2010

Top Oral Presentations

Tingjia Lao, Zoology - Morphological Homology vs. Developmental Homology - A Case Study Using Insect Wing Veings

Two structures can be homologous when they have a common origin. Morphological similarity is an important character to identify homology (morphological homology). However, morphological similarity can be deceivable because intensive evolutionary modification and convergent evolution. Comparison of developmental system is an alternative mean to identify homology (developmental homology). Utilizing these two homology concepts is powerful to understand the evolution of homologous structures. Interestingly, however, the two concepts sometimes bring different, even controversial results.

In our research, we use insect wing veins as a model system to further understand the relationship between these two homology concepts. All extant insect wings are thought to be homologous, and it is even possible to homologize each wing vein among different species. We have analyzed developmental homology of wing veins in two insects, Drosophila and Tribolium. Wing vein formation has been well studied in Drosophila, identifying a battery of "vein genes" important for vein formation. We depleted the function of these vein genes in Tribolium via RNA interference (RNAi), and compared the obtained phenotypes to those in Drosophila. RNAi for most of these genes in Tribolium resulted in abnormality in vein formation, suggesting that the function of these "vein genes" has been conserved since their last common ancestor. Interestingly, however, the affected veins were somewhat different between species. This is puzzling as these results suggest that the underlying developmental mechanism for the morphologically homologous structures can be different, adding another complication to the two homology concepts. We will discuss the possible explanation for this apparent disagreement.

Lydia Manning, Sociology and Gerontology - The Lived Experience of Spirituality: A Phenomenological Exploration of Women's Spirituality in Advanced Age

Research suggests that spirituality is important to a large percentage of the older adult population.  Against the backdrop of a dramatic increase in the number of individuals living longer, particularly older women, it is vital that researchers explore the intersection of spirituality and aging for women in late life.  This project explores the experience of spirituality through individual interviews with 15 women ages of 8o and older using a phenomenological approach. I investigate how these women "experience" their spirituality. I present an understanding of their spirituality that is grounded in the voices and descriptions of women in my study.  This research is significant in that it recognizes the importance of spirituality in the lives of women in advanced age by providing scholarly and intellectual expression regarding the experiences and voices of older women, a population that has been traditionally understudied and marginalized.  In addition, this research addresses the knowledge gap in the current research on spirituality and women within gerontology.  Findings include how the women in this study: use spirituality as a resource; experience their spirituality in the context of relationships; and demonstrate their spirituality as a pathway to resilience.

Mandy Zylstra, Kinesiology and Health - Active Workstations at Work: The Impact of Walking While Working on Leisure Time Physical Activity

Levels of physical activity at work are decreasing as jobs and technology change.  The active workstation is a potential solution to incorporating more physical activity into the office setting, as studies have demonstrated that users of an active workstation burn more calories than they would if they were sitting by allowing employees to walk and work at the same time.  With roughly half of the working population employed in sedentary occupations, transformation of the built work environment by introducing the option of walking while at work is a plausible option to increasing the employee's physical activity levels and fight cardiovascular diseases, obesity, diabetes, etc.  However, it is not known how increasing physical activity levels at work impacts levels of physical activity level during their leisure time.  This study examined the impact of using an active workstation at work on leisure time physical activity levels.  Four participants used the active workstation for one year.  Their levels of physical activity were measured using an accelerometer at baseline, 4, 8, and 12 months, to see if levels of leisure time activity changed as a result of walking at work.  Accelerometer data was analyzed in SPSS using a repeated measures ANOVA to examine how activity levels for the entire day, work day, and non-work day (DV) compared across time (IV).  Results demonstrated that there was a significant difference across time for both the entire day (F(4,12)= 3.294; p<.05; Eta2 = .483) and the work day (F(4,12)= 3.714; p<.03; Eta2=.553), but there was no significant difference across time for the non-work day (F(4, 12)= .675; p>.05; Eta2=.184).  Even with low statistical power, these results demonstrate that active workstation usage increases activity levels during the workday, but does not affect leisure time physical activity levels.  This was a preliminary study and further research is needed with more participants to verify the findings.

 Top Poster Presentations

Gwen Bausmith, Lore Denisse Rivera Hernandez, & Sarah Van Frank, Institute of Environmental Science - Crawford House and Woods Demonstration Site

The Crawford House and Woods' rebirth as a demonstration site for eco-friendly living practices, energy efficiency and as a historical touchstone is the brainchild of The City of Hamilton's Vision 2020 Commission's Green Committee. Originally built in 1835, the brick structure has been a fixture in the community for many years, serving various public purposes in the last few decades, but lately falling into disrepair. Recognizing an opportunity to go beyond simply demolishing or refurbishing the structure, the committee set out to reintroduce the homestead as a place for learning, gathering, gaining inspiration and improving the image of the city for residents and visitors alike.  Our team of Miami University IES graduate students, has prepared a comprehensive feasibility report for achieving the committee's vision by concentrating on the concepts of creating a local demonstration site, educating visitors about the benefits of and paths to achieving healthy environmental stewardship, connecting the history of the area's early settlers to modern ideas of sustainability and creating a place of civic pride. Borrowing from site visits in our own region, research into distant sites and the plethora of literature resources available, our team has designed a unique facility. The reborn Crawford House and Woods site will be at once a historical landmark, venue for local economic stimulus, center of education, showcase of ideas and opportunities and a familiar, yet improved location for community gathering.   Visitors to the site will begin the tour in a room that holds true to the structure's original construction methods and materials (similar to those employed in many existing Hamilton homes) and will continue incrementally forward through the present day's practices and on to those of the future. The entire property, including the outdoor areas, will be utilized for all aspects of its mission. Interactive displays, structural cut-outs, signage, literature, site personnel and civic groups will round out the educational mission. We envision interested homeowners researching insulation technologies, elementary students learning about homestead life and sustainability, while Master Gardeners teach Hamiltonians the ins and outs of organic gardening.

