University of California, Davis

  • Continuous data collection, 24 hours per day
  • Only desired weight readings recorded; others ignored
  • Complete background data collection allowing simultaneous use of PC

The McDonald Lab in the Department of Nutrition at the University of California, Davis devotes its studies to the characteristics of senescence (aging) in humans and animals. Dr. McDonald, a Professor in the Department of Nutrition, recently embarked on a study to evaluate the relationship among aging, food consumption, and rapid senescence.

Dr. McDonald already knows that, in general, rats and humans tend to eat less as they age. Moreover, Dr. McDonald has discovered that older rats experience an increase in the rate of weight loss and a decrease in food intake near the end of the life span. The results of Dr. McDonald’s investigations in rats will be used to evaluate possible mechanisms associated with the “failure to thrive” syndrome observed in senescent humans.

The Model

To model the study, Dr. McDonald is focusing on the eating habits in older rats. The study will take place over a several year time period and a statistically significant number of rats will be monitored.

The model involves tracking the eating habits of older rats. The eating habits are monitored by weighing both the rat’s food container and the rat itself. Scientists in the lab weigh the food container on a Denver XL 6100 balance, and weigh the rat (including the cage) using a Pennsylvania Scale Model 7300. The project scientists emphasized that since constant monitoring of weights is a difficult task, the process had to be automated.

To automate the process, the weight readings are transmitted through the serial ports of the scales to a personal computer running WinWedge. The rat’s weight and the food container weight are transmitted through com port 3 and com port 4, respectively, into the PC. WinWedge captures the data readings on serial ports com 3 and com 4 and directs the data via dynamic data exchange (DDE) to a Microsoft Excel spreadsheet for analysis and graphing. Excel is able to easily handle the charting and statistical analysis of the data.

The system also utilizes several macros that trigger WinWedge to read only those weights within certain specified parameters. It is important to record a reading only when the rat’s weight decreases by 5 or more grams. Other readings are to be ignored. In addition, it is necessary to record the food container weight when it is descending in value as this indicates that the rat has eaten. Increases in the weight of the food container are not recorded as they may indicate that the rat is leaning on the container. With the help of TAL’s technical support staff, Dr. McDonald’s requirements were met with a series of Excel macros that ignore unwanted readings and date and time stamp the acceptable readings. Dr. McDonald expects that the results of these investigations will offer insight into mechanisms that reflect altered food intake in the elderly.

WinWedge Collects Data around the Clock

Cynthia Blanton, a graduate student in Dr. McDonald’s laboratory, noted that this project would not have been feasible had it not been for the automation of data collection offered by WinWedge. The weight readings would have been impossible to track using a manual data entry method. With the use of WinWedge, the entire process is automated and runs completely independently. Therefore, the data collection takes place 24 hours a day, 7 days a week with 100% accuracy.

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