What's up with the weather?

[Jaedar]

It's almost 30 degrees here! And its almost 8 in the evening, RAARGH! It's not supposed to be this hot in Sweden! I don't live this much north because I want heat! Anything more than 25 is just torture.

Seriously, fuck the weather. Stupid global warming ruining my summer. It isn't supposed to be this bloody hot. I can't even think its so bloody steamy.

[bobby 55]

Crazy aint it? I posted last year about the 35 degrees centigrade we had in August....which is still our winter.

[Xesum]

Global Warming will fix itself eventually, so there's no need to worry.

[chris the cynic]

Global Warming will fix itself eventually, so there's no need to worry.

Assume for a moment that that is true (which it very well may be), what makes you think you'll survive the fix?

[Jaedar]

Global Warming will fix itself eventually, so there's no need to worry.

Assume for a moment that that is true (which it very well may be), what makes you think you'll survive the fix?

tbh, most of us(as in, us of this forum) will probably be dead of old age before it comes to apocalyptic problems. So really, we won't live to see it either way. Unless some biologist finds a way to stop aging(which isn't as sci-fi as it sounds)

[bobby 55]

The thing that concerns me more than the actual temperature is storms. Each summer for the past couple of years they seem to be growing in intensity. I'll be dead before global warming is either fixed or we're all fried, but I don't want to die by lightning or a falling tree etc. before my time.

[nerdenstein]

Haha that being said, Middle of July and it was heavy rain earlier.
It has been nice and hot all week too.
Stupid, Typical British Weather.

[OiNutter]

Unless some biologist finds a way to stop aging(which isn't as sci-fi as it sounds)

???

[Jaedar]

Unless some biologist finds a way to stop aging(which isn't as sci-fi as it sounds)

???

Unless I'm mistaken, they've found the thing that causes aging(telomerase? telomers? something like that). Basically, its a thing that protects your DNA from degrading, but it degrades itself with every copying of your cells, and when its gone, the DNA starts degrading which is aging afaik. They just gots to figure out how to repair it or activate the stemcell power in each cell, because stemcells repair their own telomerase(?).

That's sort of how it was explained to me in my Biology class anyhow.

[EER]

Because you are in Sweden, I assume you have a beard. Just shave your beard, throw off your bear pelt and you'll see 30 degrees is quite okay. Now 40 degrees, THAT is hot!

[DDL]

Unless I'm mistaken, they've found the thing that causes aging(telomerase? telomers? something like that). Basically, its a thing that protects your DNA from degrading, but it degrades itself with every copying of your cells, and when its gone, the DNA starts degrading which is aging afaik. They just gots to figure out how to repair it or activate the stemcell power in each cell, because stemcells repair their own telomerase(?).

Not necessarily true.

Aging is a hugely pleiotropic phenomenon: a massive number of factors contribute to our getting old and dying, many of which are almost entirely unstudied. Aging isn't really a discrete condition, per se, it's simply an accumulation of shit deemed irrelevant by selective pressure. Nothing in the history of evolution of..well, I was going to say "humans", but then thought "mammals", but actually..fuck: living organisms would actually work (even bacteria get old), has ever selected positively for a capacity to live significantly beyond breeding age: you're born, you have kids, your job is done. Anything after that is irrelevant. Your genes have been passed on, and those genes were the genes that got you to the point of having kids, not genes that allow you to live for ages.

So anything, anything, that even marginally increases your chance of getting from your birth, to having children, no matter how detrimental it might be in old age, will be selected for.

Yes, telomerase is involved: as organisms with linear DNA molecules (as opposed to circular), every time a cell divides, it loses a tiny bit from the end of each strand of DNA: in essence, a DNA copying enzyme has to land on DNA before it can start copying, and it can't copy the DNA directly underneath it (in the 'landing site'), only the stuff it moves over as it starts working. So cells evolved an enzyme -telomerase- that adds short DNA repeats -telomeres- to the ends of all chromosomes, providing them with disposable junk that can safely act as a landing site for DNA polymerase, avoiding the risk of losing actual genetic information. And yes, as you age, telomerase activity ceases, and cells thus either stop dividing altogether, or divide, lose information, and die (or become cancerous).

BUT

For one thing, telomerase is only active in a small fraction of cells: namely those that are rapidly dividing anyway. yes, it's switched on all over the place during embryogenesis and so on, and to a lesser extent during childhood, but after that? Blood progenitor cells, gut lining, dermal tissue, sperm progenitors...hair follices, maybe. Stem cells, yes: but stem cells are essentially totally undifferentiated cells, and are a highly controversial subject anyway.

