Tag: Poster 6

Pace of Early Epiphyseal Fusion in Captive Macaca

Presenters: Samantha Buckley and Sarah Walker

Mentor: Frances White

PM Poster Presentation

Poster 6

Epiphyseal fusion is an important developmental indicator in all mammals. Among cercopithecids, the sequence of epiphyseal fusion is known but the pacing of these fusions is uncertain. The pace at which the fusion occurs is a window into the growth of an animal that the fusion sequence alone cannot provide. The pace and sequence of epiphyseal fusion in long bones are reported here from a sample of 23 Macaca mulatta from the UO Grand collection, consisting of captive juveniles of known age. We scored 33 epiphyses on 25 bones, including all major long bones, the pelvis, and metapodials. We scored the epiphyses as “0” if there was no fusion, “1” if the joint is fusing, and “2” if the epiphysis has completely fused to the diaphysis. All specimens were scored by two coders to ensure intercoder reliability. Only scores with full agreement were included. Because we scored epiphyses in the process of fusing, we are able to comment on the pace of fusion within M. mulatta more than previous studies. Results indicate that metapodial fusion has begun by birth, but continues to fuse until 60 months. Our only explanation for their typical exclusion from fusion charts is because metapodials fuse so early. Addi- tionally, by twelve months, five other epiphyses have begun to fuse: proximal and distal humeral epiphyses, proximal tibia, femoral head, and the greater trochanter. Our results agree with those previously reported by Cheverud (1981). Our sample is younger, allowing us to add new data especially on metapodial fusion.

More Than Just Words: EMOTAIX-Tropes Examines Linguistic Predictors of Mental Health

Presenter: Jackie Cowell

Mentor: Jennifer Ablow

Poster: 6

Major: Psychology 

Given the fundamental role that language plays in our lives, it is apparent that the words people use reveal information the ways in which they experience and interact with those around them. Examining the language use of at-risk first- time mothers is especially pertinent as risk factors such as maternal depression and anxiety lead to adverse child outcomes including delayed emotional development, behavioral problems and lower IQ (Bergman et at., 2007). To broaden the understanding of how language is used in emotion processing with regards to mental health outcomes, we used EMOTAIX-Tropes, a text-analysis software program aimed at assessing the emotional lexicon, to examine 65 first-time mothers’ use of emotion language such as words denoting worry, happiness, or anger. The women were interviewed using the Adult Attachment Interview (AAI) and were recorded and transcribed verbatim, then analyzed via EMOTAIX-Tropes, which divides and classifies emotion terms into semantic categories according to valence (positive or negative). Additionally, participants filled out questionnaires to assess levels of depression (CESD) (Radloff, 1977), anxiety (BAI) (Beck, Brown, Epstein & Steer, 1998), trauma history (TSC) (Elliot & Briere, 1992), alexithymia (TAS) (Bagby, Parker & Taylor, 1994), and intelligence (Shipley, 1940). We hypothesized that participants’ emotional language would correlate with self-reported measures of distress, such that those with greater symptomatology will use more negative affect terms. Preliminary Results show that depression is positively correlated with the use of negative emotion words. Further analyses will look at the correlation between emotion language and other mental health factors.

Correlations between Static and Dynamic Asymmetry in Runners

Presenter: Varneet Brar

Mentors: Li-Shan Chou and JJ Hannigan, Human Physiology

Poster: 6

Major: Human Physiology 

Asymmetry between limbs can be assessed statically, as measured by passive flexibility and range of motion (ROM), and dynamically, as measured by joint angle ROM during gait. Both types of asymmetry have been suggested as possible factors in developing a lower limb injury. The purpose of this study was to identify if there is a correlation between static and dynamic asymmetry. Sixty healthy subjects running at least 20 miles per week participated in the study. Dynamic joint angle ROM for the hip and knee was collected as subjects ran continuous laps in the UO Motion Analysis Laboratory using a 10 camera motion capture system. Static flexibility and ROM were measured by a trained clinician using a goniometer. Static and dynamic asymmetry between limbs was then calculated using an established method: the symmetry index (SI). Pearson correlation coefficients were used to test the strength of the relationships between static and dynamic SI. A moderate, significant correlation was found between static hip internal rotation ROM and dynamic hip internal rotation ROM (r = 0.296, p = 0.035). No additional significant correlations were found. As internal hip rotation has been linked to lower limb injury, future studies should investigate whether clinical correction for static asymmetry, especially for hip internal rotation, alters asymmetry during running gait. Correcting these asymmetries may help prevent injury setbacks for both recreational and competitive runners.

