Questions tagged [senescence]

The process of biological aging or the state of an organism being biologically old.

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6answers
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Why do we age? or Do we have a theory of senescence?

There seem to be a number of ideas about why we age. Hypotheses include the gradual accumulation of cell metabolic products affecting organism function and the reduction of telomere length during cell ...
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3answers
169 views

Does DNA influence death (e.g. by cell aging)

I know that we age because of errors in the cell replication process and these errors eventually leads to death. If we exclude environmental factors, are there any other factors that can cause these ...
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0answers
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Senescence in space

How is senescence of individual eukaryotic cells and tissues affected by gravity and zero-gravity environments? In other words, can eukaryotic cells live forever in space (given the appropriate ...
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0answers
87 views

Hydra immortality

Recent research on immortality ha been on an organism named Hydra. I have heard about it being related to some FoxO gene, which has been found in several other organisms but how does telomerase affect ...
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1answer
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Do people grow shorter as they age, how common is it, and what triggers it?

Is it true that people become gradually shorter as they age? If it is, is it more common in one gender than the other? And is it known what triggers this? (Considering that the "shortening" probably ...
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0answers
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Why do people die? [duplicate]

what is the reason people die naturally even though they have no known disease? I see people become physically weak at times they get old and die eventually in case they are not attacked by any known ...
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3answers
885 views

Have there been studies done to test Immortality of cancer cells in culture?

This website on cultured cancer cells () says cancer cells may be immortal. I am wondering if there has been any research done to find if cancer cells are really immortal. How old is the still ...
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2answers
187 views

Would a person live longer, if such a person lived in a planet with lower gravity? (say, Mars) [closed]

I was wondering: some companies plan to colonize Mars, many of us know. But if one were to live on Mars, would this person live longer? It seems to me that a lower gravity would mean less overall ...
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1answer
177 views

Do Blanding's Turtles die of old age?

I have recently found articles and various claims that turtles (Blanding's turtles as an exact example) could possibly live indefinitely. http://discovermagazine.com/2002/jun/featturtle This is said ...
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2answers
1k views

Can plants live forever? [duplicate]

I know that some plants die for old age like a lettuce. But there are trees like Baobabs or larger Ficus in the tropics of whom we don't know their age. And trees like spruce reaching 9950 years old, ...
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2answers
223 views

How well does the radius of a tree correlate with its age?

I'm looking for a cheap non-invasive ways to approximate the age of a tree (a birch). Measuring the radius pops up in the mind as the first alternative. How would one do that? Measure at multiple ...
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2answers
2k views

What determines the autumn leaf color?

It is autumn out there. Green, brown, red, yellow, and mixed-colored leaves drop from the trees to the ground. What determines the colors of the leaves? Wikipedia tells me Leaf senescence is the ...
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0answers
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What is the role of RAGEs?

According to articles I read, AGEs (advanced glycation end products) activate RAGEs (receptors for AGEs). This activation increases the ROS (reactive oxygen species) levels in the cells. 2003 - ...
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1answer
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About modern dating techniques

In a comment to this question, it was said that Radiocarbon dating won't work. For a start the tree needs to be dead, which since you're not using the rings I'm assuming it isn't. Also the atomic ...
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1answer
108 views

What are senescent cells doing in our bodies? [closed]

I'm reading a paper that mentioned the elimination of senescent cells delays aging. I'd like to receive more information about it. The Baker study published in Nature demonstrates that targeted ...
3
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1answer
355 views

Circulating factors affecting human health/longevity

Circulating factors present in young mice have been shown to promote rejuvenation of aged mice, suggesting that tissues have inherent capabilities to regenerate, and circulating factors may be ...
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1answer
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Do we know if RHEB is more sensitive to some amino acids than other amino acids?

RHEB (Ras homolog enriched in brain) senses amino acid levels in order to recruit mTOR. See this review describing the process of how RHEB recruits mTOR. So does RHEB have differential selectivity ...
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3answers
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Is there any kind of immortality in plants?

