91����Ƶ

Ph.D. in Mathematics, 91����Ƶ of Tennessee, Knoxville, (1999)

B.S. in Mathematics and Environmental Science, Taylor 91����Ƶ, (1993)

Expertise

Research Interests

mathematical modeling and computer simulation of infectious diseases with specific interest in tick-borne diseases

Articles

White, A. and Gaff, H. (2018). Review: Application of tick control technologies for blacklegged, lone star, and American dog ticks. Journal of Integrated Pest Management 9 (1) , pp. 10.

Maliyoni, M., Chirove, F., Gaff, H. and Govinder, K. S. (2017). A Stochastic Tick-Borne Disease Model: Exploring the Probability of Pathogen Persistence. Bulletin of Mathematical Biology 79 (9) , pp. 1999-2021.

Shannon, A. B., Rucinsky, R., Gaff, H. and Brinkerhoff, R. J. (2017). Borrelia miyamotoi, Other Vector-Borne Agents in Cat Blood and Ticks in Eastern Maryland. 6 , pp. 1-5.

Manore, C. A., Ostfeld, R. S., Augusto, F. B., Gaff, H. and LaDeau, S. L. (2017). Defining the Risk of Zika and Chikungunya Virus Transmission in Human Population Centers of the Eastern United 91����Ƶs. PLoS Neglected Tropical Diseases 11 (1) , pp. e0005255.

Nadolny, R. M. and Gaff, H. (2017). Natural history of Amblyomma maculatum in Virginia. Ticks and Tick-borne Diseases.

Nadolny, R. M. and Gaff, H. (2017). Natural history of Ixodes affinisin Virginia. Ticks and Tick-borne Diseases.

Butler, J., Butler IV, M. J. and Gaff, H. (2017). Snap, crackle, and pop: acoustic-based model estimation of snapping shrimp populations in healthy and degraded hard-bottom habitats. Ecological Indicators 77 , pp. 377-385.

Fister, K. Renee., Gaff, H., Schaefer, E., Buford, G. and Norris, B. (2016). Investigating cholera using an SIR model with age-class structure and optimal control. Involve, a Journal of Mathematics 9 (1) , pp. 83-100.

Campana, M. G., Hawkins, M. T., Henson, L. H., Stewardson, K., Young, H. S., Card, L. R., Lock, J., Agwanda, B., Brinkerhoff, J., Gaff, H., Helgen, K. M., Maldonado, J. E., McShea, W. J. and Fleischer, R. C. (2016). Simultaneous identification of host, ectoparasite and pathogen DNA via in-solution capture. Molecular ecology resources 16 (5) , pp. 1224-39.

Walter, K. S., Pepin, K. M., Webb, C. T., Gaff, H., Krause, P. J., Pitzer, V. E. and Diuk-Wasser, M. A. (2016). Invasion of two tick-borne diseases across New England: harnessing human surveillance data to capture underlying ecological invasion processes. Proceedings. Biological sciences 283 (1832).

Heller, E. L., Wright, C. L., Nadolny, R. M., Hynes, W. L., Gaff, H. and Walters, E. L. (2016). New Records of Ixodes affinis (Acari: Ixodidae) Parasitizing Avian Hosts in Southeastern Virginia. Journal of medical entomology 53 (2) , pp. 441-5.

Nadolny, R., Gaff, H., Carlsson, J. and Gauthier, D. (2015). Comparative landscape genetics of two invading ticks: evidence of the ecological mechanisms underlying tick range expansions. 35 , pp. 153-162.

Nadolny, R., Gaff, H., Carlsson, J. and Gauthier, D. (2015). Comparative population genetics of two invading ticks: Evidence of the ecological mechanisms underlying tick range expansions. Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases 35 , pp. 153-62.

Wright, C. L., Sonenshine, D., Gaff, H. and Hynes, W. L. (2015). Rickettsia parkeri Transmission to Amblyomma americanum by Cofeeding with Amblyomma maculatum (Acari: Ixodidae) and Potential for Spillover. Journal of medical entomology 52 (5) , pp. 1090-5.

