My Science School

They are just 46 mm (less than two inches) long, and live in burrows underground in the dry scrubland of South Africa and Zimbabwe. They are called rain frogs because they only come out after a shower of rain which is usually a rare event in their habitat.

The Namaqua rain frog has rather surprising weapon in its limited arsenal. When threatened, it puffs itself up and lets out a series of high-pitched squeaks!

The red-eyed tree frog is another tiny package of surprises. It lives in SOUTH America and has, as its name suggest, large brilliant red peepers, bright orange feet and blue and yellow sides.

It can inflate the area below its mouth and use it to amplify its mating call. The skin stretches so much, the frog becomes transparent. Then, this frog that can fit into a teacup, lets out a booming croak!

Male red-eyed treefrogs inflate their vocal sacs and rise on all fours in an attempt to attract females and deter other males from entering their territory.  During this process, at least two males face each other and quiver, their bodies violently shaking.  This quivering ritual establishes territory and demonstrates strength and intimidation.

 

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Scientists believe it to be the second-most poisonous vertebrate in the world after the golden arrow poison frog of South America. A poison called tetrodotoxin is present in pufferfish liver and sometimes skin. Pufferfish are also known as bubblefish, blowfish, balloonfish and toadfish. They have thin spines that are visible only when they are completely puffed up. The fish inflates its yellow underbelly by filling it with water when attached, making it too big for the predator to bite or swallow.

When the puffer is threatened, the stomach expands into the peritoneal space and the stomach unfolds to fill gaps beneath the head, dorsal, anal fin and caudal peduncle. The fish balloons and the spines that lie on the surface of its skin stick out, making it a highly unattractive meal!

Although puffers have evolved to suck in water, if lifted out they can sometimes suck in air. They sometimes have difficulties expelling this from their stomach, so take extra care when catching them.

 

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The greater sage grouse lives in North America. It is the largest species of grouse in that continent. It is a massive white-breasted bird with brown-black features on its head and back. The male has two yellow sacs on each side of the throat. In breeding season, the male inflates the sacs to amplify the pooping sounds it makes to lure the females. All the males gather in a spot called a lek and strut their stuff. They can be heard up to five kilometres away!

Other birds, such as the magnificent frigatebird and the great bustard also inflate their throat sacs called gular pouches. The frigatebird has a striking red one and it spends an hour inflating it.

 

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Indian and Polynesian sailors have historically been guided by lodestars to find their way at sea. But research shows that harbour seals have been doing it much before humans attempted it. Harbour seals are marine mammals. They live along the Atlantic and Pacific coastlines of the Northern Hemisphere, and hunt for food at night. Obviously, in the dark, they cannot follow the landmarks that are visible on land.

In 2006, German and Danish scientists placed two harbours seals – named Nick and Malte – in a specially constructed floating planetarium. The team trained the two to swim in the direction of specific lodestars. They discovered that the animals could identify a single star out of a projection of the Northern Hemisphere night sky. This showed that the seals followed specific lodestars as navigational aids when they swam far from the shore. Remember, this was an experiment. So do the seals in the wild navigate by following individual stars? Researchers believe they do. Star-based navigation enables the seals to efficiently search an area for food.

 

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Scientists say migrating birds rely on the magnetic compass after sunset. They also use the individual stars for navigation at night. All animals with “camera eyes”, the kind of eyes humans have, can make out individual stars. Insects with compound eyes cannot do this so they see the starry sky and the Milky Way as patterns of light. But scientists do not have an answer for one question: how do birds flying at night change the point of reference when they cross the equator? How do they follow the stars that change their orientation across the equator?

One example of birds that understand stellar navigation is the indigo bunting of North America. These birds fly south for winter, and they do it at night. There is less competition for food at night and there are fewer disturbances after dark. In one experiment, researchers captured these migrating birds and placed them under a starlit dome. And this is what they found.

Indigo buntings watch the rotation of close star patterns around a centre point, such as the North Star. From this they determine the directions. Before migrating, songbirds orient themselves by hopping in the direction they want to travel. In the experiment, the starlit dome rotated around the North Star, which is what happens in the night sky. The smart birds observed it and began to fly south. Then the researchers removed the constellations within 35 degrees of the North Star. The birds became disoriented and couldn’t fly anywhere.

