Friday, November 28, 2008

Adrian Kantrowitz (1918-2008)

Last week heart surgeon and pacemaker pioneer Andrian Kantrowitz died in Ann Arbor, Michigan. Among his many roles, Kantrowitz was an Adjunct Professor in the Department of Physics here at Oakland University where I work. Soon after I arrived at OU in 1998, Emeritus Professor Norm Tepley and I visited Kantrowitz’s company L.VAD Technology in Detroit, which makes a left ventricular assist device that helps the heart pump blood. In February 2005 I invited Kantrowitz to give our weekly physics colloquium. At the time his health was already fragile and he gave his lecture sitting down. But it was an excellent talk to one of the largest crowds we ever had at our colloquium series.
Machines in Our Hearts: The Cardiac Pacemaker, the Implantable Defibrillator, and American Health Care, by Kirk Jeffrey, superimposed on Intermediate Physics for Medicine and Biology.
Machines in Our Hearts: The Cardiac Pacemaker,
the Implantable Defibrillator, and American Health Care,
by Kirk Jeffrey.

Kantrowitz had an inspirational life story. As a young man, he served as a battalion surgeon in World War Two. He later performed the first heart transplant in the United States. He also played a role in the early development of the pacemaker, a topic discussed in Chapter 7 of the 4th edition of Intermediate Physics for Medicine and Biology. Kirk Jeffrey, in his book 
Machines in Our Hearts: The Cardiac Pacemaker, the Implantable Defibrillator, and American Health Care, wrote
GE [General Electric] had developed an implantable pacemaker in its electronics laboratory in cooperation with heart surgeon Adrian Kantrowitz of Maimonides Hospital in Brooklyn. This project began in 1960, apparently in response to the announcement of the Chardack-Greatbatch pacemaker. The initial model was implanted in May 1961 and, as was common with these early devices, the designers made improvements based on the experience of the early patients.

The GE pacemakers had one remarkable technological feature—an external control unit that communicated with the implanted generator by magnetic induction. When taped to the skin on the patient's abdomen, the controller enabled the physician to set the pacing rate anywhere between 64 and 120 beats per minute. Kantrowitz viewed rate control as a means to safeguard the elderly patient.
You can learn more about Adrian Kantrowitz from obituaries in the New York Times, the Washington Post and the Los Angeles Times.

Friday, November 21, 2008

Howard Hughes Medical Institute Holiday Lectures on Science

Each year in early December the Howard Hughes Medical Institute presents their Holiday Lectures on Science. Not sure you can make it to Chevy Chase, Maryland for this year’s lectures? Don’t worry, all the lectures are webcast live, and then are available as on-demand webcasts and on DVD.

This year the live webcast is December 4 and 5, starting at 10:00 A.M. each day. The topic is “Making Your Mind: Molecules, Motion, and Memory,” presented by Eric Kandel and Thomas Jessell.

Eric R. Kandel, M.D. and Thomas M. Jessell, Ph.D. of Columbia University will help us understand how the nervous system turns an idea into action—from the complex processing that takes place in the brain to the direct marching orders the spinal cord gives to the muscles. Modern neuroscience equates mind with the organ we call the brain, an astounding network more than 100 billion neurons connected in a vast complicated web. The presenters will help us puzzle out how the brain is organized and identify the seat of human memory. The question of understanding how the brain functions is rivaled by the question of how such a complex network of cells develops in the first place.
I have watched these Holiday Lectures the last couple years, and they are extremely well done. They are aimed at high school students interested in careers in science or medicine. I think that readers of the 4th edition of Intermediate Physics for Medicine and Biology will find them very informative and inspirational.

Topics from previous years (all available as free on-demand webcasts) are

plus many others. Also at the HHMI website are other lectures, animations, videos, virtual labs, and a virtual museum. It is all cool science. The website is ideal for someone trying to get up-to-date on hot topics in medicine and biology. Enjoy.

Friday, November 14, 2008

Virtual Journal of Biological Physics Research

Looking for a way to keep up with the scientific literature in biological physics? Make a habit of perusing the Virtual Journal of Biological Physics Research. The journal’s website states that
this semi-monthly virtual journal contains articles that have appeared in one of the participating source journals and that fall within a number of contemporary topical areas in biological physics research. The articles are primarily those that have been published in the previous month; however, at the discretion of the editors older articles may also appear, particularly review articles. Links to other useful Web resources on biological physics are also provided.
The virtual journal is free and the abstracts are free, but sometimes in order to download a pdf of the full article you need a subscription to the participating source journal. Examples of participating journals are the Biophysical Journal, Physical Review E, and the Proceedings of the National Academy of Sciences. You can sign up to have the virtual journal delivered by email if you prefer. The virtual journal is published by the American Institute of Physics and the American Physical Society.

