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General Science / If Humans Were Wiped Out Would The World Survive ? (A nuclear power question)

« on: 13/04/2008 04:00:11 »

There has just been a book published about this very subject; "The World without us" by Alan Weisman. The premise is what would happen if all humans just vanished instantly.

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Cells, Microbes & Viruses / Is TB (tuberculosis) returning to the UK and other western countries?

« on: 13/04/2008 03:52:10 »

M. lepra and M. tuberculosis are so closely related that they can cause a certain degree of immunity against the other; so throughout history there have tended to be waves of either leprosy or TB. TB appears to have won out as it is the more aggressive disease and is also thriving due to the HIV pandemic.
Interesting it has been found that in HIV patients that are also affected with leprosy; their leprosy only becomes a problem when the HIV is treated and their T cell count increase as then their immune system starts to fight the leprosy producing the gross inflammation which results in some of the symptoms of leprosy.
It is thought that M. lepra rose from the mutation of M. bovis and that humans picked M. bovis up from domesticated cattle through living with them or by consuming dairy products. Therefore it was more likely to have arisen in countries that had domesticated cattle and where the people consumed dairy products and were not lactose intolerant.

3

Physiology & Medicine / Is a short nap better than nothing?

« on: 12/04/2008 17:20:01 »

I thought it was something to do with your sleep cycle; so you might feel refreshed after 20 minutes and wake up but if you ignore the urge to get up and go back to sleep and wake after an hour you will feel terrible. This varies from individual to individual. I don't know if there is any scientific basis to this.

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Cells, Microbes & Viruses / Where does pandemic / avian flu originate?

« on: 12/04/2008 11:15:58 »

People are complacent about the spread of certain infectious diseases as for many years it appeared that antibiotics had conquered all and people do not realise that our arsenal is quickly becoming ineffective and once bacterial resistance becomes a real problem even the simplest surgery will become much more dangerous. The importance of following instructions and finishing courses of antibiotics also needs to be stressed to the general public. Sorry for the hijack, oops!

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Cells, Microbes & Viruses / How do stem cells divide?

« on: 12/04/2008 11:03:21 »

Hi, I have just listened to the podcast on stem cells and I am wondering where this all fits in with normal cell division. Do differentiated cells divide when they get to a certain size or are they produced by stem cells dividing?



_{Mod edit - formatted the subject as a question.  Please try to do this to help keep the forum tidy and easy to navigate - thanks!}

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Physiology & Medicine / why are our tongues always wet?

« on: 12/04/2008 10:47:57 »

Do the chemicals from the food not need to dissolve in water in order for our taste buds to taste them?

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Physiology & Medicine / Have I "googled" my brain?

« on: 12/04/2008 10:46:18 »

Hi, I am slightly worried that constant use and easy access to Google is affecting my ability to recall information. Before the days of Google if I needed to remember some information I would think and think and eventually it would come to me. Nowadays as long as I have access to a computer I have instant access to the answer and my recall seems to have got a lot worse. Has a lack of use affected the physical structure of my brain or is this what getting older is like?

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Cells, Microbes & Viruses / Where does pandemic / avian flu originate?

« on: 12/04/2008 10:22:25 »

As far as I know, just because we are descended from individuals who survived the Spanish flu pandemic; it does not mean that we have immunity. Although we do get a certain number of antibodies passed from mother to baby (through breast milk) these only give a very short lived protection. If that particular type of H1N1/Spanish re-emerged very few individuals would be immune. In the case of Spanish flu it was the immune response that did the actual damage.
Large scale vaccination programs would probably not be effective for a number of reasons;

1. By the time enough vaccine was made, the virus might have mutated (as it is an unstable RNA virus) as the vaccine would would not be as effective.

2. The logistics of carrying out such a wide spread vaccination program; the last time that this was achieved was the smallpox vaccination program.

Pandemics tend to happen in three waves and the northern and southern hemispheres tend to have different flu seasons. I think that people are not really worried as this is old news and they have heard the "we are all going to die" many times before. People also do not know how many people die annually in a normal year and tend to think that the flu is like a bad cold.