So, individual stars are not that important for the birds. What they need to see is the rotation of the close star patterns around a centre point. This helps them to determine where north is. They use this information to fly south.

 

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Whenever we talk of the navigational skills of explorers, we wonder: How did these seafarers find their way about the sea with no navigational aids like sat-nav? The answer is always the same. Sailors of olden days followed the stars. They understood star formation and aligned their route to how the stars appeared in the night sky. But man is not only the creature that “followed the stars.” Sea creatures and birds are known to have looked up to the heavens for guidance. Recent studies in this field show that dung beetles too use the stars for navigation! And they have a brain the size of a grain of wheat!

Dung beetles are African insects. During the day, the beetles walk in a straight line rolling the dung. The beetles survive because of the dung. The dun provides them with food and drink, and during the hot African noon, the beetles simply climb on the dung to keep themselves cool. So the beetle fights for the smallest bit of dung, and carries it away even during the night.

At night, moonlight is their guide. On the days the moon is not visible, dung beetles follow the Milky Way. Human, birds and sea creatures follow just the lodestar. Just one star is enough for them. But the eyes of the dung beetle are not that sharp. The Milky Way has a straight band that is easy for the beetles to follow. For the Milky Way to be seen, the sky has to be clear. So, should we not keep the sky clear, without pollution, so the poor beetles trying to cart their food do not lose their way?

 

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          Physical exercise is difficult in a humid atmosphere if you are not used to it. This is because sweat cannot evaporate into the air properly, making it very difficult for the body to cool down. Athletes and other sports players will train in humid conditions in order to prepare themselves for competition in such an environment.

          The combination of warm weather and high humidity will slow you down and make your workouts much more difficult. However, high humidity levels aren’t an issue in cooler weather. While it's difficult to determine the exact temperature that high humidity becomes a problem (due to all of the variables: body size, personal heat tolerance, etc.), most people need to pay attention when the air temperature hits 77° F (25° C), and the dew point is 57° F (13.9° C).

          Think of “dew point” as the temperature at which dew drops form. When the dew point gets close to the temperature, the amount of moisture in the air becomes excessive. When you work out and perspire in these conditions, your sweat starts to fail at cooling you off.

          The wetness of sweat is not what makes you cool. Cooling happens when your sweat evaporates off of your skin. Energy is required to turn liquid into gas. Your body heat is the energy source, so when your sweat evaporates, it takes your heat with it. When it's hot and the humidity is high, the air is already saturated with moisture, causing this evaporation process to slow down or stop — leaving you drenched and uncomfortably hot.

          Why is humidity not problematic in cool weather? Warm air has the capacity to hold a lot more water vapor than cool air. The hotter the air is, the more moisture it can hold. So even when the humidity is high on cooler days, it’s not an issue when exercising outdoors.

          For example, I did an outdoor LTHR run in early January when the temperature was a chilly 38° F (3.3° C). According to Sport Tracks, the humidity was a steep 74% for that run, but it wasn’t a factor. I didn’t even start sweating until 10 minutes in, and when I did, it evaporated and successfully cooled me off. What made that run difficult was going as fast as I could for 30 minutes non-stop.

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It is a method of farming by which crops are grown without disturbing the soil by tilling. If there is no tilling the crop residue on the soil prevents evaporation of rain water and more water infiltrates the soil. There is better retention of organic matter in the soil and nutrients are well recycled, thereby improving the fertility of the soil. It minimizes soil erosion and no ploughing means there is no airblown dust. It is more profitable as it does away with the labour, irrigation and machinery associated with tilling.

Tilling also damages ancient structures like burial mounds under the earth as archaeologists have found in the UK.

It was Edward Faulkner’s book Plowman’s Folly which started the idea of no-till farming in the 1940s. No till farming is widely practiced in the US. Indian farmers started adopting the practice in the 1960s. In the Indo-Gangetic plains, rice-wheat cultivation is done using this method. In parts of Andhra Pradesh rice-maize cultivation is done without tilling.

 

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Snoring is nothing but the sound produced by the vibration of certain parts in your upper airway. When we sleepy, our body muscles, including those in the upper airway, relax and the soft tissues such as the tongue, soft palate, uvula, tonsillar pillars become slack. Sometimes they relax so much that the upper airway partly closes and becomes too narrow for enough air to travel through to the lungs.

