Dell announced a change campaign called "Dell 2.0," reducing the number of employees and diversifying the company's products. While chairman of the board after relinquishing his CEO position, Michael Dell still had significant input in the company during Rollins' years as CEO. With the return of Michael Dell as CEO, the company saw immediate changes in operations, the exodus of many senior vice-presidents and new personnel brought in from outside the company. Michael Dell announced a number of initiatives and plans (part of the "Dell 2.0" initiative) to improve the company's financial performance. These include elimination of 2006 bonuses for employees with some discretionary awards, reduction in the number of managers reporting directly to Michael Dell from 20 to 12, and reduction of "bureaucracy". Jim Schneider retired as CFO and was replaced by Donald Carty, as the company came under an SEC probe for its accounting practices.
Who relinquished his position as CEO to take a seat on the board?
Michael Dell

After the Kangxi Emperor's death in the winter of 1722, his fourth son, Prince Yong (), became the Yongzheng Emperor. In the later years of Kangxi's reign, Yongzheng and his brothers had fought, and there were rumours that he had usurped the throne(most of the rumours believe that Yongzheng's brother Yingzhen (Kangxi's 14th son) is the real successor of Kangxi Emperor, the reason why Yingzhen failed to sit on the throne is because Yongzheng and his confidant Keduo Long tampered the content of Kangxi's testament at the night when Kangxi passed away), a charge for which there is little evidence. In fact, his father had trusted him with delicate political issues and discussed state policy with him. When Yongzheng came to power at the age of 45, he felt a sense of urgency about the problems which had accumulated in his father's later years and did not need instruction in how to exercise power. In the words of one recent historian, he was "severe, suspicious, and jealous, but extremely capable and resourceful," and in the words of another, turned out to be an "early modern state-maker of the first order."
How old was Yongzheng when he took over?
45

Housekeeping genes are critical for carrying out basic cell functions and so are expressed at a relatively constant level (constitutively). Since their expression is constant, housekeeping genes are used as experimental controls when analysing gene expression. Not all essential genes are housekeeping genes since some essential genes are developmentally regulated or expressed at certain times during the organism's life cycle.
When are some essential genes expressed?
at certain times during the organism's life cycle