Tropical Forest Regeneration Patterns and Conservation Strategies in Costa Rica

This week (24 Jan) the second half of the One Health Exchange session focused in on patterns of tropical forest regeneration and their impacts on coastal gradients, and species interaction.  A discussion lead by Dr. Erin Stewart Lindquist PhD (Assistant Professor of Biological Sciences and Coordinator of Environmental Sustainability at Meredith College) centered mainly on her research at the Cabo Blanco Absolute Natural Reserve, located on the Pacific side of Costa Rica on the southern tip of the Nicoya Peninsula.

Historically, much of Costa Rica’s forests were either over harvested or cleared for raising cattle and only 15% of the nation’s forests still remain.  The Cabo Blanco Absolute Natural Reserve was first instated in 1963 and thus serves as an excellent opportunity to study forest regeneration. 

In a major publication co-authored by Gini Knight, Common Trees of Cabo Blanco Absolute Nature Reserve / Arboles Comunes de la Reserva Natural Absoluta Cabo Blanco, Dr. Lindquist described the forest as having a diverse species richness with seasonal rain and seasonal flowering plants.  But perhaps more importantly, the team described the forest’s environmental gradients comprised of two main areas; a small coastal forest, and a larger inland forest. 

This unique dichotomy gave way to an interesting and profound discovery as Dr. Lindquist began to study two populations of land crabs that lived in the coastal forest.  She described an inverse relationship between the density of the crab populations and tree density, species richness, seed survivorship, and seedling survivorship; needless to say, the crab population held major implications for the forest environment.

Tying it back into our One Health Exchange, a rich understanding of forest regeneration is vital to human, animal, and environmental health.  Forests can serve as an incredible natural resource allowing for the natural production of medicines, food, shelter, fuel, industry, etc.  With so much continual deforestation today, an understanding of how forests regenerate based on human and animal interaction is crucial.

Post authored by Christopher Akiba, UNC MPH candidate

Up next (31 Jan) Pollutants and Environmental Health by Joel Meyer, PhD, Assistant Professor of Environmental Toxicology at Duke and Mercury dynamics in aquatic systems: linking natural resource management with human health policy by Derek Aday, PhD, Associate Professor of Biology at NCSU 

The Neem Tree: Nature's Bio-Defense at its Best

One of the speakers this week was Dr. Peter Radtke, PhD and CEO of JustNeem. JustNeem is a corporation based in the Triangle that produces skin care products made from neem that is sourced from Mauritania, where they support neem planting and reforestation. The presentation explained the medical and environmental uses of neem, and the economic and social benefits of neem plantations. neem can survive temperatures up to 40°c and salinity up to a third of sea water, giving it the ability to grow in Sub Saharan Africa, and even desert countries like Saudi Arabia. This unique ability to survive in hostile environments makes it an ideal candidate for reforestation and dune stabilization, thus providing a source of livelihood in underdeveloped desert countries.

The medicinal properties of neem come from its remarkable array of bioactive compounds. Dr. Radtke explained his realization of how this came to be – that all living things are in a constant fight for survival, and the defenses that the neem tree has evolved can be harnessed to fight our own potential pathogens. Almost every part of the neem tree’s body has bioactive compounds. These compounds have anti-viral, anti-fungal, anti-bacterial, and anti-inflammatory properties among others. Each component has a somewhat different mode of action, so no pathogen has been able to evolve resistance against them.

When questioned about whether anyone has tried to create synthetic compounds based on the bioactive molecules, Dr. Radtke remarked that he is grateful that nobody has succeeded – a synthetic molecule working independently would eventually lead to the development of resistance. The amazing thing about these bioactive components are that they are toxic to pathogens that are detrimental to human health and economics, but have been found safe for other organisms so far. Neem has been used extensively in the Indian subcontinent for thousands of years without any toxic effects on humans.

The question of neem’s persistence in the environment was also raised. With a half-life of about two weeks, these compounds are safe but short-lived. A sun protectant vehicle and certain delivery methods can extend its half-life in the environment.

There was a final discussion about the veterinary use of neem. Its bitter taste, lack of toxicity and medicinal properties make it an ideal product for certain veterinary uses, such as a flea repellant in young animals, or wound healing for wild and large animals. 

Post authored by Dipika Kadaba, veterinarian and graduate student at Duke University's Nicholas School of the Environment.

