January 19, 2012

The state of Indian rural education 2011

Image Credit: Royd Tauro

This post was chosen as an Editor's Selection for ResearchBlogging.orgA friend of mine recently pointed me towards an incredible resource. It’s called the Annual Status of Education Report (or ASER, which means impact in Hindi). ASER is an ambitious survey of the state of Indian rural education, conducted yearly since 2005, and their 2011 report came out a few days ago.

The level of organization here is truly impressive. It’s the largest survey conducted outside the government, combining the efforts of over 25,000 young volunteers from local organizations. Together, they survey nearly 300,000 households in over 16,000 villages in all states of India, and conduct basic level reading and numeracy tests on over 700,000 children.

Behind this coordinated effort is a simple and powerful idea, that effective policy needs to be based on evidence. The report takes a refreshingly no-nonsense approach. Rather than starting off with a long list of dignitaries to thank and lofty goals to implement, ASER gets right down to the point, with figures and tables. They focus on two basic goals. How many children are enrolled in schools (and what kind of school)? And are these children learning the very basics of reading and numeracy? By comparing trends of schooling and learning in different states, they have put together the most detailed picture so far of what’s working and what isn’t in rural education. The general picture that is emerging is one of rising enrollment but declining learning outcomes, from levels that were already low.

So let’s get down to the data. While reading through the report, some surprising facts and numbers jumped out at me.

More kids are going to school than ever before. Among 6 to 14 year olds in rural India, 97% are attending school. The toughest demographic to keep in school is 11 to 14 year-old girls, and even here the numbers are improving. Attendance in this age range has gone up from 90% to 95%. This is a remarkable achievement, and a necessary first step towards a right to education.

The graph shows the percentage of children who are NOT in school. Attendance is on the rise, so these numbers are falling.

Over a quarter of these children are now enrolled in private schools. With the new Right to Education Act, government schools are now free and, according to the statistics, are performing better than rural private schools. Nonetheless, private school education is on the rise, suggesting that there is still not enough access to the government school network.

Teachers are attending school regularly. Their attendance is at 87% (on the day of the survey). Gujarat is doing particularly well with 96% of teachers attending, and ten states have greater than 90% teacher attendance. However, as these results are based on a single day of measurement, you should take them with a grain of salt.

But the students aren’t. Student attendance is at 71%, a number that has dropped in the last four years. Some states have dropped over 10 percent here. Bihar is at the bottom of the list here, with 50% student attendance.

A quarter of all students are attending school in a language they don’t speak at home.

Half of all rural schools do not have a functioning toilet. Nearly a quarter do not have separate girls toilets. A quarter do not have access to drinking water. Adequate drinking water and functioning, separate toilets for boys and girls are now a mandated requirement by the Right to Education Act that came into effect in 2010.

More than half of students in the fifth grade can’t read at second grade level. Similar statistics arise for basic math levels. The ability to read complete sentences or add and subtract numbers is not a very ambitious standard for learning, and Indian schools are failing to achieve even this.

The percentage of fifth graders who can't perform at second grade level is on the rise.

What’s more, the math and reading levels are falling further. Learning outcomes have fallen over the last six years. Some states have dropped by over 10 percent in the last year alone.

What could be causing this drastic decline? Continue reading →

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January 15, 2012

Role models can reduce the gender gap: an experiment in rural India

Girls from the Birbhum village district in West Bengal, escaping the summer sun. Image credit: basoo!

I’m back at home in India, and visited my local toy store today, looking for a science kit for a wide-eyed young friend. A woman walks in, seeking a toy for a one-year-old child. “A boy, not a girl”, she hastens to add. The shopkeeper smiles, and says that at one year of age there isn’t really a difference. “I know”, replies the woman, “but I don’t want you to pick out a doll.”