 George Daly, Geology - Magmatic Evolution of the Santa Barbara G trachyte, Terceira, Azores

  Two geochemical and volcanological issues yet to be fully understood in the Azores are the magmatic processes that produce silicic magmas in an ocean island setting1,2 and the pre-eruptive processes that produce chemically-zoned, silicic deposits.3  These problems are addressed in this study of Terceira, one of nine islands that comprise the Azores archipelago in the central North Atlantic Ocean.  Santa Barbara volcano, located on Terceira's western end, is the youngest and most historically active eruptive center on Terceira.  Previous volcanological studies have described the Santa Barbara deposits in detail1,2 but little is known about the geochemical compositions or the pre-eruptive processes and timescales that produced these deposits.  With an approximate date of ~2000 years before present, the Santa Barbara "G" volcanic deposit (SB-G) represents one of the most recent eruptions of the Santa Barbara volcano and is preserved as a sequence of pumiceous air fall deposits and associated lava domes and lava flows.1,2  This study investigates the pre-eruptive processes that produced the SB-G deposit by obtaining major and trace element and strontium, lead and neodymium isotopic compositions from representative samples of the SB-G trachytes: silicic rocks that formed from the solidification of lava with a high silica, sodium and potassium content.  SB-G trachytes show variations in major and trace elements that can be attributed primarily to fractional crystallization of a common parental magma as its chemical composition evolves (increases in silica content) when different minerals crystallize from the cooling melt.  However, the geochemistry of lava collected from the nearby village of Silveira Pequena suggests it was derived from injection of a separate batch of less evolved magma into the system.  Significant variations in strontium isotopic compositions suggest that open-system processes were important and consistent with the assimilation of hydrothermally altered crust with a seawater component.  A positive correlation of lead isotope ratios with niobium concentration may be attributed to assimilation of older volcanic edifice basalts (less evolved volcanic rocks) or differentiates.  Thorium isotopic analyses in glass and mineral separates will further help elucidate the processes and timescales operating in the magmatic system of the Santa Barbara volcano.

1) Self (1976) Journal of the Geological Society of London 132, 645-666. 2) Calvert et al. (2006) Journal of Volcanology and Geothermal Research 156, 103-115. 3) Widom et al. (1992) Contributions to Mineralogy and Petrology 111, 311-328.

Meera Seshadri, Zoology - Gender Differences in the Nociceptin/Orphanin FQ (N/OFQ)-Mediated Neuroendocrine Response Following Stress

The hypothesis of this project is that estrogen affects the prolactin (PRL) secretory response to stress.  PRL is an anterior pituitary hormone. Stress increases PRL and activates the hypothalamic-pituitary-adrenal (HPA) axis, causing the adrenal glands to produce corticosterone (CORT) (Freeman, et al., 2000), a corticosteroid that enters the bloodstream and causes blood glucose to rise, increasing metabolism. PRL secreted into the blood, enters the brain through PRL receptors (PRL-R) present in the choroid plexus (site of cerebrospinal fluid synthesis) (Walsh, et al., 1987). PRL-R mRNA expression levels in the choroid plexus increase when circulating PRL levels increase in response to stress (Fujikawa, et al., 2004). Endogenous opioid peptides (EOPs), found in the central nervous system, regulate prolactin secretion. Nociceptin/Orphanin FQ (N/OFQ), an EOP, stimulates PRL secretion (Bryant, et al., 1998). Blocking N/OFQ receptors blocks the PRL response to a physiological stimulus, i.e. suckling (Chesterfield, et al., 2006), but the role of N/OFQ in mediating the stress response is not known. The study of the stress response is vital in understanding the mental and physical disorders caused by several anxiety disorders.  We pharmacologically blocked the PRL response in rats by administering a synthetic peptide (Comp B, an N/OFQ receptor antagonist) to block N/OFQ receptors. To test the effects of N/OFQ on the stress-induced changes in PRL-R expression levels in the choroid plexus, male and female Sprague-Dawley rats were pretreated with saline or Comp B (1 µg, icv) 10 min before they were subjected to 5 min of restraint stress. Animals were sacrificed one h after the onset of stress. The choroid plexus was collected at the time of sacrifice and PRL-R mRNA levels were determined. The data collected from this experiment showed that stress caused a more robust increase in PRL secretion in females compared to males. N/OFQ was involved in mediating the stress-induced increase in PRL but not CORT levels in males and females.  Hence, N/OFQ was not involved in the activation of the HPA axis.  Stress caused an increase in PRL-R mRNA levels in females, but not in males. To determine the role of estrogen in this response, ovariectomized (OVX) female rats with (OVX + E2) and without (OVX- E2) estrogen replacement were subjected to 5 min of restraint stress. OVX + E2 treated animals had higher, circulating PRL levels at rest and a more robust PRL response to stress than OVX - E2 treated females. Stress also produced an increase in PRL-R mRNA levels in the choroid plexus of OVX + E2 rats, but did not affect PRL-R mRNA levels in OVX – E2 treated females. These results suggest that estrogen modulates the stress-induced increase in circulating PRL levels and in PRL-R expression in the choroid plexus. The role of N/OFQ in mediating this E2 dependent stress response is currently under investigation.