Edward Williams
Edward Williams, DMSc, M.Ed., PA-C
Chair, Department of Physician Assistant Studies
Director, Physician Assistant Program

Dr. Williams hails from Montgomery, Alabama and joined the U.S. Army in 1991 as a Combat Medic.  During his time as a medic, he developed a passion for training and education. In 2001, Dr. Williams was accepted into the Army’s Physician Assistant Program.  He graduated with a Bachelor of Science in Physician Assistant Studies in 2003 from The University of Nebraska then later earned his Masters of Science in the same field in 2004 with a specialty in Family Practice.  In June of 2012, Professor Williams earned his Master’s in Education from the University of Phoenix while stationed in South Korea. In 2022 Dr. Williams earned his Doctor of Medical Science degree from The University of Lynchburg with a concentration in PA education.

During his service in the Army, he was awarded many awards and decorations to include the Bronze Star, the Air Medal, and the Legion of Merit. As a Physician Assistant, he has served as the Medical Officer for several battalions and served as the Officer in Charge of a Troop Medical Clinic in South Korea. Professor Williams retired from the Army after 22 years of service. Edward is married to his wife, Jill, and has two children, Drew and Lauren.

Dr. Williams is fulfilling a long-term goal of instructing on a professional level.  He is eager to impart his medical knowledge to future Physician Assistants and believes it is important to give back to the Physician Assistant profession that continues to give so much to those in need.

Gloria Richard-Davis
Gloria Richard-Davis, MD, FACOG
Medical Director of Physician Assistant Studies

Dr. Gloria Richard-Davis joined UAMS physician assistance program in January 2014 as the medical director.

She received her medical doctor (MD) degree from Louisiana State University School of Medicine New Orleans in 1982 and received her Bachelors of Science (BS) degree from Southern University in 1977.  She completed her Residency in Obstetrics and Gynecology and her Internship in Transitional Medicine from Madigan Army Medical, Tacoma, WA in 1986. After serving in the Army for several years and private practice, she returned to training and completed her fellowship in Reproductive Endocrinology and Infertility (REI) at Hutzel Hospital, Wayne State University, Detroit MI in 1994. She recently completed her masters of business (MBA) at University of Arkansas Little Rock in May 2017.

Dr. Richard-Davis served in the Army Medical Corp for 8 years with tours at Fort Lewis, Madigan Army Medical Center, 121 Evacuation Hospital in Seoul, South Korea and Fort Bragg, NC Womack Army Hospital. She began at the rank of 2nd Lt in medical school and was promoted from Captain to Major, while serving in Korea. She separated from the Army in 1990 and joined a multi-specialty group practicing general obstetrics and gynecology.

Dr. Richard Davis joined UAMS in January 2013 as Division Director, Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology. She was former Chair of Obstetrics and Gynecology and Associated Director of Center for Women Health Research at Meharry Medical College in Nashville from 2007-2013. She also served as as Chief of the Veteran Women Reproductive Services at Tennessee Valley Hospital Veteran Authorities, Chief of Service of Obstetrics and Gynecology at Nashville General Hospital. Prior to Nashville, she practiced in New Orleans beginning at Tulane University School of Medicine as an Assistant Professor, Clinical Professor and Assistant Dean at Tulane University School of Medicine until 1998. She practiced private REI for 2 years with Fertility and Laser Institute in Metairie and Baton Rouge. She was recruited to Ochsner Clinic to lead their division of REI establishing Ochsner’s first IVF center.

She practices REI, trains obstetrics and gynecology residents, teach medical and PA students and does medical research in the areas of menopause, fibroids and infertility. She serves on board of trustee for the North American Menopause Society (NAMS) and in leadership roles in multiple professional organizations like NAMS, ASRM, AAMC. She has received millions of dollars in grants and awards. She has over 50 peer reviewed publication, multiple chapters and has published a book on infertility- Planning Parenthood.

Nadja Vawryk Button
Nadja Vawryk Button, MHS, PA-C
Assistant Professor

Before becoming a Physician Assistant, Ms. Vawryk Button worked for twenty years in Emergency Medical Services (EMS) in various capacities, as a Paramedic, an EMS educator, and regional EMS Quality Improvement Coordinator.

She graduated from the University of Maryland with a Bachelor of Science degree in Emergency Health Services and completed a Master of Science degree at Towson University in Instructional Technology.  At the Lock Haven University of Pennsylvania, she attained a Master of Health Science degree in Physician Assistant Studies.

