JL asked this interesting question =)
Here is the answer as promised:
Thymine is actually methylated-Uracil.
The methylation will make DNA unrecognizable by nucleases and thus ensuring the integrity of the DNA genome for replication.
Also cytosine can spontaneously deaminate to become uracil (C--> U mutation is quite common). However, DNA repair proteins will be able to recognise/differentiate and fix it since this uracil is not methylated.
News in Science
From Scientific American:
1)
Rutgers University researchers have found brain cells responsible for helping people overcome fear of things they once found scary. The finding, published in Nature, could pave the way for these so-called intercalated cells in the amygdala, a brain region that processes fear, to become drug targets for treating phobias (such as fear of heights and closed spaces) as well as post-traumatic stress disorder in soldiers and others. Scientists trained two rat populations--one with these cells intact and the other with them disabled--to fear a certain sound by giving them a mild shock every time it was played. After awhile, the animals would freeze in their tracks when they heard the noise, bracing for pain. The team then played the tone sans the shock. When they sounded the note again a week later, rats with healthy intercalated cells weren't bothered, whereas the others froze. The scientists believe that intercalated cells form "extinction memories," which associate something previously feared (such as an air raid siren or a car backfiring) with a harmless outcome.
Kind of interesting 'cos I used to do some readings on memory and learning
2)
Believe it or not, the world is becoming a happier place, at least according to the University of Michigan Institute for Social Research's 2005 to 2007 World Values Survey. The cheeriest country?: Denmark. The gloomiest: Zimbabwe—no surprise given the political unrest there. The U.S. ranks 16th on the list, just after New Zealand. According to the research, published in the journal Perspectives on Psychological Science, people are happiest in countries with the most tolerant social norms and most democratic political systems: Iceland, Switzerland, the Netherlands and Canada all rank among the top 10 happiest countries in the world. Researchers have surveyed more than 350,000 people on how happy they have been for the past 26 years based on their responses to the same two questions: "Taking all things together, would you say you are very happy, rather happy, not very happy, not at all happy?" As well as, "All things considered, how satisfied are you with your life as a whole these days?" Democratization and rising social tolerance have even more of an impact than economic growth on happiness, although all are important contributors. The citizens of India, Ireland, Mexico, Puerto Rico and South Korea all indicate that they're becoming happier. Alas, those in Austria, Belgium, the U.K. and Germany say their joie de vivre is waning.
food 4 thought: I read an article last year in ZaoBao last year. the reason for Danish Happiness is because most of them venture out/travel to find out what they want to do with their live after graduation. When they return and decide to become a cobbler or painter, it is accepted with blessings.
3) (For ZL who has been working hard @ pathlight)
Autism Genes That Control Early Learning
A new genetic analysis of large, inbred Middle Eastern families found that genes linked to a heightened risk of autism are crucial to a child's ability to learn.
A group of scientists, led by a team at Children's Hospital Boston, has pinpointed six new genes that may contribute to autism, a disorder characterized by asocial behavior, difficulty communicating and repetitive actions that affects an estimated one in 150 children born in the U.S. each year. They report in Science that all of the linked genes are involved in forming new and stronger connections, called synapses, between nerve cellsin the brain, which is the biological basis of learning and memory formation. "We're showing, on the one hand, that autism seems to have a large genetic component," says study co-author Christopher Walsh, chief of genetics at Children's Hospital. "But, the genes that are involved are actually those that are involved in responding to the environment and learning." The findings, Walsh says, reinforces the importance of early diagnosis of autism and intervention, particularly behavioral therapy and learning in enriched environments through repeated activities. Performing these sorts of tasks may help strengthen cellular connections, compensating for the malfunctioning genes. The researchers studied 88 families in which one or more children had been diagnosed with autism, and the parents of each autistic child were cousins. Marrying second and third—and even first cousins—is not uncommon in the Middle East, and by studying such families scientists were able to track recessive genetic traits (caused by mutations that only affect individuals with two copies of the flawed genes). Such traits occur far more frequently in inbred families than in others. The team found a total of six mutations affecting genes that had previously not been linked to autism. The mutations came in the form of deletions, where part or all of both copies of the genes were missing in a child with the disorder. All of the genes are known to be involved in parts of the same process: creating and strengthening