Community > Posts By > NathanielZ
Topic:
Aging
Edited by
NathanielZ
on
Sat 07/14/12 12:48 AM
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The effect on mitochondrial dna is complex. The causes of death are many but the telomere count is a slow march towards death. Reduced telomeres have shown links to effects than cause death. For humans, the length of the remaining telomere is usually an indicator of how many divisions a dividing cell has left. One study found an inverse relationship between telomere length and pulse pressure, indicating a possible direct relationship between vascular aging and telomere length [HYPERTENSION; Jeanclos,E; 36(2):195-200 (2000)]. Higher levels of oxidative stress increase the rate of telomere shortening [TRENDS IN BIOCHEMICAL SCIENCES 27(7):339-344 (2002)]. Once the telomere is gone, functional genetic DNA would be lost with each cell division. Prior to complete erosion of the telomere a signal is sent to p53 protein (possibly by ATM protein) to stop the cell cycle causing the cell to go into a slow-decaying, non-replicative state known as replicative senescence. Telomeres protect chromosomes like the plastic cap that prevents shoe-laces from becoming frayed at the ends. Telomeres have been shown to be seven times more vulnerable to hydroxyl radical oxidation than similar-sized DNA control fragments, indicating that telomeres could sacrificially protect coding DNA from oxidative damage [JOURNAL OF BIOLOGICAL CHEMISTRY; Henle,ES; 274(2):962-971 (1999)]. Telomere ComplexTelomere Complex Telomeres are actually a loop-like structure which is associated with an assortment of proteins, the most notable of which are the Telomeric Repeat-binding Factors (TRFs). TRF1 regulates telomere length, assisting the telomerase enzyme. TRF2 models the telomere into the T−loop structure. TRF2 may be protecting the single-stranded 3'−end overhang from degradation, and by binding to ATM prevents the ATM-dependent DNA damage response [THE EMBO JOURNAL; Blasco,MA; 24(6):1095-1103 (2005)]. Loss of TRF2 from telomeres directly signals apoptosis [SCIENCE; Karlseder,J; 283:1321-1325 (1999)]. TRF2 stimulates the helicase activity of both WRN (of Werner's Syndrome) and BLM (of Bloom Syndrome), which may play a role in telomere maintenance [JOURNAL OF BIOLOGICAL CHEMISTRY; Opresko,PL; 277(43):41110-41119 (2002)]. Ku proteins (normally active in double-strand break repair) prevent aberrant telomere-telomere fusions. Tankyrase is a PARP — Poly (Adenosine diphosphate-Ribose) Polymerase — which can ADP-ribosylate TRF1, thereby removing it from DNA and allowing telomerase lengthening of the telomere [SCIENCE; Pirrotta,V; 299:528-529 (2003)]. TRF2 is regulated by PARP−2 [MOLECULAR AND CELLULAR BIOLOGY; Dantzer,F; 24(4):1595-1607 (2004)]. Germ cells, stem cells and "immortalized" cancer cells contain an enzyme called telomerase that replaces lost telomeres, thus preventing them from experiencing a Hayflick Limit. Telomerase is a reverse transcriptase, meaning an enzyme that makes DNA from an RNA template (the reverse of normal transcription which uses DNA as the template for making RNA). In human germ cells or 85% of cancer cells human TElomerase Reverse Transcriptase (hTERT) and an RNA template are sufficient conditions for the creation of new telomeres. Because most cells normally express the RNA template, derepression of hTERT is the critical step for acquiring telomerase activity. Defects in proteins required to maintain telomere function can also lead to chromosome instability and cancer [EXPERIMENTAL GERONTOLOGY 36:1619-1637 (2001)]. Telomerase expression can actually make cells more resistant to apoptosis induced by oxidative stress [FEBS LETTERS; Ren,J; 488:133-138 (2001)]. Human stem cell producing leukocyte with shortened telomeres has no impact on the function of new cells according to studies. Many studies in fact show that expression of telomerase in somatic cells or the supplement of telomerase increases incidences of cancer. Cellular senescence is a defense mechanism trigger after about 60 divisions (Hayflict limit) is accommodates for the oxidative stress which as you pointed out is rather complex nevertheless, without the trigger triggered cellular senescence, damaged cells are more likely to have mutations that become cancerous that would have otherwise stopped developing and destroyed. While telomere shortening does pose a problem in the long run, human stem cells are able to function well into a person's normal life. These stem cells determine the functionality of their specific cells so stem cells in good order will produce good specific cells. This has been shown in the stem cells of old patients which does not appear to work as well as young people's stem cells. Rather it isn't the number of stem cells that decrease (in some cases it increases) although it is tissue dependent but functionality changes. There is a loss of homeostasis and as a result, the stem cell produce different ratios of progenitors resulting in a different ratio of specific offspring. Oddly, when the stem cell of an old patient is transplanted into a younger patient, homeostasis is restored which is attributed to the SC Niche, a group of cells housing the Stem Cell which sends signals on when to divide and what to divide into. The "old" stem