Wright, C. L., Gaff, H., Sonenshine, D. and Hynes, W. L. (2015). Experimental vertical transmission of Rickettsia parkeri in the Gulf Coast tick, Amblyomma maculatum. Ticks and tick-borne diseases 6 (5) , pp. 568-73.

Parham, P. E., Waldock, J., Christophides, G. K., Hemming, D., Agusto, F., Evans, K. J., Fefferman, N., Gaff, H., Gumel, A., LaDeau, S., Lenhart, S., Mickens, R. E., Naumova, E. N., Ostfeld, R. S., Ready, P. D., Thomas, M. B., Velasco-Hernandez, J. and Michael, E. (2015). Climate, environmental and socio-economic change: weighing up the balance in vector-borne disease transmission. Philosophical transactions of the Royal Society of London. Series B, Biological sciences 370 (1665).

Florin, D., Brinkerhoff, R. J., Gaff, H., Jiang, J., Robbins, R. G., Eickmeyer, W., Butler, J., Nielsen, D., Wright, C., White, A., Gimpel, M. and Richards, A. (2014). Additional U.S. collections of the Gulf Coast tick, Amblyomma maculatum (Acari: Ixodidae), from the 91����Ƶ of Delaware, the first reported field collections of adult specimens from the 91����Ƶ of Maryland, and data regarding this tick from surveillance of migratory songbirds in Maryland. Systematic & Applied Acarology 19 (3) , pp. 257-262.

Wright, C., Hynes, W. L., White, B., Marshall, M., Gaff, H. and Gauthier, D. (2014). Single-tube real-time PCR assay for differentiation of Ixodes affinis and Ixodes scapularis. Ticks and Tick-borne Diseases 5 , pp. 48–52.

Nadolny, R., Wright, C., Sonenshine, D., Hynes, W. L. and Gaff, H. (2014). Ticks and spotted fever group rickettsiae of southeastern Virginia. Ticks and Tick-borne Diseases 5 , pp. 53–57.

Brown, J., Kelman, P. and Gaff, H. (2014). Using Pheromones to Enhance Field Tick Collection Techniques. Letters in Biomathematics 1 (1).

Zheng, H., Gaff, H., Smith, G. and DeLisle, S. (2014). Whole-system replication to optimize aberration-detection methods for biosurveillance. PLoS ONe 9 (7) , pp. e100845.

Gaff, H., White, A., Leas, K., Kelman, P., Squire, J. C., Livingston, D. L., Sullivan, G. A., Baker, E. W. and Sonenshine, D. (2014). TickBot: A novel robotic device for controlling tick populations in the natural environment. Ticks and tick-borne diseases.

Wright, C. L., Gaff, H. and Hynes, W. L. (2014). Prevalence of Ehrlichia chaffeensis and Ehrlichia ewingii in Amblyomma americanum and Dermacentor variabilis collected from southeastern Virginia, 2010-2011. Ticks and tick-borne diseases 5 (6) , pp. 978-82.

Stich, R. W., Blagburn, B. L., Bowman, D. D., Carpenter, C., Cortinas, M. R., Ewing, S. A., Foley, D., Foley, J. E., Gaff, H., Hickling, G. J., Lash, R. R., Little, S. E., Lund, C., Lund, R., Mather, T. N., Needham, G. R., Nicholson, W. L., Sharp, J., Varela-Stokes, A. and Wang, D. (2014). Quantitative factors proposed to influence the prevalence of canine tick-borne disease agents in the United 91����Ƶs. Parasites & vectors 7 , pp. 417.

Chitanga, S., Gaff, H. and Mukaratirwa, S. (2014). Tick-borne pathogens of potential zoonotic importance in the southern African Region. Journal of the South African Veterinary Association 85 (1) , pp. 1084.

Tracy, J. K., Schluterman, N. H., Greene, C., Sow, S. O. and Gaff, H. (2014). Planning for human papillomavirus (HPV) vaccination in sub-Saharan Africa: a modeling-based approach. Vaccine 32 (26) , pp. 3316-22.

Gaines, D. N., Operario, D. J., Stroup, S., Stromdahl, E., Wright, C., Gaff, H., Broyhill, J., Smith, J., Norris, D. E., Henning, T., Lucas, A. and Houpt, E. (2014). Ehrlichia and spotted fever group Rickettsiae surveillance in Amblyomma americanum in Virginia through use of a novel six-plex real-time PCR assay. Vector borne and zoonotic diseases (Larchmont, N.Y.) 14 (5) , pp. 307-16.

