A Trip Down Your Toilet December 10, 2010
Posted by Mrs Weird Scientist in Brain Power, Environment, Human Body, Tough Stuff.Tags: energy, gas, poo, renewable, waste
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Nope, I’m not giving a lesson on plumbing. But I am going to give you the scoop on a secret that starts inside your toilet, all thanks to the crew at Thames Water who are helping people stay warm this winter. What’s this secret? Well, when a toilet takes your daily (or whatever frequency..let’s not go there) offering, all that human gunk can get converted into renewable gas to heat your home.
In fact, my dog Tiko got so excited about this concept, he decided to contribute. Before we see what he got up to though, let’s first find out what’s happening in the bowels of your toilet and then follow it through the twists and turns of the pipes below.
A Good Kind Of Gas
Each time you perch on the toilet, you may soon take heart that you’re not the only one who’s a bit lighter – you’re taking a burden off the environment as well. Approximately 200 homeowners in an English town called Didcot are among the first in the UK to benefit from gas made from their own waste and supplied through the national grid to heat their houses. The future plan is to make this process available throughout the UK.
So why all the fuss to find new sources of energy? Well, the UK has a goal for 2020 to have 15 percent of the energy it produces come from renewable sources. Producing gas in this way is a strong step toward that goal. Oh, and if you’re worried your house will be smelly, fear not! The gas is odorless and your house will remain toasty.
From Flush To Finish
From the time you flush your toilet to the time your house gets heat, it’s around 23 days. Let’s take it step-by-step, based on the procedure and image below that Thames Water has generously shared.
Waste has a bit of a path to travel before making your home warm. But it's worth the trip because it brings the UK closer to its energy goals.
- All the muck from toilets and stuff like sinks and dishwashers gets channeled to the Didcot works. Let me tell you, with 13.8 million customers, it’s a lot of waste!
- Waste gets separated into sludge and water inside settlement tanks
- Water is put through cleaning processes and then back to the environment it goes via a local watercourse
- Sludge goes a different route. It gets heated in massive containers called digesters. All the heat gets anaerobic digestion going, which is where bacteria breaks down biodegradable material. Now, we’re left with biomethane – also called biogas
- The gas gets collected and goes into a gas cleaning machine
- After the biomethane gets cleaned and smells more like normal gas, it goes to the national gas grid
- From here, it’s just like any other gas in the grid. Off it goes to heat up your home and fuel other things like your stove
Tiko Turds
Once Tiko heard about the capabilities of poo, he did what all good and respectable dogs do – he went to relieve himself. But instead of trotting to the door for me to let him outside, he wanted to do his part to help heat up the house. The cheeky mutt raced into the bathroom and plonked himself down on the toilet.
When Tiko found out that human waste from toilets was being used as a renewable source of energy to heat homes, he decided to help out. Now, where's the air freshener?
I appreciate that he’s determined to help the environment but I tried to explain that nobody wants to sit on a toilet seat covered in his fur. He responded by barking at me to close the door because he wanted some privacy.
On second thought, I should be grateful I have such an environmentally conscious dog, even if he is a modest one.
Get Smarter The Dirty Way October 5, 2010
Posted by Mrs Weird Scientist in Brain Power, Human Body, Psychology and Behavior, Tough Stuff.Tags: bacteria, dirt, intelligence, learning, smarter
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Sometimes, intelligence can happen in the dirtiest of places. A new study suggests that exposure to certain kinds of bacteria outside could help improve learning.
Researchers at The Sage Colleges in New York studied Mycobacterium vaccae, which earlier studies showed might have antidepressant properties. In this new study, it seems that M. vaccae could help increase learning behavior. Their work was presented at the 110th General Meeting of the American Society for Microbiology in San Diego.
To learn how the research began, let’s ask some mice.
What Do Mice Say About It?
Why mice? It’s one way to initially test out an idea. If all goes well, then we might see how it affects humans. But to find out what happens when mice get up close and personal to bacteria, we have to take a step back and check out an experiment some other researchers did years ago.
Let’s Start With Dead Bacteria
In an earlier experiment, mice were injected with heat-killed bacteria. It got neurons in their brains growing, which then led to more serotonin – a brain messenger – being released. Serotonin is a member of a chemical crew called neurotransmitters that have all sorts of neat roles.
