Science Tidbits for June 26, 2012

Two quick news items for today and one video.

First up, more information on the effect that the 2009 H1N1 pandemic virus had. The H1N1 “swine” flu inflicted a particularly severe toll based on an interesting application of a couple concepts from the world of epidemiology and public health.

There are multiple ways to describe the death rates of a disease, one of which is simply the number of people that die from the disease. This simple measurement of mortality doesn’t tell us everything. Influenza typically kills a mix of the very young and very old. The 2009 H1N1 pandemic flu killed far more young people than the seasonal flu normally does, which changes the effect on society.

The concept to stress here is that of patient or person years. Functionally, every person that lives one year lives a person year. If you have fifty people that live one year, you can express this as fifty person years. If they are patients, you would say that there were fifty patient years.

A good way to bring this to the classroom is to compare one young person and one older person. Let’s say that the young person can expect to live sixty more years, while the older person can expect to live twenty more years. If both people die from the same disease, at the same time, the young person lost more years than the older person. Sure, if either one of them had survived the disease, either could have been hit by a bus the very next day, but statistically, the death of the younger person was a greater loss of potential years of life. If we have a very large population, with perhaps tens of thousands of young people and old people falling into our patient group. For every young person that dies, three older people have to die to add up to the same number of patient years.

It sounds like a very cold and callous way to look at the lives and deaths of real people, but this system is used to determine what level of risk is acceptable for a medication. How many patient years are saved from the treatment and how many are lost from side effects? How severe was an outbreak? How useful was a new safety technology installed in automobiles? Many concepts in public health take an impersonal look at an issue because of the sheer number of people involved.

This can lead to a great discussion of the differences between patient and population centered medicine, if that is in the scope of the class you are teaching.

The second tidbit is a quick explanation of a piece that was in the news a couple of weeks ago. A woman eating parboiled squid bit into what appeared to be a tasty piece of meat, but was in reality a reproductive organ of the male meal. This can either be passed along to students asking if it was real, or be used in a zoology course when discussing the reproductive strategies of a variety of invertebrates.

Finally, a video that I have used in teaching about the process of mitosis.

I have shown the video as is to a course, muted it and described the steps in the video, pausing to point out specific features, and have included it as a link on a course website (both Moodle and Blackboard). However you approach the multimodal classroom, videos like this can be very useful in helping students understand how something like mitosis works, and can be used at multiple levels of difficulty, from simply learning the phases of mitosis in order to beginning to understand the function of spindle fibers.

Teach on.


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