Alonzo, J., Gaff, H. and Watson, G. S. (2013). A Laboratory for Collaboration: Rehearsal Communication Skills for Biologists and Mathematicians. Biology International 53.

Gaff, H. and Nadolny, R. (2013). Identifying requirements for the invasion of a tick species and tick-borne pathogen through TICKSIM. Mathematical Biosciences and Engineering 10 , pp. 625–635.

Adongo, D., Fister, K., Gaff, H. and Hartley, D. (2013). Optimal control applied to Rift Valley fever. Natural Resource Modeling 26 , pp. 385–402.

Niu, T., Hartley, D., Papelis, Y. and Gaff, H. (2012). An epidemiological model of Rift Valley fever with spatial dynamics. Computational and Mathematical Methods in Medicine 2012 , pp. 1–12.

Hartley, D., Barker, C., A Le Menach, Niu, T., Gaff, H. and Reisen, W. (2012). The effects of temperature on the emergence and seasonality of West Nile virus in California. American Journal of Tropical Medicine & Hygiene 86 , pp. 884–894.

Fedrow, A., Wright, C., Gaff, H., Sonenshine, D., Hynes, W. L. and Richards, A. (2012). In vitro propagation of Candidatus Rickettsia andeanae isolated from Amblyomma maculatum. FEMS Immunology and Medical Microbiology 64 (74-81).

Alexanderian, A., Gobbert, M., Fister, K., Gaff, H., Lenhart, S. and Schaefer, E. (2011). An age-structured model for the spread of epidemic cholera: analysis and simulation. Nonlinear Analysis: Real World Applications 12 , pp. 3483–3498.

Gaff, H., Lyons, M. M. and Watson, G. S. (2011). Classroom manipulative to engage students in mathematical modeling of disease spread: 1+1 = achoo!. Mathematical Modeling of Natural Phenomena 6 (6) , pp. 215-226.

Tracy, L., Gaff, H., Burgess, C., Sow, S., Gravitt, P. and Tracy, J. (2011). Estimating the impact of human papillomavirus (HPV) vaccination on HPV prevalence and cervical cancer incidence in Mali. Clinical Infectious Diseases 52 , pp. 641–645.

Mukandavire, Z., Liao, S., Wang, J., Gaff, H., Smith, D. and Morris, J. G. . (2011). Estimating the reproductive numbers for the 2008-2009 cholera outbreaks in Zimbabwe. Proceedings of the National Academies 108 (21) , pp. 8767-8772.

Nadolny, R. M., Wright, C. L., Hynes, W. L., Sonenshine, D. and Gaff, H. (2011). Ixodes affinis (Acari: Ixodidae) in southeastern Virginia and implications for the spread of Borrelia burgdorferi, the agent of Lyme disease. Journal of Vector Ecology 36 (2) , pp. 464 - 467.

Gaff, H., Burgess, C., Jackson, J., Niu, T., Papelis, Y. and Hartley, D. (2011). Mathematical model to assess the relative effectiveness of Rift Valley fever countermeasures. International Journal of Artificial Life Research 2 (2) , pp. 1-18.

Hartley, D. M., Rinderknecht, J. L., Nipp, T. L., Clarke, N. P., Snowder, G. D., Gaff, H. and Advisory Group, F. RVF. (2011). Potential effects of Rift Valley fever in the United 91����Ƶs. Emerging Infectious Diseases 17 (8).

Gaff, H. (2011). Preliminary analysis of an agent-based model for a tick-borne disease. Mathematical Biosciences and Engineering 8 (2) , pp. 465–475 .

Wright, C., Nadolny, R., Jiang, J., Richards, A., Sonenshine, D., Gaff, H. and Hynes, W. L. (2011). Tidewater Spotted Fever: Detection of Rickettsia parkeri in Gulf Coast ticks, southeastern Virginia. Emerging Infectious Diseases 17 (5) , pp. 896-898.

Gaff, H., Schaefer, E. and Lenhart, S. (2011). Use of optimal control models to predict treatment time for managing tick-borne disease. Journal of Biological Dynamics 5 , pp. 517–530.