This is a small example, but I find it sad how we impose these gender roles onto infants. You don’t need to be a sociologist to realize that much of one’s gender identity depends on society. If you ask an adolescent girl growing up in the United States what she wants to be when she grows up, her answer will be quite different from that of a girl in India or Afghanistan. Every society creates certain expectations for its children, and this affects the kinds of educational opportunities and careers they aspire towards. Crucially, study after study has shown that these ambitions really matter. What a child believes about their capabilities has a strong bearing on what they will actually achieve.

In the developing world, girls are routinely subject to lower expectations than boys. This bias creates an inequality in educational and societal opportunities. This raises an important question. Is it possible to reduce the gender gap in a society by changing the beliefs of individuals? A clever new study to be published in Science argues that in rural India, the answer is yes. The authors argue that the presence of a prominent female role model in an Indian village reduces the gender gap in that village.

Think for a moment about how you would test such a claim. Well, you’d have to randomly divide villages into two different groups. In the first set of villages, you make no change. In the second set, you put a woman in charge of each village. Then you wait and see how things change. It’s important that you choose the villages at random, because it ensures that there won’t be any other difference between the two groups. If you do see a difference develop, you can conclude that it must be caused by the change you made – in this case, the presence of a woman leader.

The insight by the authors was that India has already implemented such an experiment.

Continue reading →

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December 18, 2011

Towards nature’s fastest draw

It’s not easy to move fast. I say this not just out of laziness. The fact is, in the animal kingdom, moving quickly comes at a considerable energy expense. It also tends to wear down muscles and joints. So you can be pretty sure that whenever you see an animal that’s clocking in at a record speed, it’s doing so for a very, very good reason.

Take the case of the mantis shrimp. These incredible crustaceans come in two varieties: stabbers, and smashers. Sheila Patek is a biologist who studies them for a living. In a fascinating TED talk from 2004, she describes how mantis shrimp have the fastest blow in the animal kingdom. Their strike force is so great that it creates a visible shock wave in water, in a bizarre phenomenon known as cavitation. Patek goes on to describe the engineering solutions that these animals use to create and sustain their powerful smash.

I may not know karate, but I know crazy.

Since 2004, the list of nature’s fastest has had more than a few additions. It’s the time of the year for holiday lists, so I decided to list some of the most impressive record holders in this regard. To do this, I relied mainly on references I found on the wonderful website of Patek’s lab.

The life forms that follow are pushing the limits of physics and engineering. Typically, they are doing this to rein death and terror onto hapless prey. They are the Terminator 2′s of our world. So please join me, as we descend down this list towards the most lethal of all blows. This is a quest for the fastest draw in nature.

But first, let’s start with something fast that we’re familiar with. When talking about short intervals of time, we often use the phrase ‘in the blink of an eyelid’. The time it actually takes us to blink an eyelid is about 3 tenths of a second or 300 milliseconds.

A blink of an eye  (300 milliseconds)

So, our first point of reference is 10 milliseconds, or 1/30th of a blink of an eye

The ballistic tongue of the salamander (< 10 milliseconds)

The explosive tongue of the giant palm salamander of Central America bursts out in under 10 milliseconds, targeting flying bugs that don’t know what hit them. To achieve this feat, the tongue of this cold blooded sniper needs to output energy at the rate of a whopping 18,000 Watts per kilogram of muscle.

It stores this energy like a tightly coiled spring. As it relies on the principle of a slingshot, it can even operate in cold temperatures when muscles are slow to contract.

This tongue has been called the world’s most powerful muscle, but it’s no comparison to what follows.

The vacuum suction of the anglerfish (<5 milliseconds)

An anglerfish has what seems like a rather improbable fishing strategy.

You couldn't dream this stuff up. Source: NOAA photo library

It lures its prey in with a shiny dangling object attached to its head. All of a sudden, its mouth expands to more that 12 times its original size. The low pressure region thus created sucks in water at great speed, as well as whatever unfortunate fish happens to be swimming nearby. It’s a process that looks alarmingly like this.