Upon graduation, she practiced in rural St. Francis Kansas as a family practice PA, and was clinic manager.  She implemented and managed the clinic’s Electronic Medical Records program.  While there, she was a recipient of the National Health Services Corps (NHSC) tuition reimbursement.  Later she practiced as an Emergency Department PA in rural Georgia.

Previously she served at the Mercer University PA Program as the Clinical Coordinator, then as Quality Enhancement and Technology coordinator managing the PA program educational administration and testing databases.

Ms. Vawryk Button is proud to have been one of the original UAMS Physician Assistant faculty, and hopes to share her clinical knowledge of family practice and emergency medicine, her interest in quality enhancement and technology, and her calling to care for citizens in rural communities.

Chance Gee
Chance Gee, MPAS, PA-C
Director of Admissions, Assistant Professor

Chance Gee completed his undergraduate education at Texas A&M University in College Station in 2006; earning a Bachelor of Science degree in Biomedical Sciences.  In 2010, he earned his Masters of Physician Assistant Studies degree from the University of Texas Medical Branch in Galveston, Texas.  Upon gaining national certification, Mr. Gee worked in a private practice setting in Texas in the field of Internal Medicine.  Most recently, he has worked with the department of Burn Surgery at Arkansas Children’s Hospital in Little Rock.

Mr. Gee is excited about the opportunity to share his knowledge and prior experiences with future physician assistants.  Mr. Gee has been married to his lovely wife, Maria, since 2016, and together they have a beautiful daughter and 3 dogs.  Mr. Gee is an avid sports fan, and in his spare time he enjoys hunting, fishing, and playing golf.

Melissa Halverson
Melissa Halverson, Pharm.D., M.P.H.
Associate Professor

Dr. Melissa Halverson graduated from the University of Arkansas for Medical Sciences in May 2014 earning both a doctorate in Pharmacy as well as a Master in Public Health.  She has lived in central Arkansas since 2004 when her family moved to Little Rock from Suwanee, Georgia, part of the Metro-Atlanta area.

During her time as a dual-degree student at UAMS, she spent many hours volunteering at the 12th Street Health and Wellness Center (a student-run, interprofessional, free clinic).  She completed her culminating experience project at the center where she initiated the evaluation of a patient’s health literacy status, which would influence the way the professional students communicate with the patient.

After graduation she accepted an ambulatory care residency position with the UAMS College of Pharmacy with a significant amount of time dedicated to the 12th Street Health and Wellness Center.  During her time as a resident she helped the center become a Vaccines for Children provider, implement a patient-centered, interprofessional diabetes education class held at the center, as well as other UAMS clinics, and saw the center provide dental services for the first time.

Dr. Halverson began teaching in the UAMS Physician Assistant Program while earning a teaching certificate as part of the residency program and is excited to continue teaching with the program as a full-time faculty member.  Along with teaching responsibilities, she will help coordinate the service learning portion of the curriculum. With her enthusiasm for interprofessional education, Dr. Halverson continues to volunteer at the 12th Street Health and Wellness Center and actively promote interprofessional education on the UAMS campus.

Oleg Karaduta
Oleg Karaduta, MD
Director of Research, Assistant Professor

Oleg Karaduta studied general medicine at Volgograd State Medical University, graduating Summa Cum Laude. Dr. Karaduta subsequently completed his residency in General Surgery in 2004. He became the Chief Resident at Volgograd Regional Hospital in 2006, supervising students and junior residents. Dr. Karaduta completed his research fellowship on vascular surgery that was supported by an American-Austrian Foundation.

In 2007 he accepted his first faculty position at the Volgograd Medical University where he directed courses of “General Surgery” and “Nursing Surgical Patients” for foreign medical students from all over the world.

In 2011 Dr. Karaduta joined UAMS as a researcher developing a novel approach for the management of cardiovascular disease in chronic kidney disease. During his postdoctoral fellowship in the Department of Biochemistry and Molecular Biology (UAMS) Oleg Karaduta studied gut microbiome and metabolomics profiles concurrent with amelioration of chronic kidney disease. As an established investigator he was able to secure external funding from Burroughs Wellcome Fund, as well as multiple awards from scientific societies: MSACL, AHA, ASMS.

