unobserved

How to know the unknowable in observational studiesOutlineIntroductionProblem Setup2.1. Causal Graph2.2. Model With and Without Z2.3. Strength of Z as a ConfounderSensitivity Analysis3.1. Goal3.2. Robustness ValuePySensemakrConclusionAcknowledgementsReferences1. IntroductionThe specter of unobserved confounding (aka omitted variable bias) is a notorious problem in observational studies. In most observational studies, unless we can reasonably assume that treatment assignment is as-if random as in a natural experiment, we…

Kidneys perform a vital function in removing waste and toxins from the blood, but how exactly cells transport that fluid through the organs has remained a mystery. Now researchers at Johns Hopkins University have investigated the mechanical forces at work and found a previously unobserved pumping action by kidney cells.All the blood in your body passes through the kidneys dozens of times per day, flowing through tiny tubes and filtering units before the “clean” blood makes its way back out into the bloodstream. But the…