B.S. degree from James Madison University and a J.D. from the University of Richmond School of Law.
Mark Daly
Chief Technology Officer
Mark Daly is the Chief Technology Officer at Digital Diagnostics where he oversees the engineering, algorithm, R&D, product, and strategic execution teams. Prior to Digital Diagnostics, Mark worked at Philips, where he successfully integrated startups and led teams to achieve significant growth targets.
Mark’s expertise spans more than 20 years with expertise managing critical patient care systems at the University of Maryland Medical Center to co-founding Analytical Informatics, a successful health IT startup acquired by Philips. He has a strong technical foundation with a B.S. in Computer Engineering from the Milwaukee School of Engineering and has contributed significantly to product development, operations, and international market launches in his engineering and product leadership roles.
Mark’s career exemplifies his ability to drive innovation, operational efficiency, and strategic growth in complex and dynamic environments.
Danika Dougherty
Chief of Staff
Danika Dougherty is the Chief of Staff at Digital Diagnostics, where she is responsible for providing comprehensive support and strategic guidance to the company’s executive team.
She has a decade of experience in marketing, customer success, and sales in the healthcare and consumer product industries. Prior to joining Digital Diagnostics, Danika held several roles at Dyson, including National Account Manager for Amazon and Commercial Marketing Manager for Great Britian and Europe. Throughout her time at Dyson, she played a pivotal role in driving the company’s marketing initiatives, facilitating the distribution of marketing campaigns, leading international campaign launches, and helping to design the overarching global marketing strategy.
Danika holds a B.S. in Applied Mathematics from Columbia University and is pursuing a Master of Health Administration from the University of Iowa College of Public Health.
Andy Jones
Vice President of Product and Support
As Vice President of Product and Support at Digital Diagnostics, Andy Jones leads a team that is dedicated to helping further the company’s goal of positively impacting patient care through the deployment of AI diagnostic systems.
Andy brings more than a decade of experience in the healthcare industry specializing in professional services and customer success. Prior to joining Digital Diagnostics, Andy served as Manager of Professional Services at Zendesk, during which time he played a pivotal role in the growth and development of the Professional Services Team. Before Zendesk, Andy spent 8 years at Epic Systems Corporation in a number of different roles, overseeing successful enterprise multi-state implementations, building executive-level relationships across Epic customers, and supporting the growth of the Epic’s array of products.
Andy holds a B.A. in International Economics and Finance from Austin College Sherman and an M.A. in Global Affairs and Management from Thunderbird School of Global Management.
Jacque Engle
Vice President of Marketing
Jacque Engle is the Vice President of Marketing at Digital Diagnostics, where she is responsible for the company’s marketing, communication and public relations strategy and functions.
She has nearly a decade and a half of experience leading, mentoring and developing marketing and communications teams with a passion for creative problem solving and innovating new ways for tackling challenges. Jacque has deep expertise in implementing strategies to drive brand awareness and increase performance across multiple channels. She specializes in connecting data-driven insights to compelling marketing and communication strategies.
Prior to joining Digital Diagnostics, Jacque led several high-visibility marketing and communication teams at Nationwide and CenterPoint Properties. She holds a Bachelor of Arts in strategic communication and general business marketing from The Ohio State University.
Juli Goldstein, MHS, CPB
Vice President of Government Affairs and Market Access
Juli Goldstein serves as the Vice President of Government Affairs and Market Access at Digital Diagnostics, the company that brought the first fully autonomous AI cleared by the FDA for the detection of diabetic retinopathy to market. In her role, Juli leads the efforts for establishing payment and reimbursement, strategic market access planning, policy engagement and the creation of real-world evidence.
Prior to joining Digital Diagnostics, Juli led policy, reimbursement and commercial strategy across major medical device companies, including Medela LLC and Abbott Inc. She has also served as a leader with national and global payer organizations, including Kaiser Permanente and the World Health Organization, where she authored clinical standards of care and health policy initiatives.
Juli holds her Master’s degree in Health Science and International Health from the Johns Hopkins University Bloomberg School of Public Health and is credentialed as a Certified Professional Biller with the American Academy of Professional Coders.
Meghan Lemerond
Vice President of Customer Success
Meghan Lemerond is the Vice President of Customer Success at Digital Diagnostics, where she is responsible for developing and leading a team that is passionate about driving the successful adoption and expansion of the company’s autonomous AI diagnostic systems.
