Glycine (Gly) Has Been Implicated in Several Neurological Disorders, Including

question 552

Multiple Choice

Glycine (Gly) has been implicated in several neurological disorders, including malignant brain tumors.  However, the precise measurement of Gly has been difficult, primarily due to the spectral overlap with myo-inositol (mI) .  A novel approach to measuring Gly and mI in healthy and tumorous human brains provides more reliable spectral differentiation between Gly and mI, such that alterations of Gly in brain tumors can now be evaluated more precisely.  A group of researchers plans to conduct 2 parallel studies to measure and compare Gly levels among healthy and tumorous brains.  Study A will use the current approach to measure Gly in the brain, whereas study B will use the novel approach.  All other factors being equal, which of the following statements is most likely true concerning these 2 studies?

• A)Compared to study A, study B will have a higher probability of establishing a difference in Gly that does not exist between groups
• B)Differences in Gly levels between groups in study A will be statistically different from the differences in Gly levels between groups in study B
• C)Study B will have a higher probability of establishing a true difference in Gly between groups than study A
• D)The confidence interval for the difference in Gly levels among healthy and tumorous brains will most likely include the null value in study A
• E)The difference in Gly levels among healthy and tumorous brains will be statistically significant only in study B

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Definitions:

Randomly Selected

A method or process where selections are made in such a way that each item or person has an equal chance of being chosen, ensuring unbiased results.

Control Group

A group in an experiment or study that does not receive treatment, used as a benchmark to measure the effects of the treatment.

Natural Experiments

Observational studies where the conditions are naturally occurring rather than being controlled or manipulated by the researcher, used to infer causality.

Random Experiments

Procedures or trials that yield different outcomes, each with a specific probability, even when repeated under the same conditions.