Can bacteria help learning? Some curious researchers decided to find out.
Time To Try Living Stuff
Since one of serotonin’s roles is to contribute to learning, a different group of researchers wondered if live bacteria could improve learning in mice. They fed the mice some live bacteria and then got the mice to navigate a maze. Another bunch of mice didn’t get the bacteria and still had to do the maze. This way, researchers could compare the two results. So who won?
Fast, Wee Critters
The mice who got live bacteria navigated the maze twice as fast as those who got none. Another cool thing was that those bacteria-guzzling mice showed less anxiety. Imagine if you had to do a maze? You might be nervous too! Researchers think the bacteria helped the mice get less worked up about finding their way out, plus helped them figure it out quicker too.
But do these benefits last? Unfortunately, nope. Three weeks later, researchers tested the mice again, but didn’t give them bacteria. This time, the mice couldn’t do it any faster. We can’t say for sure that this will help humans. But the results tell us that M. vaccae might play a role in learning and anxiety in mammals.
Getting More Out Of Playtime
It could be that when kids spend time outdoors – like during lunchtime – exposure to the bacteria may have some pretty smart benefits. If not, at least you can have fun kicking up some dirt. At my age, I’d probably be considered daft if I do that but maybe the bacteria will balance it all out? Somehow though, I think if my dog Tiko was perched nearby, he’d loudly bark “no.”
Whale Poo Is Good For You September 12, 2010
Posted by Mrs Weird Scientist in Animals, Brain Power, Environment, Ocean, Tough Stuff.Tags: CO2, feces, global warming, poo, whales
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In fact, it’s good for all living things. Australian researchers recently found that whale poo is battling one of the planet’s toughest battles ever – climate change. The poor whales previously had a horrid reputation. Since they breathe out a common greenhouse gas known as carbon dioxide (CO2), they were disliked for contributing to global warming. Estimates are that they breathe out 200,000 tonnes of CO2 a year. Eep! It isn’t surprising people had a bad opinion of them!
But there’s way more to the story than this one fact. Let’s start with the basics and see how something so gross can actually be good for us all. Major science geeks can read the full study results in the Fish and Fisheries journal.
Benefits Of Whale Poo
A young sperm whale gracefully swims in the Southern Ocean. A trip up to the surface might mean a poopy feeding for the hungry phytoplankton, helping to fight global warming. Image credit: National Oceanic and Atmospheric Administration (NOAA).
In the Southern Ocean, we’ve got an estimated 12,000 sperm whales. They hunt down fish and squid for food. Once digested, out comes all that poo. Why should we care about whale feces? Well, it contains loads of iron. All of those whales poop out approximately 50 tonnes of iron each year.
What’s so special about the iron? It’s a fabulously delicious food for phytoplankton, which are marine plants that exist up near the surface of the ocean. These helpful plants like to take in CO2 from the atmosphere through a process called photosynthesis.
Better still is that the whales pop out their poop (even I chuckled as I wrote that) in a liquid form that’s close to the surface of the ocean, making it easier for the phytoplankton to access. After, the whale dives down into the ocean, presumably feeling a little – or a lot – lighter!
Let’s Do The Math
First, we have to see how much CO2 gets sucked up by the plants, which is all thanks to the whale poo. It’s 400,000 tonnes. Now that’s twice as much as the 200,000 tonnes they breathe out through respiration each year. The 200,000 tonnes is equivalent to emissions from 40,000 cars!
I got in touch with Steve Nicol of the Australian Antarctic Division to find out how the study all started. He explained:
Our research was actually looking at baleen (krill eating) whales and the iron that they release. The research was stimulated by some ideas raised by Victor Smetacek and we had the samples and the expertise here in Hobart to do the measurements necessary to test these ideas.
When I asked Steve what we can do to help, his answer was a simple one. Simple but not necessarily easy to attain, especially given the attraction of whale hunting in many places around the world. According to Steve:
Many populations of great whales are recovering fairly fast – some at about the maximum rate possible. The best assistance we can give them is to avoid killing them – either accidentally or deliberately.
Don’t Judge Too Soon
I think an important lesson here is that we can’t judge too quickly and instead, should always look at the big picture. When we first hear about all the CO2 the whales are putting out there, it’s easy to think badly of these massive sea creatures. But with the Southern Ocean normally being a poor source of iron, the whales are making sure those phytoplankton are happily fed. This way, the phytoplankton can do their job of taking out the nasty CO2.
