Engineering Commons^™

An Interactive Exploration Of Gender And Engineering: Unpacking The Experience, Debbie Chachra, Lynn Stein, Alisha Sarang-Sieminski, Caitrin Lynch, Yevgeniya Zastavker

Debbie Chachra

The engineering student experience is understood to differ for male and female students; gendered interactions affect the development of academic and professional role confidence, as well as engineering identity. The purpose of this session is twofold. First, we aim to introduce participants to concepts of gender schemas, privilege, and identity using a range of interactive activities, including brainstorming and structured discussion. Second, we intend to share information about and obtain feedback on a Gender Discussion Exploration Kit, which the participants will be encouraged to review, use, and share at their home institutions.

Effect Of Applied Uniaxial Stress On Rate And Mechanical Effects Of Cross-Linking In Tissue-Derived Biomaterials, Debbie Chachra, Paul Gratzer, Christopher Pereira, J. Lee

Debbie Chachra

Conformational changes in collagen fibrils, and indeed the triple helix, can be produced by application of mechanical stress or strain. We have demonstrated that the rate of cross-linking in glutaraldehyde and epoxide homobifunctional reagents can be modulated by uniaxial stress (strain). Two poly(glycidyl ether) epoxides were used: Denacol^® EX-810 (a small bifunctional reagent), and Denacol EX-512 (a large polyfunctional reagent). To prevent any possible effect from being masked by saturation of cross-linking sites, bovine pericardium was cross-linked to such an extent that the increase in collagen denaturation temperature, T_d, was one-half of the maximal rise achievable with …

Outside The Classroom: Gender Differences In Extracurricular Activities Of Engineering Students, Debbie Chachra, Helen Chen, Deborah Kilgore, Sheri Sheppard

Debbie Chachra

Data from the Academic Pathways Study, a component of the NSF-funded Center for the Advancement of Engineering Education, were used to investigate engineering student involvement in extracurricular activities. The study design used a variety of methods: the results presented here are from longitudinal and cross-sectional surveys of engineering students as well as interviews with graduating seniors. Quantitative data from both surveys suggest that women place higher importance on extracurricular activities than their male counterparts, as well as reporting higher participation in both engineering-related and non-engineering-related extracurricular activities. In addition, the importance of non-engineering extracurricular activities and the level of involvement …

Work In Progress - Using Video And Self-Reflection To Enhance Undergraduate Teams, Nick Tatar, Debbie Chachra, Yevgeniya Zastavker, Jonathan Stolk

Debbie Chachra

Engineers today must be able to communicate and collaborate in teams. They also must be comfortable making adjustments within the team to maintain flow and progress toward project goals. With these goals in mind, students in a first-semester engineering seminar course were asked to videotape a team meeting in their design course and to write a self-reflection paper after viewing their video. After analyzing the video, students were asked to provide clear suggestions in their self-reflection paper for improving their own and their team's performance. Our preliminary analysis showed that video-supported reflections: 1) may be more effective than memory for …

Shelf-Life Of Bioprosthetic Heart Valves: A Structural And Mechanical Study, Maryse Julien, Dany Letouneau, Yves Marois, Alain Cardou, Martin King, Robert Guidoin, Debbie Chachra, J. Lee

Debbie Chachra

This study was undertaken to evaluate the influence of storage conditions on the shelf-life of porcine bioprosthetic valves. Fifty-five unimplanted porcine bioprostheses have been evaluated. The valves were stored in 0.5% buffered glutaraldehyde solution for different periods of time (7, 23 and 32 months). Twenty-eight valves were refrigerated while the remaining valves were stored at room temperature. The pH of the glutaraldehyde solution at room temperature decreased with time of storage, while that kept in the refrigerator remained stable over the course of the study. Macroscopic observations showed that the valve tissues kept at room temperature, especially for the periods …

Drowning In Method, Thirsty For Values: A Call For Cultural Inquiry, Jonathan Stolk, Mark Somerville, Debbie Chachra

Debbie Chachra

A decade or more has passed since publication of most calls for reform in engineering education. In the ensuing time, there has been significant work on the design, implementation, and transferability of appropriate methodsand techniques - accompanied by, in most cases, little discussion of the values and beliefs of the people involved. But many theories of change rely on a fundamental shift in human beliefs and values, and purport that institutionalization of methods is impossible without this shift. Given this, now may be a reasonable time to re-visit the questions: What are the values of people involved in engineering education, …

Beyond Course-Based Engineering Ethics Instruction Commentary On “Topics And Cases For Online Education In Engineering”, Debbie Chachra

Debbie Chachra

Discusses how online forums and materials could be used to enhance face-to-face courses in engineering and science ethics.

Lumbar Vertebral Density And Mechanical Properties In Aged Ovariectomized Rats Treated With Estrogen And Norethindrone Or Norgestimate, Carla Vanin, Neil Maclusky, Debbie Chachra, Mehran Kasra, Marc Grynpas, Robert Casper

Debbie Chachra

OBJECTIVE: This study was designed to investigate the effects of estrogen alone or combined with two different progestins, norethindrone or norgestimate, on bone density and compressive mechanical properties in an aged rat model.

STUDY DESIGN: Twenty 11-month-old female Sprague-Dawley rats were sham operated (intact control) and 80 wee overiectomized. Three groups of 20 ovariectomized rats were implanted with Silastic silicon rubber (Dow Corning, Midland, Mich.) capsules containing 5% estradiol (wt/wt) in cholesterol. All rats in the intact control (group 1) and the ovariectomized (group 2) and the first of the overiectomized plus estrogen (group 3) groups were injected subcutaneously daily …

Fluoride Treatment Increased Serum Igf-1, Bone Turnover, And Bone Mass, But Not Bone Strength, In Rabbits, C. Turner, L. Garetto, A. Dunipace, W. Zhang, M. Wilson, Marc Grynpas, Debbie Chachra, R. Mcclintock, M. Peacock, G. Stookey

Debbie Chachra

We hypothesized that fluoride partly acts by changing the levels of circulating calcium-regulating hormones and skeletal growth factors. The effects of oral fluoride on 24 female, Dutch-Belted, young adult rabbits were studied. The rabbits were divided into two study groups, one control and the other receiving about 16 mg fluoride/rabbit/day in their drinking water. After 6 months of fluoride dosing, all rabbits were euthanized and bone and blood samples were taken for analyses. Fluoride treatment increased serum and bone fluoride levels by over an order of magnitude (P < 0.001), but did not affect body weight or the following serum biochemical variables: urea, creatinine, phosphorus, total protein, albumin, bilirubin, SGOT, or total alkaline phosphatase. No skeletal fluorosis or osteomalacia was observed histologically, nor did fluoride affect serum PTH or Vitamin D metabolites (P > 0.4). BAP was increased 37% (P < 0.05) by fluoride; serum TRAP was increased 42% (P < 0.05); serum IGF-1 was increased 40% (P < 0.05). Fluoride increased the vertebral BV/TV by 35% (P …