Interdisciplinary

Jacobus de Roode, PhD

PROFESSOR, EMORY COLLEGE OF ARTS AND SCIENCES, BIOLOGY

Lance Waller, PhD

PROFESSOR, ROLLINS SCHOOL OF PUBLIC HEALTH, BIOSTATISTICS AND BIOINFORMATICS

Applying Landscape Statistics and Agent-based Modeling to the Biology of Animal Migration

Billions of animals, including whales, turtles, and butterflies, undertake long-distance seasonal migrations. Despite decades of study, we still do not understand how animals navigate to locate their migration destinations. Biologists like to believe that migratory animals know their ultimate destination and how to get there, a process known as “true navigation”. However, animals may instead rely on simpler mechanisms, following rules such as “fly south when temperatures drop”, a process known as compass navigation. A major impediment to distinguishing these strategies is a lack of data-based statistical and modeling approaches tailored to the study of animal migration. Another impediment is that biologists often neglect the importance of landscape characteristics. Thus, although it may seem that animals “know” where to go, they may simply get funneled through the landscape by mountains and oceans. We will develop statistical and agent-based models to study animal migration and validate these models using data relating to the migration of the iconic monarch butterfly. North American monarchs undertake a spectacular annual migration by which they fly up to 4,500 km to reach overwintering sites in Mexico. Combining the spatial statistical expertise of PI Waller with the biological studies of PI de Roode, this interdisciplinary proposal will determine the importance of landscape features in driving monarch migration, and reveal whether monarchs “know where to go” or follow simpler rules to reach their overwintering sites. Validating our methods in a well described system will increase applicability to other migrant species, many of which are important for public health.

Ebrahim Haroon, MD

ASSOCIATE PROFESSOR,SCHOOL OF MEDICINE,PSYCHIATRY AND BEHAVIORAL SCIENCES

Deqiang Qiu, PhD

ASSOCIATE PROFESSOR, SCHOOL OF MEDICINE, RADIOLOGY AND IMAGING SCIENCES

Identifying Neurodegenerative Risk in the Inflammatory Subtype of Depression

Depressed individuals are at a 2-5-fold higher risk of developing Alzheimer’s Disease (AD). Identifying depressed patients at elevated risk of developing dementia can lead to early preventive therapies. One pathway contributing to this risk is chronic inflammation, which is seen among ~30% of subjects with major depression (MD) and in early/preclinical stages of AD. Inflammation is well-known to stimulate pathologies akin to brain degeneration among depressed and non-depressed individuals in their middle-ages (40+). Our main prediction is that depressed individuals with increases in inflammation will be at a greater risk of developing dementia. We believe that this risk could be identified and tracked using plasma and spinal fluid (CSF) measures of AD-related proteins such as beta-amyloid and tau. Under Aim 1, we will examine if inflammatory markers in the blood of depressed individuals are related to increases in AD markers in the plasma and CSF. Aim 2 will examine if depressed individuals with combined increases in inflammation and AD markers will demonstrate greater changes in brain regions with increased vulnerability to AD. Finally, Aim 3 will examine if increases in inflammatory and AD markers will predict cognitive difficulties in depression. We will use plasma and spinal fluid samples from 56 depressed and 25 non-depressed individuals who have participated in an ongoing study on depression to measure immune and AD markers. Our goal is to use the data collected from this experiment to inform the design of a larger study to be funded by NIH.