Now, if only human poo had such fantastic capabilities.
The Return Of Bed Bugs – Smarter Ones January 13, 2010
Posted by Mrs Weird Scientist in Animals, Evolution, Insects, Tough Stuff.Tags: bed bugs, bites, DDT, infestation, pests
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Your mattress may be home to more than your pillow or favorite stuffed animal. It could be the home of bed bugs!
The title reads like a horror movie but for those who have battled it out with bed bugs, it makes a lot of sense. Others might think that ‘don’t let the bed bugs bite’ was just some bedtime line their parents used as a cute joke.
In fact, let’s see now who knew that bed bugs really existed. Try out the poll below (be honest!).
Bed Bug Basics
Bed bugs are small, reddish brown insects that feed on human blood, which engorges them and makes them bigger. They are from the insect family Cimicidae and common bed bugs are formally called Cimex lectularius. They tend to be most active at night, coming out of the cracks in walls or bed frames and other hiding places to get their bloody grub. They can travel in suitcases, so hotels are a hot spot for bed bugs as well as other places that see plenty of people coming and going. Cornell University has an ace fact sheet to give you the lowdown on bed bugs. You can also have some fun playing around on Pest World for Kids, a website created by the National Pest Management Association (NPMA). But let’s get back to finding out why these wee pesky critters have returned and what makes them smarter today.
Gone But Not For Long
Here we have a bed bug hiding in a wood bed frame. The bed bug looks like it's having a Sunday snooze but I bet it's getting rest so it can hunt for fresh blood! Image credit: Thomas Oldani
Bed bugs were once nearly destroyed in our modern environment, where the use of chemicals such as dichlorodiphenyltrichloroethane – otherwise more easily known as DDT – kept these beasties at bay. DDT is a pesticide that is either very useful or very toxic, depending on who you ask or what journal study you read. Ultimately though, it was banned.
The Good And Bad Of DDT
DDT was used to keep mosquitoes under control, mostly because they spread malaria. It was used to keep lice numbers down too. So what happened when it was banned? As somewhat of a side effect of its use, DDT had kept bed bug numbers down. After it was banned, a bunch of other chemicals were used to treat bed bug infestations. The bed bugs, however, got smart and developed resistance to some of these chemicals. That resulted in a big UH OH for society as bed bug infestations are now on a major rise! Scientists from the University of Massachusetts Amherst and Korea’s Seoul National University decided that it would be important to find out more about resistant strains of bed bugs in New York. The work was published in the Journal of Entomology. Let’s see what they discovered, shall we?
When researchers got busy observing bed bugs in New York, they found these pests had mutations in their nerve cells. What does this mean? It means they are resistant to the chemicals used to kill them. Where the chemicals would previously have paralyzed and killed the bed bugs, the mutations mean that bed bugs are now outsmarting their opponents – us!
Let The Bed Bug Collecting Begin!
To get the scoop on bed bug resistance, researchers took a sample of easily controllable ones from Florida and compared these to ones from New York that were harder to deal with. So just how resistant were these little bugs?
Look at this partially engorged bed bug. It probably looks similar to the bed bugs in Milan after they feasted on my blood. Oh, and a fun fact of the day: the Italian word for bed bugs is cimice dei letti.
Researchers found that the bed bugs in New York had up to 264 times the resistance to the modern chemical used to kill bed bugs – deltamethrin. If we picture a nerve cell, it has these little sodium channels on the outer membrane bit. This is where the flurry of nerve impulses come to life. In the New York bed bugs, this nervous system mutation means they can keep feeding long after those Florida ones have been exterminated.
Grossaroo
When I was in grade 3, I made up the word ‘grossaroo’ to describe anything yucky. This word is fitting in the case of what happened to me recently when I was working at an agency in Milan. After a few nights at what seemed to be a nice corporate flat, I began to get loads of itchy, inflamed red bites. I awoke one night to find a flattened-looking bug moving across my otherwise clean, crisp white sheets.
