The present invention provides an apparatus and method for keeping track of a number of articles, especially for example articles that are being carried while travelling on business andor vacation. In particular, methods, systems and apparatuses are disclosed that are directed to an air flow mixer that is structured and arranged to promote cross flow of portions of the air streams relative to each other through the air flow mixer. Microwave-shielding regions may promote uniform cooking and inhibit overcooking of food products. The capillary structure is disposed on an inner surface of the tube. The radiator includes a first reduced portion inserted in the tube, a second reduced portion located opposite to the first reduced portion and fins for dissipating heat generated by the light-emitting diode. In some embodiments the method includes the steps of: endovascularly delivering a replacement valve and an expandable anchor in an unexpanded configuration within a catheter to a vicinity of the heart valve; deploying the anchor from the catheter; expanding the anchor to contact tissue at an anchor site; and retrieving the anchor into the catheter.