Note 4.

Investment in Equity Securities

As of September 30, 2014 and December 31, 2013 the Company had a $2,705,000 and $2,701,000 investment, respectively, in the common stock of Mevion Medical Systems, Inc. (“Mevion”), formerly Still River Systems, Inc., representing an approximate 0.77% interest in Mevion. The Company accounts for this investment under the cost method.

The Company carries its investment in Mevion at cost and reviews it for impairment on a quarterly basis, or as events or circumstances might indicate that the carrying value of the investment may not be recoverable. The Company evaluated this investment for impairment at December 31, 2013 and reviewed it at September 30, 2014 in light of both current market conditions and the ongoing needs of Mevion to raise cash to continue its development of the first compact, single room proton beam radiation therapy (“PBRT”) system. Based on the latest valuation evidence available, the Company estimates that there is currently an unrealized loss (impairment) of approximately $2.4 million.

In assessing whether the impairment is other than temporary, we evaluated the length of time and extent to which market value has been below cost, the financial condition and near term prospects of Mevion and our ability and intent to retain our investment for a period sufficient to allow for an anticipated recovery in the market value. Although the investment is not without risk, and the manufacture of the first unit has taken longer than originally anticipated, the Company believes that the current market value is a temporary situation and the successful clinical operation of the first MEVION S250 system at Barnes Jewish Hospital and Mevion’s significant revenue backlog provide a significantly higher potential valuation. The Company also has knowledge that Mevion filed a registration statement with the SEC for a possible Initial Public Offering (“IPO”). There is no guarantee that Mevion will be able to complete this transaction, nor does the Company have information that provides indication of the valuations being considered in connection with this event.

Mevion’s first PBRT unit at Barnes Jewish Hospital is complete. The first treatment at Barnes Jewish Hospital was performed in mid-December 2013. Mevion is continuing the installation process at five other sites, including the Company’s site at University of Florida Cancer Center at Orlando Health (formerly the MD Anderson Cancer Center Orlando). The Company’s first site broke ground for construction in September 2012 and the accelerator was delivered to the site in early November 2014.