I yelped and quickly squished it with my slipper, only to see it turn into a smattering of blood, which it just took from its recent feeding of my body! Just after, I saw another one. By morning, my bed looked like a crime scene with all those splats of blood and bugs. Eeek! Fortunately, I got moved to a new place and had everything washed. Hopefully, those Milan bed bugs weren’t too hard for the building owners to get rid of, unless they’re resistant beasts like those New York ones.
Bed Bug Warrior To The Rescue
So now you know (if you didn’t already!) that bed bugs do exist. Not only that, but they’re continually evolving to get smarter, doing so in ways that make it harder to get rid of them. For now, you can be smart by being extra cautious when traveling. Always check for signs of bed bugs around the mattress and furniture. Since not everyone shows bites from these little pests, prevention will remain the best line of defense. And while it’s not necessarily smart, it sure is fun when checking for bed bugs to yell “YOU’RE GOING DOWN!” If your parents ask what you’re doing, you can explain that you’re the self-appointed family warrior here to protect everyone from bed bugs.
Image credits: Unless otherwise specified, images courtesy of the National Pest Management Association.
Evolution Gets Colorful August 24, 2009
Posted by Mrs Weird Scientist in Brain Power, Environment, Evolution, Tough Stuff.Tags: autumn, ice age, trees
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Summer is still going strong but soon it will be fall – a time when we can enjoy the pretty autumn leaves. Or as I always like to do, throw leaves at my wee dog and race through the massive piles of foliage.
Unless you’ve traveled a bit and have a sharp eye for detail, you might not have noticed that autumn leaves are usually red in America but yellow in Europe. Seems strange, doesn’t it? If you’re wondering why, then you’re not the only one. Two professors thought about these differences too and they came up with a cool theory.
Prof. Simcha Lev-Yadun of the Department of Science Education at the University of Haifa-Oranim in Israel and Prof. Jarmo Holopainen of the University of Kuopio in Finland had their work published in New Phytologist.
Stepping Back In Time
Red leaves in America serve as a warning flag to ward off insects. But in Europe, none of these evolutionary 'tricks' are needed, which means leaves are yellow.
To find out more, we have to step back 35 million years to sort out the mystery. Up until that time, huge areas of the globe were rich in evergreen forests. Then, a bunch of ice ages and dry spells came into the picture. Lots of the tree species evolved to become deciduous – meaning they lose their leaves depending on the season. Some trees even started to produce red leaves to keep the pesky insects away. But, something else came into play and you might be surprised to learn just what it was!
Look To The Mountains
It’s true. We have to check out the orientation of the mountains to get the scoop on why the leaves evolved to be red in America but yellow in Europe. In North America, north-to-south mountain chains created a protected area, enabling the plants and animals to migrate south or north. Joining them were the insects. So, the leaves in America remained red to continue warding off these annoying bugs.
But in Europe, the mountains are oriented from east-to-west, leaving no protected areas as the ice and other environmental conditions came to visit. Loads of the tree species just couldn’t survive the extreme cold. When they died, so did those insects that needed the trees for their survival. By the time the ice ages were over, those trees that had managed to survive didn’t have to deal with the now-extinct insects. So, no need for red leaves to keep them away!
Curious Minds Want To Know
I asked Simcha Lev-Yadun how he ended up studying leaves. While my background is in the life sciences (medicine and nutrition), I always wonder how people end up in the many different, neat areas of science. He explained:
I wanted to be a biologist and archaeologist since I was ten years old. For me, science is a lifestyle, not a job. At the age of 57…I look backwards and see that I made the right decision.
He also shared his plans to meet up in Scandinavia with his colleague Jarmo Holopainen, where they hope to find out even more about why plants have such cool and different colors.
My Wishful Thinking
While my dog Tiko probably doesn’t care much about leaf color when he dashes through the crisp autumn leaves, I like to understand what makes one leaf a bright yellow and another a brilliant red. Now, if only leaves could somehow evolve to become fluorescent pink, my favorite color. Somehow though, I just don’t see it happening!
The Recipe For A Perfectly Sticky Web May 31, 2009
Posted by Mrs Weird Scientist in Animals, Brain Power, Evolution, Insects, Tough Stuff.Tags: evolve, spider, web
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Have you ever tried to bake a cake, only to find out that when it came out of the oven, it was dry and hard? Maybe you realized that you’d put in too much sugar. Or, maybe you cooked it for too long. Would you believe that spiders have a similar challenge when it comes to spinning their webs? Too much of a good thing can actually leave a web that’s far from perfect.