And this strange kiss of death can take place in less than 5 milliseconds, or 1/60th of a blink of an eye.

The blinding strike of the mantis shrimp (2.7 milliseconds)

This has to be one of the most impressive punches in nature.

Sheila Patek and collaborators measured that the blow of the mantis shrimp can reach a peak speed of 51 mph (23 m/s), in less than 1/100 of the blink of an eye. All this while underwater! It’s so fast that it actually creates a visible shock wave. Meanwhile, its limb experiences over 10,000 g of acceleration.

When you can wield a shock wave, you qualify as badass. Source: Patek et al, Nature 428, 819-820 (2004)

To put this number in context, think of this: a typical person can handle an acceleration of about 5 g before losing consciousness, while decelerations of 100 g are about the highest that humans have survived, in Indy car racing accidents. A bullet shot out of a Beretta gun is accelerated by about 40,000 g.

If you were a snail or a clam, this could well be the last thing that you see:

Needless to say, a mollusk doesn’t stand much of a chance against this punch. The muscle that powers this impressive blow is delivering a mind-numbing 470,000 Watts per kilogram. It’s quite literally blowing the competition out of the water.

Well.. not quite. Read on.

Continue reading →

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December 7, 2011

Woohoo! I made it to Open Lab!

I’m totally floored. Two days ago, I received an email from veteran science writer Jennifer Oullette, informing me that one of my posts had made the cut for Open Lab.

This is me when I saw Jennifer's email in my inbox

And this is me after reading it

If you’re unfamiliar with Open Lab, it’s an annual print compilation of some of the best science writing on the web. Scientific American books has agreed to publish this edition, and it will hit bookstores sometime next fall. The editors Jennifer Oullette and Bora Zivkovic faced the daunting task of winnowing down 720 submissions to 51 finalists. The complete list of their selections is available here, and you can read about their selection criteria in Jennifer’s wonderful defense of the blogging form.

I’m incredibly humbled to be included, especially along such a star studded blogging cast. I’m stunned that I’ll be sharing a book with some of the names on that list. I started this blog less than a year ago, because I couldn’t quite contain my excitement about science. This selection means that I must be doing something right!

But it means more than that. The online science writing community is a group of crazily passionate people. They have families and busy day jobs. Yet they manage to find the time to build something beautiful, something they care deeply about. It’s an incredible meritocracy where the biggest names tirelessly plug the work of the newcomers. The only thing that matters is that what you create is interesting.

My blogging has slowed down to a standstill of late. But rather than offer a lame excuse about being busy, I’m instead going to take inspiration from my fusion powered blogparents. Everyone’s busy. Regardless, I’m going to strive to work harder, to stay up later, and most importantly, to stay interesting. And of course, I won’t forget to have a lot of fun along the way.

P.S. I WON I WON I WON I WON…

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October 19, 2011

How a new understanding of itch leads to better pain treatments


"Happiness is having a scratch for every itch" - Ogden Nash. (Image credit: doug88888)

It begins with an itch. That familiar irritating feeling, swiftly followed by the inevitable scratch. For most of us it ends here, in a fleeting moment of bliss. But then there are those tortured few for whom scratching provides little relief.

In 1660, the German physician Samuel Hafenreffer defined an itch as “an unpleasant sensation associated with the desire to scratch.” As an operational definition, it does the job. As far as we know, every animal with a backbone has a scratching reflex. It’s a useful instinct to rid yourself of fleas, mites, mosquitoes and other small insects that might carry infection. But this protective mechanism can also go awry.

In a masterful essay entitled The Itch, the surgeon Atul Gawande recounts the case of an HIV patient suffering from a severe chronic itch. The patient had recently been diagnosed with shingles, a disease whose symptoms often include extreme itchiness. After many sleepless nights of relentless scratching, she woke up one morning with a greenish fluid trickling down her face. Hours later, in the emergency room, her doctors informed her that she had managed to scratch through her skull, all the way to her brain.