Jungck, J. R., Gaff, H., Fagen, A. and Lobov, J. B. (2010). From the National Academies "Beyond BIO2010: Celebration and Opportunities" at the Intersection of Biology. CBE--Life Sciences Education 9 (3) , pp. 143-147.

Jungck, J. R., Gaff, H. and Weisstein, A. (2010). Mathematical Manipulative Models: In Defense of “Beanbag Biology”. CBE–Life Sciences Education 9 , pp. 201–211.

Neilan, R. M., Schaefer, E., Gaff, H., Fister, K. R. and Lenhart, S. (2010). Modeling optimal intervention strategies for cholera. Bulletin of Mathematical Biology 72 (8) , pp. 2004-2018.

Lyons, M. M., Ward, J. E., Gaff, H., Hicks, R., Drake, J. and Dobbs, F. (2010). Theory of island biogeography on a microscopic scale: organic aggregates as islands for aquatic pathogens. Aquatic Microbial Ecology 60 (1).

Gaff, H. and Schaefer, E. (2009). Optimal control applied to vaccination and treatment strategies for various epidemiological models. Mathematical Biosciences and Engineering 6 , pp. 469-492.

Duke-Sylvester, S. M., Perencevich, E. N., Furuno, J. P., Real, L. A. and Gaff, H. (2008). Advancing epidemiological science through computational modeling: a review with novel examples. Annales Zoologici Fennici 45 , pp. 385-401.

Gaff, H., Gross, L. and Schaefer, E. (2008). Results from a mathematical model for human monocytic ehrlichiosis. Clinical Microbiology and Infection 15 (s2) , pp. 15-16.

Gaff, H., Hartley, D. and Leahy, N. (2007). An epidemiological model for Rift Valley fever virus, Electronic Journal of Differential Equations. 2007 (115) , pp. 1-12.

Gaff, H., Hartley, D. and Leahy, N. (2007). An epidemiological modelfor Rift Valley fever virus. Electronic Journal of Differential Equations 2007 115 , pp. 1-12.

Gaff, H. and Gross, L. J. (2007). Analysis of a tick-borne disease model with varying populaton sizes in various habitats. Bulletin of Mathematical Biology 69 , pp. 265-288.

Joshi, H. R., Lenhart, S., Lou, H. and Gaff, H. (2007). Harvesting control in an integrodifference population model with concave growth term. Nonlinear Analysis: Hybrid Systems 1 , pp. 417-429.

Gaff, H. and Gross, L. (2007). Modeling tick-borne disease: a metapopulation analysis. Bulletin of Mathematical Biology 69 , pp. 265–288.

Gaff, H., Joshi, H. R. and Lenhart, S. (2007). Optimal harvesting during an invasion of a sublethal plan pathogen. Environmental and Development Economics 12 , pp. 673-686.

Furuno, J. P., Harris, A. D., Wright, M. O., Hartley, D. M., McGregor, J. C., Gaff, H., Hebden, J. N., Standiford, H. C. and Perencevich, E. N. (2007). Utility of active surveillance culturing for methicillin-resistant Staphylococcus aureus upon intensive care unit discharge. Infection Control and Hospital Epidemiology 28 , pp. 666-670.

Joshi, H. R., Lenhardt, S. and Gaff, H. (2006). Optimal harvesting in an integro-difference population model. Optimal Control Applications and Methods 26 , pp. 61-75.

Gaff, H., Chick, J., DeAngelis, D., Gross, L., Trexler, J. and Salinas, R. (2004). Evaluation of and insights from ALFISH: a spatially-explicit, landscape-level simulation of fish populations in the Everglades. Hydrobiologia 520 , pp. 73–86.

Gaff, H., DeAngelis, Gross, L., Salinas, R. and Shorrosh, M. (2000). A dynamic landscape model for fish in the Everglades and its application to restoration. Ecological Modelling 127 , pp. 33–52.

Book Chapters

Fister, K. Renee., Gaff, H., Lenhart, S., Numfor, E., Schaefer, E. and Wang, J. (2016). Optimal Control of Vaccination in an Age-Structured Cholera Model Mathematical and Statistical Modeling for Emerging and Re-emerging Infectious Diseases (pp. 221-248) Springer Nature.

