Ed:
I just want to do a quick reminder of what we talked about this morning and how things actually get sorted and the basic problems arise, or at least legislation about air pollution has arisen out of a sequence of events over obviously several hundred years as we dealt with this morning.

Martin:
I think you have to be prepared to be flexible, because classes go at different rates. You have to set your objectives for the session, of course, and you have to get through those objectives, but the amount of detail that you bring in and the pace that you go I think needs to be adjusted for each class.

It might be a Monday morning, it might be a Friday afternoon - you can tell by watching their response how well things are going. Sometimes your own explanations might be better on one day than on another, but you have to make adjustments. If you weren't to do it that way, you might as well record everything and just show the videotape, which would be pointless.

The point about a lecture is that it's an interactive session. Even if it's being delivered from one side, it's still interactive because of the information that's coming back to the lecturer about the rate of learning of the students. I think if you take account of that you can adjust the pace and make some effective progress.

Martin:
We have got 2 parts of the hypothalamus here, the suprachiasmatic nucleus and the paraventricular nucleus and you can see that these abbreviations are identified further down, if you don't know what they stand for at the moment.

There are these 2 regions in the hypothalamus which then integrate those signals coming from the eye, with other signals coming into the brain. There is also some kind of timekeeper at this point. There is also some kind of clock in there so this is not entirely driven by external events, it is more that it is regulated by external events, the timekeeper is ticking away in there and the signals from the eye are adjusting the phase of that clock, and then signals goes through the hind brain and down the spinal cord.

The rest of the system is there, we don't need to know the details, but the end point is that melatonin is secreted from the pineal gland, so this is happening in the pineal. And in general dark stimulates melatonin and the more dark there is the longer the secretion of melatonin. I am sure that is a familiar concept to you.

That's what happens in mammals. In birds things are a little different. One species and more than one species here, the male is continually randomizing the situation, so we end up with one species.

The female is continually selecting the situation. If it went entirely down the female route we would end up with sub species because we would end up with cuckoos which were entirely meadow pippit-like, or entirely robin-like, in terms of their eggs, but that is not how it is because the males are diluting this effect out and taking away this specialization.

So I think this is a really interesting story because it shows that evolution is going on as we speak.

Kate:
One other thing I really noticed in your lecture was setting the little activity, or the task that you ask groups to go away and talk about a particular point. Could you describe how you've came to use that kind of activity in your lecture?

Ed:
It is something that I am doing more, especially in courses where, like this one, its environmental protection, it's for engineers, and the concern of environmental protection is not first on their agenda.

So if it is something where we want their opinion, and I would love to know what their opinion is on say environmental protection, do they thinks its important at all? Then you will get a very good snapshot of the opinion if you split them into groups and they make a list and then you take the papers you read them, you can find out whether they actually care about the subject.

You might suspect that they do or don't, but if you ask them and they write it down, you have it for certain. It's also a good technique for getting them to do something different.

A 50 minute lecture with nothing but talking from the front, nothing but writing, is a very long time and I think anything you can do to mix it up and get them think a bit and discuss something is a good thing.

I guess the only down side really is that they won't take it seriously, and they will just be talking about something completely different from your lecture, but on the whole that doesn't tend to happen. If you stage it right it tends to be successful.

Ed:
We made the list and I asked you to make your own list of the factors. None of you were actually wrong, none you have listed things that aren't a factor when looking at air pollution from static sources.

We are going to highlight certain specific ones and look at why they have an impact, why they are important and how they fit into a mathematical model for looking at plume dispersion and contamination.

Martin:
So that is our first diversion off into the world of light detection and seasonality. There is a lot more we could say about that, but I thought it would be interesting to put that in context because we tend to think of commercial birds as, if not insensitive to light, certainly not completely dominated by day length, but they are just selected birds and wild birds have these systems but accentuated in different ways.

So the second diversion, is about cuckoos, a little light relief at the end of the course.

Ed:
We will detail on Friday next week at 10 o'clock the final bits of this course, we will look at the examples sheets as well, so we are kind of half way through this particular section.