After finishing his postdoctoral fellowship Dr. Karaduta accepted faculty appointment at the Department of Biochemistry and Molecular Biology (UAMS).

He left DBMB in 2021 to become core faculty and Director of Research in College of Health Professions in the rank of Assistant Professor in the Department of Physician Assistant Studies, leading PA program in the state of Arkansas.

Samantha LawsonSamantha Lawson, MPAS, PA-C
Assistant Professor

Professor Samantha Lawson is an Arkansas native, growing up in Little Rock. Her path to science and medicine was not a conventional one. She attended Southern Methodist University for undergraduate studies, where she earned a Bachelor of Arts in Art History and Bachelor of Arts in Italian Area Studies. After graduating, she spent some time working and living in Italy. Upon arriving back to the United States, she returned to school part time to prepare for Physician Assistant school while also working full time in a pediatric clinic. There, she developed a passion for patient care in the clinical setting. She was a member of the Inaugural Class of the UAMS Physician Assistant Program, which graduated in 2015. After graduating, she worked in orthopedic joint replacement surgery for two years, and then went on to work in a family practice clinic for the next four years.

Samantha joined the UAMS Physician Assistant Program faculty in April 2022. She is excited to be returning to UAMS to help educate future PA providers and shape the PA profession. In her free time, she enjoys cooking, traveling, and spending time with her husband while they try to keep up with their two adorable and very active daughters.

Hillary Mayberry
Hillary Mayberry, MPAS, PA-C
Director of Clinical Education, Assistant Professor

Hillary is from central Arkansas and a graduate of the University of Arkansas, where she received a Bachelor’s degree in Biology with a Minor in Spanish.  She first called UAMS home in 2013 when she began working as a Research Technician in the Pharmacology/Toxicology Department doing stroke and hypertension research prior to attending PA school.  She is a proud graduate of the UAMS Physician Assistant Studies Program where she received her Master’s degree in 2018.  She continued her time at UAMS by working in Plastic and Reconstructive Surgery.  During her time in surgery, Hillary acted as a preceptor, mentor, and enjoyed lecturing to the PA students.

She is passionate about education and is excited to help shape future PAs.  In her free time, Hillary enjoys spending time with her husband and their daughter, traveling, and doing anything outdoors, to include camping, kayaking, hiking, etc.

Audra NosalAudra Nosal, M.S., PA-C
Director of Didactic Education, Assistant Professor

Audra Nosal graduated from Harding University with a Bachelor of Arts in Spanish in 2016 and continued her education at Harding, completing a Masters of Physician Assistant Studies in 2018. Upon graduating, she earned NCCPA national certification as a PA and practiced in family medicine in Sherwood, Arkansas. Most recently, she has worked at UAMS in the COVID Triage Unit to provide community testing and vaccinations throughout the state.

During her career, Audra has participated in numerous medical mission campaigns to Central and South America. She continues to be passionate about improving healthcare access for rural and underserved populations, both abroad and in Arkansas. In her free time, she enjoys being outdoors, traveling, spending time with her family and friends, and completing renovation projects at her home. Audra is excited to be joining the UAMS PA program to train competent and compassionate providers.

Lachan SiebenmorgenLachan E. Siebenmorgen, MPAS, PA-C
Director of Didactic Education, Assistant Professor

Professor Siebenmorgen is a native of Central Arkansas. She grew up in Marche, a small Polish community in North Little Rock. In 2014, she graduated from the University of Central Arkansas as an Undergraduate Scholar with a Bachelor’s of Science in Biology and a Minor of Applied Mathematics. During that time, she participated in research in areas regarding both breast cancer and the effects of menopause on vascular contractility. After completing her undergraduate education, she attended the University of Arkansas for Medical Sciences Physician Assistant Studies Program, and graduated in 2016. She has maintained her national certification as a practicing Physician Assistant, including full-time work in Emergency Medicine from 2016 to present. She is excited to begin her role as faculty in the UAMS Physician Assistant Program. She enjoys creating new food recipes, reading, and nearly all outdoor activities with her husband, young daughter and 2 dogs.

