Toadfish Monastery

I recalled one tiny detail about toilet paper that hasn't been mentioned yet: the reason for its thinness is that it must dissolve with water to prevent  pipe clogging. Multi-ply is just a way to have thinner paper while at the same time conforming with the standard.

A good point and I am relieved <groan> to see you are still applying your mind to this topic.

In the first flush of enthusiasm for this topic, readers were on a roll with responses. Now it has passed and interest is petering out...




Thank heaven.

<groan>

Hey, even the Economist has succeeded in dragging a bit of toilet humour over three editions (see Letters section for the last two weeks).

Changing the subject, I have a question about seasonal flu (and peaks for swine flu).

In England, seasonal flu occurs in the winter. Winter is cold and dismal. The sun is a long way away.

In Australia (Sydney etc) seasonal flu occurs in the winter. Winter is not very cold and dismal but more like a mild English Summer.

Why do we get "seasonal" flu in England? If it is anything to do with the weather, and basing expectation on the Australian conditions, we might expect to get flu pretty much all the time, except in heat waves.

Am I being very stupid here?

Hmmm....  reputedly it has to do with humidity, but you are right - while it makes sense on a relative basis (winter being the most likely time to catch it, because conditions are most condusive to spreading it), it doesn't add up on an absolute level (x set of conditions are adequate to effectively spread it). To continue your example, Calgary summers (especially June/July) are like an English winter - wet, cold and dismal with occasional snow.  Our winters are sunny and very low humidity (and bloody cold!).

I think that the relative factor is more to do with people spending time indoors and in large groups - especially school children (hmm.... when's summer break in Oz?). 

I always heard that frequent changes in temperature make the body more susceptible to catch the flu. In winter people frequently is switching between hot clothes to a cold environment outside to a warm environment inside, etc. You could argue that in the summer is the same but backwards (hot outside, cool inside) but a warmer enclosed environment is a much better vector.

I think the flu has a rather narrow temperature window outside of which it does not function well. So outside the window it has to be transmitted directly* while inside it can stay alive outside the host for a time an thus be transmitted indirectly.
I think the main flu season is in the change periods from winter** to summer and the other way around when the human immune system is under stress.
The common cold is pretty unkwnon in arctic and antarctic conditions but people coming from those regions into temperate zones almost immediately catch it. In this case it is because the immune system has fallen asleep due to lack of work.

*eased by many people sticking close together
**also defined as the season where people try to heat up their dwellings to levels they thought intolerably warm in summer 

Quote from: Swatopluk on September 17, 2009, 03:26:13 PM
**also defined as the season where people try to heat up their dwellings to levels they thought intolerably warm in summer 

LOL, being from a cold climate with hot summers (back home) I've noticed the opposite - nobody would suffer through air-con temperatures in the winter, but think it's great in the summer (and are usually wearing less clothing to boot).

So it's to do with the immune system not coping with "changes" in temperature?

But this still doesn't make sense as far as UK goes as we get big changes all the time.

I think the virus likes moist air and is damaged rapidly by ultra-violet light. A dark, moist, recirculated air environment makes it as happy as a pig in ... a sty.

Read recently that some company is trying to interest aircraft makers in installing UV virus killers in the ventillation systems. Think it takes about 8 of them at £10000 each for a normalish commercial aircraft.

I hadn't heard the outside temperature change argument before. Certainly I'd read that the rise in internal body temperature during a fever is a general immune response to slow down subverted cell virus factory production while the correct antibody production is ramped up by (I think) clonal B cells.

The sore throat is an effect of the subverted cells being destroyed by generic stampers (I forget the proper name).  As I understand it, artificially bringing body temperature down too soon may make you feel better but can increase the virus load.

Quote from: beagle on September 17, 2009, 08:56:41 PM
I think the virus likes moist air and is damaged rapidly by ultra-violet light. A dark, moist, recirculated air environment makes it as happy as a pig in ... a sty.

Doesn't jive with Calgary winters - we are dehydrating and largely sunny in the winters.  OTOH, the temperature-change theory does - I've personally seen it go from -25 C at midnight to +20 C at noon. 

Atmospheric pressure changes are hell for migraine sufferers here (due to Chinook winds).

Maybe, but the virus transmission probably occurs indoors, in heavily recycled air under not natural wavelength balanced artificial light.

I'll consult my betters at work on this one , and report back if I understand the explanation (big if).


edit:

P.S.  The schools are shut during summer.  A thousand people with little immunity in an enclosed space is a great environment for our little friends.  Possibly King Herod was an underrated epidemiologist.

Quote from: beagle on September 17, 2009, 09:09:16 PM
Maybe, but the virus transmission probably occurs indoors, in heavily recycled air under not natural wavelength balanced artificial light.

True enough - and even though we get sun in the winter, days are pathetically short and the angle of incidence is low. However, considering that many, many people are office-bound these days, I'm not convinced that indoor air conditions vary significantly with the seasons (drier with air-con than with heat in some climates).

Children as vectors is very likely, although I think it gets passed in parallel (parents in offices handing off to children passing back to other childrens' parents.