Most other stuff is done dividing. Muscles cells rarely if ever divide once terminally differentiated (kinda implied in the name, huh?), exercise simply makes your exisiting cells get bigger. Nerve cells never divide. Telomerase is irrelevant in these cells, as they do not copy their DNA anymore. And yet they still fall apart. Neurodegeneration is a major player in old age, and can safely be said to be totally unconnected with telomerase activity. Nerve cells, instead, just accumulate oxidative damage from all that heavy thinking you do, and eventually just fall apart. Sure, you could theoretically enlist stem cells to come and replace lost tissue, and in the case of muscle atrophy, this might work quite well. In the case of neural tissue, well..... given that all the information you've accumulated in your life is stored in the form of "connections in neural tissue", you would simply be replacing old-age senility and forgetfulness with "youthful ignorance": either way, the information has still been lost. You've gone from being an old man who's forgotten his wife's face and can barely walk, to a young man who never knew his wife and hasn't yet learned to walk.

Then there's cancer. Accumulation of DNA damage will eventually, always, lead to cell death, or cancer. It is thermodynamically impossible to replicate and repair DNA with 100% fidelity (plus...this would totally fuck the entire concept of evolution), thus errors will always accumulate. The longer you live, the more errors. This is unavoidable. Are you a man? You will get prostate cancer.

And then..hell, there's shit we just don't know anything about. The longer people live, the more fucked-up things start happening. Increasing the average human lifespan has thus far simply resulted in an increase in 'cancer' as a cause of death. Who knows what fucked up stuff lies over the next hill? Hell, the leading cause of age-related death in yeast is accumulation of 'extrachromosomal circles': if they live long enough, they eventually just die because they're packed with tons of DNA they copied and circularised by mistake. Could that happen in humans? Who knows!!??

So yeah: complicated.

Sadly.

I'm hoping to upload myself, personally.

[Jaedar]

It is thermodynamically impossible to replicate and repair DNA with 100% fidelity (plus...this would totally fuck the entire concept of evolution), thus errors will always accumulate.

Don't know about that bit actually. Aren't the thermodynamic laws and rules basically limited to closed systems?

Stem cells, yes: but stem cells are essentially totally undifferentiated cells, and are a highly controversial subject anyway.

Only because there's no viable way to grow huge amounts of them yet. They're basically controversial because the best way we have to procure them currently is to harvest them from unborn human embryos. I'm telling you, biologists are clever(well...), give them a few more decades and they'll have figured out how to turn regular cells into stem cells or something like that. Or how to harvest them from grown adults, and then grow them in tubes.

I'm hoping to upload myself, personally.

Cybernetic future society ftw.

[DDL]

The universe is a closed system. :p

Anyway, consider it this way (from a mass-action kinetics approach): for every 2-fold reduction in error rate, you'd need to double the number of repair enzymes. To get an error rate of zero, therefore, you need an infinite number of repair enzymes. And they wouldn't all fit in a cell, trust me.

As for stem cells, yes: we can already harvest a variety of partially differentiated stem cells from non-embryonic sources (so you could take liver progenitor stem cells and make them turn into new liver), but we're still learning the chemical cues they need..and de-differentiation (while appealing) is a bit tricky: DNA imprinting comes into play -say, a partially differentiated liver progenitor cell already knows it will never be a brain cell, lung cell, blood cell, etc, so genes exclusive to those cell types get progressively silenced: methlyated, bound up in histones, and so on, because it makes everything else more efficient. But then, if you de-differentiate that cell back to a pluripotent stem cell (that could turn into anything), it keeps that silencing..and we're not too sure how to reverse that yet.

And yes, as you noted, stem cells propagated up to large numbers run into the telomerase problem: the cells may already be 'old'. (it's thought one reason dolly the sheep didn't live so long was that the fibroblast used to get DNA for cloning was already fairly telomerically frayed, thus the sheep was born already 14 years old..so to speak)

[Jane_Denton]

Lately the weather where I live can only be described as Manic Depressive!

It's so hot and sunny one day you feel like you are going to cook from the inside out, then the next day it's cool and pouring rain...

[justanotherfan]

The world is indeed a small place since I have been cooking with the heat in my place as well... I've got two ceiling fans going... another fan set in the window of my bedroom facing out, and a fan in my living room in my window that is sucking air in, where I have my puter ! Before I had discovered the miracle of effective air circulation I was sticking an ice pack down the back of my shirt (seriously).

I just installed an industrial fan, but in a regular sized room. It's nice and quiet on low, and on high it actually makes nearby rooms windy. The old fan was one of those 20$ Cadtire ceiling fans, and the motor started clicking after a few years (they're 30$ now).