synapses. Normally, when nerve cells (neurons) activate in response to an environmental factor (such as processing a new face or a new sound), synapses between two active cells change to provide stronger connections so the cells can pass on information more efficiently. As the brain develops, new connections are continuously formed among nerve cells, reinforced and, in some instances, broken as the brain starts to mature and divvy up its different functions to specific groups of neurons. According to the findings, "All of the relevant mutations could disrupt the formation of vital neural connections during a critical period when experience is shaping the brain," says Thomas Insel, director of the National Institute for Mental Health (NIMH) in Bethesda, Md. To wit, most children are diagnosed with autism between the ages of one and three years of age. Walsh says the team believes these deletions—which in most cases found here only remove some, but not all, of the DNA that makes up a gene—may mean that the genes can regain some of their normal function. In fact, some of these genes may just be switched off. "This presents the possibility that in some kids we could get the gene going again without necessarily having to put it back in the brain," he says. Jim Sutcliffe, a molecular physiologist at Vanderbilt University in Nashville, Tenn., in a Science editorial notes that the majority of autism research is geared toward prenatal development, even though the brain continues to develop well after a child is born. "Experience and environmental input play an important role in subsequent development," he says. He calls the notion that learning in early life is disrupted by these autism genes "an intriguing proposal," but says that further research is needed to validate it. Dan Geschwind, a neurologist at the University of California, Los Angeles, says that to test the hypothesis that autism genes affect synaptic strength, it would be important to examine the 20 to 30 other genes that have been implicated in autism and see which ones also play a role in strengthening neuronal connections. "If its a significant proportion," he says, "that would provide support for the hypothesis being put forward." Walsh notes that many children diagnosed with autism tend to show vast improvement when they are placed in environments that allow them to practice learning repetitively. He says that these activities essentially train the neurons to make up for their lost function. "Our work reinforces the importance of early intervention and behavioral therapy," he says. "The more we understand about genetics the more we understand how important the environment is."
1)
Rutgers University researchers have found brain cells responsible for helping people overcome fear of things they once found scary. The finding, published in Nature, could pave the way for these so-called intercalated cells in the amygdala, a brain region that processes fear, to become drug targets for treating phobias (such as fear of heights and closed spaces) as well as post-traumatic stress disorder in soldiers and others. Scientists trained two rat populations--one with these cells intact and the other with them disabled--to fear a certain sound by giving them a mild shock every time it was played. After awhile, the animals would freeze in their tracks when they heard the noise, bracing for pain. The team then played the tone sans the shock. When they sounded the note again a week later, rats with healthy intercalated cells weren't bothered, whereas the others froze. The scientists believe that intercalated cells form "extinction memories," which associate something previously feared (such as an air raid siren or a car backfiring) with a harmless outcome.
Kind of interesting 'cos I used to do some readings on memory and learning
2)
Believe it or not, the world is becoming a happier place, at least according to the University of Michigan Institute for Social Research's 2005 to 2007 World Values Survey. The cheeriest country?: Denmark. The gloomiest: Zimbabwe—no surprise given the political unrest there. The U.S. ranks 16th on the list, just after New Zealand. According to the research, published in the journal Perspectives on Psychological Science, people are happiest in countries with the most tolerant social norms and most democratic political systems: Iceland, Switzerland, the Netherlands and Canada all rank among the top 10 happiest countries in the world. Researchers have surveyed more than 350,000 people on how happy they have been for the past 26 years based on their responses to the same two questions: "Taking all things together, would you say you are very happy, rather happy, not very happy, not at all happy?" As well as, "All things considered, how satisfied are you with your life as a whole these days?" Democratization and rising social tolerance have even more of an impact than economic growth on happiness, although all are important contributors. The citizens of India, Ireland, Mexico, Puerto Rico and South Korea all indicate that they're becoming happier. Alas, those in Austria, Belgium, the U.K. and Germany say their joie de vivre is waning.
food 4 thought: I read an article last year in ZaoBao last year. the reason for Danish Happiness is because most of them venture out/travel to find out what they want to do with their live after graduation. When they return and decide to become a cobbler or painter, it is accepted with blessings.
