Plik:University of California seal in library sticker.png

As explained below, this picture is in the public domain (at least in the USA) to the best of my knowledge. WARNING: Even if this picture is in the public domain (meaning that it not protected by copyright laws), its use might still be restricted due to trademark protection or similar laws.

Library sticker from the University of California.
This sticker contains the following text:
(In the seal of the University of California:)
THE UNIVERSITY OF CALIFORNIA
LET THERE BE LIGHT
1868
(Below the seal of the University of California:)
THE LIBRARY
OF THE UNIVERSITY
OF CALIFORNIA
GIFT OF
Prof. G. C. Evans

Apparently the sticker refers to Professor Griffith Conrad Evans, who according to Wikipedia was a professor at the University of California, Berkeley and died in the year 1973. Therefore I assume that this sticker has been published sometime before 1977 (in the USA and without any copyright notice) which means that it is now in the public domain (at least in the USA).
The University of California seal might actually have been published in the USA already before 1923, but since it has been published without a copyright notice, it does not really matter if it has been published before 1923 or in the time from 1923 to 1977. In both cases, it is now in the public domain (at least in the USA).

I created this PNG image of the sticker by cutting an old image which I found at http://commons.wikimedia.org/wiki/File:Carl_Gottfried_Neumann_-_Die_elektrischen_Kr%C3%A4fte_002.jpg
This old image is part of the scans from the book "Die elektrischen Kräfte" which has apparently been written by Carl Gottfried Neumann and published by B. G. Teubner in 1873, and been donated to the library of the University of California, Berkeley.
Simply scanning a book does not involve any creative work, therefore I believe that the person(s) who scanned and uploaded the old image cannot claim any copyright for their work.
In the unlikely case that I have any copyright for the work which I did on this picture, I hereby release all my copyrights related to this picture into the public domain.

Additional comments about copyright status:
I (User:Casecrer) contaced Janice Gonsalves (jang@ber...), who is an employee at the University of California, Berkeley and deals with legal issues related to the university seal, to confirm that this image is not protected by copyright-law.
On March 15, 2013, she responded that the seal has been around since the 1880s and therefore if it was copyrighted, the copyright would have expired long ago. However she also pointed out that the seal is a trademark.
I forwarded a copy of her e-mail to the OTR system. The ticket number is Ticket#2013032010013829. The OTRS volunteer Johan Bos responded that the current license template is sufficient and the OTR system is not needed for this image.

Some other sources claim that the seal was not created in the 1880s, but a few decades later. But at least they all seem to agree that this seal has been created before 1977. Anonymous: The version of the seal shown here was designed by Tiffany & Co in 1910 (http://brand.universityofcalifornia.edu/guidelines/the-uc-seal.html#!).