I asked a question about immortality of hydra and learned good things about senescence. Now I would like to know about immortality in plants, if there is some kind of immortality in plants and how ...
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2answers
478 views

Do couples having children later in life act as an evolutionary mechanism?

Ok, this may be just wild nonsense and I have to warn that my knowledge on the subject is limited. I was reading about how in some countries people choose to have children later in life. After that ...
134
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1answer
17k views

Do bacteria die of old age?

I know that the cells of mammals at least stop dividing when they are old, and then die a programmed cell death. Then other cells have to replace them. But in a bacterial colony, each cell ...
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3answers
4k views

Why do some trees have a life span, while some don't?

I have heard that there is no limit on the growth of trees, but then why do some trees, such as boxelders and poplars, tend to live shorter than redwoods, for example? Some advertisements for improved ...
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1answer
373 views

How are new people created from the DNA of an aged person. i.e. Why are we young?

The question "why do we age" has been asked numerous times. But why are we young? The cells of the adult human being are an age (time>0), but how can old cells create new cells that are younger than ...
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1answer
335 views

Senescence, immortality and evolution?

Many have heard about the fabled "immortal" jellyfish, Turritopsis dohrnii, which doesn't die from aging (senescence) and can revert the aging process indefinitely. It is rather remarkable that only ...
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1answer
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Do crocodiles age?

I was watching a talk by Michio Kaku and he mentioned that crocodiles (or possibly alligators, I forget offhand) don't actually age -- they can die, but they essentially go through no aging process ...
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1answer
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Do trees age on a microscopic level?

Most animals age via at least two mechinisms: at a "macroscopic" level, basically wear and tear to the point where (on evolutionary time scales) it's more genetically advantageous to optimize for ...
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0answers
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How can stem cells be counted in body?

In the study of supercentenarian woman here, it was found that all her blood cells are formed from only two stem cells (ancestor stem cells). How scientists can distinguish cell ancestors? Aren't ...
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1answer
94 views

How well supported is the hypothesis that aging is mainly caused by the number of mutations in tissues?

I heard the hypothesis, that the (main) reason of aging is the increasing number of mutations in body tissues. The higher the number of mutations is, the older tissue is. Is this true? And how well ...
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1answer
408 views

Fibrinous inflammation, exudate and scarring in monotonous movements and ageing

I have palpated many hard organs during my work and studies. I have seen many young and old people who have hard organs, like very hard shoulder - very common. I have interviewed some of them, some ...
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0answers
290 views

What is the name of systemic tension of muscles?

I meat a overtrained friend (25 years old) who cannot rest. He has all muscles and most of the skin very tense. He is practising regularly in gym and sleep badly. He moves like a stick figure and has ...
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2answers
119 views

In what ways can mechanisms of apoptosis be damaged?

How many ways can an Apoptosis mechanism be made disfunctional or irreparably damaged? If a cell has damaged Apoptosis mechanisms and it divides will its daughter cells have such damage?
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2answers
753 views

How does the telomere repeat sequence vary in Eukaryotes?

Question: How does the telomeric repeating sequence vary in non-vertebrate Eukaryotes? If you know the repeating sequence of a given species I would appreciate hearing it. Background: Telomerase is ...
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2answers
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Is there an advantage to linear chromosomes?

The DNA copying enzymes have a hard time working to the end of a chromosome. For circular chromosomes this is not a problem, since there is not a sharp 'end'. However, for a linear chromosome, without ...
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1answer
198 views

How do mosquitoes maintain telomere length?

While the vast majority of eukaryotic organisms maintain their chromosome ends (telomeres) via telomerase, an enzyme system that generates short, tandem repeats on the ends of chromosomes, other ...
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0answers
40 views

Can we define biological age? [duplicate]

How can we define ageing from a biological standpoint without making an appeal to chronological age? Related, but less important, are there any metrics we can use to determine someone's biological ...
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1answer
106 views

How does the body repair extracellular damage caused by glucose?