3) (For ZL who has been working hard @ pathlight)
Autism Genes That Control Early Learning
A new genetic analysis of large, inbred Middle Eastern families found that genes linked to a heightened risk of autism are crucial to a child's ability to learn.
A group of scientists, led by a team at Children's Hospital Boston, has pinpointed six new genes that may contribute to autism, a disorder characterized by asocial behavior, difficulty communicating and repetitive actions that affects an estimated one in 150 children born in the U.S. each year. They report in Science that all of the linked genes are involved in forming new and stronger connections, called synapses, between nerve cellsin the brain, which is the biological basis of learning and memory formation. "We're showing, on the one hand, that autism seems to have a large genetic component," says study co-author Christopher Walsh, chief of genetics at Children's Hospital. "But, the genes that are involved are actually those that are involved in responding to the environment and learning." The findings, Walsh says, reinforces the importance of early diagnosis of autism and intervention, particularly behavioral therapy and learning in enriched environments through repeated activities. Performing these sorts of tasks may help strengthen cellular connections, compensating for the malfunctioning genes. The researchers studied 88 families in which one or more children had been diagnosed with autism, and the parents of each autistic child were cousins. Marrying second and third—and even first cousins—is not uncommon in the Middle East, and by studying such families scientists were able to track recessive genetic traits (caused by mutations that only affect individuals with two copies of the flawed genes). Such traits occur far more frequently in inbred families than in others. The team found a total of six mutations affecting genes that had previously not been linked to autism. The mutations came in the form of deletions, where part or all of both copies of the genes were missing in a child with the disorder. All of the genes are known to be involved in parts of the same process: creating and strengthening synapses. Normally, when nerve cells (neurons) activate in response to an environmental factor (such as processing a new face or a new sound), synapses between two active cells change to provide stronger connections so the cells can pass on information more efficiently. As the brain develops, new connections are continuously formed among nerve cells, reinforced and, in some instances, broken as the brain starts to mature and divvy up its different functions to specific groups of neurons. According to the findings, "All of the relevant mutations could disrupt the formation of vital neural connections during a critical period when experience is shaping the brain," says Thomas Insel, director of the National Institute for Mental Health (NIMH) in Bethesda, Md. To wit, most children are diagnosed with autism between the ages of one and three years of age. Walsh says the team believes these deletions—which in most cases found here only remove some, but not all, of the DNA that makes up a gene—may mean that the genes can regain some of their normal function. In fact, some of these genes may just be switched off. "This presents the possibility that in some kids we could get the gene going again without necessarily having to put it back in the brain," he says. Jim Sutcliffe, a molecular physiologist at Vanderbilt University in Nashville, Tenn., in a Science editorial notes that the majority of autism research is geared toward prenatal development, even though the brain continues to develop well after a child is born. "Experience and environmental input play an important role in subsequent development," he says. He calls the notion that learning in early life is disrupted by these autism genes "an intriguing proposal," but says that further research is needed to validate it. Dan Geschwind, a neurologist at the University of California, Los Angeles, says that to test the hypothesis that autism genes affect synaptic strength, it would be important to examine the 20 to 30 other genes that have been implicated in autism and see which ones also play a role in strengthening neuronal connections. "If its a significant proportion," he says, "that would provide support for the hypothesis being put forward." Walsh notes that many children diagnosed with autism tend to show vast improvement when they are placed in environments that allow them to practice learning repetitively. He says that these activities essentially train the neurons to make up for their lost function. "Our work reinforces the importance of early intervention and behavioral therapy," he says. "The more we understand about genetics the more we understand how important the environment is."
Achieving Ur Dreams
Just last week during Civics, I showed my class part of "The Last Lecture' by Randy Pausch. The clip was introduced to me by my brother 2 months ago but I only got the time to review it recently and found it interesting possibly useful for my students.
Who is he? Below is a short excerpt from TIME:
http://www.time.com/time/specials/2007/article/0,28804,1733748_1733756_1736194,00.html
From his talk, I am sure the takeaways from each individual will be different because all of us have different experiences - some of us have already been there and done it, been there but forgotten about it or never been there. But regardless, there is something for everyone to think about.
1. Brick walls are there for a reason: they let us prove how badly we want things.
2. If someone criticize you that is good because it showed that the person cares. If one day no one bothers, then you worry because they have given up on you.
