Lourena Arone II
University of Arizona
Department of Plant Sciences
NOTE: Lourena was a client in Fall 2018; please review her prior information.
Please attached find the excel file with the data and a Word document with my preliminary analysis and description of what I did. My main question is to assess if there is any different type of analysis I can do with my data what is important to present in my results from my statistic analysis (eg: R square value, etc etc etc
Client: Lourena Arone (University of Arizona – CALS, Department of Plant Sciences)
Consultants: Elmira(Lead), Innocent(Author), Cheng
13 September 2018, 2:30-4:00 pm
A. Summary of the client’s problem
Lourena is studying 10 Atoxigenic genotypes of A. flavus. These are types of bacterias that degrade Aflatoxins (potent mycotoxins produced by several Aspergillus species). These 10 different genotypes of bacterias are commonly used to degrade toxic (Aflatoxins) from contaminated food. She had 3 main study questions: 1) Do rates of reducing toxic from contaminated food differ among these 10 different genotypes? 2) Does temperature conditions affect the efficiency of these 10 Atoxigenic genotypes of A. flavus in terms of reducing toxic? 3) compare the rate of aflatoxin reduction by the genotypes over a long period of time (21 days at a temperature of 31 degree C)
We discussed the experiments she conducted and data collected in the effort to answer the first 2 questions. Due to time constraint, we did not discuss in detail how she conducted the experiment to answer the last question.
Experiment to answer the first question:
- Each of the 10 different genotypes of bacteria was placed in a well sealed and temperature controlled flasks that contain a starch solution and 5mgs of toxic (Aflatoxin). Each sample of these 10 flasks was replicated four times. Four similar flasks containing only the starch solution and 5mgs of toxic were used as controls (no bacterias were added). At the beginning of the experiment, a random sample of 4 flasks was drowned, the concentration of toxic in each of the four flasks was measured and then an average of 4 concentrations was used as the baseline toxic concentration for all 40 flasks. All 40 treated and 4 control flasks were incubated for 7 days. After 7 days, the concentrations of toxic were again measured in all flasks. Concentrations in four flasks of a kind were averaged. ANOVA was used to test if the average concentrations of toxic differ among treated and control flasks.
Experiment to answer the second question:
- Three fungi (AF36, Afla-guard, and AF13) were selected to experiment how temperature conditions affect the efficiency of AF36 and Afla-guard in reducing toxic. AF13 is a toxic producing fungus and was used as a positive control. Similar measurements and lab settings like in the above experiments were repeated. Each of the three fungi was placed in flasks containing the starch solution and 5mgs of the toxic (similar lab experiments like above) and four samples of each of the three flasks were created. The initial concentrations of the toxic were measured and the average of four flasks concentrations was used as the baseline toxic. Four samples of each of the 3 fungi were stored at 10, 15, 25, 35 degrees Celsius. After 7 days, concentrations of toxic were measured and ANOVA was used to compare concentrations by temperature.
Lourena's consultation question was to find out if there are other ways (possibly better) of analyzing her data. After we learned more about her research design and experiments she conducted, we proposed and agreed to get back to her after we discuss her question in the class. We talked about a possibility of using a different analysis for the data she collected in the second experiments. She mentioned that it would be nice to analyze data differently but she was not familiar with other methods besides ANOVA. We promised to have a short report that would explain how she would conduct a different analysis for her second experiments' data.
We finished the meeting at 4 pm, because of time-constrained we did not talk in details about her third research question, experiment design and how she collected data.