Amber Teigen
Amber Teigen, DMSc, PA-C
Associate Program Director, Assistant Professor

Dr. Teigen attended Wake Forest University for her undergraduate studies and received a Bachelor of Science in Health and Exercise Science. She continued her education at Saint Louis University, earning a Master of Medical Science in Physician Assistant Studies. She recently earned her Doctor of Medical Science degree with a concentration in Healthcare Professions Education from Rocky Mountain University of Health Professions. Her clinical experience includes 1 year as an orthopedic surgery PA and several years as a PA in Interventional Radiology at Washington University School of Medicine in Saint Louis. During her employment at Washington University, she implemented an Interventional Radiology elective rotation for PA students from Saint Louis University. She also served on the Admissions Committee for the Saint Louis University Physician Assistant Program and was an Adjunct Professor for the program shortly before joining the University of Arkansas for Medical Science Physician Assistant Studies Program as full-time faculty.

She joined the UAMS PA Program faculty in March 2016 as Assistant Professor and has served as Director of Didactic Education; she is currently serving as Associate Program Director. She also serves as faculty in the UAMS Mindfulness Program as a certified Koru Mindfulness instructor and a Mindfulness-based Stress Reduction teacher-in-training; she also has interests in Lifestyle Medicine and Interprofessional Education.  In her free time, she enjoys spending time with her family, playing pickleball and spikeball, hiking, visiting national parks, participating in various outdoor activities, and reading.

Brittany WilkersonBrittany Wilkerson, MPAS, PA-C
Assistant Professor

Professor Brittany Wilkerson is a native of Central Arkansas.  She completed her undergraduate studies at Philander Smith College, where she obtained her Bachelor of Science degree with a major in Biology and a minor in Chemistry.   As an undergraduate, Professor Wilkerson volunteered at the University of Arkansas for Medical Science (UAMS) Cancer Institute Modular Mammography Program.  She also participated in undergraduate research as a scholar for the Arkansas IDeA Network of Biomedical Research Excellence, the National Science Foundation, and the National Institute of Health/National Institute of Diabetes, Digestive, and Kidney Diseases. Professor Wilkerson continued her education at the UAMS College of Health Professions, earning a Master of Science in Physician Assistant (PA) Studies.  After obtaining national certification from the National Commission on Certification of Physician Assistants, Professor Wilkerson practiced as the Bleeding Disorders PA at Arkansas Children’s Hospital, with a focus on rare benign Hematological disorders.  She was also one of the investigators in multiple research studies regarding genetic therapy for Hemophilia. Professor Wilkerson is excited to begin her role as a faculty member and alumnus of the UAMS Physician Assistant Program.  In her spare time, she enjoys spending time with her family and traveling.

Adjunct/Additional Faculty

Sarah Anderson, ;Natalie S. Bradford, M.M.S., PA-C; Anne Brown, ; Laura O’Hern,


Jeffrey DeSantis

Jeffrey DeSantis
Educational Coordinator

Jeffrey DeSantis comes to the Physician Assistant program as an Educational Coordinator with extensive higher educational experience in program management and coordination. Most recently he lead UAMS through its ten year reaccreditation for the Higher Learning Commission, UAMS’ regional accreditor which is necessary for students to be able to sit for state board licensing examinations and obtain federal financial aid. He has held positions at several universities including instructor, academic advisor, registrar, and systems administrator at both private and public institutions and he is currently pursuing his Doctorate in Higher Educational Leadership at the University of Arkansas at Little Rock. He holds advanced degrees in Higher Education from Suffolk University, and Interdisciplinary Studies from Boston University as well as a Bachelor’s degree in philosophy from SUNY Brockport and a graduate certificate in Business from UA Little Rock. His professional interests include program assessment, curriculum development, program accreditation and enrollment management. He lives in Little Rock with his wife Dr. Kathryn King and two young children Julian and Alexandra.

Linda Haubenstein
Linda Haubenstein
Assistant to the Chair

Linda Gammon Haubenstein, originally from New Orleans, LA, joined the UAMS Physician Assistant Staff in January 2013. She moved from Davenport, IA where she worked for the Genesis Health Services Foundation, Genesis Medical Center, for 12 years. Linda is married to Kurt J. Haubenstein and they have three children.

LaDonna Walton
LaDonna Walton
Administrative Analyst

LaDonna Walton attended Henderson State University and continued her education at Remington College where she received a degree in Medical Assistant and Office Management.  I have a passion for people where I can offer support for a bigger picture to become better.   I devoted my past experiences working as Court Liaison and Therapeutic Operation Specialist, counseling with clients with Drug and Alcohol addiction.  I am happy to be part of UAMS working in College of Health Professions in the Physician Assistant program as an Administrative Analyst.