cell behaves like new again despite having a shorter telomere and the accumulation of DNA damage due to oxidation. In other words, telomere shortening isn't a problem in one life span. Perhaps 2 or 3 but it isn't a problem within the first 100 years. The decrease in lifespan due to telomere shortening as only been been in the lab with the telomeres of stem cell being forced to reduce and is uncharacteristic of normal aging. It can't necessarily be extended to far more complex organisms as humans in such a simple assertion. Anti-oxidants such as vitamin C, Vitamin E, and CoQ-10 have been shown to increase the lifespan of short lived mice such as the UCadiz mice, but has no effect whatsoever on long lived mice. Evidence of reduced longevity asserted in an experiment involving a genetic mutation resulting in the elimination of telomere isn't enough to account for the lifespan observed in nature ex with mice that die naturally (whose telomeres are in good health and die by some other means) |
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So, I am pretty sure my profile says "looking for a woman" and all of my about me and conversations are geared towards that fact. But somehow, just somehow, I have gotten message after message from guys wanting sex. Seriously? What the hell is going on? Dumb in which context? I am very "smart" when it comes to science but I'm an idiot when it comes to sports. “Everybody is a genius. But if you judge a fish by its ability to climb a tree, it will live its whole life believing that it is stupid.” ― Albert Einstein |
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Topic:
Aging
Edited by
NathanielZ
on
Fri 07/13/12 11:35 AM
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yeah, what you're referring to is called Caloric Restriction/Dietary Restriction in animals. It's the only thing that scientists know for sure would extend the lifespan of any animal by slowing down metabolism which slows down whatever causes aging which they assume to be "damage". Aubrey de grey has even created a list of 7 forms of damage:
1. Extracellular Aggregates 2. Intracellular Aggregates 3. Mutant Mitochondria 4. Tissue stiffening (ex: Plaque build-up) 5. Nuclear/epi mutations 6. Death resistent cells (cancer) 7. Missing Cells When we think about death, no one really dies of the widely thought idea of aging of just dying peacefully in bed. It always happens when a person dies of an actual illness such as a heart attack or cancer. Aubrey essentially targeted the cause of all death causing diseases which would also be the cause of aging. While the telomeres does shorten and theoretically causes cellular senescence in many cases, scientists have determined that it is not a big contributor to aging. Aubrey has determined that in a normal life span, telomeres will not shorten enough to cause a problem. Other studies involving hematopoietic stem cells (blood stem cells) has shown that stem cells devoid of telomeres are able to produce blood just as well as stem cells with full lengthened telomeres. The telomere theory of aging also has shown that telomere length has no correlation with life span. Humans have short telomeres relative to other animals and we life a lot longer - for example, a fly has telomeres many multitudes longer and yet their maximal life-span is only a few weeks. I think someone has also posted a reasonable question about aging funding on futurist Ray Kurzweil's forum: http://www.kurzweilai.net/forums/topic/why-the-hell-are-we-funding-cancer-and-heart-disease-research-but-not-aging |
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Topic:
at your first date....
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never dated so Idk
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Edited by
NathanielZ
on
Thu 07/12/12 09:11 PM
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It isn't as simple as one straight forward answer.
Like all things opinionated, it depends on the perspective. How I see a man vs boy: A man has determined a Goal Legally: Age Biologically: Puberty Society: Someone who conforms to societal laws (debatable of course) and so on.... |
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Topic:
What captures men's hearts?
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Sciency
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Topic:
rate me
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It seems to me that you'd be attractive to the ladies.
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Topic:
Rate maybe?
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Thanks guys! =D
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It probably won't catch anything. Antispware/antiviruses don't make mistakes. Make sure the database is updated.
IF it really is a virus, then the only way to get rid of it is to download a different antivirus program (which you can't since it won't let you) or remove it manually which requires trial and error and is hard without doing it myself. |
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Topic:
Love dont live here anymore.
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I haven't lost anyone really close to me - maybe my grandparents, but I was so young that I barely remember but I know it will happen sooner or later.