When we inhale, the air hits these respiratory structures, causing them to vibrate and create the turbulent sound we call snore. The narrower the airway, the louder the snoring.

Anything that prevents you from breathing through your nose can cause you to snore. This can include congestion from a cold and allergies. Those who have enlarged tongue or excess weight around the neck are more prone to snoring. Snoring is also a symptom of sleep apnea, a potentially serious sleep disorder in which breathing repeatedly stops and starts.

 

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• During photosynthesis, trees absorb CO2 from the atmosphere, and store it as carbon for long time periods. At present, forest store as much as 45% of all land carbon. Deforestation affects this carbon cycle.


• Deforestation is considered to be one of the contributing factors to global warming and climate change. Trees absorb not only the carbon dioxide that we exhale, but also the heat-trapping greenhouse gases that human activities emit. With increase in deforestation, larger amount of these gases will enter the atmosphere and global warming will increase further. About 300 billion tonnes of carbon, 40 times the annual greenhouse gas emissions from fossil fuels, is stored in trees, according to Greenpeace.


• While fossil fuel combustion is the largest source of carbon dioxide emission, deforestation is the second largest. When trees die (or are cut or burnt), they release the stored carbon dioxide into the air.


• Forests release large quantities of water into the atmosphere via perspiration. This replenishes the clouds and triggers rain, which in turn, maintains the forests. When forests are destroyed, it affects rainfall and thereby causes drought.


• As much as 70% of the world’s plants and animals live in forests. They are losing their habitats due to deforestation. Loss of habitat can lead to species extinction. For instance, in Malaysia and Indonesia, Bornean rainforests are cut down to make way for producing palm oil. The effect of deforestation is so much that it is driving the extinction of orangutans, the world’s largest tree-dwelling great apes, native to the rainforests of Borneo and Sumatra. Removing trees deprives the forest of its canopy, which blocks the sun’s rays during the day and retains heat at night. That disruption leads to more extreme temperature swings that can, in turn, affect plants and animals.


• Trees roots stabilize the soil around the tree and hold them in place. When they are cut, the soil is free to wash or blow away, which can lead to soil erosion.


• Deforestation can also cause flooding. Coastal vegetation lessens the impact of waves and winds associated with a storm surge. Without this vegetation, coastal villages are susceptible to damaging floods.

 

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Deforestation is the destruction of forests in order to make the land available for other uses. The Earth loses 18.7 million acres of forests per year, which is equal to 27 football fields every minute, according to the World Wildlife Fund (WWF).

Common methods of deforestation are clear cutting and burning of trees. These methods leave the land completely barren. Clear cutting is when large swaths of land are cut down all at once. This sudden change causes severe damage to the ecosystem.

Cause of deforestation

• A major contributor to deforestation is the practice of slash-and-burn technique of farming. Farmers clear forest by cutting down trees, burn them and then grow crops in the soils fertilized by the ashes. Typically, the land produces for only a few years. The farmers abandon the area and move on to a new patch of land and begin the process again.


• Grazing of livestock, mining and drilling are the other major causes.


• Trees are also cut to be used as fuel.


• Forests are also cleared for housing and urbanisation; for industries, dams and other infrastructural projects.


• Wood is used in the making of paper, furniture and the construction of buildings. Some of the loggers act illegally. They also build roads to access more and more remote forests, and this leads to further deforestation.


• Not all deforestation is intentional. Some are caused by a combination of human and natural factors such as wildfires, which may prevent the growth of young trees.

 

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• In the concrete jungle that Mumbai is, Aarey Milk Colony is a treasured green patch. It has over 5, 00,000 trees. On October 4, 2019, when the Bombay High Court allowed the State government to go ahead with the felling of 2,600 trees to make space for a proposed Metro Rail car shed, the residents protested. But it was too late, as the Brihanmumbai Municipal Corporation (BMC) acted soon after the order and had already cut 1,500 trees (under the cover of darkness). The issue became bigger and uglier – clashes broke out between the police and environmental activists, leading to the arrest of at least 29 persons. Thea matter was taken to the Supreme Court and it, in a special hearing on October 7, 2019, ordered the BMC to halt the felling of trees in the Aarey forest. But it did not order the halt or shifting of the metro shed project from Mumbai’s Aarey in its subsequent hearing.