Gauthier, D., Latour, R. J., Gaff, H. and Vogelbein, W. K. Mycobacteriosis in Chesapeake Bay Striped Bass (Morone saxatilis) Northeast Atlantic Coast Striped Bass Fisheries Management.

Gaff, H., Kocan, K. M. and Sonenshine, D. (2014). Tick-borne Rickettsioses II (Anaplasmataceae) Biology of Ticks Volume 2, Second Edition USA: Oxford 91����Ƶ Press.

Gammack, D., Schaefer, E. and Gaff, H. (2013). Global dynamics emerging from local interactions: agent-based modeling for the life sciences Mathematical concepts and methods in modern biology : using modern discrete models Amsterdam: Academic Press.

Gaff, H. and Schaefer, E. (2008). Metapopulation models in tick-borne disease transmission modelling Modelling parasitic Disease Transmission: Biology to Control Austin, TX, USA: Landes Bioscience / Eurekah.

Gaff, H. and Schaefer, E. (2008). Modeling parasitic Disease Transmission: Biology to Control Austin, TX: Biosceince / Eureukah.

Conference Proceeding

A, W. and Gaff, H. (2016). Ticky Business Simulation. Proceedings of the 2016 Student Capstone Conference Suffolk, VA: Virginia Modeling, Analysis and Simulation Center (VMASC).

A, W., C, W., E, S. and Gaff, H. (2015). Dynamics of two pathogens in a single tick population Proceedings of the 2015 Student Capstone Conference Suffolk, VA: Virginia Modeling, Analysis and Simulation Center (VMASC).

A, W., R, N. and Gaff, H. (2014). Modeling Effectiveness of Tick Control by a Species that Exhibits Predator-prey Role Reversal Proceedings of the 2014 Student Capstone Conference Suffolk, VA: Virginia Modeling, Analysis and Simulation Center (VMASC).

Drake Tillinghast, D. and Gaff, H. (2012). An agent-based model of the dynamics of a tick-borne disease Suffolk, Virginia: Proceedings of the 2012 Student Capstone Conference.

Eggleston, J., Gaff, H. and Watson, G. S. (2012). Mathematics in a biological context: the use of modeling, analysis and simulation to enhance STEM education Suffolk, Virginia: Proceedings of the 2012 Student Capstone Conference.

Wigglesworth-Ballard, L., Wiles, L. and Gaff, H. (2012). Simulation of infectious disease spread in a clinical lab setting: a pilot study Suffolk, Virginia: Proceedings of the 2012 Student Capstone Conference.

Goodman, K., Gaff, H. and De Leo, G. (2012). The application of interactive behavior change technologies to enhance patient education among adults diagnosed with diabetes Suffolk, Virginia: Proceedings of the 2012 Student Capstone Conference.

Scott, G. and Gaff, H. (2011). Preliminary modeling solutions for prevention of Medicare insolvency for the Baby Boomer generation Suffolk, Virginia: Proceedings of the 2011 Student Capstone Conference.

Alzahrani, M., Gaff, H. and Shuman, D. (2011). Using modeling and simulation to improve oral health services delivery in Norfolk Public Health District Dental Clinic, Little Creek Suffolk, Virginia: Proceedings of the 2011 Student Capstone Conference.

Goodman, K. and Gaff, H. (2010). An analysis of biosurveillance and potential threats to public health Suffolk, Virginia: Proceedings of the 2010 Student Capstone Conference.

Jackson, J. and Gaff, H. (2010). The use of Getis and Ord cluster analysis for analyzing rainfall data in relation to Rift Valley fever outbreaks Suffolk, Virginia: Proceedings of the 2010 Student Capstone Conference.

Wigglesworth-Ballard, L. and Gaff, H. (2010). Use of polyethylene microspheres to simulate hospital acquired infections: a teaching strategy for healthcare students and workers Suffolk, Virginia: Proceedings of the 2010 Student Capstone Conference.

Alzahrani, M. and Gaff, H. (2010). Using modeling and simulation to improve oral health services delivery Suffolk, Virginia: Proceedings of the 2010 Student Capstone Conference.