3. Make time for what matters -- Time is all you have. And you may find one day that you have less than you think.
4. Experience is what you get when you didn’t get what you wanted.
5. If we do something which is pioneering, we will get arrows in the back. But at the end of the day, a whole lot of people will have a whole lot of fun.
6. Be good at something; it makes you valuable.
If I may add my own:
Be Patient. Dreams need you to take the first step and slowly advance. So be prepared but don't lose faith in your choices because you never know when the right moment comes for you to take the plunge. Even should all fail, check out 4. =)
For my ex-students who are starting to venture out into the real world:
(http://www.businessweek.com/smallbiz/content/may2008/sb20080516_673343.htm)
Like millions of people, I watched the video of Randy Pausch giving his "last lecture" at Carnegie Mellon. Pausch, who is dying of cancer, created a lecture that offered life lessons (BusinessWeek.com, 11/21/07) as a guide for his children when they grow older. I developed an even greater appreciation for Pausch's wisdom after reading his book, The Last Lecture, and realizing many of the lessons can be applied to business leaders, entrepreneurs, small business owners, and managers in how they interact with customers and employees.
Encourage creativity. Pausch recalled how he liked to paint things on the wall of his bedroom. His parents were dismayed at first but soon relented after they saw how excited he became when he was painting. Pausch said he's lucky to have had parents who encouraged creativity and allowed him to express himself in unconventional ways. This reminds me of a recent article I came across about Google's (GOOG) Zurich offices. The office space is intended to inspire creativity with slides, aquariums, cable car shells that serve as conference rooms, even igloo-shaped work spaces. Google understands that to be creative, you can't always be sitting in a cubicle. Encourage creativity in your company's workplace.
Learn from Captain Kirk. Pausch was a fan of the Star Trek series growing up. He found a role model in Enterprise Captain James T. Kirk, who, according to Pausch, had the essence of a dynamic manager: He knew how to delegate, had the passion to inspire, and looked good in what he wore to work. "He never professed to have skills greater than his subordinates…but he established the vision, the tone."
Celebrate brick walls. "Brick walls are there for a reason," writes Pausch. "They give us a chance to show how badly we want something." Entrepreneurs and small business owners are faced with hurdles every day, some seemingly insurmountable. But if you're passionate about what you do, those brick walls are easier to scale and you have more fun on the climb.
Dream big. Pausch was attending camp in the summer of 1969 when men first walked on the moon. He remembers his camp counselors sending everyone back to their tents before the big event because it was getting late. Pausch thought to himself, "My species has gotten off of our planet and landed in a new world for the first time, and you people think bedtime matters?" When you put people on the moon, argues Pausch, you're inspiring everyone to achieve to their maximum potential. "Give yourself permission to dream. Fuel your kids' dreams, too. Once in a while, that might even mean letting them stay up past their bedtimes."
The same goes for your employees. People want more than a paycheck. They want to know their work is adding up to something meaningful. No, you may not be working on a project as exciting as sending a man to the moon, but in some small way, you are making the world a better place. Help your employees see the big picture and, more important, fuel their dreams of career and personal success.
Be the first penguin. Create a culture that celebrates risk. Pausch writes: "[I] encouraged students to attempt hard things and not to worry about failing…failure is not just acceptable, it's often essential." To encourage this way of thinking, Pausch would reward the group of students who took the biggest gamble with a stuffed animal—a penguin. The idea came to him when he realized that when penguins jump into the water where there are predators, one has to go first. According to Pausch, "Experience is what you get when you didn't get what you wanted."
Rediscover the lost art of thank-you notes. In business I have received just a couple of handwritten thank-you notes. But because they are so unusual, and so personal, I was left with a strong impression of the individuals who sent them. So it didn't surprise me that one chapter in The Last Lecture is dedicated to "the simplest yet most powerful things humans can do for each other…showing gratitude." Pausch shows that magical things happen when you send old fashioned thank-you notes. "If you are a B+ student, your handwritten thank-you note will raise you at least a half-grade in the eyes of a future boss or admissions officer. You'll become an 'A' to them."