For this web to catch its prey, it needs to have just the right amount of stickiness and strength. If all goes well for the spider, dinner will soon be served!
For a spider to catch its prey, the web needs to be sticky but still remain strong. If the balance isn’t right, the web won’t catch a bug and it’ll be one hungry and grumpy spider!
A Killer Web Evolves
If you’re a spider, you’ve got your work cut out for you! To catch your prey, you want a web sticky enough that the bug gets caught inside but strong enough that the web doesn’t break from its struggles. With such a fine balance needed, spiders have evolved to get it just right.
Let the Construction Work Begin
To build those impressive webs we see, spiders start by putting down lines of dry silk. Then, they weave spirals of sticky silk to nab their prey. But, spiders of yesteryear didn’t build their webs in quite the same way.
Millions of years ago, spiders would lay down a coating of dry adhesive on these spirals. Rather than stick to the web, a bug would be entangled by these dry spirals. As a cool fact you can throw out at your friends, there are still some spiders today that weave their webs with this dry adhesive – we call them deinopoid spiders.
Yet things began to change, with orb weaving spiders evolving to make webs that were more effective at catching prey. Rather than continue to use this dry adhesive, spiders started to go the sticky route by using wet drops of a glue-like substance. When you think of glue, it seems that the sticker the glue, the better. Not for spiders though!
Curious Scientists Start Investigating
Some scientists started to wonder about these sticky webs – is stickier always better? To find out, Ingi Agnarsson of the University of Puerto Rico in San Juan and Todd Blackledge of the University of Akron in Ohio went on a mission to check out a lot of different spiders. They observed 17 species of orb weaving spiders. You’d have to like spiders quite a bit to watch so many different kinds! The full study results are in the Journal of Zoology.
It’s All About Force
The researchers tested the strength of the strands and the stickiness of them too. How’d they do that? Well, they stuck a piece of sandpaper in the web and then measured how much force was required to remove it.
To break a strand on the web, a specific amount of force is needed. When the researchers put the web to the test, they found that by using anywhere from 20% to 70% of this force needed to break the web, the sandpaper was released.
So, a stickier web might hold the insect but as it continues to struggle, the force would ultimately break strands of the web, causing the insect to be released. Yet, with the glue being a bit less sticky, the insect could pull away from a single strand, but it would get caught by the next one. Since the strands don’t break, they can continue to stick to the bug, making its fight a much harder one.
Spiders Are Impressive
It’s actually really impressive and cool when you think about the work that goes into creating a web with just the right balance of stickiness and strength. As for me, I’ll leave the bug-catching to those smart spiders. I think I’ll just stick to making cakes instead. Pun fully intended! Now if only there was a recipe for making good jokes…
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Hairy Frogs Have An Unusual Defense June 2, 2008
Posted by Mrs Weird Scientist in Animals, Tough Stuff.Tags: claws, defense, hairy frogs
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When I think about frogs, I usually picture the cute, little ones hopping around the lake near my house. Well, there are many types of frogs and one in particular is almost the stuff of nightmares! Not only is it a super duper hairy creature but it has a peculiar defense mechanism that has intrigued scientists.
Credit: Gustavocarra for Wikimedia Commons. Check out the claws on this bad boy! If the hairy frog feels threatened, he will bring forth his dangerous claws through the toe pads on his hind legs. Hmmm. I have a feeling that unlike dogs, throwing him a treat won’t make him like me!
Trichobatrachus robustus – as the frog is formally named – breaks its own bones to create special claws that force their way through the frog’s toe pads. It’s thought that this action is performed when the frog is threatened. While we already know that salamanders do something similar by pushing their ribs through the skin to create spiky barbs, the frog’s maneuver is unique! Not only that, but the closest action we’ve seen from other frogs involves bony spines that stick out from the wrist. The difference, however, is that the bones project out naturally, which is different from the hairy frog where the claws force their way out as a form of defense.