Presentations

Gaff, H., Sonenshine, D. and Squire, J. (September , 2016). Control of ticks through the use of a tick-killing robot Oral Presentation International Congress of Entomology Orlando, Florida.

Gaff, H. (July , 2015). Tick-borne disease models Oral Presentation Analysis and Differential Equation Meeting Salt Rock, South Africa.

Gaff, H. (July , 2015). Modeling tick-borne disease Oral Presentation Joint workshop on stochastic epidemic modelling and pseudo spectral solutions of PDEs Pietermaritzburg, South Africa.

Gaff, H. (March , 2015). Modeling tick control through the use of a tick-killing robot Oral Presentation UNISA-UP Workshop on Theoretical and Mathematical Epidemiology Pretoria, South Africa.

Gaff, H. (October , 2014). Manipulatives Engage Students in Building Causal Mathematical Models of Biological Phenomena Lecture Biomathematics, Ecology, Education and Research .

Gaff, H. (May , 2014). Modeling tick control through the use of a tick-killing robot Lecture AMS-Knoxville .

Gaff, H. (March , 2014). 2013 update on ODU Tick Research Group: invasions, robots and more Lecture MidAtlantic Tick Summit Maryland.

Gaff, H. (February 13, 2014). The potential for tick control through the use of a tick-killing robot Lecture Virginia Mosquito Control Meeting Virginia Beach, VA.

Gaff, H. (November , 2013). Invading Virginia: a comparison of the invasion patterns of Ixodes affinis and Amblyomma maculatum Lecture Entomological Society of America Annual Meeting Austin, Texas.

Gaff, H. (October , 2013). Modeling tick control through the use of a tick-killing robot Lecture Biomathematics and Ecology: Education and Research Marymount 91����Ƶ, Virginia.

Gaff, H. (June , 2013). Effect of host abundance on tick-borne pathogens Lecture Society for Mathematical Biology Annual Meeting Tempe, Arizona.

Gaff, H. (February , 2013). Prevention of Tick Borne Disease with Integrated Pest Management (IPM) Lecture Maryland Association for Environmental & Outdoor Education Annual Meeting Ocean City, Maryland.

Gaff, H. (March , 2012). Impact of migration patterns on tick-borne disease expansion Keynote/Plenary Address Illinois Section of the Mathematics Association of America Normal, Illinois.

Gaff, H. (January , 2012). Estimating tick-borne disease risk using modeling and surveillance Lecture International Conference on Mathematical and Theoretical Biology Pune, India.

Gaff, H. (January , 2012). Dynamics of tick-borne diseases during tick home range expansion Oral Presentation Mathematical Methods In Systems Biology And Population Dynamics AIMS Muizenberg Cape Town, South Africa.

Gaff, H. (December , 2011). Estimating tick-borne disease risk through surveillance and modeling Keynote/Plenary Address International Symposium on Biomathematics and Ecology: Education and Research Portland, Oregon.

Gaff, H. (September , 2011). Estimating tick-borne disease risk through surveillance and modeling Oral Presentation AWM 40th Anniversary Conference Brown 91����Ƶ.

Gaff, H. (July , 2011). Agent-based models of interacting populations 8th European Conference on Mathematical and Theoretical Biology, and Annual Meeting of The Society for Mathematical Biology Krakow, Poland.

Gaff, H. (July , 2011). Overview: Reports from US - African BioMathematics Initiative: Conservation Biology 8th European Conference on Mathematical and Theoretical Biology, and Annual Meeting of The Society for Mathematical Biology Krakow, Poland.

Gaff, H., Sonenshine, D. and Hynes, W. L. (June , 2011). In vitro propagation of Candidatus Rickettsia andeanae isolated from Amblyomma maculatum Oral Presentation 6th International Meeting on Rickettsiae and Rickettsial Diseases Herklion, Crete, Greece.

Gaff, H., Hynes, W. L. and Sonenshine, D. (June , 2011). Tidewater spotted fever: detection of Rickettsia parkeri in Gulf Coast ticks, Southeastern Virginia Oral Presentation 6th International Meeting on Rickettsiae and Rickettsial Diseases Herklion, Crete, Greece.