Have fun. Pausch's colleagues say they will remember him as a person who had fun. Pausch writes: "I don't know how not to have fun. I'm dying and I'm having fun. And I'm going to keep having fun every day I have left. Because there's no other way to play it."
Who is he? Below is a short excerpt from TIME:
http://www.time.com/time/specials/2007/article/0,28804,1733748_1733756_1736194,00.html
From his talk, I am sure the takeaways from each individual will be different because all of us have different experiences - some of us have already been there and done it, been there but forgotten about it or never been there. But regardless, there is something for everyone to think about.
1. Brick walls are there for a reason: they let us prove how badly we want things.
2. If someone criticize you that is good because it showed that the person cares. If one day no one bothers, then you worry because they have given up on you.
3. Make time for what matters -- Time is all you have. And you may find one day that you have less than you think.
4. Experience is what you get when you didn’t get what you wanted.
5. If we do something which is pioneering, we will get arrows in the back. But at the end of the day, a whole lot of people will have a whole lot of fun.
6. Be good at something; it makes you valuable.
If I may add my own:
Be Patient. Dreams need you to take the first step and slowly advance. So be prepared but don't lose faith in your choices because you never know when the right moment comes for you to take the plunge. Even should all fail, check out 4. =)
For my ex-students who are starting to venture out into the real world:
(http://www.businessweek.com/smallbiz/content/may2008/sb20080516_673343.htm)
Like millions of people, I watched the video of Randy Pausch giving his "last lecture" at Carnegie Mellon. Pausch, who is dying of cancer, created a lecture that offered life lessons (BusinessWeek.com, 11/21/07) as a guide for his children when they grow older. I developed an even greater appreciation for Pausch's wisdom after reading his book, The Last Lecture, and realizing many of the lessons can be applied to business leaders, entrepreneurs, small business owners, and managers in how they interact with customers and employees.
Encourage creativity. Pausch recalled how he liked to paint things on the wall of his bedroom. His parents were dismayed at first but soon relented after they saw how excited he became when he was painting. Pausch said he's lucky to have had parents who encouraged creativity and allowed him to express himself in unconventional ways. This reminds me of a recent article I came across about Google's (GOOG) Zurich offices. The office space is intended to inspire creativity with slides, aquariums, cable car shells that serve as conference rooms, even igloo-shaped work spaces. Google understands that to be creative, you can't always be sitting in a cubicle. Encourage creativity in your company's workplace.
Learn from Captain Kirk. Pausch was a fan of the Star Trek series growing up. He found a role model in Enterprise Captain James T. Kirk, who, according to Pausch, had the essence of a dynamic manager: He knew how to delegate, had the passion to inspire, and looked good in what he wore to work. "He never professed to have skills greater than his subordinates…but he established the vision, the tone."
Celebrate brick walls. "Brick walls are there for a reason," writes Pausch. "They give us a chance to show how badly we want something." Entrepreneurs and small business owners are faced with hurdles every day, some seemingly insurmountable. But if you're passionate about what you do, those brick walls are easier to scale and you have more fun on the climb.
Dream big. Pausch was attending camp in the summer of 1969 when men first walked on the moon. He remembers his camp counselors sending everyone back to their tents before the big event because it was getting late. Pausch thought to himself, "My species has gotten off of our planet and landed in a new world for the first time, and you people think bedtime matters?" When you put people on the moon, argues Pausch, you're inspiring everyone to achieve to their maximum potential. "Give yourself permission to dream. Fuel your kids' dreams, too. Once in a while, that might even mean letting them stay up past their bedtimes."
The same goes for your employees. People want more than a paycheck. They want to know their work is adding up to something meaningful. No, you may not be working on a project as exciting as sending a man to the moon, but in some small way, you are making the world a better place. Help your employees see the big picture and, more important, fuel their dreams of career and personal success.
Be the first penguin. Create a culture that celebrates risk. Pausch writes: "[I] encouraged students to attempt hard things and not to worry about failing…failure is not just acceptable, it's often essential." To encourage this way of thinking, Pausch would reward the group of students who took the biggest gamble with a stuffed animal—a penguin. The idea came to him when he realized that when penguins jump into the water where there are predators, one has to go first. According to Pausch, "Experience is what you get when you didn't get what you wanted."
