Tag: Poster 65

The Study on Global AGEing and Adult Health (SAGE): Body Composition Measurements among Aging Populations

Presenter: Austin Wong

Mentors: Josh Snodgrass and Melissa Liebert, Anthropology

Poster: 65

Major: Biology

Frequently used as a predictor of obesity-related health risks, body mass index (BMI) estimates general adiposity instead of abdominal obesity, and does not distinguish between fat and lean mass. Further, previous research has found it is possible for adults to maintain a normal BMI, yet increase their waist circumference (WC) over time.

This makes BMI a less accurate predictor of cardiometabolic risk in older adults (/50 years old). While measures of central obesity have been found to be better indicators of cardiovascular disease than BMI, debate continues over the optimal measure of central adiposity. The current study uses data from the World Health Organization Study on global AGEing and adult health (SAGE), a longitudinal study of nationally representative samples from older adults
in six middle income countries (China, Ghana, Mexico, India, Russian Federation, and South Africa). We examine associations among body composition measures (BMI, WC, waist-to-stature ratio, and body adiposity index) across age groups, sex, and country. Furthermore, this study investigates associations between body composition measures and hypertension. We hypothesize that: 1)abdominal obesity measures will increase with age groups but decrease in those over 80 years old, 2) stronger associations will be found between abdominal adiposity measurements and blood pressure, and 3) diverse associations will be found in the populations examined due to a variety of factors including diet, urbanization, and health care access.

Examining the Feasibility of Exon Skipping as a Potential Gene Therapy for USH1F Patients

Presenter: Willem Griffiths

Faculty Mentor: Jennifer Phillips, Judy Pierce

Presentation Type: Poster 65

Primary Research Area: Science

Major: Biology

Usher syndrome (USH) is the most frequent cause of hereditary deaf-blindness, accounting for over 50% of the deaf- blind population. USH type 1F, one of the most severe forms of USH, is rare globally, but the Founder effect has made it the most prevalent type of USH in the Ashkenazi Jewish population. USH1F patients have profound congenital deafness and early-onset progressive vision loss due to photoreceptor degeneration. USH1F is caused by mutations in the PCDH15 gene, which encodes a large, multidomain cell adhesion protein. The truncated PCDH15 protein disrupts the organization of stereocilia in the inner ear and leads to dysfunction and eventual death in photoreceptor cells. Due to the size and complex alternative splicing of PCDH15, the straightforward gene-replacement therapies being pursued for other forms of USH are not feasible for this gene. We are testing the feasibility of using an antisense splice-inhibitor to delete Exon 8 from the PCDH15 transcript. Although the resulting protein would be slightly shorter than normal, all downstream functional domains would remain intact, so it is possible that this modified form of PCDH15 would maintain its functional integrity in the absence of Exon 8. Zebrafish mutants with nonsense mutations in the orthologous pcdh15 exon have been generated via targeted mutagenesis using CRISPR/Cas9 gene editing. These loss of function mutants display phenotypes characteristic of human USH1F. The Exon 8 splice-blocking oligonucleotides will be tested on these mutants in order to determine whether the modified pcdh15 protein can rescue the phenotype.

Abundance, Density, and Diet of Duikers at Lomako, DRC

Presenter(s): Troi Feinberg − General Science

Faculty Mentor(s): Frances White, Colin Brand

Poster 65

Research Area: Natural Science

Duikers are a widespread family of tiny forest-living antelope that occur across sub-Saharan Africa. While approximately 22 species have been identified, little is known about the biology and behavior of many of these species due to their solitary and reclusive nature. Additionally, these species are sensitive to human disturbance and are often among the first species to be hunted and relocate. The objective of this study was to characterize the abundance and density of duikers inhabiting the forest near the N’dele field site in the Lomako Forest Reserve, Democratic Republic of Congo. Auditory or visual observation of duikers was recorded using all-occurrence sampling over nine months from 1983-1984. We also analyzed stomach contents of animals taken by hunters from outside the study area to gain insight on their diets. We encountered three species of duiker at the field site: Cephalophus weynsi, Cephalophus silvicultor, and Philantomba monticola. We detected C. weynsi 63 times, C. silvicultor once, and P. monticola 35 times. A preliminary estimate of overall density was 4.075 per sq. km. across all species. This result is comparable to duiker densities in other protected areas. Analyses of stomach contents (N=6) revealed that C. weynsi consumed at least 23 different plant species, including the following most prevalent food items: Celtis tessmanii, Dialium sp., and Landolphia congolensis. These data contribute to our broader understanding of duiker biology and are useful for monitoring trends in population size and density at this location over time.

Early Observational Data on Arthropods Associated with Winter Decomposition in the Pacific Northwest

Presenter(s): Brittany Falconer

Faculty Mentor(s): Jeanne McLaughlin

Poster 65

Session: Sciences

Forensic Entomology plays an important role within the field of medicolegal death investigations. By studying the presence of certain arthropod species, scientists are able to provide an estimate of post-mortem interval (PMI), or how long an individual has been deceased, for a set of remains in question. This estimate of PMI is based on a known set of growth, development, and succession patterns for necrophagous and predatory arthropods that are associated with remains. Though forensic entomology provides important information for forensic investigators, there are a multitude of factors that can affect succession patterns. Geographic location and temperature are two big factors that can influence how arthropods behave. In a separate research project studying winter decomposition rates using pig heads, insect activity appeared to contradict previously known arthropod succession rates and temperature thresholds. Arthropods exhibit a lower thermal limit, sometimes called a critical thermal minimum, which affects their activity in lower temperatures. Within the research site, maggot activity was present throughout the cold winter temperatures, many days well below freezing. Additionally, female flies needing to lay eggs tend to appear on decomposing remains first, then necrophagous and predatory beetles follow after. The first arthropods observed on the remains were beetles, contradictory to previous observations. Geographic location also influences the behavior of certain species of arthropods and could affect how the arthropods within the research site were behaving.