SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
(Rule 13d-102)
INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT
TO RULES 13d-1 (b) (c), AND (d) AND AMENDMENTS THERETO FILED
PURSUANT TO RULE 13d-2 (b)
(Amendment No. 1)
Mercury Computer Systems, Inc.
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(Name of Issuer)
Common Stock, $0.01 par value
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(Title of Class of Securities)
589378108
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(CUSIP Number)
December 31, 2007
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(Date of Event which Requires Filing of this Statement)
Check the appropriate box to designate the rule pursuant to which this Schedule
is filed:
|X| Rule 13d-1(b)
|_| Rule 13d-1(c)
|_| Rule 13d-1(d)
*The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter
disclosures provided in a prior cover page.
The information required on the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).
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CUSIP No. 589378108 13G Page 2 of 8 Pages
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1. NAMES OR REPORTING PERSONS
S.S. OR I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS
Renaissance Technologies LLC 26-0385758
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2. CHECK APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS):
(a) |_|
(b) |_|
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3. SEC USE ONLY
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4. CITIZENSHIP OR PLACE OF ORGANIZATION
Delaware
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5. SOLE VOTING POWER
1,797,400
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NUMBER OF 6. SHARED VOTING POWER
SHARES
BENEFICIALLY 0
OWNED BY -----------------------------------------------------------------
EACH 7. SOLE DISPOSITIVE POWER
REPORTING
PERSON 1,797,400
WITH -----------------------------------------------------------------
8. SHARED DISPOSITIVE POWER
0
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9. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
1,797,400
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10. CHECK IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES
(SEE INSTRUCTIONS) |_|
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11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
7.93%
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12. TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)
IA
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Page 2 of 8 Pages
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CUSIP No. 589378108 13G Page 3 of 8 Pages
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1. NAMES OR REPORTING PERSONS
S.S. OR I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS
James H. Simons
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2. CHECK APPROPRIATE BOX IF A MEMBER OF A GROUP (SEE INSTRUCTIONS):
(a) |_|
(b) |_|
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3. SEC USE ONLY
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4. CITIZENSHIP OR PLACE OF ORGANIZATION
United States
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5. SOLE VOTING POWER
1,797,400
-----------------------------------------------------------------
NUMBER OF 6. SHARED VOTING POWER
SHARES
BENEFICIALLY 0
OWNED BY -----------------------------------------------------------------
EACH 7. SOLE DISPOSITIVE POWER
REPORTING
PERSON 1,797,400
WITH -----------------------------------------------------------------
8. SHARED DISPOSITIVE POWER
0
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9. AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
1,797,400
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10. CHECK IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES
(SEE INSTRUCTIONS) |_|
--------------------------------------------------------------------------------
11. PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
7.93%
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12. TYPE OF REPORTING PERSON (SEE INSTRUCTIONS)
IN
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Page 3 of 8 Pages
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CUSIP No. 589378108 13G Page 4 of 8 Pages
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Item 1.
(a) Name of Issuer.
Mercury Computer Systems, Inc.
(b) Address of Issuer's Principal Executive Offices.
199 Riverneck Road
Chelmsford, MA 01824
Item 2.
(a) Name of Person Filing.
This Schedule 13G is being filed by Renaissance Technologies LLC
("RTC") and James H. Simons ("Simons").
(b) Address of Principal Business Office or, if none, Residence.
The principal business address of the reporting persons is:
800 Third Avenue
New York, New York 10022
(c) Citizenship.
Dr. Simons is a United States citizen and
RTC is a Delaware limited liability company
(d) Title of Class of Securities.
Common Stock, $0.01 par value
(e) CUSIP Number.
589378108
Page 4 of 8 Pages
Item 3. If this statement is filed pursuant to Rule 13d-1(b) or 13d-2(b) or (c),
check whether the person filing is a:
(a) |_| Broker or dealer registered under Section 15 of the Act.
(b) |_| Bank as defined in Section 3(a)(6) of the Act.
(c) |_| Insurance Company as defined in Section 3(a)(19) of the Act.
(d) |_| Investment Company registered under Section 8 of the Investment
Company Act.
(e) |X| Investment Adviser in accordance with Sec. 240.13d-1(b)(1)(ii)(E).
(f) |_| Employee Benefit Plan or Endowment Fund in accordance with Sec.
240.13d1(b)(1)(ii)(F).
(g) |_| Parent holding company, in accordance with Sec.
240.13d-1(b)(ii)(G).
(h) |_| A savings association as defined in Section 3(b) of the Federal
Deposit Insurance Act.
(i) |_| A church plan that is excluded from the definition of an
investment company under Section 3(c)(14) of the Investment
Company Act of 1940.
(j) |_| Group, in accordance with Sec. 240.13d-1(b)(1)(ii)(J).
If this statement is filed pursuant to Sec. 240.13d-1(c), check this box
|_|.
Item 4. Ownership
(a) Amount Beneficially Owned.
RTC: 1,797,400 shares
Simons: 1,797,400 shares, comprising the shares beneficially
owned by RTC, because of Dr. Simons' position as control
person of RTC.
(b) Percent of Class. RTC: 7.93%
Simons: 7.93%
(c) Number of shares as to which each such person has
(i) sole power to vote or to direct the vote: RTC: 1,797,400
Simons: 1,797,400
(ii) shared power to vote or to direct the vote: 0
(iii) sole power to dispose or to direct the
disposition of: RTC: 1,797,400
Simons: 1,797,400
(iv) shared power to dispose or to direct the
disposition of: 0
Page 5 of 8 Pages
Item 5. Ownership of Five Percent or Less of a Class.
If this statement is being filed to report the fact that as of the
date hereof the reporting person has ceased to be the beneficial
owner of more than five percent of the class of securities, check
the following |_|
Item 6. Ownership of More than Five Percent on Behalf of Another Person.
Certain funds and accounts managed by RTC have the right to receive
dividends and proceeds from the sale of the securities which are the
subject of this report. RIEF Trading LLC holds of record more than
5% of such securities.
Item 7. Identification and Classification of the Subsidiary Which Acquired
the Security Being Reported on by the Parent Holding Company or
Control Person.
Not applicable.
Item 8. Identification and Classification of Members of the Group.
Not applicable.
Item 9. Notice of Dissolution of Group.
Not applicable.
Page 6 of 8 Pages
Item 10. Certification.
By signing below I certify that, to the best of my knowledge and belief,
the securities referred to above were not acquired and are not held for the
purpose of or with the effect of changing or influencing the control of the
issuer of the securities and were not acquired and are not held in connection
with or as a participant in any transaction having that purpose or effect.
SIGNATURE
After reasonable inquiry and to the best of my knowledge and belief, I
certify that the information set forth in this statement is true, complete and
correct.
Date: February 12, 2008
/s/ James H. Simons
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James H. Simons
Renaissance Technologies LLC
By: /s/ Mark Silber
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Mark Silber
Executive Vice President
Attention: Intentional misstatements or omissions of fact constitute
Federal criminal violations (see 18 U.S.C. 1001).
Page 7 of 8 Pages
SCHEDULE 13G
EXHIBIT INDEX
EXHIBIT NO. EXHIBIT
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99.1 Agreement Pursuant to Rule 13d-1(k)(1)(iii) (incorporated by
reference to Exhibit 99.1 to the initial filing of this Schedule
13G on February 12, 2007).
Page 8 of 8 Pages