Rediscover the lost art of thank-you notes. In business I have received just a couple of handwritten thank-you notes. But because they are so unusual, and so personal, I was left with a strong impression of the individuals who sent them. So it didn't surprise me that one chapter in The Last Lecture is dedicated to "the simplest yet most powerful things humans can do for each other…showing gratitude." Pausch shows that magical things happen when you send old fashioned thank-you notes. "If you are a B+ student, your handwritten thank-you note will raise you at least a half-grade in the eyes of a future boss or admissions officer. You'll become an 'A' to them."
Have fun. Pausch's colleagues say they will remember him as a person who had fun. Pausch writes: "I don't know how not to have fun. I'm dying and I'm having fun. And I'm going to keep having fun every day I have left. Because there's no other way to play it."
Buzz Around
So I tried working around this new template I found for the blog, throwing in some elements here and there to make it look a little cooler and also not forgetting the tagboard which I have been incessantly reminded to put up, be it this batch or last batch. On recommendation, I have changed the tagboard provider so hopefully this will serve me well by not expiring because of inactivity. =)
There are many reasons why this blog suffers periods of constipation - due to the piles of work, lack of questions and inspiration. Hopefuly we get more questions this term to share!
Here are some:
1) CT MCQ question 5: which got me really stumped for the longest time in class - I apologised; when you are rushing the marking day and night, your brain do get a little bit more than fried. I think my eyes nearly popped out last night as I struggled to clear that last pile.
Anyway it took me a while to realise why I have never considered this question a problem until I tried too hard to break sentence up:
if you read statement C as it is meant to be, it is trying to tell you that melting point of FA increase with (increasing) chain length and decreases with (increasing) degree of unsaturation. The (increasing) component is implicit in the sentence structure - a linguistic issue. Just like: the food will go bad with time...
2) what is myoglobin?
Myoglobin is a single-chain globular protein of 153 amino acids, containing a heme (iron-containing porphyrin) prosthetic group in the center around which the remaining apoprotein folds. It is the primary oxygen-carrying pigment of muscle tissues.
(http://en.wikipedia.org/wiki/Myoglobin)
I remembered talking to some of you about red meat versus white meat. And yup. myoglobin contributes to why some animals are considered red meat and others white meat and also why some of us are the ideal machine to run 2.4km under 10 min while some of us struggle to do so but score in sprint =).
--------------------
A comment made by students during the week: Sir, you have friends all over the world...I pondered for a while and realised that it matters not if you have friends or not all over the world but to be remembered or remembered because you or that someone made an impact in each other's life. that is really what makes the memories so wonderful. maybe if there is chance, I will share why some of these pple are important to me.
There are many reasons why this blog suffers periods of constipation - due to the piles of work, lack of questions and inspiration. Hopefuly we get more questions this term to share!
Here are some:
1) CT MCQ question 5: which got me really stumped for the longest time in class - I apologised; when you are rushing the marking day and night, your brain do get a little bit more than fried. I think my eyes nearly popped out last night as I struggled to clear that last pile.
Anyway it took me a while to realise why I have never considered this question a problem until I tried too hard to break sentence up:
if you read statement C as it is meant to be, it is trying to tell you that melting point of FA increase with (increasing) chain length and decreases with (increasing) degree of unsaturation. The (increasing) component is implicit in the sentence structure - a linguistic issue. Just like: the food will go bad with time...
2) what is myoglobin?
Myoglobin is a single-chain globular protein of 153 amino acids, containing a heme (iron-containing porphyrin) prosthetic group in the center around which the remaining apoprotein folds. It is the primary oxygen-carrying pigment of muscle tissues.
(http://en.wikipedia.org/wiki/Myoglobin)
I remembered talking to some of you about red meat versus white meat. And yup. myoglobin contributes to why some animals are considered red meat and others white meat and also why some of us are the ideal machine to run 2.4km under 10 min while some of us struggle to do so but score in sprint =).
--------------------
A comment made by students during the week: Sir, you have friends all over the world...I pondered for a while and realised that it matters not if you have friends or not all over the world but to be remembered or remembered because you or that someone made an impact in each other's life. that is really what makes the memories so wonderful. maybe if there is chance, I will share why some of these pple are important to me.
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