Expression, purification, and characterization of a carbohydrate-active enzyme: A research-inspired methods optimization experiment for the biochemistry laboratory.

The development and implementation of research-inspired, discovery-based experiences into science laboratory curricula is a proven strategy for increasing student engagement and ownership of experiments. In the novel laboratory module described herein, students learn to express, purify, and characterize a carbohydrate-active enzyme using modern techniques and instrumentation commonly found in a research laboratory. Unlike in a traditional cookbook-style experiment, students generate their own hypotheses regarding expression conditions and quantify the amount of protein isolated using their selected variables. Over the course of three 3-hour laboratory periods, students learn to use sterile technique to express a protein using recombinant DNA in E. coli, purify the resulting enzyme via affinity chromatography and dialysis, analyze the success of their purification scheme via SDS-PAGE, assess the activity of the enzyme via an HPLC-based assay, and quantify the amount of protein isolated via a Bradford assay. Following the completion of this experiment, students were asked to evaluate their experience via an optional survey. All students strongly agreed that this laboratory module was more interesting to them than traditional experiments because of its lack of a pre-determined outcome and desired additional opportunities to participate in the experimental design process. This experiment serves as an example of how research-inspired, discovery-based experiences can benefit both the students and instructor; students learned important skills necessary for real-world biochemistry research and a more concrete understanding of the research process, while generating new knowledge to enhance the scholarly endeavors of the instructor.

Sustained Benefit Over Four-Year Follow-Up of Michigan's Project Healthy Schools.

OBJECTIVES: We determined the sustainability of effects of a school-based intervention to improve health behaviors and cardiovascular risk factors among middle school children. METHODS: We administered a questionnaire and health screenings to 5 schools in Ann Arbor and 2 schools in Ypsilanti, Michigan. We assessed demographics, physiological factors, diet, physical activity, and sedentary behaviors from 1126 students who received a health curriculum (Project Healthy Schools) in the fall of sixth grade in 2005, 2006, and 2007. We administered the questionnaire and screening again in the spring and each subsequent spring through ninth grade to all available, consenting students. RESULTS: In the 4 years following the school-based intervention, total cholesterol, low-density lipoprotein cholesterol, and triglycerides improved, and for most years systolic and diastolic blood pressure improved. Serum glucose and body mass index did not change. Physical activity increased and sedentary behaviors diminished. CONCLUSIONS: Project Healthy Schools is associated with sustainable improvements in both cardiovascular parameters and healthy behaviors.

The Project TALENT Twin and Sibling Study.

Project TALENT is a US national longitudinal study of about 377,000 individuals born in 1942-1946, first assessed in 1960. Students in about 1,200 schools participated in a 2-day battery covering aptitudes, abilities, interests, and individual and family characteristics (Flanagan, 1962; www.projectTALENT.org). Follow-up assessments 1, 5, and 11 years later assessed educational and occupational outcomes. The sample includes approximately 92,000 siblings from 40,000 families, including 2,500 twin pairs and 1,200 other siblings of twins. Until recently, almost no behavior genetic research has been conducted with the sample. In the original data collection information was not collected with the intent to link family members. Recently, we developed algorithms using names, addresses, birthdates, and information about family structure to link siblings and identify twins. We are testing several methods to determine zygosity, including use of yearbook photographs. In this paper, we summarize the design and measures in Project TALENT, describe the Twin and Sibling sample, and present our twin-sib-classmate model. In most twin and family designs, the 'shared environment' includes factors specific to the family combined with between-family differences associated with macro-level variables such as socioeconomic status. The school-based sampling design used in Project TALENT provides a unique opportunity to partition the shared environment into variation shared by siblings, specific to twins, and associated with school- and community-level factors. The availability of many measured characteristics on the family, schools, and neighborhoods enhances the ability to study the impact of specific factors on behavioral variation.

Understanding childhood obesity in America: linkages between household income, community resources, and children's behaviors.

BACKGROUND: Understanding childhood obesity's root causes is critical to the creation of strategies to improve our children's health. We sought to define the association between childhood obesity and household income and how household income and childhood behaviors promote childhood obesity. METHODS: We assessed body mass index in 109,634 Massachusetts children, identifying the percentage of children who were overweight/obese versus the percentage of children in each community residing in low-income homes. We compared activity patterns and diet in 999 sixth graders residing in 4 Michigan communities with varying annual household income. RESULTS: In Massachusetts, percentage of overweight/obese by community varied from 9.6% to 42.8%. As household income dropped, percentage of overweight/obese children rose. In Michigan sixth graders, as household income goes down, frequency of fried food consumption per day doubles from 0.23 to 0.54 (P < .002), and daily TV/video time triples from 0.55 to 2.00 hours (P < .001), whereas vegetable consumption and moderate/vigorous exercise go down. CONCLUSIONS: The prevalence of overweight/obese children rises in communities with lower household income. Children residing in lower income communities exhibit poorer dietary and physical activity behaviors, which affect obesity.

Health status and behavior among middle-school children in a midwest community: what are the underpinnings of childhood obesity?

BACKGROUND: Childhood obesity is one of the nation's foremost health challenges. How much of this is due to lifestyle choices? The objective of the study was to determine health behaviors that contribute to obesity in sixth-grade children. METHODS: To assess which health habits contribute to childhood obesity, we studied body mass index, blood pressure, lipid profile, glucose, and heart rate recovery after a 3-minute step test among sixth-grade children enrolled in a school-based intervention study from 2004 to 2009, comparing health behaviors and physiologic markers in obese versus nonobese children. Univariate associations with obesity (P values≤.10) were entered into a stepwise logistic regression to identify independent predictors. RESULTS: Among 1,003 sixth graders (55% white, 15% African American; average age 11.5 years), 150 (15%) were obese. Obese students had higher levels of total cholesterol, low-density lipoprotein cholesterol, triglycerides, blood pressure, and recovery heart rates. They consumed more regular soda and school lunches but were less likely to engage in physical activities. Obese students were more likely to watch TV≥2 hours per day. Independent predictors were watching TV or video games (odds ratio [OR] 1.19, 95% CI 1.06-1.33) and school lunch consumption (OR 1.29, 95% CI 1.02-1.64); moderate exercise was protective (OR 0.89, 95% CI 0.82-0.98). CONCLUSIONS: Obesity is present in 15% of our sixth graders and is associated with major differences in cardiovascular risk factors. Opportunities to improve childhood health should emphasize programs that increase physical activity, reduce recreational screen time, and improve nutritional value of school lunches. Whether genetic or not, childhood obesity can be attacked.