Category Science

3-billion-year-old crystals hint at lost continent’s fate

Tiny zircon crystals coughed up by volcanic eruptions on the island of Mauritius are around 2.5-3 billion years old. That’s a billions of years older than the island itself; Mauritius that nestled between Madagascar and India before the two landmasses split apart around 84 million years ago.

Comparing the crystals’ ages with those of nearby landmasses, researchers retraced Mauritia’s fate. Volcanic eruptions and shifting tectonic plates fragmented Mauritia and the land, including the zircon crystals, was recycled into the rising plume of magma that fuelled the eruptions that eventually built Mauritius.

 

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Humans Have Bogged Down the Earth with 30 Trillion Metric Tons of Stuff

The amount of manmade goods around today is 30 trillion metric tonnes. That’s about 50 kilogrammes for every square metre of Earth’s surface. Researchers refer to this tsunami of stuff as the ‘technosphere’. The term is a way of helping people recognizes the magnitude and pervasive influence of humans on the planet. In Earth’s biological ecosystems, animal and plant waste are generally reused by other organisms in an efficient cycle of life. Much of the material in the technosphere, by contrast, ends up in landfills where it often doesn’t decay or get reused.

 

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22 species of wildlife have gone extinct in India

The Botanical Survey of India (BSI) says that India is home to 11.5% of all flora in the world. According to the International Union for Conservation of Nature, since 1750, more than double the numbers of plants have disappeared from the wild than birds, mammals and amphibians combined.

Eighteen species of plants (4 non-flowering and 14 flowering) are extinct. Notable among them – Lastreopsis wattii, a fern in Manipur discovered in 1882, three species from the genus Ophiorrhiza discovered from peninsular India, and Corypha taliera Roxb, a palm species discovered in the Bengal region.

The cheetah (Acionyx jubatus) and the Sumatran rhinoceros (Dicerorhinus sumatrensisi) are considered extinct in India. The pink-headed duck (Rhodonessa caryophyllaceai) is feared extinct since 1950 and the Himalayan quail (Ophrysia supercililios) was last reported in 1876. The Zoological Survey of India (ZSI) says that the four animals can be found in other parts of the world. India has about 6.49% of all the fauna species in the world.

“Competition, predation, natural selection, and human induced factors like hunting, habitat degradation” are some of the reasons that have led to these extinctions.

 

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India’s first dragon blood tree discovered in Assam

Researchers have discovered Dracaena cambodiana, a dragon tree species, in the Dongka Sarpo area of West Karbi Anglong, Assam, adding to India’s botanical wealth a plant whose sap turns bright red after coming in contact with air. This is the first time that a dragon tree species has been reported from India.

Dracaena cambodiana is an important medicinal and ornamental tree. Several antifungal and antibacterial compounds, antioxidants, flavonoids, etc. have been extracted from various parts of the plant. The bright red resin has also been used since ancient times as varnish, incense and dye.

The population size of the dragon tree species in Assam was estimated to be fewer than 50 mature individuals. Dracaena seeds are usually dispersed by birds. But due to the large fruit size, only a few species of birds are able to swallow the fruits, thus limiting the scope of its natural conservation. Forest officers are working hard to propagate it; Dracaena saplings are currently growing in nurseries in Sonitpur, Guwahati, Dhemaji and Jorhat.

 

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Scientists create robotic contact lens that lets you zoom in by blinking

Scientists from the University of California, San Diego, have created a robotic soft contact lens that lets you zoom in by blinking twice.

The lens mimics the natural electric signals in the human eyeball that are active even when the eye itself is closed. Researchers measured the electrical potential of the eye – called the “electro-oculographic signal” – made lenses that would respond to that activity.

The lens is made from polymers that expand when electric current is applied. It’s controlled using five electrodes surrounding the eye that act like human muscles. A person blinking twice in succession causes the lens to change its focal length, allowing it to zoom in and out just like users do on their phones. Because the lenses depend on electrical signals, they should function even if a person is blind. This will prove useful in creating visual prostheses.

A lead researcher said: “Even if your eye cannot see anything, many people still can move their eyeball and generate this electro-oculographic signal.”

In the future, this lens can also be used for adjustable glasses and remotely-operated robotics.

 

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What is in the weasel family? which animals are related to mongoose?Do raccoon live in family?

Some of the most effective hunters among the carnivores are actually the smallest. The weasels, for example, are fearsome fighters, able to kill prey much larger than themselves. The fisher marten of North America preys on the formidable porcupine, while a wolverine can bring down a reindeer.

The weasel family includes weasels, polecats and martens, skunks, otters and badgers. They are generally small animals, though the giant otter can measure over 1.8 metres from nose to tail. They have long bodies with short legs and often a long tail, and can be found on and under the ground in the trees and in the water.

Most members of the weasel family feed on smaller mammals, especially rodents, but some will also eat worms, fruit, and insects. The honey badger breaks open beehives to reach the honey inside, while otters feed on fish, frogs and other water creatures. The sea otter uses a stone to crack open shellfish.

Many members of the weasel family can produce a foul-smelling liquid called musk, both to mark their territories and to defend themselves against predators. The best-known of these is the skunk. If threatened, it will turn its back on its attacker and spray musk for distances of up to seven metres.

Apart from some otters and badgers, members of the weasel family are solitary mammals, keeping to their own territories and fight. Males and females usually come together only to breed.

Although hyenas look as though they should belong to the dog family, they are actually a separate group of carnivores. Most hyenas are meat-eaters. Some live in groups and hunt or feed together. They can kill large prey such as wildebeest after chasing them for several kilometres. A hyena’s strong jaws and large teeth can crush even large bones, horns and hooves, making sure there is little left after a kill.

The aardwolf differs from other hyenas because it is nocturnal, solitary, and feeds not on meat but on termites.

 

          The carnivore group also includes the mongoose family and the raccoon family, many of which do not rely on meat in their diets. The mongoose family (civets and genets and mongooses) are mostly solitary animals, but some, such as the meerkats, live in large groups. While feeding above ground they all watch out for predators, and will even band together to drive them away.

 

 

 

The raccoon family includes raccoons, coatis and pandas. All except the giant panda are quite small animals with long tails. They are good climbers, and some feed and nest in trees. Most members of the raccoon family live alone and are nocturnal, apart from coatis which form groups of females and feed during the day.

Raccoons and coatis feed on a wide range of foods including rodents, insects, frogs, plants and fruits. Red pandas, the smaller, lesser-known relatives of the giant panda, feed on fruit, bamboo and other plant material, while giant pandas them-selves usually feed only on bamboo.

Giant pandas are solitary animals that live in bamboo forests in the mountains of China. Although the small areas where they live are protected, the surrounding forest has been cut down. This means that giant pandas cannot move to a new area to breed or to find fresh supplies of bamboo. Giant pandas also breed very slowly, raising only one young at a time. Both of these factors make them among the rarest mammals in the world.

Picture Credit : Google