That is why I am doing all I can to research aging...hopefully I can extend our lifespan long enough for technology to catch up. If the brain can be mapped and our memory data can be stored on a chip, from then on, I no longer need to worry. |
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Edited by
NathanielZ
on
Fri 07/06/12 12:45 PM
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oh crap. You're suddenly not ALLOWED download anything?
This is almost 100% the symptom of a Virus. Can you not download any software or does this pertain to utilities only? If it's a virus that isn't being picked up by your antivirus and you can't download a different antivirus, then it's going to get complicated. I'd need to see what's going on to help. ThreatFire doesn't have a scanner. It acts more like a firewall. It monitors programs that run or are running in memory rather than search through the entire hard drive. A virus program can only directly slow down your computer when it's in memory. |
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Keep both SuperAntiSpyware and AVG then,
download ThreatFire and yeah it's free. It has helped me stop some unknown viruses a while back. |
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oh, your other computers are fast....then it's not the internet.
If it's a virus avg can't pick up, I suggest threatfire. Threatfire is a little more advanced. It will tell you when something seems weird, but it'll be up to your better judgement to determine if it's good or bad. You can try avast, but not all 3 combined. 1.5gb of ram won't be able to handle that much. AVG is a really good antivirus, so if they didn't pick anything up, AVAST probably won't either. |
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Tell me more about the characteristics of the slowing.
You said the pages won't reload and it won't save passwords, but that's aspects of the internet speed, not your computer. If only the internet is slow, then there's nothing we can do. It means your service provider is having trouble with their servers. You'll just have to wait it out. |
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Topic:
cold comfort
Edited by
NathanielZ
on
Fri 07/06/12 12:53 AM
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Actually Trees contribute very little to Carbon Dioxide consumption. The majority of the oxygen that we breath came from photosynthetic blue-green algea. Oxygen is released during photosynthesis btw.
Early earth had very little oxygen - mainly carbon dioxide (The Super continent pangaea was much hotter than earth today. Animals such as triops were adapted to surviving in the hotter temperature but now they can only be found in a few locations). For a few million years, there were only anaerobic bacteria but oxidative phosphorylation was much more efficient so aerobic bacteria began to dominate producing the oxygen we breath. There is no shortage of algea in the world and trees account for very little of the oxygen, so the increase in CO2 has to be due to the massive release of CO2 from industry, cars, and respiration. While there are cycles of warm and cold, the correlation of CO2 vs Temperature is so precise that it is undeniable that humans have impacted temperature this time. |
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Edited by
NathanielZ
on
Thu 07/05/12 08:55 PM
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Eh, I just felt like it. I just decided to search for it, and I found this site.
I actually don't even see this site much as a dating site. Everything people talk about here is akin to a lot of usual non-dating teen sites I see (in which a ton of sex language is used)...except that here everything isn't has crazy. People here are clearly smarter and some debates we get into actually get me thinking about my responses. |
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Edited by
NathanielZ
on
Thu 07/05/12 08:18 PM
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SuperAntiSpyware is only an antispyware software.
There are a lot of other classifications of malware besides spyware. That software does not protect against Viruses and a ton of other malware. How most anti-virus/spyware/malware works is by a file containing hundreds of thousands of signature but even so, it doesn't contain everything which is why you need software from different companies to make up for what the other doesn't have. ThreatFire is a zero-day protection that detects malicious software behavior rather than relies on signitures but whether it detects a virus or harmless behavior will be up to the computer owner because the software doesn't know. What I suggest you do now is download AVAST and MalwareBytes Anti-Malware. Both are free and very good. (That is, if you ONLY have SuperAntiSpyware which is sorely lacking in the grand scheme of malware) |
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But chkdsk also repairs the damage.
http://www.hard-drive-help.com/image-files/chkdsk.gif |
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Edited by
NathanielZ
on
Thu 07/05/12 08:00 PM
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See the problem that concerns me is how it could suddenly get so slow.
Suddenly usually means hardware problems or malware. If only the internet is slow, then it isn't the computer's fault and there's no way to fix it except by waiting it out. I doubt switching the browser would do anything since it's been working fine for a while. So i guess my question is: 1. Is the entire computer slow or only things that has to do with the internet (such as web browsing) 2. Is your malware scanners updated? Which do you have? 3. Is it faster now after chkdsk? |
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oh. 36 processes isn't that much.
And chrome always adds a lot of processes when it runs..... It's so bizzare that your computer is running slowly. So if you let your computer sit for 30 seconds or so without doing anything, how high is the CPU usage? You can use TaskManager to check (turn it on first, and then wait). |
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