• In September, reports emerged that the Jharkhand’s Water Resources Department has approved the cutting of around 3.44 lakh trees in Jharkhand’s Palamau Tiger Reserve to make way for the North Koel reservoir, also known as Mandal dam. As per latest estimation, the reserve has nil tigers. However, the felling of so many trees will damage the ecosystem, warn wildlife experts. The reserve has already suffered significant damage because of the expansion of road and railway network.

Development projects such as these are among the top reasons for the deforestation. According to the central government statistics, between 2015 and 2018, about 20,000 hectares of forest land was cleared for development activities such as mining, thermal power plants, dams, roads, railways and irrigation projects. Under the Forest (Conservation) Act, 1980, forest areas can be diverted by the environment ministry for non-forestry purposes such as mining. To compensate, authorities should carry out afforestation at a different place. However, they are in no way a substitute the diverse and natural forests that have been lost permanently due to deforestation, say experts.

It is an irony that the world, while seeking to slow the pace of climate change on the one side, continues to cut down trees in large numbers on the other hand. Trees are part of the solution in our fight against climate change.

 

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Monkeys go to college

There is an organization in the USA called Helping Hands that trains capuchin monkeys to help people who are paralyzed and confined to a wheelchair

In 1977, a psychologist with Boston’s Tufts University, called Mary Willard wanted to help from who was a quadriplegic. Quadriplegic are paralyzed from the neck down. Her professor suggested she train capuchin monkeys because not only are they highly intelligent, they are also small (they weigh between 3-6 kilos) and live for more than 30 years. Their natural curiosity and tiny hands make them ideal for performing delicate tasks.

With a grant of $2000, Willard begins training capuchins. Her first trained monkey Hellion was placed with 25-year-old Robert Foster in 1979. She was with him for more than 20 years. Willard begins Helping Hands, affectionately known as Monkey College, in 1982. In the last 25 years, it has placed over 100 capuchin monkeys with needy patients. The monkeys live with foster families when they are very young for 3-5 years till they are get used to people. Then they go to the college where they are trained for a further 2-3 years to become full-fledged ‘helping hands’.

Each monkey is trained to do everyday tasks such as turning switches on and off, changing DVD’s and CD’s, picking up dropped items such as keys, pens or phones, heating food in a microwave, turning the pages of a book, fetching food and drink and even scratching a troublesome itch! Their owners either use a laser pointer to show them what to do or give verbal commands.

The capuchins are bred at the local Southwick’s Zoo. The organization spends $35,000 to train and care for each monkey. The money is raised through donations and grants. The patients receive them free of charge. After the monkeys grow old, foster families look after them.

Not only do the monkeys enable their owners to lead more independent lives, they also help these people overcome depression and loneliness.

Clever Capuchins

Capuchins are the most intelligent species of South American or New World monkeys. They are adept at observing people and imitating their actions, especially in handling objects and using tools. They are named after the order of Catholic friars called Capuchins because their cap of dark hair resembles the friar’s headgear.

Other animal helpers

Dogs are widely used as guides for the blind. Some dogs are trained to alert the deaf to fire alarms and other warning devices that use sound. Miniature horses are now popular as guides for the blind because they live longer. These guide ponies are about the size of large dogs and can be trained just as well.

 

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1. Parrots are intelligent birds. How do we know this? Scientists tell us that they are capable of complex thinking - the genes that play a role in their brain development are similar to those that evolved to give humans large brains. One example of this is the way parrots make noises that resemble sounds we make syringes conversations. We click our tongue in a particular way to convey, “Not going to happen.” Parrots click their tongue to make very similar sounds. It is quite astonishing to know that humans and parrots have similar traits.


2. In one experiment, the genome of the blue-fronted Amazon parrot was compared with that of 30 other birds. The results showed that regions of brain development genome in parrots are the same as those found in humans. Humans ended up with bigger brains and more brain cells and so capabilities, including language skills than primates. Parrots have bigger brains than other birds and more communication skills.


3. Parrots live far longer than expected based on their body size and metabolism. Some live up to 80 years. Parrots genes associated with lifespan help repair DNA damage, slow down cell death due to stress, and limit cell overgrowth and cancers. Amazing!


