Increases in electrical conductivity attenuate the introduced electromagnetic wave, and thus the penetration depth decreases. Shielding provides an electrically conductive barrier to attenuate electromagnetic waves external to the shield. Thus, any exciting frequency lower than the cutoff frequency will attenuate, rather than propagate. Noise barriers can attenuate these noises. This in turn can "attenuate the effects" of endogenous opioid peptides. Preserving the right atrial appendage might attenuate this effect. Solid cages generally attenuate fields over a broader range of frequencies than mesh cages. This enabled researchers to apply CD47 as a potential target to attenuate immune rejection. Cables attenuate a signal in direct proportion to length. Active circuits are able to filter, attenuate or boost the signal from the pickup. Certain construction materials can attenuate cell phone signal strength. Its job is to attenuate the frequencies above that limit. Additionally, high capacitance develops across the glass and conducting solution which can attenuate high-frequency responses. Interestingly, no consequences were shown to attenuate cognitive processing. Suppression of HoxA5 has been shown to attenuate hemangioma growth.