She has a decade of experience cultivating and fostering customer relationships in the EdTech and MedTech industries with a passion for achieving desired outcomes in a meaningful way. By relying heavily on cross-functional partnerships, data-driven decision-making, and operational excellence, Meghan specializes in developing high-performing teams that deliver exceptional customer experiences, reduce churn, and drive growth.
Meghan earned a B.A. in Business Administration and Political Science from St. Norbert College.
Ali Satvat
Director
Ali Satvat (Menlo Park) joined KKR in 2012. He co-leads the Health Care industry team within KKR’s Americas Private Equity platform and serves as Global Head of KKR’s Health Care Strategic Growth platform. He is a member of the Investment Committee and the Portfolio Management Committee for Americas Private Equity and chairs the Investment Committee and the Portfolio Management Committee for Health Care Strategic Growth. Mr. Satvat has served on multiple public and private boards of directors, including most recently Blue Sprig Pediatrics, BridgeBio Pharma, Clarify Health Solutions, Cordis, Digital Diagnostics, Geode Health, Headlands Research, Impel NeuroPharma, Paige.AI, Sapphiros, SkinSpirit, Treeline Biosciences, and Trilogy MedWaste, and has been actively involved with various historical investments such as Ajax Health, Arbor Pharmaceuticals, Coherus BioSciences, Eidos Therapeutics, Falcon Vision, GenesisCare, Gland Pharma, Panasonic Healthcare, PRA Health Sciences, Slayback Pharma, Spirox and Zeus Health.
Prior to joining KKR, Mr. Satvat was a principal with Apax Partners, where he focused on health care private equity and growth equity investments. Previously, he held various positions with Johnson & Johnson Development Corporation, Audax Group and The Blackstone Group. Mr. Satvat holds an A.B., magna cum laude, in History and Science from Harvard College and an M.B.A. in Health Care Management and Entrepreneurial Management from the Wharton School of the University of Pennsylvania. He previously served as a member of the board of directors of the Healthcare Private Equity Association.
George Barrett
Director
George Barrett is a healthcare industry leader, educator, and frequent lecturer on leadership, with a distinguished career as a business executive of global corporations.
Barrett is the former Chairman and CEO of Cardinal Health, a multinational healthcare services and products company ranked 15 on the Fortune 500, where he was repeatedly recognized as a top CEO by investors, peers, and employees. Prior to Cardinal Health, Barrett was president and CEO of Teva Pharmaceutical’s North American business and corporate executive vice president for global pharmaceuticals.
Barrett serves on a number of boards of directors, including: Target Corporation; Resilience, a first-of-its kind biopharmaceutical manufacturing and technology company; Olive, a healthcare-focused AI company; and on the Advisory Board of InStride, a public benefit corporation that provides workforce education. He is a member of the board of Children’s Hospitals’ Solutions for Patient Safety; Nationwide Children’s Hospital; and The Columbus Foundation, one of the nation’s largest community foundations. He is adjunct faculty at Columbia University Mailman School of Public Health and is a frequent lecturer at other leading universities. A lifelong musician and performer, Barrett is a trustee of the Rock & Roll Hall of Fame.
Barrett earned a bachelor’s degree from Brown University in history and music, and an MBA from New York University. A former director of the Fourth District of the Federal Reserve Bank, he holds multiple Honorary Doctorates and is the recipient of numerous honors for a life dedicated to statesmanship and community service.
Stephen Weiss
Director
Stephen L. Weiss is a Managing Director at Cedar Pine LLC, a private investment firm specializing in strategic, long-term assets with expertise as operators and investors in healthcare, finance, and real estate. He is responsible for direct investing in non-public companies with a focus on healthcare and technology. He currently sits on the boards of Digital Diagnostics and Nimble Robotics and is also a board observer at Wasabi Technologies. Steve has been a leader in the investment industry for over three decades working with some of the world’s most influential CEOs and investors.
Prior to joining Cedar Pine, Steve was the Founder and Managing Partner of Short Hills Capital Partners LLC and served in senior management and investment roles at Salomon Brothers, SAC Capital, and Lehman Brothers. Steve is an author of three books including The Billion Dollar Mistake: Learning the Art of Investing through the Missteps of Legendary Investors. He was also a Visiting Teaching Fellow at UNC’s Kenan Flagler Business School. Since 2012, Steve has been a regular on The Halftime Report on CNBC, a leading business news network.
