I was interested to read about factors influencing the "hunger hormone's"—ghrelin's—effectiveness ("Still Hungry?" SN: 4/2/05, p. 216). One factor not considered but seemingly very significant is physical activity. I suggest that it is more useful to understand and encourage the positive effects of physical activity on overall well-being than to develop new drugs that artificially manipulate the release of hormones and encourage our increasingly sedentary lifestyles.
I do not dismiss or take lightly the findings you post. I just ask you to look into the deeper hungers that often are the source of people's overeating. As a psychotherapist, I can tell you people eat for reasons other than physiological hunger, such as emotional aspects. As we continue to view a human in isolated parts, and not as a unified whole, we deny the very complexity of being human. Perhaps this makes for neat scientific research, but the results are sadly lacking in relevance for the complexity of life as we humans experience it.
If the intention of the article was to inform readers about the chemistry of hunger, couldn't it also encourage respect, if not an informed compassion, for those of us who are not on good terms with our food? The article includes not one flippant word, but your cover illustration made me wince, and reading text around the repulsive face and glistening lips was disturbing.
The technique of ultrasonic leak detection through sensors mounted on the skin of a spacecraft or space station sounds good ("Leak Locator: Ultrasound for finding holes in spacecraft," SN: 4/2/05, p. 212) until the structures being monitored become more complex than a single sheet of aluminum. Then, resolving ambiguities from reflections and localizing the exact point of leakage may become difficult. Perhaps a portable device, with four or more transducers, could be pressed against a section of the hull to listen for the same ultrasonic hiss described here.