EX-24

                                                                    EXHIBIT 24.1
                                                                    ------------



                                POWER OF ATTORNEY



KNOW ALL MEN BY THESE PRESENT, that I, GEORGE SOROS, hereby make, constitute and
appoint each of Armando T. Belly, Jodye Anzalotta, John F. Brown, Maryann
Canfield, Richard D. Holahan, Jr. and Robert Soros acting individually, as my
agent and attorney-in-fact for the purpose of executing in my name, (a) in my
personal capacity or (b) in my capacity as Chairman of, member of or in other
capacities with Soros Fund Management LLC ("SFM LLC") and each of its affiliates
or entities advised by me or SFM LLC, all documents, certificates, instruments,
statements, filings and agreements ("documents") to be filed with or delivered
to any foreign or domestic governmental or regulatory body or required or
requested by any other person or entity pursuant to any legal or regulatory
requirement relating to the acquisition, ownership, management or disposition of
securities, futures contracts, or other investments, and any other documents
relating or ancillary thereto, including but not limited to, all documents
relating to filings with the Commodities Futures Trading Commission and National
Futures Association, the United States Securities and Exchange Commission (the
"SEC") pursuant to the Commodities Exchange Act and the Securities Act of 1933
or the Securities Exchange Act of 1934 (the "Act") and the rules and regulations
promulgated thereunder, including all documents relating to the beneficial
ownership of securities required to be filed with the SEC pursuant to Section
13(d) or Section 16(a) of the Act and information statements on Form 13F
required to be filed with the SEC pursuant to Section 13(f) of the Act.

All past acts of the attorney-in-fact in furtherance of the foregoing are hereby
ratified and confirmed.

Execution of this power of attorney revokes that certain Power of Attorney dated
as of the 15th day of January 2002 with respect to the same matters addressed
above.

This power of attorney shall be valid from the date hereof until revoked by me.

IN WITNESS WHEREOF, I have executed this instrument as of the 30th day of
October, 2002.


                                        /s/ George Soros
                                        ---------------------------------------
                                        GEORGE SOROS

EX-24

                                                                    EXHIBIT 24.2
                                                                    ------------



                                POWER OF ATTORNEY


KNOW ALL BY THESE PRESENTS, that I, FRANK H. PEARL, hereby make, constitute and
appoint RODD MACKLIN as my agent and attorney-in-fact for the purpose of
executing in my name, (a) in my personal capacity or (b) in my capacity as
Chairman of, member of or in other capacities with Perseus LLC ("Perseus") and
each of its affiliates or entities advised by me or Perseus, all documents,
certificates, instruments, statements, filings and agreements ("documents") to
be filed with or delivered to any foreign or domestic governmental or regulatory
body or required or requested by any other person or entity pursuant to any
legal or regulatory requirement relating to the acquisition, ownership,
management or disposition of securities, futures contracts, or other
investments, and any other documents relating or ancillary thereto, including
but not limited to, all documents relating to filings with the Commodities
Futures Trading Commission and National Futures Association, the United States
Securities and Exchange Commission (the "SEC") pursuant to the Commodities
Exchange Act and the Securities Act of 1933 or the Securities Exchange Act of
1934 (the "Act") and the rules and regulations promulgated thereunder, including
all documents relating to the beneficial ownership of securities required to be
filed with the SEC pursuant to Section 13(d) or Section 16(a) of the Act and
information statements on Form 13F required to be filed with the SEC pursuant to
Section 13(f) of the Act.

All past acts of the attorney-in-fact in furtherance of the foregoing are hereby
ratified and confirmed.

This power of attorney shall be valid from the date hereof until revoked by me.

IN WITNESS WHEREOF, I have executed this instrument as of the 9th day of April,
2003.



                                        /s/ Frank H. Pearl
                                        ---------------------------------------
                                        FRANK H. PEARL