Senator William H. Frist, MD
Director
Senator William Frist, MD, is a nationally recognized heart and lung transplant surgeon, former U.S. Senate Majority Leader, founding partner of Frist Cressey Ventures and Special Partner of the health service investment firm Cressey & Company.
As a U.S. Senator representing Tennessee from 1994 -2006 (the first practicing physician elected to the Senate since 1928), Dr. Frist was elected Majority Leader of the Senate, having served fewer total years in Congress than any person chosen to lead that body in history. His leadership was instrumental in the passage of the 2003 Medicare Modernization Act that established Medicare Advantage and the historic PEPFAR legislation that has provided life-saving treatment globally to 20 million people.
Senator Frist graduated from Princeton University and Harvard Medical School, and completed surgical training at Massachusetts General Hospital and Stanford.
As a leading authority on virtual healthcare delivery, Senator Frist speaks nationally on health reform, government policy, global health, and education reform. He is Co-Chair of the Health Project at the Bipartisan Policy Center. His board service includes the Robert Wood Johnson Foundation, The Nature Conservancy, and three publicly-traded companies: Select Medical, Teladoc Health, and Smile Direct Club.
Dr. Frist is married and has three sons and lives on a farm in Franklin, Tennessee.
Drew Oetting
Director
Drew Oetting is co-founder and Managing Partner for 8VC, a Silicon Valley-based venture capital firm which manages over $3.5B. Drew focuses on software, healthcare delivery, and bio-IT investments.
Drew serves on the Competitiveness Council of Cerberus. He is a board member of Thorn, a non-profit which builds technology to prevent child trafficking and LivingOnOne, an impact film making studio.
He is a board trustee for the Claremont McKenna Center for Innovation and Entrepreneurship, as well as at the Robert Day Financial Economics Institute
Drew grew up in Iowa City, Iowa and received a BS in math and economics from Claremont McKenna College.
Ambassador Howard Leach
Director
Howard H. Leach is a business executive and private investor. He serves as president of Leach Capital, LLC, Palm Beach, Florida. Howard served as the United States Ambassador to France from 2001 to 2005. He was a member of the Board of Regents of the University of California from 1990 to 2001 and served as chairman of that board from 1993 to 1995.
Howard has served as director of various companies, including president of Foley Timber and Land Company, Perry, Florida; chairman of Hunter Fan Company, Memphis, Tennessee; Shippers Development Company, Salinas, California; Dr. Pepper Company; the FL Aerospace Corporation (successor to Midland Ross Corporation); and Hibernia Bank and as chairman of Sybron Corporation and the Union Ice Company.
Howard is active in civic activities and serves on the Boards of The Society of the Four Arts, the Palm Beach Civic Association, the Preservation Foundation of Palm Beach, The American Society of the French Legion of Honor, and the Center for Strategic and International Studies. He is also on the Board of the American Hospital of Paris Foundation. He was a member of the California State Board of Agriculture and the U.S. Chamber of Commerce Committee on Agriculture.
Howard has been active in Republican politics for many years. He served as finance chairman of the Republican National Committee from 1995 to 1997. Howard is a graduate of Yale University and attended Stanford Graduate School of Business. He served as an officer in the U.S. Air Force from 1953 through 1955.
Howard and his wife, Gretchen, reside in Palm Beach, Florida.
Seth Rainford
Board Advisor
Seth Rainford is Co-Founder and Board Advisor at Digital Diagnostics where he contributes to expanding market opportunities.
Rainford brings nearly two decades of executive experience in the healthcare industry including the successful management of large-scale P&L’s, strong organic & inorganic business development expertise, as well as complex multi-site operations leadership.
Rainford most recently served as President and Chief Operating Officer at Digital Diagnostics and previously as Regional Vice President & General Manager of LabCorp in the Greater Chicago Area, leading a strategic transformation of the Midwest business unit. Prior to LabCorp, he served as Vice President at Northwestern Medicine, where he drove the commercialization and scaling of their outreach diagnostics business.
Rainford received his MBA in business administration from Purdue University.
Lisa Tseng, MD
Board Observer
Since joining UnitedHealth Group in 2009, Dr. Lisa Tseng has built and led businesses that have improved consumer experience and health outcomes while improving affordability. She currently serves as Executive Vice President, focusing on strategic partnerships and scaling innovative health solutions.
