Tamara Ilic
Patric Youell
Science 9B
January 21st, 2016
Science News 2015
Not all bodies act their age
Ageing has always been one of the most mysterious topics of science and life that provoke curiosity in people. Study out of Duke University analysed health of approximately one thousand 38 year-olds (figure 1) and came to a conclusion that people grow old at extreamly different rates. Some resemble up to decade older while others resemble few years younger. This so called "biological age" is persistent to be based on three health indicators: body mass index, blood pressure and cholesterol level. The question that captured scientists and the publics attention is "Why some people can live to 120 with no disease, and others are already in bad shape at age 70" (Martin Hetzer, molecular biologist at the Salk institute for Biological studies in La Jolla, California)
Recent studies came to a conclusion that molecular damage within cells might be the essence of ageing. Researchers have been comparing and examining teeth of young and old people and found that young and healthy people have long stretches of DNA compacted in neat bundles known as heterochromatin, while bundles of old people are not as stable and compacted. Examining the teeth of young and old people researchers found that some people are ageing much faster than others, the most common reason of premature ageing is known to be Werner syndrome. Werner syndrome, known as the "adult progeria" is caused by deficiency of Werner protein. Werner syndrome causes mutation and disorganisation of ones heterochromatin (figure 2) which leads to cellular ageing, cataracts, osteoporosis and other signs of ageing.
Ageing may also begin when essential barriers of brain stem cells break down. When young stem cells divide, they build a wall that separates the cellular junk called ubiquitin from one daughter cell and enters another, the one without ubiquitin is able to grow and divide properly. As people grow old barrier that keeps the cellular junk from spreading breaks down (figure 3). Ubiquitin enters both daughter cells and reduces their ability to produce new healthy cells. The blood-brain barrier is another protective barrier that weakens over time. This barrier protects protects the brain from dangerous poisons in blood. However, this barrier leaks out with age and becomes unable to protect the brain from toxins in blood. Individuals with weak barrier have problem with learning and memorising. Ageing triggers emotional and regenerative deterioration in the brain of an adult. It increases sensibility and neurodegenerative disorder. Experiments in which the heterochronic parabiosis method is used show that circulating vitality factors in blood change adding phenotypes in brain. Heterochronic Parabiosis is a method in which the circulatory systems of two animals, young and old, are physically joined together. This experimental model is used in ageing research.
Microbe discoveries spur rethink of treetop of life
Biologists have set up a theory that somewhere between 2-1 billion years ago simple-celled organisms, prokaryotes, performed process of endosymbiosis to absorb once free-living bacteria which developed into sausage-like organelle known as mitochondrion. Product of endosymbiosis was a complex cell called eukaryote which triggered the complexity of life. In 2015, scientists have discovered microbes ,in Arctic see-mud, which they believe are the closest relatives found to eukaryotes. Researchers have been analysing the mud and found previously unknown, unusual singled-celled microbe which they named Lokiarcheota. What's so interesting about this microbe is that it carries similar DNA to a single-celled organism called archaea, sister group to bacteria, yet Lokiarcheota has a similar dynamic structure to eukaryotes, which would help them swallow another bacteria. Biologists have recommended to represent the combination of bacteria and archaea as a ring of life rather than the tree (figure 4), since ring provides a clear image of bacteria and archaea merging to form eukaryotes, while tree does't show any merging.
"We don't have all the existing pieces right now because a lot of the diversity of microbial eukaryotes remains unexposed." (Patrick Keeling, studies early eukaryote history at the University of British Columbia in Vancouver) Up to late 1980's scientists thought that eukaryotes spreads out to three tree branches of mostly multicellular organisms (Kingdoms of: animals, plants and fungi) although new studies have downgraded the multicellular kingdoms to secondary smaller branches of mostly single celled protists which stretched to 5-7 branches.
Best evidence for water on Mars
Not so long ago scientists have discovered a frozen liquid on planet Mars. In 2015 they have unravelled a liquid form of salty mineral water. The founding of the brine, the salty mineral solution, (look at figure 5) is the most significant evidence founded yet. The liquid was spotted oozing against the hillside marks, by the Reconnaissance Orbiter Spacecraft. With this discovery scientists have gotten a more clear picture of physical aspects of the "Red Planet". The finding of the liquid indicated that there is possible life on Mars. This finding is very outstanding for the future of humanity, since this might lead to birth of new primitive life and another planet which humans might settle.
Since 2012 the Curiosity Rover (figure 6) has been roaming Mars and had spotted interesting scientific discoveries. Nitrogen, which is used to make biological molecules such as, DNA and proteins has been found laying on the surface of Mars.
