I believe that "overseeing" here means supervising others' activities.

All of the above supervise the people under them.

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Note added at 42 mins (2016-02-11 17:06:00 GMT)
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Chief Physician - Wikipedia, the free encyclopedia
https://en.wikipedia.org/wiki/Chief_Physician
Wikipedia
A Chief Physician, also called Head Physician, Senior Consultant, Chief of ... as the title of the most senior physician of a particular department within a larger ...
Emergency Department Physician Jobs, Employment in ...
www.indeed.com/q-Emergency-Department-Physician-l-Mic...
Indeed.com
Jobs 1 - 10 of 788 - 788 Emergency Department Physician Jobs available in Michigan on Indeed.com. one search. all ... Associate Section Head (Physician) Job.

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Note added at 47 mins (2016-02-11 17:10:56 GMT)
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What to Expect - Emergency Department - Highland ...
https://www.urmc.rochester.edu/...
University of Rochester Medical Center
The attending physician—the senior physician in charge of all patient care in the Emergency Department—might be involved in a patient's care. But if you have ...
[PDF]Approaching Full Capacity in the Emergency Department
www.acep.org/content.aspx?...
American College of Emergency Physicians
Emergency department (ED) crowding occurs when demand outstrips supply. ..... ongoing assessment should be communicated to the ED physician in charge.

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Note added at 53 mins (2016-02-11 17:17:14 GMT)
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Screwed: The Path of a Healer - Page 71 - Google Books Result
https://books.google.com/books?isbn=1450294375
Amnon Goldstein - 2011 - ‎Biography & Autobiography
The need for a new Head Surgeon was greatly felt after the death of Dr. Eger. Therefore ... Previously, he used to be in charge of the surgical emergency room.