Light Microscopy Measurements of Muscle Sarcomere Lengths in Fresh Tissue
Discovery oriented lab experiences that require critical and analytical analysis, with a minimum of sophisticated instrumentation, are important tools for advancing scientific curiosity and maturity. The goal of the lab exercise presented here is for students to gain functional anatomy knowledge together with microscopy and metric analysis skills via the measurement of skeletal muscle sarcomere lengths in fresh muscle. Following a discussion of the microanatomy and physiology of striated muscle sarcomeres, students are directed to make and observe wet mount slides at 400X of very small amounts of fresh fish, such as flounder, for the presence of A and I bands. Due to the anisotropic (A) and isotropic (I) light refraction characteristics of actin and myosin, the students will be able to see the bands clearly without any stain, as well as gain a qualitative appreciation for muscle fiber diameter and length. Next, after a discussion on how they might measure sarcomere lengths, the students calibrate their microscopes at 400X and 1000X with a stage micrometer. They then calibrate a mm ruler, based on ocular units, that will be used to measure linear sarcomeres on a printed-to-scale digital photograph of their flounder tissue. Using their raw data, they calculate sarcomere µm lengths. Results are surprisingly similar to previously reported sarcomere lengths measured with electron microscopy (EM). The students are asked to critically compare the advantages and disadvantages of their techniques with those involving EM, and to form a list of potential variables for future research.
Dept of Biological Sciences, Meredith College, Raleigh, NC
P203 • Holly Boettger-Tong1, Vivia L. Fowler2, Gareth Jones3, Brooke Bennett-Day4
Lessons Learned From Three Years of the Math/Science Student Preparation and Retention (SPARC) Collaborative
Retaining potential science and math majors to graduation is a challenge faced by most institutions, regardless of the size of the undergraduate student body. In 2011, Wesleyan College, a small, single-sex undergraduate liberal arts institution, began a program designed to test the hypothesis that intensive faculty advising, upperclass student peer mentoring and academic Bootcamp experiences would have a positive impact on student performance and retention in STEM fields. The participants chosen for this initiative were two small cohorts of Pell-eligible students (SPARC Scholars) from the state of Georgia intending to major in science or mathematics. An additional set of students were matched to this cohort in terms of their socioeconomic status, SAT scores and their intended majors. Comparisons of GPA and midterm deficiencies between the SPARC cohorts and the matched groups were made and the data indicate that SPARC scholars had a higher average GPA and fewer midterm deficiencies than the matched students. In addition, pre/post assessment of the impact of week-long summer academic Bootcamps indicated marked effects on cohort cohesiveness (Bootcamp I) and measurable improvements in student spatial reasoning skills (Bootcamp II). Self-reported data indicated that SPARC scholars viewed their Bootcamp and advising experiences favorably and that Peer Advisors had a positive impact on Scholars’ academic experience. The first cohort of SPARC scholars are Juniors and retention in the major stands at approximately 60%, which exceeds the national (and Wesleyan’s historical) average. Based in part on data obtained from the SPARC program, Wesleyan has recently instituted a peer mentoring initiative aimed specifically at first year students enrolled in Introductory Biology (BIO 110) entitled PASS (Peer Assisted Student Support). Preliminary data from this initiative suggests a positive correlation between PASS session attendance and student achievement in this introductory majors course.