Beware The Claw
David Blackburn from Harvard University has studied these interesting frogs; the work is published in the journal Biology Letters. Blackburn found that when at rest, the frog’s claws are sheltered in a bunch of connective tissue. A piece of collagen joins the sharp bit of the claw and a bone found at the tip of the frog’s toe. At the other end of the claw is an attached muscle. Blackburn thinks that when the frog is threatened and under attack, it will contract the muscle, which causes the claw to be pulled downwards. Then, the sharp bit tears away from the bony end and pokes through the toe pad. The end result is a contraption that looks really intimidating. But wait, there’s more to the hairy frog than just these claws! They also have some other neat features. When they breed, male frogs produce long strands of skin and arteries that resemble hair. While researchers aren’t totally sure why the hair exists, they think it might be to bring in more oxygen through the frog’s skin.
Feeling Hungry
In some parts of the world, these hairy frogs are cooked and eaten. Yes, you did just read that correctly – food! The people who hunt the frogs have to be careful not to get hurt by the frog’s claws, so they use spears and similar weapons to capture the creatures. Now, I’m all one for trying new foods but in this case, I think I will pass, thank you very much!
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Blame Your Brain For Temper Tantrums March 9, 2008
Posted by Mrs Weird Scientist in Human Body, Psychology and Behavior, Tough Stuff.Tags: brain, teenagers, temper
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Temper tantrums aren’t just a reaction that young kids exhibit when they get upset or angry. Teens can also go berserk over all sorts of issues. Yet, some teens seem to keep their cool while others fly off the handle at just the slightest aggravation. Now, a study suggests that the connection may lie in a teenager’s brain.
Checking Out Families
Nicholas Allen from the University of Melbourne, Australia investigated 137 children between the ages of 11 and 14. As part of the experiment, he also observed their parents. Allen and his team of researchers used questions – such as curfews – that were expected to trigger arguments. They videotaped these disagreements and found that there were loads of differences between the families. Some families kept calm while others were more aggressive and could barely even speak to one another.
What An Enormous Amygdala You Have
When researchers took scans of the children’s brains, they narrowed in on three specific areas. The first was the amygdala, which is what gets people fired up to react impulsively to situations. The other parts they checked out were pre-frontal regions known as the anterior cingulate cortex (ACC) and orbitofrontal cortex (OFC) – areas of the brain that play a role in the more thoughtful types of responses. The results were really interesting!
Researchers found that the boys and girls who reacted more aggressively to the family discussions had bigger amygdalas. As for the temperamental boys, they had smaller ACCs on the left side of the brain, which researchers think explains why they remained aggressive for a longer period of time. On top of that, the boys who had smaller OFCs on the left side were more likely to respond to mopey parents by acting just as moody!
Making Sense Of The Results
Basically, what the results show is that those grumpy, tantrum-prone teens aren’t getting enough control from the pre-frontal parts over the amygdala. So, the impulsive behaviors end up ruling over the thoughtful and more reflective areas of the brain. What’s the end result? You got it – temper tantrums! The results also suggest that the areas of the brain controlling emotions and aggression are different in boys and girls.
My title for this blog entry is actually a bit misleading because it implies that the structural differences in the brain are fully responsible for aggression, when this just isn’t the case. The research gives us helpful clues to one contributing factor in the puzzle of temper tantrums. Learning more about why some teens are calm when others can freak out so easily and intensely can perhaps allow researchers to find better strategies for helping teens handle their aggression. As for my teenage years, I didn’t blame my brain for temper tantrums – I usually just blamed my parents, as most of us teens do!
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Gene Mutations Can Mean Longer Life March 4, 2008
Posted by Mrs Weird Scientist in Genetics, Human Body, Tough Stuff.Tags: aging, centenarian, longevity
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While they won’t make someone live forever, researchers recently identified some variations in genes that can allow people to live longer. Your genes are your special and unique instructions that determine things like your hair and eye color.
Say Hello To Centenarians
Nir Barzilai and his team are from the Albert Einstein College of Medicine, which is part of Yeshiva University in New York. Their work involved research subjects of Ashkenazi Jewish descent who were all 100 years of age or older. The fancy term we like to use for people in this age bracket is centenarian. Barzilai and his colleagues identified two gene mutations in the centenarians. If you’re a keen bean, you can read the full, more technical version in the Proceedings of the National Academy of Sciences.
Mutations Can Be Good
You might be wondering to yourself that it seems odd for a mutation to result in greater longevity – something we consider beneficial! The word mutation can leave us thinking of disease, death and just generally bad stuff. While this is often the case, genetic mutations can also lead to positive changes. It’s thought that these changes occur to help humans or other organisms evolve and better adapt to their environment.