So we know that glucose is an aldehyde that can cause cell damage to the lysine and arginine residues on proteins through the Maillard Reaction (among other damaging reactions that glucose ...
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1answer
675 views

How much does the Hayflick limit/telomere length vary across taxa and within humans?

Since they seem to be quite connected, I'm curious if anyone knows of research comparing the Hayflick limit (and presumably by extension telomere length) between different taxa. I've heard the ...
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2answers
3k views

Cell life: division for immortality or reproduction with aging

Are the two cells that are derived from one cell, ‘twin sisters’ or a ‘mother and a daughter’? In other words, can a cell really be divided to live an "immortal" life or is cell reproduction the ...
5
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1answer
237 views

Difference In Telomeres Between A Thale Cress Plant And A Methuselah Tree

From what I have read and understood telomeres cap off how many times a cell can divide before it can no longer divide and that is what causes aging. A thale cress plant apparently has a life cycle ...
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2answers
446 views

How is it that the WI-38 cell line isolated by Hayflick in 1962 is still very much around and not affected by the 'Hayflick Limit'?

I have searched the net and I have not been able to come up with an clear answer. Edit: Here is the para quoted from Nature http://www.nature.com/news/medical-research-cell-division-1.13273 "So began ...
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1answer
220 views

Hibernation, Metabolism and Aging

People are beginning to seriously research space travel applications of therapeutic hypothermia, specifically for reducing metabolism and stress on humans traveling to Mars. It seems that as you ...
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1answer
117 views

Telomere elongation methods?

What sort of telomere elongation methods are there currently? Would this stop aging? (edit: No, probably) I couldn't turn up anything good on google. I was thinking that maybe you could sequence ...
9
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1answer
646 views

What evolutionary pressures pushed Galápagos tortoises to mature so slowly and live so long?

I read that they take up to 40 years (in the wild) to reach the age of reproduction and are thought to live over 100 years, with one in captivity reaching over 170 years. Can someone explain in ...
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3answers
411 views

What reasons allow for women to outlive men?

It is a well-known fact that women tend to outlive men. I often hear people unscientifically stating that men generally generally die younger because of the higher stress encountered in their work ...
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1answer
1k views

Exercise causes number of cell divisions to approach Hayflick limit faster? And hence shorten life expectancy?

A world class athlete spends a lot of time performing intense exercises. Correct me if I'm wrong, but I assume that these intense exercises causes significant damage to the athlete's cells, but with ...
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0answers
106 views

Papers linking telomeres and aging [closed]

I'm currently writing a piece of work about telomeres and aging, and wondered if you could share some good papers you've either read or know of.
5
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1answer
337 views

Is cell senescence in culture comparable to that in vivo?

A cell is 'senescent' when is has permanently left the cell-cycle. This can be caused by stresses, or by reaching the 'Hayflick limit' (the cell has reached its replicative lifespan, as defined by its ...
3
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1answer
569 views

Does the speed of electrical impulses through neurones decrease with age?

From what I read on the NatGeo app, it stated that the speed of the electrical impulses that are sent by a neurone will be approximately 332 kilometers per hour. Will the speed of this electrical ...
9
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1answer
9k views

How does the NAD+/NADH ratio affect lifespan in vertebrates?

Here's the proximate physical implication of the ratio (from the Wikipedia article on NADH). The balance between the oxidized and reduced forms of nicotinamide adenine dinucleotide is called the ...
5
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1answer
110 views

Why would we overexpress Sir2 by overexpressing its hypomorph (dSir2-EP2300) in C. elegans?

Can't we just overexpress regular Sir2 in the paper? Rather than overexpress a reduced-function gene? The paper is Burnett C, Valentini S, Cabreiro F, Goss M, Somogyvári M, Piper MD, Hoddinott M, ...
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1answer
107 views

Age-associated neurodegenerative diseases

Age-associated neurodegenerative diseases encompass Alzheimer's Disease and Parkinson's Disease. What other neurodegenerative diseases could be described as age-associated? Multiple Sclerosis? Brain ...