Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of Thermo Fisher Scientific (NYSE: TMO) fell more than 10% in early trading and closed off almost that much after lowering full-year earnings and revenue guidance.

So what: Third-quarter results were better. Thermo earned $1.07 in adjusted earnings per share, up 19% year over year, on $2.97 billion in revenue, a 13% increase. Both figures were roughly in line with Q3 estimates for the testing and instrumentation specialist.

Now what: For the full year, Thermo now expects $4.11 to $4.17 a share in profit on $11.62 to $11.7 billion in revenue -- down from $4.15 to $4.25 a share on $11.79 to $11.89 billion in revenue. Management cited tough conditions in the government and academic sectors in justifying the cut. Do you believe that explanation? Would you buy shares at current prices? Please weigh in using the comments box below.

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Fool contributor Tim Beyers is a member of the Motley Fool Rule Breakers stock-picking team. He didn't own shares in any of the companies mentioned at the time of publication. Check out Tim's portfolio holdings and Foolish writings, or connect with him on Google+ or Twitter, where he goes by @milehighfool. You can also get his insights delivered directly to your RSS reader.

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