4. According to New Scientist, wild keas (a New Zealand mountain parrot with a long, narrow bill and mainly olive-green plumage) sometimes burst into playful behaviour when they hear recorded laughter. They are the first bird known to respond to laughter-like sounds. What did they do? The keas soared one after the other in aerobatic loops, exchanged foot-kicking high fives in mid-air and tossed objects to each other. They behaved like they were copying one another. When the recording stopped, they simply went back to whatever they were doing.


5. The playful behaviour of the keas is accompanied by a special warbling call they make. This is significant because it looks like the laughter they are exposed to is contagious, just like it happens in human conversations. All the birds in a flock - male, female, young ones - join the fun. One report said, “On hearing the calls, many birds started to spontaneously play with non-playing birds, or with an object close by, or by performing aerial acrobatics.”


6. The African grey parrot Alex was said to have the intelligence of a five-year-old human. Researchers at the University of York and the University of St. Andrews observed captive greater vasa parrots (Coracopsis vasa) using date seeds and pebbles to break cockle shells. Male vasas ate the powder and then offered a regurgitated calcium-rich snack to females before mating.


7. Parrot toes are zygodactyl. Have you noticed the toe-arrangement on the parrot’s foot? Parrot toes are aligned for maximum grip: two in front and two behind, like two pairs of thumbs opposite to each other. Beaks that can crack the world’s toughest nuts and feet that have a solid grip together make parrots dexterous climbers and healthy nut-eaters.


8. Parrots generally are omnivores - they eat fruits, seeds, nuts, insects and even meat. Rainbow-coloured Lories and lorikeets of the South Pacific use their brush-tipped tongue to sip nectar and are ready to eat meat when available. Keas were found to attack and kill sheep in 1868.


9. Of the roughly 350 known species of parrots, most live in the tropical and subtropical regions of Australia, Asia, Central and South America and Africa. Keas live in the alpine regions of New Zealand and nest in ground burrows. The endangered maroon-fronted parrot (Rhynchopsitta terrisi) lives 6000 feet above ground in the Sierra Madre Oriental Mountains of Mexico.


10. Though parrots do have some taste glands at the backs of their throats, most of their 300 or so taste buds are located on the roofs of their mouths. Compared with the 10,000 taste buds in a human mouth, the birds’ palate may not seem like much, but parrots do show definite preferences for certain foods.


11. Parrots come in different shapes and sizes. The pygmy parrot (Micropsitta pusio) weighs a mere ounce and is about the size of our finger. The world’s longest parrot is the brilliant hyacinth macaw (Anodorhynchus hyacinthinus). It is nearly 3.5 feet from tip to tail. A fully-grown, flightless, nocturnal kakapo (Strigops habroptilus) of New Zealand can weigh as much as nine pounds.


12. A parrot’s brilliant plumage contains Psittacofulvins, a bacteria-resistant pigment that only parrots are known to produce.

It gives the birds’ feathers red, yellow and green colouration. They also protect the glorious     plumage from degradation.

 

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          Most people enjoy the sunshine, and the ultraviolet (UV) rays produced by the Sun help us to produce certain vitamins in our bodies. However, too much exposure is very harmful and can lead to serious diseases such as skin cancer. Always protect your-self with sunscreen and try to keep covered up for most of the time that you spend in the sunshine.

          The main risk factor for sunburn, premature skin aging, skin damage, and skin cancer is exposure to UV light from the sun. More than 90 percent of skin cancers are caused by sun exposure. Using tanning beds and tanning lamps also increases the risk for skin damage and skin cancer.

          The risk for skin damage and skin cancer is related to the number of sunburns a person experiences throughout his or her lifetime. The following physical characteristics also increase the risk for sunburn, skin damage, and skin cancer:

• Blond or red hair


• Blue or green eyes


• Fair skin


• Freckles


• Moles (also called nevi)

          The risk for skin damage and skin cancer is higher in people with lighter skin. However, people who have darker skin also must protect their skin from the sun to reduce lifetime exposure to harmful UV rays and help prevent skin damage and skin cancer. Lifetime exposure to the sun, which is associated with an increased risk for skin cancer, often is higher in older people and in men.

          Certain medications (e.g., antibiotics, antidepressants, acne medications [retinoids]) can increase sun sensitivity. Patients should speak with a physician about medications that can make the skin more sensitive to the sun.

          Having a family member with skin cancer increases the risk for the disease in adults and also in children. It is important to learn what to look for and how to monitor the skin for significant changes (e.g., asymmetrical mole, sores that do not heal normally).

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