(125)The power to adopt acts in accordance with Article 290 TFEU should also be delegated to the Commission in respect of prescribing a temporary reduction in the level of own funds or risk weights specified under this Regulation in order to take account of specific circumstances, to clarify the exemption of certain exposures from the application of provisions of this Regulation on large exposures, to specify amounts relevant to the calculation of capital requirements for the trading book to take account of developments in the economic and monetary field, to adjust the categories of investment firms eligible for certain derogations to required levels of own funds to take account of developments on financial markets, to clarify the requirement that investment firms hold own funds equivalent to one quarter of their fixed overheads of the preceding year to ensure uniform application of this Regulation, to determine the elements of own funds from which deductions of an institution's holdings of the instruments of relevant entities should be made, to introduce additional transitional provisions relating to the treatment of actuarial gains and losses in measuring defined benefit pension liabilities of institutions. It is of particular importance that the Commission carry out appropriate consultations during its preparatory work, including at expert level. The Commission, when preparing and drawing up delegated acts, should ensure a simultaneous, timely and appropriate transmission of relevant documents to the European Parliament and to the Council.