Patric Youell
Science 9B
January 21st, 2016
Science News 2015
Not all bodies act their age
Ageing has always been one of the most mysterious topics of science and life that provoke curiosity in people. Study out of Duke University analysed health of approximately one thousand 38 year-olds (figure 1) and came to a conclusion that people grow old at extreamly different rates. Some resemble up to decade older while others resemble few years younger. This so called "biological age" is persistent to be based on three health indicators: body mass index, blood pressure and cholesterol level. The question that captured scientists and the publics attention is "Why some people can live to 120 with no disease, and others are already in bad shape at age 70" (Martin Hetzer, molecular biologist at the Salk institute for Biological studies in La Jolla, California)
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| Figure1 Scientists examined heath of almost one thousand 38-yearolds based on three health indicators: body mass index, blood pressure and cholesterol level and found out that some resemble a decade older while other resemble few years younger. |
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| Figure2In normal cells (left) DNA is compacted in neat bundles. Cells affected with Werner syndrome(right) have disorganised heterochomatin and their DNA is not compacted in neat bundles. You can notice how premature ageing causes the enlargement of a nuclei. |
Ageing may also begin when essential barriers of brain stem cells break down. When young stem cells divide, they build a wall that separates the cellular junk called ubiquitin from one daughter cell and enters another, the one without ubiquitin is able to grow and divide properly. As people grow old barrier that keeps the cellular junk from spreading breaks down (figure 3). Ubiquitin enters both daughter cells and reduces their ability to produce new healthy cells. The blood-brain barrier is another protective barrier that weakens over time. This barrier protects protects the brain from dangerous poisons in blood. However, this barrier leaks out with age and becomes unable to protect the brain from toxins in blood. Individuals with weak barrier have problem with learning and memorising. Ageing triggers emotional and regenerative deterioration in the brain of an adult. It increases sensibility and neurodegenerative disorder. Experiments in which the heterochronic parabiosis method is used show that circulating vitality factors in blood change adding phenotypes in brain. Heterochronic Parabiosis is a method in which the circulatory systems of two animals, young and old, are physically joined together. This experimental model is used in ageing research.
 |
| Figure3 Young brain stem cell (left) ubiquitin enters only one daughter cell, while in old stem cell (right) ubiquitin enters both cells and reduces their ability to produce healthy cells. |
Microbe discoveries spur rethink of treetop of life
Biologists have set up a theory that somewhere between 2-1 billion years ago simple-celled organisms, prokaryotes, performed process of endosymbiosis to absorb once free-living bacteria which developed into sausage-like organelle known as mitochondrion. Product of endosymbiosis was a complex cell called eukaryote which triggered the complexity of life. In 2015, scientists have discovered microbes ,in Arctic see-mud, which they believe are the closest relatives found to eukaryotes. Researchers have been analysing the mud and found previously unknown, unusual singled-celled microbe which they named Lokiarcheota. What's so interesting about this microbe is that it carries similar DNA to a single-celled organism called archaea, sister group to bacteria, yet Lokiarcheota has a similar dynamic structure to eukaryotes, which would help them swallow another bacteria. Biologists have recommended to represent the combination of bacteria and archaea as a ring of life rather than the tree (figure 4), since ring provides a clear image of bacteria and archaea merging to form eukaryotes, while tree does't show any merging.
 |
| Figure4 Tree top of life (upper sketch) doesn't show a clear model of archaea and bacteria merging to form a eukaryote, while ring of life (lower sketch) shows very understandable image of merging and the outcome. |
Best evidence for water on Mars
Not so long ago scientists have discovered a frozen liquid on planet Mars. In 2015 they have unravelled a liquid form of salty mineral water. The founding of the brine, the salty mineral solution, (look at figure 5) is the most significant evidence founded yet. The liquid was spotted oozing against the hillside marks, by the Reconnaissance Orbiter Spacecraft. With this discovery scientists have gotten a more clear picture of physical aspects of the "Red Planet". The finding of the liquid indicated that there is possible life on Mars. This finding is very outstanding for the future of humanity, since this might lead to birth of new primitive life and another planet which humans might settle.
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| Figure 5 This image shows the oozing salty mineral liquid against the hillside marks of the Red planet. |
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| Figure 6 NASA's car-sized robotic rover that has dicovered nitrogen used in forming DNA and proteins. |
The study of six Martian meteorites, which were blasted into space because of asteroid impacts, had exposed that one of their substances is methane, which is the food source of microbes on Earth. If microbes are present on Mars they could use the methane from the martian rocks to extract energy which could lead to the forming of life on Mars. To discover if there is actually life on Mars is yet to be known until 2020 when NASA plans to launch a rover on the planet. The rover would collect rock samples which would be sent back to Earth for further analyses.
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