A packaged microelectronic element includes connection component incorporating a dielectric layer carrying traces remote from an outer surface, posts extending from the traces and projecting beyond the outer surface of the dielectric, and pads exposed at the outer surface of the dielectric layer, the pads being connected to the posts by the traces. The harness applies elastic, compressive reinforcement on the left ventricle to reduce deleterious wall tension and to resist shape change of the ventricle during the mechanical cardiac cycle. At least one of the TX beamformer, the noise whitener and the RX MMSE receiver, or any combination thereof are capable of jointly processing a carrier and its image subcarrier to compensate the IQ imbalance in the beamforming system. 261 recommendation, certain group of blocks exceed the allowable packet size. The chin bar and face shield include a plurality of magnetic elements that magnetically connect the lower edge of the face shield to the chin bar. The gas-permeable membrane can preferably take the form of either a \u201ccurtain\u201d or \u201ccartridge\u201d and the R ratio of the membrane may be optimized by adjusting the differential pressure across the membrane.