Searching for Simpler Models of Astrophysical Pattern Formation

Presenter: Eryn Cangi

Co-Presenters: Daniel Abrams

Faculty Mentor: Daniel Abrams, James Imamura

Presentation Type: Poster 6

Primary Research Area: Science

Major: Physics

Funding Source: REU, National Science Foundation and Northwestern University, $4500

In astrophysics, it is easy to solve problems relating two objects, such as two stars in a binary star or a planet and its moon. Systems of more than three bodies are both unsolvable analytically (“by hand”) and require large amounts of computation time to simulate, scaling with the square of the number of objects. Thus, astrophysical synchronization, in which orbital periods of objects converge, is well understood for systems of two or three objects but largely unexplored for systems of many objects. We investigate the possibility of using mathematical models of nonlinear oscillations (in which objects that oscillate in some way change their frequency in a non-constant fashion) in lieu of Newtonian gravitation to understand how systems of astronomical objects form larger structures. In particular, we use methods drawn from the study of the Kuramoto model, a model which has been used to describe synchronization in systems containing many similar objects, such as the blinking of fireflies or people marching across a bridge. With modification, this model can produce either strong synchronization (one synchronized group) or partial synchronization (two or more groups of synchronized objects form). This partial synchronization may be suggestive of astronomical systems. As an example, we developed a model for N small objects orbiting a massive planet and in MATLAB. Preliminary models show promise that this approach will yield new insight into astronomical synchronization across a range of length scales.

Dominance Hierarchies Are Not Linear in Semi-Free Ranging Black and White Ruffed Lemurs (Varecia variegata)

Presenter(s): India Brock − Biological Anthropology, Environmental Science

Co Presenter(s): Nora Sawyer

Faculty Mentor(s): Frances White, Colin Brand

Poster 6

Research Area: Primate Behavioral Ecology

Dominance rank and the linearity of social hierarchies have important consequences for social behavior in many species, including many primates. Of particular interest are lemurs, which are the only taxonomic primate group that exhibits female feeding priority and social dominance in multiple genera, including Varecia. Previous research has revealed significantly linear dominance hierarchies in some female dominant species (Lemur catta) but not others (Propithecus verreauxi). Here, we investigate the dominance linearity of another female dominant lemur species: the black and white ruffed lemur. We predicted the dominance hierarchy to be significantly linear both before and after rank changes. We collected behavioral data on semi- free ranging ruffed lemurs (N=8) housed at the Duke Primate Center. We used all-occurrence sampling to record interactions between individuals between Sep 1991 and Mar 1993. We constructed dominance matrices using decided interactions and split the data into one of three time periods based on the eviction of a dominant female. We calculated the dominance linearity (h’) for each time period. Contrary to our prediction, we found no significance difference in linearity across any of the time periods: Pre-Event (h’=0.37, ns), Event (h’=0.33, ns) Post-Event (h’= 0.33, ns). This study demonstrates that ruffed lemurs exhibit a more shallow hierarchy more similar to P. verreauxi than to L. catta.

Determining the Function of LRIG1 in Colon Cancer Cell Behavior

Presenter(s): TJ Ekstrom

Faculty Mentor(s): Anne Zemper & Kate Walsh

Poster 6

Session: Sciences

Regulation of the Epidermal Growth Factor Receptor (EGFR) signaling cascade is critical for cellular homeostasis. Disruption of EGFR control of cell migration and proliferation is seen in many types of cancer cells. The transmembrane protein, Leucine-rich repeats and immunoglobulin-like domains 1 (LRIG1) controls cellular growth via negative regulation of the ErbB family of receptor tyrosine kinases, including EGFR. LRIG1 functions as a tumor suppressor and its expression is often reduced in cancers. In vitro studies of LRIG1 expression could lead to new insights into its regulatory role in highly proliferative tissues like the colon. The colon is a dynamic organ where EGFR and its regulation by LRIG1 may be essential in maintaining homeostasis. The colonic cancer cell line Caco-2 will be used to overexpress LRIG1 and determine changes in EGFR signaling. To overexpress LRIG1, the cells were transfected using a constitutively expressed myc tagged LRIG1 plasmid and selected for using an antibiotic. A scratch assay was performed on cell lines to assess changes in cellular migration and proliferation behavior. An increase of LRIG1 protein in the transfected cells is expected to decrease migration and proliferation. The activity of proteins negatively regulated by LRIG1 within the EGFR signaling cascade including proteins such as pEGFR and pErk 1/2 will decrease as viewed by western blot analysis and immunocytochemistry. Successful manipulation of the Caco-2 cell line will create an in vitro tool to study LRIG1 and its correlation to colon homeostasis.