Dr. Tseng led the implementation of utilization management, quality improvement, provider enrollment and credentialing, claims service center, provider training, electronic visit verification, and program integrity services to support a $3.5 billion state program. She served as the CEO of Optum Complex Care Management, which is the market leader in delivering person-centric care to people with complex medical, behavioral, and long-term care needs in 36 states.
Dr. Tseng led the development and operation of a post-acute transition program in more than 47 markets and 30 states providing transitional care to members discharged from hospitals and nursing facilities. She designed the end-to-end clinical model, process, and system that enabled clinicians to be by the member’s side within 24 hours and with a full view of the member’s medical and pharmaceutical history.
Dr. Tseng led the development of urgent care clinics that provide on-demand access to high quality care at low prices in several states, including same-day labs and imaging, occupational health, and wellness programs. She led the advancement of Specialty Pharmacy Clinical Management Programs, which have improved member and provider experience, improved medication adherence, reduced hospitalizations and ER visits, and reduced total cost of care. Her team built an innovative, direct-to-consumer hearing aid business that reduced the cost of hearing aids by more than 70%, making hearing healthcare more accessible for 48 million Americans with hearing loss. The business received the Business Intelligence Group Award for Consumer Friendly Company of the Year.
Dr. Tseng served as Chief of Staff for UnitedHealthcare’s Public and Senior Markets Group including Medicare and Medicaid. She also served as Vice President of Strategy and Business Development at Fidelity Investments, Vice President of Corporate Integration Strategy for AARP Services, and management consultant at Oliver Wyman. Dr. Tseng holds a Bachelor of Science degree in Physiological Science and minor in Neuroscience from UCLA and Medical Degree from the UCLA School of Medicine. She served on the National Leadership Team of the American Medical Student Association and was the National President of the Asian Pacific American Medical Student Association. Dr. Tseng has also served on the board of several community health clinics. She was the business chair for the Minneapolis Walk4Hearing.
She has been recognized by Modern Healthcare’s Up & Comers Award, Women’s Health Leadership TRUST, Minneapolis St. Paul Business Journal Women in Business Award, Women Worth Watching, Business Journal Diversity in Business Award, and UnitedHealth Group Innovation Award. Dr. Tseng was also profiled in the Entrepreneur magazine, Managed Care magazine, and Diversity Journal.
Mayank Taneja
Board Observer
Mayank is the Vice President of Venture Investments for OSF Ventures, the corporate investment arm of OSF HealthCare.
In this role, Mayank manages the venture program and leads efforts to invest in devices, diagnostics, emerging digital solutions and technology-enabled services that can improve patient outcomes or reduce costs to the Ministry.
Mayank joined OSF Ventures in 2016 as one of the early members of the venture team. He brings experience in the health care industry across multiple disciplines including the practice of medicine, working with early stage companies and supporting venture investments and innovation strategies. Mayank has been named one of Becker’s Hospital Review’s Rising Stars in Healthcare.
He currently serves as a board member on GYANT and a board bserver on InsightRx, CancerIQ, Digital Diagnostics, Exo Imaging, PhotoniCare, VIDA and Tailormed. Mayank also served as a board observer on Paradigm Diagnostics, Current Health, SilverCloud and CareSignal prior to their acquisitions.
Before joining the OSF Ventures team, Mayank worked with the usability services team at OSF HealthCare and helped medical device startups pilot their technologies and perform human factors studies for submission to the US Food and Drug Administration. He also assisted the OSF medical simulation for-profit spinoff, SIMNEXT LLC, with early business support and go-to-market strategy.
Prior to joining OSF HealthCare, Mayank worked at Zimmer Inc. in its post-market risk surveillance division as part of the Zimmer Leadership Program. He received his medical school degree from Maulana Azad Medical College in India and his MBA from The Ohio State University (Fisher College). Mayank practiced internal medicine for four years in New Delhi, India.
Joe Grogan
Policy Advisor
Joseph Grogan was most recently the director of the United States Domestic Policy Council and assistant to President Donald Trump. Appointed by Acting Chief of Staff Mick Mulvaney, Grogan converted the traditionally small office into an influential policy council.
Grogan worked from 2017 to January 2019 as a health care official in the Office of Management and Budget. He was appointed a member of the White House Coronavirus Task Force in January 2020.
He currently serves on the board of directors of Verde Technologies.
