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And even if it was, we wouldn't be able to explain why, since the great majority of cases are "idiopathic" -- a fancy way of saying that the cause is not know.
Looie496 (
talk)
20:54, 9 February 2014 (UTC)reply
Another possibility is since Parkinson's affects older people more so than younger ones, countries with older populations will have a higher overall prevalence.
105.236.146.239 (
talk)
09:56, 9 February 2014 (UTC)reply
Yes, Parkinson's (which is really several similar syndromes) tends to develop in older people. In nations with lower life-expectancies people tend to die from infections, parasites, accidents, violence, hunger, and sheer exhaustion from a life of manual labor. They don't get old or sedentary enough to suffer metabolic, immune and regulatory disfunctions related to aging such as type II diabetes, Parkinsons, Alzheimer's and cancer. Forgive me, since I have no idea what single article of ours addresses this.
μηδείς (
talk)
21:23, 9 February 2014 (UTC)reply
To clarify a little what's already been said, because everyone dies of *something*, as you eliminate the causes of death that happen earlier in life, the percentage of people who die of things that take longer to develop (degenerative diseases like Parkinson's, some cancers, Alzheimer's, etc) must increase. Hence, it's inevitable that the better we get at treating things like infectious diseases, the more crash-resistant our cars become, the more people give up smoking, etc - the more people are going to die of Parkinson's, Alzheimer's, etc. If we find either a preventative or a cure for Parkinson's, then the percentage of Alzheimer's, cancer, etc will suddenly increase because all of those people who would have died of Parkinson's will now live to get one of these other conditions. The better medicine and accident prevention gets, the closer we edge towards something as unlikely as "Being struck by lightning" as the single largest cause of death!
SteveBaker (
talk)
17:14, 10 February 2014 (UTC)reply
A reasonable comparison can be found at
Feral cat#Life span and survival. The more dangerous or "wild" the conditions are, the shorter the lifespan is likely to be. Being safe and protected in "tame" circumstances tends to lead to a longer lifespan and a greater likelihood of dying from various "old-timers'" diseases such as Parkinson's. ←
Baseball BugsWhat's up, Doc?carrots→
18:12, 10 February 2014 (UTC)reply
The effects of various environmental toxins can't be excluded, either. Parkinsonism happens when for some reason, the "dark matter" (substantia nigra) of certain parts of the brain dies off. The pesticide rotenone, widely used because it has a fairly low mammalian toxicity but kills insects rapidly in low doses, has been connected with the onset of parkinsonism in the laboratory. Other chemicals may have similar effects (the most notable example was an undesired byproduct in a "designer drug" synthesized to have opiate-like effects on the user... several abusers of the designer drug came down with irreversible Parkinsonism, one of whom only recovered to some extent after stem-cell therapy).
loupgarous (
talk)
16:42, 13 February 2014 (UTC)reply
Have u ever noticed your car glass(window) during winter,when there is a dew you see the moisture on ur car.when u get in to the car u will find the moisture on the same window glass but inside.i want to know what is the nature of glass?is glass behaves like a cloth?how can we see moisture inside the car glass(window) even its close? — Preceding
unsigned comment added by
Aamirsayeed1410 (
talk •
contribs)
08:00, 9 February 2014 (UTC)reply
The moisture you notice on the inside is not the same moisture from the outside that has somehow traveled through the glass. The moisture is caused by
condensation. In short, warm air can hold more moisture (water vapor) than cold air. When warm air comes into contact with the cold glass, the water vapor in the warm air is deposited as liquid water on the glass. When you get into the car, you warm up the inside and your breath introduces more water vapor to the interior which condenses on the inside of the glass.--
William ThweattTalkContribs08:16, 9 February 2014 (UTC)reply
Also, if you exited your vehicle and closed the doors/windows, you trapped air inside. If the temperature cools outside, making the glass colder than when you closed up the vehicle, the water vapor from the warmer air inside the car will be deposited on the inside of the glass as condensation.--
William ThweattTalkContribs08:21, 9 February 2014 (UTC)reply
From extensive personal experience/experimentation, hot, because the warmer the air is, the more water it takes up.
However, although this will clear the windscreen most quickly (and will keep it clear while the air continues to blow), if this warm and now moister air remains in the car it will simply cool down and redeposit the water as condensation again. My strategy is, once the screen is clear, to lower the side windows for a while during the drive, allowing cooler but hopefully dryer external air to replace the internal air with its moisture load. {The poster formerly known as 87.81.230.195}
212.95.237.92 (
talk)
14:39, 10 February 2014 (UTC)reply
If your car has air-conditioning - then turning on the A/C (with the heat turned to whatever level is comfortable - and the air-flow set to "recirculate") will rapidly dry out the air inside the car - thereby removing the source of the condensation while keeping the temperature comfortable at whatever level you like.
