SCIENCE REPORTER, SEPTEMBER 2014 8

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A mountain foot bridge for civil applica� ons developed by R&DE (E), a premier DRDO laboratory, was handed over for public use by Dr. R. Chidambaram, Principal Scien� fi c Advisor to Government of India on 17 July 2014, near HESCO (Himalayan Environmental Studies and Conserva� on Organiza� on), Dehradun, U1 arakhand.

DRDO TECHNOLOGY TO IMPROVE ACCESS IN MOUNTAIN REGIONS Dr Avinash Chander, Scien� fi c Advisor

to Raksha Mantri, Secretary-Department of Defence R&D and DG-DRDO in his message sent on the occasion said, “The technology of making Foot Bridges for armed forces developed by DRDO can be u� lized to bring relief to the fl ood aff ected people. The low cost mountain foot bridges cos� ng just Rs 6.5 lakh each, being

ENTER a silk tex� le shop, and you will be fascinated by the hundreds of gli1 ering hues that are imparted to silk by blending diff erent dyes. Delve deeper and a diff erent story unravels – one of high environmental impact.

Cul� vated silk, in its natural form is white or yellow. To impart colour to silk, the fabric is put through an elaborate dyeing process which involves handling of various synthe� c dyes. Some of these are known to be of health risk. In addi� on, the huge quan� � es of water used for bleaching, washing, and rinsing in the dyeing process result in large volumes of waste water. The remnant dyes in the waste water escape conven� onal water treatment procedures and persist in the environment. For these reasons the dyeing industry is considered to be a highly pollu� ng one.

Hence, sericulture scien� sts have been trying ‘greener’ methods of dyeing silk at the very source itself. The focus of these a1 empts is naturally the silkworm.

Scien� sts at the Na� onal Ins� tute of Agrobiological Sciences in Japan have iden� fi ed genes responsible for producing fl uorescent proteins in some organisms and transferred them to silkworms. The transgenic silkworms produced fl uorescent red, orange and green silk. However, the silk glows in that colour only

under ultraviolet light illumina� on and so is not of much commercial interest. Furthermore, the transgenic silk is fragile and needed an alterna� ve process to harvest the fi bres from the cocoons at lower temperatures to preserve the rich fl uorescent colours.

In India, scien� sts at the Central

easy to transport and deploy are expected to be of great help by making disaster-hit regions accessible and thus facilita� ng relief and rescue work.”

AE er the U1 arakhand disaster in 2013, it was proposed to develop suitable foot bridges in steel to keep the cost of the bridge low. The 13.5 m steel bridge for civil applica� ons has a 1.5 m wide pathway, and is deployable within 2 to 3 hours.

The bridge is designed to withstanding condi� ons prevailing in glacial regions. The joints of the bridge facilitate easy assembly in cold condi� ons and a 35 m bridge can be launched in about one hour. Though it is designed to prevent any appreciable accumula� on of fresh snow, it has been designed for accumula� on of up to 250 mm of fresh snow. The military bridging system has successfully completed user assisted technical trials in Assam and Arunachal Pradesh.

(le� ) The mountain foot bridge being handed over for public use by Dr. R. Chidambaram, Principal Scientifi c Adviser to the Government of India and DRDO offi cials

GREENING THE SILK

Coloured silk produced from transgenic silkworms under normal and UV illumination

SCIENCE REPORTER, SEPTEMBER 20149

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‘BIGFOOT’ SAMPLES ANALYZED

IN North America, they’re called Bigfoot or Sasquatch. In the Himalayan

foothills, they’re known as ye� or abominable snowmen. And Russians

call them Almasty. But in the scien� fi c laboratory, these elusive, hairy,

humanoid creatures are nothing more than bears, horses, and dogs. That’s

the conclusion of a new study—the fi rst peer-reviewed, gene� c survey of

biological samples claimed to be from the shadowy beasts.

Supposed evidence for Bigfoot and its ilk comes from observers

who spot apelike creatures dar� ng through the woods or who fi nd giant

footprints in the mud. Bigfoot believers have various ideas about what the

animals are, oE en revolving around the survival of a prehistoric humanoid.

Yet many sigh� ngs have later turned out to be hoaxes, and scien� fi c

support for the existence of the primates is scant.

