L2 Question 1.2.5 The cardiac output CO of a heart is the volume of blood ejected by the heart during a particular time period, and equals the stroke volume SV multiplied by the heart rate HR. If each beat has a volume of 70 mL and the heart beats 1.5 times each second, calculate CO in L . min-1. CO=SV x HR =(70mL) x (1.5 1/s) or s-1 =(70 x 1.5) (mL. 1/s) =(105 mL/s) x (1L/1000mL) x (60s/1 min) = (105 × 60)/1000 | | (mL x L x s)/(s x mL x min) = 6.3 L x min-1 Dimensional Analysis: Dimensional analysis is an important technique in science. It involves applying the following principle: an equation describing a physical situation can be true only if it is dimensionally homogeneous; that is, both sides of the equation have the same units. Dimensional analysis allows a quick check of whether a calculation is 'plausible'. If the dimensions do not match, then there must be an error. L5 Lecture 5 - Learning how to model Learning objectives / Understand the framework for mathematical models in science / Appreciate the uses and limitations of models V Contrast data driven models with theoretically driven models Scientific examples V Blood flow through a bypass vein graft Maths skills V Understand and interpret data from a graph
Stat L1 Example factors that need to be identified · Sample size · Power · Need for comparative designs · Ethical considerations Note: Fundamental knowledge of statistical methods by hand must be demonstrated & Statistical software must be used to come to a statistical conclusion. Textbook: A Portable Introduction to Data Analysis (5th or 5.2 edition) - textbook needed Variability: Natural Variability: The intrinsic variability of the quantity we are measuring Measurement Variabilty: Measurement error, including rounding when measuring or recording values Group Variability: Usually what we are interested in such as the change in the action potential with stimulus strength Natural variability and measurement error, the residual variability, can obscure these effects
L2 Variability: · Natural Variability Measurement Variability Group (or systematicff variability Residual (or errorff variability: Everything that is not group variability · A variable is a characteristic that we can record about the subjects or objects in a study These can be measurements we make, like a height or blood. Possible work: At the end of chapter 1 there is a quiz. (Link is i=on learning resources page - blackboard Summary of Terminology: . An experiment involves actively applying treatments to subjects and observing their responses. · An experimental treatment is a combination of factors at different levels. . The variables describing the treatments are the explanatory variables in the study. · The response from an experiment is the variable of interest. Comparative experiments: Comparative experiments are desirable to eliminate the placebo effect. Randomization helps remove possible bias in a comparative experiment. · A blind experiment is one in which the subjects do not know which treatment they are getting. · In a double-blind experiment