Young Kwon, MD, PhD
Medical Advisor
Dr. Young H. Kwon is a renowned glaucoma specialist at the University of Iowa Hospitals and Clinics, where he is Professor of Ophthalmology and Visual Sciences and holds the Clifford M. and Ruth M. Altermatt Endowed Professorship in Glaucoma.
For almost a decade, Dr. Kwon was a member of the Preferred Practice Pattern Glaucoma Panel at The American Academy of Ophthalmology, which outlines best practices for the diagnosis and treatment of glaucoma.
He has authored over 140 peer-reviewed papers and scientific book chapters, including an article in The New England Journal of Medicine (2009), and served as a Glaucoma Section Editor and Editorial Board Member of Eye, The Scientific Journal of the Royal College of Ophthalmologists (UK).
He has been recognized with many awards, including Mid-Career Clinician-Scientist Award from The American Glaucoma Society Secretariat Award and Senior Achievement Award from The American Academy of Ophthalmology and “Best Doctors in America.”
Dr. Kwon is the inventor of four patents (two of them with Dr. Abramoff) and his research has been funded through a variety of private, state, and federal organizations since 1997. He holds an MD from the Yale University School of Medicine and a PhD in Neuroscience from the Massachusetts Institute of Technology.
He completed his ophthalmology residency training at Massachusetts Eye & Ear Infirmary (a Harvard teaching hospital) and glaucoma fellowship at Yale University.
Harry Quigley, MD
Medical Advisor
Dr. Quigley was born in St. Louis and is a graduate of Harvard College and Johns Hopkins Medical School (Alpha Omega Alpha). After ophthalmic residency at the Wilmer Institute, he did a fellowship with Douglas Anderson at the Bascom Palmer Eye Institute, Miami.
He became the A. Edward Maumenee Professor of Ophthalmology in 1994, directing both the Glaucoma Center of Excellence and, until 2011, the Dana Center for Preventive Ophthalmology at Wilmer.
He was a founding member of the American Glaucoma Society, serving for 8 years as its Secretary. He was elected to 5 year terms as chief executive officer of the Association for Research in Vision and Ophthalmology (ARVO) and Editor-in-Chief of Investigative Ophthalmology and Visual Science.
He has published over 400 peer-reviewed articles, and his reports are the most cited in the ophthalmic literature over the last 30 years (Archives of Ophthalmology, 2007; H factor 118, 59,000 citations).
He has been honored with the Friedenwald Award by ARVO, the Doyne Medal by the Oxford Ophthalmological Congress, the Leslie Dana Medal by the St. Louis Society for the Blind, and by research awards from Research to Prevent Blindness, the Alcon Research Award (twice), the European Society of Ophthalmology (Prix Jules Francois), the Chicago Ophthalmological Society (best teacher), Ophthalmological Society of Scotland (Mackenzie Medal), Australian Society of Ophthalmology (Gregg Medal), Irish Ophthalmological Society (Mooney Medal), and the New York Academy of Sciences (Lewis Rudin Prize).
He is an ARVO Gold Fellow and received ARVO’s Joanne Angle Service Award from ARVO and the Life Achievement Honor Award of the American Academy of Ophthalmology. He has given 43 named lectures, including the 66th Edward Jackson Lecture (AAO).
Dr. Quigley has trained 65 glaucoma clinician–scientists who lead glaucoma centers in the U.S. and worldwide. His research has improved the early diagnosis of glaucoma and has developed instruments and techniques to identify glaucoma damage better.
His investigations found that early glaucoma damage preceded existing detection methods. He was the first to report on long-term success with laser iridotomy. His suturing technique for trabeculectomy has been widely adopted.
He has participated in pioneering studies of the epidemiology, morbidity and progression rate of glaucoma and other eye diseases in American, African, Asian, and Hispanic populations, serving as a consultant to the World Health Organization.
He conceptualized new roles for iris and choroidal volume change as risk factors in angle closure glaucoma. In the laboratory, he has demonstrated successful gene therapy to protect retinal ganglion cells from experimental glaucoma, and developed glaucoma models in monkeys, rats and mice.
Dr. Quigley is an advocate of natural gardening techniques in ecorestoration projects in Baltimore, developing Poplar Hill Park (see www.waytogarden.net). He is a Horticultural Assistant at the National Aquarium, Baltimore. His son, David, is on the University of California San Francisco faculty in Oncology and Epidemiology as a bioinformatics specialist in cancer research. His daughter, Erica, is a landscape architect, designing outdoor play spaces. He loves being asked about his 2 grand-daughters.