EXHIBIT 3.31

                          CERTIFICATE OF INCORPORATION

                                       of

                           TSI DOWNTOWN CROSSING, INC.

                  FIRST:   The name of the corporation (the "Corporation") is
TSI DOWNTOWN CROSSING, INC.

                  SECOND:  The address of the Corporation's registered office in
the State of Delaware is 1209 Orange Street, in the City of Wilmington, County
of New Castle 19801. The name of its registered agent at such address is The
Corporation Trust Company.

                  THIRD:   The nature of the business to be conducted and the
purposes to be promoted are to engage in any lawful act or activity for which
corporations may be organized under the General Corporation Law of Delaware.

                  FOURTH:  The total number of shares of stock which the
corporation shall have authority to issue is One Thousand (1,000) shares of
Common Stock, par value $1.00 per share.

                  FIFTH:   The name and mailing address of the incorporator are
as follows:

                                    Jane F. Zaletofsky
                                    Becker, Glynn, Melamed & Muffly LLP
                                    299 Park Avenue
                                    New York, New York 10171

                  SIXTH:   The Corporation shall, to the full extent permitted
by Section 145 of the General Corporation Law of the State of Delaware, as
amended from time to time, indemnify all persons whom it may indemnify pursuant
thereto.



                  SEVENTH: The following provisions are for the management of
the business and for the conduct of the affairs of the Corporation and for the
further creation, definition, limitation and regulation of the powers of the
Corporation and of its directors and stockholders:

               The number of directors of the Corporation shall be fixed
      by, or in the manner provided in, the by-laws of the Corporation.
      The election of the directors need not be by written ballot unless
      the by-laws so provide.

               The directors of the Corporation may from time to time
      adopt, amend or repeal any of the by-laws of the Corporation,
      including by-laws adopted by the stockholders, but the stockholders
      may from time to time specify provisions of the by-laws that may not
      be amended or repealed by the directors.

               The directors of the Corporation shall have the power
      without the assent or vote of the stockholders to authorize and to
      cause to be executed and delivered on behalf of the Corporation
      mortgages and liens upon all or any part of the property of the
      Corporation.

               Meetings of stockholders may be held within or without the
      State of Delaware, as the by-laws may provide.

               In addition to the powers and authorities hereinbefore or
      by law expressly conferred upon them, the directors of the
      Corporation are hereby empowered to exercise all such powers and to
      do all such acts and things as may be exercised or done by the
      Corporation, subject to the provisions of the General Corporation
      Law of the State of Delaware, of this Certificate of Incorporation,
      and to any by-laws of the Corporation; provided, however, that no
      by-law whether adopted by the stockholders or by the directors of
      the Corporation shall invalidate any prior act of the directors
      which would have been valid if such by-law had not been adopted.

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                  EIGHTH:  A director of this Corporation shall not be
personally liable to the Corporation or its stockholders for monetary damages
for breach of fiduciary duty as a director, except for liability:

                  (i)      for any breach of the director's duty of loyalty to
                  the corporation or its stockholders,

                  (ii)     for acts or omissions not in good faith, or which
                  involve intentional misconduct or a knowing violation of law,

                  (iii)    under Section 174 of the Delaware General Corporation
                  Law, or

                  (iv)     for any transaction from which the director derived
                  an improper personal benefit.

                  NINTH:   The Corporation reserves the right to amend, alter,
change or repeal any provision contained in this Certificate of Incorporation in
the manner now or hereafter prescribed by law, and all rights and powers
conferred hereby on stockholders, directors and officers of the Corporation are
subject to this reservation.

                  IN WITNESS WHEREOF, the undersigned incorporator hereby
formally acknowledges under penalties of perjury that this is her act and deed
and that the facts stated herein are true, and accordingly has hereunto set her
hand this 30th day of July, 2001.

                                                        Jane F. Zaletofsky

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