Chronic itching is triggered by various diseases, such as eczema, shingles, HIV, chronic kidney problems, or even as a side effect from some medications. In most cases, it adversely affects quality of life, as patients are constantly tortured by their incessant need to scratch themselves. Standard medications often have no effect. These are people who are suffering from an itch that they can’t get rid of.

Imagine an itch that you couldn't scratch away. This is the plight of those suffering from a chronic itch. (Image credit: Gerald Slota)

The story of itch is inextricably woven with the story of pain. Starting from the discovery of morphine in the early 1800s, there has been steady progress in the medical understanding of pain. Researchers have mapped the circuitry that transmits pain, and have developed increasingly effective painkillers and anaesthetics. In contrast, an itch was not considered life threatening, and relatively little effort was spent trying to understand it. For a long time, it was simply thought to be a dull form of pain.

But this picture is changing fast. In the last decade, researchers have learned about receptors in the nerves under our skin that react specifically to itchy substances. When these receptors fire, they send a signal racing up our spinal cord, headed to our brain where it creates an urge to scratch. Scientists now have a basic map of the roads that an itch takes on its way to our brain. And they have even been able to block some of these roads in mice, essentially preventing them from feeling an itch.

"Scratching is one of nature's sweetest gratifications, and as ready at hand as any. But repentance follows too annoyingly close at its heels." - Montaigne. (Image credit: Stuart Oikawa)

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July 24, 2011

Bacteria use slingshots to slice through slime

This post was chosen as an Editor's Selection for ResearchBlogging.orgBacteria have busy social lives. You might get a glimpse of this the next time you take a shower. The slimy discolored patches that form on bath tiles and on the inside of shower curtains are the mega-cities of the bacterial world. If you zoom into these patches of grime, you’ll find bustling microcosms that are teeming with life at a different scale.

That we can see these microbial communities with our naked eye is testament to the scale of their achievement. Perhaps the most spectacular examples are the giant mats of bacteria that lend life to the Grand Prismatic Spring in Yellowstone National Park. These macroscopic structures are just as impressive as our cities that are visible from outer space. Microbes have colonized practically all moist surfaces on earth, from the inside of our mouths (they’re responsible for dental plaque) to hot vents at the bottom of the ocean. And it all started from small beginnings.

Grand Prismatic Spring, Yellowstone National Park, USA. The people above give a sense of the scale. (Image credit: Leto-A)

The first wave of bacterial settlers that arrived on your shower curtain were few and far apart. They would try to hold on using the molecular adhesion between themselves and the shower curtain. Those that couldn’t get a grip were flushed down the drain plug.

Bacteria have an adaptation that serves them well in such tricky situations. It’s a sort of multi-purpose prong, technically known as a type IV pilus (plural: pili). These wonderful filament-like structures extend out from the bacteria, and grab on to the surface like a suction cup on a bathroom tile. What happens next is straight out of science fiction.

Once these settlers have their ‘feet’ firmly planted on the ground, the next step is to build a home. They begin to excrete a polymer substance, forming a grid that locks them into place. Many different microbes can co-inhabit these homes, from bacteria and archaea to protozoa, fungi and algae. Each species performs a specialized metabolic function, neatly occupying a niche in this city. Together these interlocked communities, or biofilms, are the beginnings of a thriving multicultural microbial civilization.

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July 14, 2011

What it feels like for a sperm, or how to get around when you are really, really small

This post was chosen as an Editor's Selection for ResearchBlogging.orgWe don’t usually learn about the physics of squishy things. Physics textbooks are filled with solid objects such as incompressible blocks, inclined planes and inelastic strings. This is the rigid world that obeys Newton’s laws of motion. Here, squishiness is an exception and drag is routinely ignored. The only elastic object around is a spring, and it is perfectly elastic. It will never bend too far and lose its shape. But any child who has played vigorously with a Slinky has stretched past the limits of this Newtonian world.