In 2012, researchers at the University of Oxford in the United

Kingdom and the Museum of Zoology in Lausanne, Switzerland, put out

a call for hair samples thought to be from anomalous primates. They

received 57 hairs from Bigfoot enthusiasts and museums around the

world, including samples from Washington, Texas, Oregon, Russia, and

India—a few as old as 50 years. Some “hairs” immediately turned out not

to be hairs at all, but rather plant or glass fi bers; others were too worn to

study.The researchers, led by Oxford gene� cist Bryan Sykes, focused on the remaining 37 samples. To iden� fy the evolu� onary

source of each sample, the team determined the sequence of a gene—found inside the mitochondria of cells—that encodes

the 12S RNA, which is oE en used for species iden� fi ca� on.

Seven of the samples didn’t yield enough DNA for iden� fi ca� on. Of the 30 that were sequenced, all matched the exact

12S RNA sequences for known species, the team reported online in the Proceedings of the Royal Society B. Ten hairs belonged

to various bear species; four were from horses; four were from wolves or dogs; one was a perfect match to a human hair; and

the others came from cows, raccoons, deer, and even a porcupine.

The fact that the fi ndings now appear in a peer-reviewed paper, says New York University’s Disotell, is key to bridging

the gap between enthusiasts hoping to understand Bigfoot and professional scien� sts with access to modern labs. It also

illustrates the proper protocol that’s needed to test a scien� fi c hypothesis, he adds. “I think this study will bring

home the message that you can’t go off and make any old claim you want; there are scien� fi c methods

to tes� ng claims.”

Sericultural Research and Training Ins� tute, Mysore ini� ated many studies in 2005 to induce the silkworms to produce colored silk of specifi c choice, including fast colors, by simply modifying the procedure used for feeding the silkworms. Generally silkworms are fed fresh mulberry leaves. In the modifi ed feeding

procedure, the leaves given for feeding from the fourth day of the fi E h instar stage were either dipped in or sprayed with known concentra� on of a given dye. A wide range of coloured cocoons were obtained by this procedure.

The CSRTI research team, led by Dr. Kanika Trivedy has collaborated with the Na� onal Chemical Laboratory, Pune to use azo dyes for this purpose. Azo dyes are not only inexpensive but also account for more than half the tex� le dyes used today.

The researchers claim, “The process signifi cantly reduces the need for trea� ng toxic dye effl uents that are generated in the tradi� onal dyeing processes.” They are now in the process of synthesising new dye molecules which can impart desired colour to silk without chemical dyeing processes.

Silk sarees woven from cocoons of worms fed with the dye Rhodamine B,

yielding light violet and pink colour silk, have been commercially released under the name “Naturals” at RMKV Silks, Bangalore. The researchers claim that this is the fi rst ever naturally coloured silk fabric in the world and have applied for patent.

Contributed by Dr M.S.S. Murthy, B-104, Terrace Garden Apartments, 2nd Main Road, BSK IIIrd Stage, Bangalore-560085

Mature silk worms fed on ordinary mullberry (extreme left) and those fed on mellberry leaves sprayed with two different dyes (left).

SCIENCE REPORTER, SEPTEMBER 2014 10

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M THE GREEN NOBEL 2014THE Goldman Environmental Prize, ins� tuted in 1990 by philanthropists Richard N.

Goldman and his wife Rhoda H. Goldman of San Francisco in California, US has oE en

been heralded as the Green Nobel.

This year, the award has gone to

Ramesh Agrawal of India (for Asia),

Desmond D’ Sa of South Africa (for

Africa), Suren Gazaryan of Russia

(for Europe), Rudi Putra of Indonesia

(for Islands and Island Na� ons),

Helen Slo1 je of the US (for North

America) and Rush Buendia of Peru (for South and Central America). The awards

were presented on 28 April 2014 during a ceremony held at the San Francisco Opera

House. Ramesh Agrawal has been selected for the Prize in recogni� on of his

contribu� on in organizing villagers to demand their right to informa� on about

industrial development projects. He succeeded in closing down a large proposed

coal mine in ChhaR sgarh, which would have had devasta� ng impact on the local

environment. He had to face the ire of powerful industrial houses who wanted to

establish coal-based energy plants without giving fair compensa� on to the people.

