Analysis of Scientific Data - Summer Semester, 2021 Week 2 Tutorial - Exercises Part A This is a short quiz to check you know the important ideas about logarithms. Without using a calculator (answers should have no decimal places), simplify the following as much as possible: 1. log10 10 = 2. log10 1000 = 3. log10 1 = 4. log10 0.01 = 5. log10 (10x) = 6. log10 200 = 7. log10 0 = 8. log2 16 = 9. log2 4 = 10. loge 2.718282 ~
Part B A high-fat diet (HFD) is known to have a negative effect on bone quality in young and old people. A study was undertaken to evaluate the effects of an HFD on bone healing in growing female rats. Twenty-six postweaning female rats were randomly assigned to two groups (13 per group): a standard diet (SD) group and an HFD (with 60% of energy from fat) group. The rats were maintained under standard laboratory conditions at a temperature of 22 + 2 ? and humidity of 55 + 5 % with a 12-hour light and dark cycle and with free access to water and food. The rats received the assigned diets for 5 weeks, and in the third week they were submitted to an osteotomy procedure (i.e. bone cut) of the left tibia. At the end of the 5 weeks, the rats were euthanised and the tibiae were removed for mechanical testing. The mechanical testing involved a force begin applied to the tibia at a speed of 1.0 mm/min to generate a tension load on the osteotomy site. The maximal load (N) and stiffness (N/mm) were measured. Lower maximal load (p = 0.040) and bending stiffness (p = 0.020) were observed in tibiae of HFD rats compared to SD rats. (a) What type of variable is maximal load? (b) What type of variable is diet? (c) Which variable is the variable of interest, that is the response variable? (d) What type of study is this? (e) What would be a suitable null hypothesis associated with the p-value for maximal load? (f) What are we able to conclude about the effect of diet on bone maximal load following osteotomy?
PART C Repetitive movements and poor posture are associated with over-use of smartphones and can significantly contribute to symptoms of pain and discomfort in the upper extremities. The severity of these symptoms can be assessed through questionnaires as well as through direct measurements of grip strength (kg). A paper in 2016 presented a study on the effect of an exercise training and posturalcorrection program that aimed to help smartphone users. The researchers recruited 100 university students as potential participants in the study. The students were randomly assigned to either a control group, who received a pamphlet, or an experimental group, who received the new training program. The following quantile plot shows the measured grip strength for all subjects after the studyhad concluded: Control 0 Experimental + + 45 xxx 40 - + 35 Grip Strength (kg)