Mr. Newton's not going to like that..

Whereas the rigid universe is notable for its strict adherence to a few basic principles, the squishy universe is a different beast altogether.

I was recently out paddling, and noticed that as you move the paddle through water, tiny whirlpools begin to develop along its sides. The whirlpools grow in size, become self-sustaining, and break off and float away. Eventually they die out, as they lose their energy to the fluid around them.

You could also watch the spirals and vortices created by rising smoke. Or notice the strange shapes made by the wind as it sweeps through the clouds. It’s as if fluids have a life of their own, often wondrous and beautiful, and other times surprising and counter-intuitive.

The brief and wondrous life of vortices

But the motion of fluids is notoriously hard to predict. It’s so difficult that if you can solve the equations of fluid flow, there are people willing to offer you a million dollars. The difficulty comes from a mathematical property of the equations known as non-linearity. Simply put, a non-linear system is one where a small change can lead to a large effect. The same thing that makes these equations difficult to solve is also what makes fluids surprising and interesting. It’s why the weather is so hard to predict – tiny changes in local temperatures and pressures can have a large effect.

At this point, most reasonable people would throw their arms up in despair. But physicists are an unreasonably persistent bunch, and when faced with an equation that they can’t solve, they try to get some insight by looking at what happens at extremes. For example, thick and syrupy fluids like glycerine behave in a surprisingly orderly fashion. Take a look at this video (watch through to the end, it’s worth it).

I bet you’ve never seen a fluid do that before. So what’s going on here? And what does this have to do with swimming sperm?

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June 29, 2011

Honeybees have handy knees!

A few days ago, I was walking home and passed by a bush of white flowers in full bloom. They looked pretty spectacular lit by the afternoon sun. On taking a closer look, I realized that what I thought were flowers were actually flower bunches, each of them made up of hundreds of tiny flowers. And on each bunch, there was a single honeybee zipping about from flower to flower.

Watching these bees through my camera lens, I could see something quite interesting. As they landed on the flowers, they would kick up grains of pollen that would rise up like dust. And then the bees would do something quite odd – they would fiddle with their knees. I zoomed in to see what was going on.

There’s something quite peculiar about this photograph. What’s that fleshy appendage stuck to the knees of the honeybee? It looks, to me, somewhat like a human ear. And even stranger – the bees don’t have it when they arrive on the flower. But in a few minutes this thing begins to grow, and in about 15 minutes it’s as engorged as you see in the picture.

In addition to collecting nectar from flowers, honey bees also collect pollen. And what you’re seeing in these photographs is an incredible adaptation that helps bees go about their business of collection. It’s called a pollen basket, and here is how it works.

Bees are hairy creatures, and they get covered in pollen. They rake themselves clean with combs that are built into the inner surfaces of their hind legs. Next, they move all this collected pollen to a joint between the segments of their legs – their knees. This joint functions as a pollen press, and it squeezes the pollen into handy little pellets. But these pellets need to be stored somehow. And so, here is the next adaptation. The outer surface of the hind leg is concave, and it is covered in many small hairs. It’s a basket! This is where the bees store these compressed pollen pellets, and that’s what you see in the above picture. The basket is actually transparent, and so the fleshy color in the pictures above is the color of pollen.

The weird thing about this is that the basket is open at the bottom. So why doesn’t the pollen fall out? That’s because there’s a single strong hair that prevents this from happening, which functions as the lid of the basket.

Although I couldn’t quite make out the details, watching this elaborate packing process through the zoom lens was quite mesmerizing and I was merrily snapping away. The bees didn’t seem to notice me at all, but I realized that I was getting odd looks from my neighbors, so I decided it was time to take my leave.

Buzzing off..

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June 26, 2011

Dissecting the language of the birds, or how to talk to a songbird

The Norse god Odin had two songbirds, named thought and mind, whose daily tweets were the source of his knowledge on our mortal affairs.