Gaff, H. (May , 2011). Results from tick survey in Southeastern Virginia, USA , and application to mathematical modeling 6th International Meeting on Rickettsiae and Rickettsial diseases Heraklion, Greece.

Gaff, H., Nadolny, R., Wright, C., Hynes, W. L. and Sonenshine, D. (February , 2011). Survey of Ticks in the Hampton Roads area: Mathematical Modeling 2010 Virginia Mosquito Control Board Association Annual Meeting Virginia Beach, VA.

Wright, C., Gaff, H., Nadolny, R., Sonenshine, D. and Hynes, W. L. (February , 2011). Survey of Ticks in the Hampton Roads area: Rickettsia parkeri 2010 Virginia Mosquito Control Board Association Annual Meeting Virginia Beach, VA.

Nadolny, R., Gaff, H., Wright, C., Hynes, W. L. and Sonenshine, D. (February , 2011). Survey of Ticks in the Hampton Roads area: Tick populations 2010 Virginia Mosquito Control Board Association Annual Meeting Virginia Beach, VA.

Gaff, H. (November , 2010). Estimating tick-borne disease risk with an agent-based model AMS Fall 2010 Southeastern Sectional Meeting Richmond, VA.

Gaff, H. (November 7, 2010). A hybrid agent-based, differential equation model to assess the impact of livestock movement on a potential Rift Valley fever epidemic Poster DTRA 2010 Chemical and Biological Defense Science and Technology Conference Orlando, Florida.

Wright, C., Nadolny, R., Sonenshine, D., Gaff, H. and Hynes, W. L. (November 5, 2010). Tidewater spotted fever: detection of R. parkeri in gulf coast ticks in southeastern Virginia VA Branch of the ASM2010 Annual Meeting Lynchburg, VA.

Gaff, H. (July , 2010). Mathematical modeling of the control of a tick-borne disease SIAM-LS10 Pittsburgh, Pennsylvania.

Gaff, H. (May , 2010). An initial mathematical model of the eco-epidemiology of mycobacteriosis in striped bass Workshop on Fish Health, Populations and Landscape Conservation Leetown, West Virginia.

Gaff, H. (January 5, 2010). Modeling spread of tick-borne disease Mathematical Methods in Systems Biology Israel.

Gaff, H. (October 24, 2009). Graduate School Opportunities NIMBioS Undergraduate Math Biology Conference, Knoxville, TN.

Gaff, H. (October 9, 2009). Optimal control of a tick-borne disease model The Second International Conference on Mathematical Modeling and Analysis of Populations in Biological Systems Huntsville, AL.

Gaff, H. (August , 2009). Preliminary report: An individual-based model of tick-borne disease American Society for Rickettsiology Annual Meeting Hilton Head, South Carolina.

Gaff, H. (July , 2009). Effects of migration on tick-borne disease risk Society of Mathematical Biology Vancouver, BR.

Gaff, H. (February , 2009). Teaching the biology and ecology of infectious disease through mathematics BIOED 2009 Christchurch, New Zealand.

Gaff, H. and Schaefer, E. (January , 2009). Metapopulation models in tick-borne disease transmission modeling SIAM Minisumposium on Mathematical Modeling of Natural Resources Washington, DC.

Gaff, H. ( 2008). Ticks, Mosquitoes, Diseases, and Mathematics Mathematics Association of America St. Michael's College, Vermont.

Gaff, H. ( 2008). Optimal control of metapopulation tick model Society of Mathematical Biology Annual Meeting Toronto.

Curry-Lourenco, K. A., Gaff, H., Marken, J. A., Pevencevich, E. N., Sechrist, S. R., Watson, G. S. and Wiles, L. (October 31, 2008). A Pilot Study to Assess the Impact of Various Infection Control Educational Tecniques and Practies on the Spread of Methicillin-Resistant Staphylococcus aureus in a Virtual Intensive Care Unit Multidisciplinary Research Presentations Norfolk, VA.

Gaff, H. (May , 2008). Modeling the emergence and transmission of Rift Valley fever 42nd Annual US-Japan Cooperative Medical Sciences Program in Virology Global Warming, the Environment, and the Emergence of Viral Diseases Satellite Symposium Nagasaki, Japan.