Looking Inside The Body
In this study, researchers found that the two mutations affect a receptor for insulin-like growth factor 1 (IGF-1). What does IGF-1 do? If you’re thinking it might influence growth, you’re definitely on the right track. IGF-1 is a guiding force in your body’s growth and maturity. It’s especially dominant during puberty and directs the intense growth and development that occurs during the adolescent years. So, what if the receptor stops working properly, as in the case of the centenarians? If the receptor is just a wee bit faulty, the result is that IGF-1 doesn’t effectively bind to the receptor. Low and behold, the pathway to aging and maturation doesn’t proceed at the same pace and ultimately, it is slowed.
For my male readers, don’t get too hopeful you’ve got the gene mutations. Thus far, the carriers identified are all women. Even more interesting is that the centenarians were shorter than an average woman. These women were approximately 2.5 centimeters shorter than the rest of the population. It makes sense, however, given the role of IGF-1 during the huge pubertal growth spurt.
Our Obsession
In westernized societies, we’re absolutely obsessed with anti-aging and finding the next product to decrease aging – whether it’s the visible, aesthetic signs of aging or the internal, physiological ones. Ironically, people have been getting injections of growth hormone for many years now, with the belief that it slows down the aging process. Given that Barzilai’s study showed it was the people with lower levels of growth hormone who are living longer, these injections could potentially be quite dangerous.
We’re Not Alone
Another thing to keep in mind is that humans are not the only ones with these types of mutations. Worms, flies and mice have similar faulty genes that increase longevity. In the coming years, researchers will probably be in a mad flurry to investigate the genes in other centenarian populations around the world. One of the hopes is to discover strategies to reduce aging in the general population. I guess for now though, I’ll just have to fake it by sticking with my anti-aging face cream!
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It’s Good To Look Like Poo February 22, 2008
Posted by Mrs Weird Scientist in Animals, Insects, Tough Stuff.Tags: butterfly, camouflage, caterpillar, poo
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Sometimes, it’s great to look like poo. That is, if you’re a caterpillar! Say hello to the Asian swallowtail caterpillar. It has some neat tricks up its sleeve to successfully stay camouflaged from predators. The first trick comes into play quite early on – when the caterpillar is black and white, with fine spines. Here, it resembles bird droppings. Later on, the caterpillars get older and grow larger, which means it’s a lot harder for the caterpillars to pass themselves off as bird poo. So, as the little critters fatten up, their color changes to a vivid green. Hmmm. Why might being green work well as a camouflage? If you guessed it’s because they can blend in with the leaves, you got it!
Credit: Ryo Futahashi. You can see the wee caterpillar on the left side of the picture looks a lot like bird droppings! On the right, the distinguished fellow is a grown caterpillar – the bright, green color really does make the caterpillar look like the surrounding leaves.
Manipulating The Caterpillar’s Camouflage
In an interesting twist of events, Ryo Futahashi and Haruhiko Fujiwara of the University of Tokyo in Japan, discovered a special way to keep the caterpillar looking like bird droppings. This means that the caterpillar still matures and develops, but it retains its poopy camouflage instead of growing into a green caterpillar that resembles leaves. How did the researchers accomplish this task? It’s not so easy.
It’s All About Genes
You might already be familiar with the concept of genes. Your genes are unique instructions that tell your body how to work. They control all sorts of stuff such as your hair or eye color. Humans aren’t the only ones with genes either! Caterpillar camouflage depends on genes. There are three genes that control the caterpillar’s camouflage. One is responsible for the green color, another for the black color and finally, one for those spikes we see on the very young caterpillars.
Tinkering With Genes
If researchers can find a way to meddle with these genes, they can change the caterpillar’s color. Hint hint. In the case of our Japanese scientists, they did their meddling with a hormone that rules the expression of all three genes. It’s called juvenile hormone. Researchers smeared a synthetic version of juvenile hormone on the back of a young caterpillar. Since the hormone controls the three genes that affect the caterpillar’s color, adding more of the hormone managed to keep the caterpillar looking poopy right through its development. It’s a cool manipulation because it teaches us more about how hormones and genes interact. As for all this talk about poo, I think my next blog post will be on something a bit more pleasant!
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