SteveBaker (
talk)
17:01, 10 February 2014 (UTC)reply
I have to disagree on using the recirculate setting (also sometimes labelled something like "MAX A/C"). The most common cause of condensation on the inside of the windows for me is when there is cold, dry air outside, but I am inside, and my breathing and maybe wet hair from showering makes it humid in there. Therefore, I want to vent the moist air from inside and replace it with dry air from outside.
However, on a moist summer day, your recirculate option might be the best you could do, as there is no dry air to be had anywhere, so you must rely on the A/C removing water for you. (BTW, where does that condensate water go, is there a drain that dumps it onto the ground ?)
StuRat (
talk)
18:23, 10 February 2014 (UTC)reply
Yes, there is a drain. In the cars where I've dealt with it the evaporator and it's housing are above the passenger side footwell, right by the recirculator input. Condensation drips from the evaporator fins into the housing, then goes out a drain. It can also freeze to the fins on humid days if the car doesn't have a regulator to keep them from getting too cold. I have never tried running A/C in winter weather, but I would expect the sub-freezing temperature air flowing over the fins would cause the moisture in the air to be converted to ice which would freeze up the evaporator and insulate it. When that happens, the moisture stops being pulled from the air as quickly because the ice works as insulation.
Katie R (
talk)
20:27, 10 February 2014 (UTC)reply
When I first came to the US, I'd never owned an airconditioned car before - and when I saw a puddle of water on the road under the rental car on a very hot, humid day - I assumed it was a leaky radiator or something...that wasn't one of my best days! :-)
SteveBaker (
talk)
21:51, 10 February 2014 (UTC)reply
BTW, if there is moisture on the inside of the car windows, right by the vents, soon after starting, that can be a sign of a leaky
heater core. A sweet smell from the coolant is another sign.
StuRat (
talk)
18:29, 10 February 2014 (UTC)reply
Mass-killer floods
Looking at the
floodplain article made me wonder: besides the
1931 Yellow River flood, do we have any articles about floods that themselves killed tons of people, e.g. the death toll was recorded as being hundreds of thousands, or more? I'm talking about the high water itself, not the flow (i.e. ruling out a flash flood that sweeps people away), or famine from being unable to grow crops in flooded fields, or illness resulting from all the refugees being packed together on high ground. I get the impression that most high-death-toll floods kill primarily with famines and illness, and the 1931 situation with hundreds of thousands of drownings would seem to be a lot rarer.
Nyttend (
talk)
21:53, 9 February 2014 (UTC)reply
Welcome to the Wikipedia Science Reference Desk Archives
The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the
current reference desk pages.
And even if it was, we wouldn't be able to explain why, since the great majority of cases are "idiopathic" -- a fancy way of saying that the cause is not know.
Looie496 (
talk)
20:54, 9 February 2014 (UTC)reply
Another possibility is since Parkinson's affects older people more so than younger ones, countries with older populations will have a higher overall prevalence.
105.236.146.239 (
talk)
09:56, 9 February 2014 (UTC)reply
Yes, Parkinson's (which is really several similar syndromes) tends to develop in older people. In nations with lower life-expectancies people tend to die from infections, parasites, accidents, violence, hunger, and sheer exhaustion from a life of manual labor. They don't get old or sedentary enough to suffer metabolic, immune and regulatory disfunctions related to aging such as type II diabetes, Parkinsons, Alzheimer's and cancer. Forgive me, since I have no idea what single article of ours addresses this.
μηδείς (
talk)
21:23, 9 February 2014 (UTC)reply
To clarify a little what's already been said, because everyone dies of *something*, as you eliminate the causes of death that happen earlier in life, the percentage of people who die of things that take longer to develop (degenerative diseases like Parkinson's, some cancers, Alzheimer's, etc) must increase. Hence, it's inevitable that the better we get at treating things like infectious diseases, the more crash-resistant our cars become, the more people give up smoking, etc - the more people are going to die of Parkinson's, Alzheimer's, etc. If we find either a preventative or a cure for Parkinson's, then the percentage of Alzheimer's, cancer, etc will suddenly increase because all of those people who would have died of Parkinson's will now live to get one of these other conditions. The better medicine and accident prevention gets, the closer we edge towards something as unlikely as "Being struck by lightning" as the single largest cause of death!
