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Unit 20: General Science

Last updated

May 14, 2022
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- 19.3E: Retroviruses
- 20.1: Epidemiology

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20.1: Epidemiology
This page explores the difference between correlation and causation, using smoking and lung cancer as a case study. It identifies criteria for establishing causation and cites John Snow's cholera maps as an early epidemiological example. The text underscores the health impact of smoking and mentions environmental health risks reported in the media. To make informed decisions regarding health claims, the author recommends five criteria for evaluating such reports.
20.2: Types of Clinical Studies
This page discusses the research methods in medicine for developing new drugs and procedures, highlighting the importance of validating improvements through various study types. It contrasts retrospective studies—which may introduce bias—with prospective studies that follow healthy populations. Clinical trials are emphasized as the gold standard due to their randomization and blinding, which help alleviate bias.
20.3: Scientific Methods
This page discusses the principles of scientific inquiry, such as skepticism and reproducibility, and emphasizes the role of hypotheses in scientific explanations. It highlights the communal nature of science, where discoveries are built on previous work, and distinguishes between basic and applied science. Additionally, the page addresses challenges related to reproducibility and ethical conduct, noting science's ability to self-correct despite the infrequency of fraud.
20.4: Scientific Papers
This page emphasizes the importance of communal collaboration in science, where findings are shared among scientists. Key aspects of effective communication include meetings and published papers, which serve as a permanent record. Typical sections of scientific papers—abstract, introduction, results, discussion, materials and methods, acknowledgments, and references—each contribute significantly to knowledge dissemination and uphold rigorous scientific standards.
20.5: Statistical Methods
This page discusses how biologists manage numerical data by comparing discrete and continuous variables. It covers relevant calculations such as mean, standard deviation, and standard error of the mean (S.E.M.) to evaluate data reliability. Confidence limits are highlighted for assessing the probable range of a population's true mean, typically at a 95% confidence level.
20.6: Drugs
This page outlines the drug testing process, which starts with testing numerous chemicals on lab animals and may lead to human trials through an IND application to the FDA. The human trials consist of three phases: Phase I focuses on safety in healthy volunteers, Phase II tests efficacy and side effects in patients, and Phase III collects comprehensive safety and effectiveness data. Upon successful completion, a NDA is submitted, and the drug is branded for market release.

Thumbnail: Original map by John Snow showing the clusters of cholera cases in the London epidemic of 1854. (Public Domain).

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