1 Dept of Biology, Wesleyan College, Macon GA; 2 Provost and Vice President for Academic Affairs, Wesleyan College, Macon GA; 3 Director of Student Success, Wesleyan College, Macon GA; 4 Dept of Psychology, Wesleyan College, Macon GA
P204 • Hart, S.K., Mikhailova, E.A., Post, C.J., McMillan, P.D., and S.K. Cox
Weather extremes and phenological changes of the shores of Lake Issaqueena
Climate change is increasing the occurrence of extreme weather and it can impact plant phenology . The objectives of this study were to document the effects of drought and heavy rain on the phenology (flowering) of plants around Lake Issaqueena, SC. Historical and current phenological studies of Lake Issaqueena were recorded by herbarium collections, temporal digital photographs taken with GPS-enabled camera (stored in Picasa 3 web albums and project website) on a monthly basis. The species of the Verbenaceae family bloomed later than they had in 1970-71. The species of the Acanthaceae, Asteraceae, Aristolichiaceae, Asclepiadaceae, Aceraceae, Berberidaceae, Betulaceae, Campanulaceae, Caprifoliaceae, Caryophyllacea, Celastraceae, Convulvulaceae, Cornaceae, Ericaceae, Euphorbiaceae, Fagaceae, Gentianaceae, Grossulariaceae, Hippocastanaceae, Iridaceae, Laminaceae, Liliaceae, Melastomataceae, Nymphaeaceae, Orobanchaceae, Polygonaceae, Pyrolaceae, Ranunculaceae, Rhamnaceae, Rosaceae, Saxifragaceae, Scrophulariaceae, Solanaceae, Styracaceae, Symplocaceae, and Violaceae bloomed earlier than they had in 1970-71. There were species within the Fabaceae and Rubiaceae families that bloomed earlier and later than the observed blooming times in 1970-71. There seems to be a phenological shift in blooming times with species blooming later in the 2012 year of drought and species blooming earlier in the 2013 year of heavy precipitation. It appears the weather extremes influence the plant phenology around Lake Issaqueena despite the temperature buffering impact of the lake.
School of Agricultural, Forest, and Environmental Sciences, Clemson University, Clemson, SC
|
205 • Yun, H., Mikhailova, E.A., and C.J. Post. 2014
Adaptation of Soil Judging to Northeast China
Soil Judging teaches students important skills for field identification of soil types, their properties, and interpretations for use. The adaptation of Soil Judging in China can be beneficial to students as well as government agencies and private sector. The objective of this study was to adapt Soil Judging to northeast region of China by a graduate student from China, who was trained using an undergraduate course in Soil Judging and a regional Soil Judging competition.Unlike the U.S., China has 14 soil orders with six soil orders somewhat similar to the ones found in the Southeast region of the U.S. A Southeastern Region Soil Judging Handbook was used for newly developed teaching materials for Northeast of China (including tables of soil physical and chemical properties, topographic maps, and scorecards). These new teaching materials can significantly improve soil education in China and mitigate problems associated with land use management.
School of Agricultural, Forest, and Environmental Sciences, Clemson University, Clemson, SC
P206 • Pilgrim, C.M.1, Mikhailova, E.A.1, Post, C.J.1, Hains, J.J.2, and S.K. Cox1
Land use changes in the Lake Issaqueena watershed, South Carolina
Over the last 75 years, the Lake Issaqueena watershed has experienced a drastic shift in land practices. This study was conducted to examine the changes in land use and land cover (LULC) that have occurred. Aerial photography of the watershed (1951, 1956, 1968, 1977, 1989, 1999, 2005, 2006 and 2009) was analyzed and classified using the geographic information system (GIS) software, ArcGIS. Seven land classes were defined: evergreen, deciduous, bare ground, pasture/grassland, cultivated and residential/other developments. From 1951-2009, the watershed experienced an increase of tree cover and bare ground (17.4% evergreen, 62.3% deciduous, 9.8% bare ground) and a decrease of pasture/grassland and cultivated (42.6% pasture/grassland and 57.1% cultivated). From 2005 to 2009, there was increase of 21.5% in residential/other developments due to a national housing boom. Prior to 1938, the area consisted of single-crop cotton farms, but after 1938 the farms were abandoned, leaving large areas with eroded soil. Starting in 1938, Clemson reforested almost 30% of the watershed, while the remainder was privately owned. Currently, 3/4 of the watershed is forestland, with a limited extent of small farms and residential developments.
1School of Agricultural, Forest, and Environmental Sciences and 2Dept. of Biological Sciences, Clemson University, Clemson, SC
Share with your friends: |
