FACTOID # 119: The United States has the world's highest number of McDonald’s restaurants per capita. Americans also die of obesity more often than any other nation, with more deaths than Mexico, Germany, Spain, Austria and Canada combined.
 
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Encyclopedia > Natural experiment

A natural experiment is a naturally occurring instance of observable phenomena which approach or duplicate a scientific experiment.


A example of a natural experiment occurred in Helena, Montana during the period from June 2002 to December 2002 when a smoking ban was in effect in all public spaces in Helena including bars and restaurants. Helena is geographically isolated and served by only one hospital. It was observed that the rate of heart attacks dropped by 60% while the smoking ban was in effect. [1] (http://webcenter.health.webmd.netscape.com/content/article/63/71871.htm)


  Results from FactBites:
 
Experiment - Wikipedia, the free encyclopedia (2106 words)
In many laboratory experiments it is good practice to have several replicate samples for the test being performed and have both a positive control and a negative control.
In human experiments, a subject (person) may be given a stimulus to which he or she should respond.
The goal of the experiment is to measure the response to a given stimulus.
A Bird Flu Reassortment Experiment Under Natural Conditions (646 words)
A second set of experiments which infect the same cell with H5N1 and a human virus is more "natural", but many combinations of reassortants and recombinants are theoretically possible.
"experiment" uses WSN/33 as the human virus and a series of related H9N2 Korean viruses as the avian source.
Thus the "natural" experiments show that many combinations are possible involving reshuffling of whole genes (reassortment) and creation of new genes (recombination).
  More results at FactBites »


 

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