SteveBaker (
talk)
17:14, 10 February 2014 (UTC)reply
A reasonable comparison can be found at
Feral cat#Life span and survival. The more dangerous or "wild" the conditions are, the shorter the lifespan is likely to be. Being safe and protected in "tame" circumstances tends to lead to a longer lifespan and a greater likelihood of dying from various "old-timers'" diseases such as Parkinson's. ←
Baseball BugsWhat's up, Doc?carrots→
18:12, 10 February 2014 (UTC)reply
The effects of various environmental toxins can't be excluded, either. Parkinsonism happens when for some reason, the "dark matter" (substantia nigra) of certain parts of the brain dies off. The pesticide rotenone, widely used because it has a fairly low mammalian toxicity but kills insects rapidly in low doses, has been connected with the onset of parkinsonism in the laboratory. Other chemicals may have similar effects (the most notable example was an undesired byproduct in a "designer drug" synthesized to have opiate-like effects on the user... several abusers of the designer drug came down with irreversible Parkinsonism, one of whom only recovered to some extent after stem-cell therapy).
loupgarous (
talk)
16:42, 13 February 2014 (UTC)reply
Have u ever noticed your car glass(window) during winter,when there is a dew you see the moisture on ur car.when u get in to the car u will find the moisture on the same window glass but inside.i want to know what is the nature of glass?is glass behaves like a cloth?how can we see moisture inside the car glass(window) even its close? — Preceding
unsigned comment added by
Aamirsayeed1410 (
talk •
contribs)
08:00, 9 February 2014 (UTC)reply
The moisture you notice on the inside is not the same moisture from the outside that has somehow traveled through the glass. The moisture is caused by
condensation. In short, warm air can hold more moisture (water vapor) than cold air. When warm air comes into contact with the cold glass, the water vapor in the warm air is deposited as liquid water on the glass. When you get into the car, you warm up the inside and your breath introduces more water vapor to the interior which condenses on the inside of the glass.--
William ThweattTalkContribs08:16, 9 February 2014 (UTC)reply
Also, if you exited your vehicle and closed the doors/windows, you trapped air inside. If the temperature cools outside, making the glass colder than when you closed up the vehicle, the water vapor from the warmer air inside the car will be deposited on the inside of the glass as condensation.--
William ThweattTalkContribs08:21, 9 February 2014 (UTC)reply
From extensive personal experience/experimentation, hot, because the warmer the air is, the more water it takes up.
However, although this will clear the windscreen most quickly (and will keep it clear while the air continues to blow), if this warm and now moister air remains in the car it will simply cool down and redeposit the water as condensation again. My strategy is, once the screen is clear, to lower the side windows for a while during the drive, allowing cooler but hopefully dryer external air to replace the internal air with its moisture load. {The poster formerly known as 87.81.230.195}
212.95.237.92 (
talk)
14:39, 10 February 2014 (UTC)reply
If your car has air-conditioning - then turning on the A/C (with the heat turned to whatever level is comfortable - and the air-flow set to "recirculate") will rapidly dry out the air inside the car - thereby removing the source of the condensation while keeping the temperature comfortable at whatever level you like.
SteveBaker (
talk)
17:01, 10 February 2014 (UTC)reply
I have to disagree on using the recirculate setting (also sometimes labelled something like "MAX A/C"). The most common cause of condensation on the inside of the windows for me is when there is cold, dry air outside, but I am inside, and my breathing and maybe wet hair from showering makes it humid in there. Therefore, I want to vent the moist air from inside and replace it with dry air from outside.
However, on a moist summer day, your recirculate option might be the best you could do, as there is no dry air to be had anywhere, so you must rely on the A/C removing water for you. (BTW, where does that condensate water go, is there a drain that dumps it onto the ground ?)
StuRat (
talk)
18:23, 10 February 2014 (UTC)reply
Yes, there is a drain. In the cars where I've dealt with it the evaporator and it's housing are above the passenger side footwell, right by the recirculator input. Condensation drips from the evaporator fins into the housing, then goes out a drain. It can also freeze to the fins on humid days if the car doesn't have a regulator to keep them from getting too cold. I have never tried running A/C in winter weather, but I would expect the sub-freezing temperature air flowing over the fins would cause the moisture in the air to be converted to ice which would freeze up the evaporator and insulate it. When that happens, the moisture stops being pulled from the air as quickly because the ice works as insulation.
Katie R (
talk)
20:27, 10 February 2014 (UTC)reply
When I first came to the US, I'd never owned an airconditioned car before - and when I saw a puddle of water on the road under the rental car on a very hot, humid day - I assumed it was a leaky radiator or something...that wasn't one of my best days! :-)
SteveBaker (
talk)
21:51, 10 February 2014 (UTC)reply
BTW, if there is moisture on the inside of the car windows, right by the vents, soon after starting, that can be a sign of a leaky
heater core. A sweet smell from the coolant is another sign.
StuRat (
talk)
18:29, 10 February 2014 (UTC)reply
Mass-killer floods
Looking at the
floodplain article made me wonder: besides the
1931 Yellow River flood, do we have any articles about floods that themselves killed tons of people, e.g. the death toll was recorded as being hundreds of thousands, or more? I'm talking about the high water itself, not the flow (i.e. ruling out a flash flood that sweeps people away), or famine from being unable to grow crops in flooded fields, or illness resulting from all the refugees being packed together on high ground. I get the impression that most high-death-toll floods kill primarily with famines and illness, and the 1931 situation with hundreds of thousands of drownings would seem to be a lot rarer.
Nyttend (
talk)
21:53, 9 February 2014 (UTC)reply