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                                                                   Exhibit 24.10

                                POWER OF ATTORNEY

STATE OF GEORGIA
COUNTY OF MCDUFFIE


         KNOW ALL MEN BY THESE PRESENTS that Boone A. Knox, having an address at
P.O. Box 26, Thomson, GA 30824, has made, constituted and appointed and BY
THESE PRESENTS, does make, constitute and appoint Douglas Crocker II and Michael
J. McHugh, or either of them, having an address at Two North Riverside Plaza,
Chicago, Illinois 60606, his true and lawful Attorney-in-Fact for him and his
name, place and stead to sign and execute in any and all capacities this Annual
Report on Form 10-K and any or all amendments to this Annual Report granting
unto each of such, Attorney-in-Fact, full power and authority to do and perform
each and every act and thing, requisite and necessary to be done in and about
the premises, as fully, to all intents and purposes as he might or could do if
personally present at the doing thereof, with full power of substitution and
revocation, hereby ratifying and confirming all that each of such
Attorney-in-Fact or his substitutes shall lawfully do or cause to be done by
virtue hereof.

         This Power of Attorney shall remain in full force and effect until
terminated by the undersigned through the instrumentality of a signed writing.

         IN WITNESS WHEREOF, Boone A. Knox, has hereunto set his hand this 20th
day of February, 2002.


                                                  /s/ Boone A. Knox
                                                  -----------------
                                                  Boone A. Knox

         I, Barbara A. Crutchfield, a Notary Public in and for said County in
the State of aforesaid, do hereby certify that Boone A. Knox, personally known
to me to be the same person whose name is subscribed to the foregoing instrument
appeared before me this day in person and acknowledged that he signed and
delivered said instrument as his own free voluntary act for the uses and
purposes therein set forth.

         Given under my hand and notarial seal this 20th day of February, 2002.


                                                  /s/ Barbara A. Crutchfield
                                                  ------------------------------
                                                     (Notary Public)


                              [SEAL]
My Commission Expires:___________________