Gaff, H. (May , 2008). Results from a metapopulation model for Human Monocytic Ehrlichiosis (HME) 5th ESCAR/ASR International Meeting on Rickettsiae and Rickettsial Disease Marseille, France.

Gaff, H. ( 2007). Implementing Biology across the Mathematics Curriculum San Jose, CA.

Gaff, H. (November , 2007). TIMBER Appalachian 91����Ƶ 91����Ƶ.

Gaff, H. (August , 2007). Modeling tick-borne diseases: a metapopulation model Joint annual meeting San Jose, CA.

Gaff, H. (January , 2007). Making Models Useful to Decision-Makers New Orleans.

Gaff, H. (January , 2006). Optimal harvesting during an invasion of a sublethal plant pathogen Joint Mathematics Meeting San Antonio, Texas.

Gaff, H. (July , 2005). From Graduate School to a Tenure-Track Faculty Position Via the Scenic Route AWM Workshop: Career Transitions, SIAM annual meeting .

Gaff, H. (July , 2005). Optimal control of a simplified tick-borne disease model The modeling of disease using optimal control, SIAM Annual Meeting .

Gaff, H. (June , 2005). A Tick-Borne Disease Model - Spread adn Control of Ehrlichiosis Biomathematics in the Commonwealth Workshop Murray, Kentucky.

Gaff, H. (April , 2005). A tick-borne disease model Workshop on infectious disease: Theoretical, ecological and economic approach Trieste, Italy.

Gaff, H. (November , 2004). A Tick-Borne Disease Model - Spread and Control of Ehrlichiosis Other MD-DC-VA Section of the Mathematics Association of America Fall Meeting .

Gaff, H. (March , 2004). Spatial Spread and Transmission Dynamics of Smallpox Other ASM Biodefense Research Meeting .

Gaff, H. (October , 2003). Impacts of Spatial Heterogeneity on Plague Women of Applied Mathematics: Research and Leadership Conference .

Gaff, H. (January , 2003). Numerical results of optimal control applied to an integro-difference model with applications to biology AMS-MAA Joint Mathematics Meetings Baltimore.

Gaff, H. (November , 1998). The effect of spatial heterogeneity on the spread and control of a tick-borne disease Poster Entomological Society of America Annual Meeting Las Vegas.

Gaff, H. (July , 1998). The effect of spatial heterogeneity on a tick-borne disease Poster Society for Industrial and Applied Mathematics Meeting Toronto.

Gaff, H. (June , 1998). Across Landscape Model for Fish Densities in The Everglades of South Florida: Aiding Restoration Planning Poster American Society for Limnology and Oceanography Meeting St. Louis.

Gaff, H. (January , 1998). Session on Environmental Mathematics Other American Mathematics Society Meeting Baltimore.

• 2017: 91����Ƶ Women’s Caucus Achievement Award, Old Dominion 91����Ƶ
• 2016: Shining Star Award for Helping students succeed academically, professionally, or personally inside and outside of the classroom setting, Old Dominion 91����Ƶ Division of Student Affairs
• 2015: Shining Star Award for Helping students succeed academically, professionally, or personally inside and outside of the classroom setting, Old Dominion 91����Ƶ Division of Student Affairs
• 2013: Distinguished Teaching Award for Outstanding Tenure-Track Teacher, College of Sciences, Old Dominion 91����Ƶ
• 2013: AWM Service Award, Association for Women in Mathematics
• 2011: Shining Star Award for Helping students succeed academically, professionally, or personally inside and outside of the classroom setting, Old Dominion 91����Ƶ Division of Student Affairs
• 2010: Shining Star Award for Helping students succeed academically, professionally, or personally inside and outside of the classroom setting, Old Dominion 91����Ƶ Division of Student Affairs
• 2010: Shining Star Award for Helping students succeed academically, professionally, or personally inside and outside of the classroom setting, Old Dominion 91����Ƶ Division of Student Affairs
• 1999: Graduate Student Academic Achievement Award for Outstanding Academic Performance, 91����Ƶ of Tennessee, Knoxville
• 1998: Employee Team Excellence Award for Promoting the Spirit of Teamwork, 91����Ƶ of Tennessee, Knoxville