The fourth edition of
Intermediate Physics for Medicine and Biology provides a great introduction to biological physics research up to the year 2005. You can keep abreast of the current literature using the Virtual Journal of Biological Physics Research.

Friday, November 7, 2008

Physics for Future Presidents

Physics for Future Presidents: The Science Behind the Headlines, by Richard Muller, superimposed on Intermediate Physics for Medicine and Biology.
Physics for Future Presidents:
The Science Behind the Headlines,
by Richard Muller.
This blog has remained free of politics throughout the fall’s presidential election. Having no intention of injecting partisanship now that the voting is over, I nevertheless would like to find a way to celebrate the election with you all. My solution: write a post about Richard Mullers recently published book Physics for Future Presidents: The Science Behind the Headlines. I checked out a copy from the Rochester Hills Public Library and started reading it. Those of you familiar with the 4th edition of Intermediate Physics for Medicine and Biology wont be surprised that I focused on the aspects of Physics for Future Presidents that have biomedical relevance.

I came to the book a skeptic, as I imagined it would be a very elementary, watered down presentation of physics. But after reading it, I came away with a positive impression of the work. It really does capture much of the physics that world leaders will need to know in the 21st century. The introduction begins

Are you intimidated by physics? Are you mystified by global warming, spy satellites, ICBMs, ABMs, fission, and fusion? Do you think all nukes, those in bombs and those in power plants, are basically the same? Are you perplexed by claims that we are running out of fossil fuels when there are counterclaims that we are not? Are you confused by the ongoing debate over global warming, when some prestigious scientists say that the debate is over? Are you baffled, bewildered, and befuddled by physics and high technology?

If so, then you are not ready to be a world leader. World leaders must understand these issues. The moment when you are being told that a terrorist left a dirty bomb hidden in midtown Manhattan is not a good time to have to telephone your local science advisor to find out how bad that situation really is. Nor is it a good time simply to assume the worst, to decide that all government resources must now be pulled off other projects to address this new emergency. You have to know enough to act wisely, quickly, proportionately.
About one-fourth of the book deals with issues related to nuclear physics (in section III, titled “Nukes”). Particularly relevant to readers of Intermediate Physics for Medicine and Biology is the chapter Radioactivity and Death. It discusses the biological effects of radiation (using the old fashioned unit of rem instead of the more modern Sievert). I particularly liked its discussion of the linear hypothesis, which states that there is no threshold for biological effects of low-dose radiation, a topic Hobbie and I discuss in our Chapter 16. Muller writes
The government asked the National Academy of Sciences to review the question [of the threshold for radiation effects], and they published a report in 2006. They examined all the papers that argued for a threshold effect and concluded that the evidence was not sufficiently compelling to change the policy [of assuming no threshold]. So the US government continues to derive its laws according to the linear hypothesis.

Future presidents should note that that was a policy decision, not a scientific one. Many people have argued that the effects of the policy are not just health, but other central aspects of national policy. Much of the fear of nuclear power, for example, comes from the projections of the number of people who will die of cancer from low levels of radiation. If the policy results in consequences that hurt people in other ways (everything from evacuating their homes to fighting in a war), then the linear hypothesis is no longer the conservative choice. This is policy, not science—at least not yet.
Other medical physics topics the book addresses with this clear, if qualitative, tone are the risk posed by environmental radioactivity, the safety of storing nuclear waste, anthrax attacks (It turns out that the spread of the spores, and their failure to kill more people, is more related to physics than biology), and the danger of microwave radiation produced by cell phones (Much of the fear of microwaves undoubtedly comes from the fact that they share the name radiation with the other, far more dangerous forms, such as gamma radiation. The fear that some people have shown toward such cell phone radiation finds its origin not in physics, but in linguistics). I would say that much of the book deals with risk analysis, and the impact physics has on estimating risk.

Muller teaches a class based on the book at Berkeley. Videos of his lectures are posted on his class website. The San Francisco Chronicle has an article about his book and lectures, and says that
self-starting students in 35 states and 43 countries have been watching the 90-minute Physics for Future Presidents talks he gives every Tuesday and Thursday morning to a packed lecture hall of 300 undergrads on campus.
I believe that readers of Intermediate Physics for Medicine and Biology—future scientists and engineers
must be able to express many concepts that Muller explores quantitatively through mathematics. Yet, I see his point that future presidents require a qualitative, rather than quantitative, understanding of physics. In any event, I welcome our new president by suggesting that one of the first book he reads (after the 4th edition of Intermediate Physics for Medicine and Biology, of course!) is Physics for Future Presidents