The One Health Journey: Personal Epiphanies & the History of One Health

This week we were privileged to hear from Cheryl Stroud, DVM, PhD, and Rear Admiral William Stokes, DVM, DACLAM, on their personal journeys to an awareness of One Health and on the history of One Health itself.

Dr. Cheryl Stroud opened with a quote from Robert Virchow: “between animal and human medicine there are no dividing lines – nor should there be.” She went on to describe her experience of growing up on a hobby farm and becoming a veterinarian, but only realizing the importance of One Health as various members of her family dealt with undiagnosed zoonoses. She noted that the veterinarian’s oath includes “promotion of public health,” a commitment that leads directly to a One Health view. While specialization is important and has led to many advances in all areas of health, it is also crucial to maintain enough of a generalist view to be able to deal with or appropriately refer issues that would be outside a practitioner’s usual scope. Dr. Stroud also gave a brief overview of the history of One Health, from Rudolph Virchow’s origination of the term “zoonosis” to the more recent tendency towards specialization and then back towards One Health with the establishment of the North Carolina One Medicine Symposium in 2000.

Rear Admiral William Stokes shared his personal journey, from growing up on a farm and wanting to be a veterinarian to his current position as Assistant Surgeon General and Rear Admiral in the U. S. Public Health Service and director of the National Toxicology Program. Dr. Stokes spoke of the impact Rachel Carson’s Silent Spring had on sparking in him an interest in ecological health and described his career path as a veterinarian for the U.S. Army and then the U.S. Public Health Service. He advised his listeners to always be ready to do whatever is needed in a given situation. Dr. Stokes stressed that One Health should be viewed not only as a public health concept but should embrace research, clinical practice, and education. He recommended the 2011 National Prevention Strategy: America’s Plan for Better Health and Wellness as a valuable resource.

During the question and answer period, the discussion turned towards the problem of silos within silos—even just within the field of human medicine there is fragmentation with different healthcare practitioners, such as doctors, nurses, and physical therapists, not always working effectively together. One Health provides an excellent framework for greater collaboration both between and within human, animal and environmental health.

Up next (January 24): Peter Radke and Magda Radke speaking on The Neem Tree: Nature’s Bio-Defense at its Best and Erin Lindquist addressing Tropical Forest Regeneration in Costa Rica.

Post authored by: Esther Giezendanner UNC MPH candidate

What is One Health?

The One Health Intellectual Exchange course is off and running! The first meeting of the semester, taking place on January 10, featured a panel of North Carolina One Health Collaborative Steering Committee Members and provided students with an overview of the One Health movement.

After an introduction to the concept, course, and consortium by One Health Chair Dr. Cheryl Stroud, Dr. Chris Woods, Associate Professor in the Departments of Medicine and Pathology at Duke University, discussed what led him to work with One Health as well as his perspective on what One Health means. To paraphrase, One Health is a holistic approach to solving the world’s public health problems.

Dr. Suzanne Kennedy-Stoskopf, Research Professor of Wildlife Infectious Disease in the Department of Clinical Sciences at the North Carolina State University College of Veterinary Medicine, presented three photos of animals that weren’t quite normal and challenged us to identify what was going on. One that sticks out was a koala being given water on a road by a biker. Upon reflection by several participants, we concluded that a severe drought in Australia in 2009 had resulted in animals, like the koala, taking extreme measures to survive (in this case, a koala leaving the comfort of eucalyptus trees to approach humans for water). When wild animals interact with humans, something most likely is wrong. Furthermore, since over 70% of emerging infectious diseases originate in wildlife, these interactions are an even greater cause for concern.

Australia, 2009: What’s going on?

To wrap up the first session, Dr. Vivian Doelling, Senior Scientist, NICEATM, Integrated Laboratory Systems, reflected on the role and perspective of industry regarding veterinary vaccines. In case you missed it: There are a lot of veterinary vaccines! Around 2000 products target 213 different animal diseases. How do we balance the needs of disease prevention and safety with the profit-driven nature of the producers? Who pays for certain vaccines for animals aimed at protecting human health? This topic led to a valuable discussion which will hopefully continue in the coming weeks.

Up next (17 Jan 2012): Dr. Stroud and Rear Admiral William Stokes of the National Institute of Environmental Health Science will be discussing “The One Health Journey: Personal Epiphanies & the History of One Health.”

Post authored by: Micheal Zelek, UNC MPH candidate