Young children have an uncanny ability to pick up new languages. Not only do they soak up vocabulary, they also construct new sentences of their own. This ability to use grammar is the essence of language. It’s not enough to know the meanings of words, you also have to understand the structures and rules by which words are put together.

The predominant view has been that humans are unique in this ability. But any time that we utter the words ‘uniquely human’, scientists seem to take it as a challenge to disprove this notion. And language is no exception. If you’re looking for the species that most closely matches our linguistic prowess, surprisingly, you won’t find it in the apes, the primates, or even in the mammals. You have to travel to a far more distant relative, all the way to a family of birds known as the songbirds.

The vocal life of a songbird is similar to ours in many ways. They learn songs by imitating their elders. Like human speech, these songs are passed down from one generation to the next. Songbirds are also best equipped to learn songs in their youth, and they have to practice to develop their ability. They can improvise and string together riffs into new songs, and over generations these modified songs can turn into new dialects. And like us, they come hard-wired with ‘speech-centers’ in their brain that are dedicated to language processing.

But languages are not just learned, they can also be invented. A striking example comes from the deaf community of Nicaragua in the 1970s. Back then, deaf people in Nicaragua were isolated both physically and through language. By the 1980s, the government set up schools for the deaf to teach them Spanish and how to lip-read. This turned out to be an unsuccessful endeavor. The teachers were growing increasingly frustrated as they were not getting through to the students.

However, things were quite different from the point of view of the students. For the first time, they were in contact with many other deaf people, and they started to exchange gestures that they had invented in isolation. At first the teachers thought this gesticulation was a kind of mime, but the reality was far more interesting. By getting together and pooling their ideas, these children had actually invented a new type of sign language, complete with its own grammatical structure. Here was proof that a new language could be born out of cultural isolation, a testament to our innate abilities to understand grammar. And in a few generations, users of this language were employing newer, more nuanced grammatical structures.

And this re-invention of language has been mirrored in the songbirds. An experiment from 2009 by Fehér and colleagues took newly hatched songbirds of the zebra finch species and raised them in sound proof chambers. They did this during their critical period of language development. Much like the Nicaraguan children, these birds were raised in a world without song. What happened next is quite surprising.

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June 18, 2011

Launch speed of the leaping sifaka

Update: Added discussion on launch angle at the end of the post.

Edit: The final numbers in this post went through a few rounds of revision. What is the world coming to, when you have to track down missing factors of 2 in your blog posts?!

This week, I’m looking at the strategies and mechanisms by which different animals solve the problem of getting around. I started off by writing about how birds and aquatic animals conserve energy on-the-go. This post is another spinoff on the theme of locomotion.

Here’s a clip from one of my favorite documentaries, David Attenborough’s Life of Mammals. It shows the incredible sifaka lemur of Madagascar, a primate that has a really remarkable way of getting around. (If the embed doesn’t work, you can watch it here)

As they launch out from the trees, they almost look like they’re defying gravity. And so, taking inspiration from Dot Physics, I thought it might be interesting to put physics to use and analyze the flight of the sifaka.

I loaded the above video into Tracker, a handy open source video analysis software. I can then use Tracker to plot the motion of the sifaka. I chose to analyze the jump at about 21 seconds in. I like this shot because it isn’t in slow motion (that messes up the physics), the camera is perfectly still (we expect no less from Attenborough’s crew), and the lemur is leaping in the plane of the camera (there are no skewed perspective issues that would be a pain to deal with). The whole jump lasts under a second, but at 30 frames per second, there should be plenty of data points.

This is what it looks like when you track the sifaka’s motion:

The red dots are the position of the sifaka at every frame. That’s the data. In order to analyze it, we need to set a scale on the video. I drew this yellow line as a reference for 1 unit of size (call it 1 sifaka long). And how big is that?

If we believe this picture that I found on the National Geographic website, then a sifaka is about half the size of this folded arms dude.

Now, to the physics..

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