A1 empts were also made on his life. However, an undeterred Agrawal, through

his grass roots movement, the Jan Chetanaa in Raigarh of ChhaR sgarh, con� nued

his mission. Its impact has been enormous, and has given hope to many other

communi� es fi gh� ng against unchecked and unlawful industrial development at the

cost of the environment, all over the country.

While Desond D’ Sa was honoured with the Prize for successfully organizing a

mass movement that led to the shutdown of a toxic waste dump in South Durban,

Suren Gazaryan, a recognized bat expert and zoologist got the prize for campaigning

to expose the corrup� on leading to illegal use of federally protected forest land

along Russia’s Black Sea coast. Rudi Putra, a noted biologist received it for his

contribu� on in geR ng dismantled illegal palm oil planta� on, which was causing

massive deforesta� on in North Sumatra, thereby protec� ng the habitat of the

cri� cally endangered Sumatra rhinos.

Helen Slo1 je earned it for providing legal assistance by using a clause in

the state cons� tu� on that gives municipali� es the right to make local land use

decisions that helped towns across New York to defend themselves from oil and gas

companies by passing local bans on franking. Ruth Buendia cornered the honour for

uni� ng the Ashaninka people in a powerful campaign against large-scale

dams that would have once again uprooted indigenous communi� es s� ll

recovering from Peru’s civil war.

Contributed by Dr. Ramesh Chandra Parida, Retired Professor of Chemistry, Orissa University of Agriculture & Technology. Address: UshaNivas, 124/2445,

Khandagiri Vihar, Bhubaneswar-751030

GREEN POTATO: TO EAT OR NOT TO EAT?

POTATO is considered to be the world’s favorite vegetable. But some� mes it shows green patches. The green pigmenta� on in the potatoes is because of the chlorophyll that gets synthesized in this region along with solanine (glycoalkaloid poison).

Solanine itself is colourless and is found in high concentra� ons in the potato leaves and stem; the potato tuber also contains a very low concentra� on of solanine. But its concentra� on increases with exposure and intensity of light.

In favorable condi� ons potato tubers give rise to new sprouts helping propagate the potato plant by means of vegeta� ve reproduc� on. So the natural tendency of the plant is to protect this part from any kind of damage. Rodents in search of food usually unearth the potato tuber and as the tubers come nearer the soil surface they get exposed to light. In response as a defense mechanism the tuber synthesizes solanine along with chlorophyll. Thus the poison protects the plants from rodents (glycoalkaloid is bi1 er in taste) and insect infesta� on and even microbial and fungitoxic ac� vity. During harves� ng, potato tubers are dumped by the farmers in the fi eld where on exposure to sunlight the surface layer of potatoes turns green and accumulates solanine.

There have been several reports in literature sta� ng the adverse eff ects of solanine glycoalkaloid poisoning in humans. The most fatal is the decrease in acetylcholinesterase enzyme ac� vity triggering the accumula� on of acetylcholine. This results in hypersensi� vity of nerves, muscular spasm, and convulsion.

The glycoalkaloid may also cause tetratogenic eff ect, which increases the abnormali� es in an off spring when taken by either of the parents before conceiving. Solanine poisoning shows symptoms like vomi� ng, diarrhea but it is oE en confused

with other gastrointes� nal problems. Generally people recover fully aE er poisoning as they do not get poisoned in high concentra� ons. Owing to its bi1 er taste people do not consume solanine containing potatoes to a larger extent.

At home when the potato is cooked usually the green parts are cut off . The solanine concentra� on can also be checked to some extent by peeling off the skin and nearer skin areas. Deep frying at about 170°C is also eff ec� ve, as in deep frying solanine leaches into the oil and loses its toxicity.

Potato should be properly stored. It should be stored in paper bags rather

than plas� c bags and should be kept in dark and cold places in order to keep the concentra� on of solanine low. Sprou� ng potatoes have a higher concentra� on of solanine, so sprou� ng potatoes should be avoided.

Contributed by Swikriti Masih (swikritimasih99@gmail.com), 5th Semester student of St. Xavier’s Kolkata, Department of Biotechnology, West Bengal; Babita Saha (babitasaha@gmail.com), senior secondary teacher (Biology) in Bhavans’ N S C Bose Vidyaniketan, Haldia; and Siraj Datta (dattasiraj@gmail.com), associate professor Department of Biotechnology, Haldia Institute of Technology, ICARE Complex, Haldia, West Bengal-721657.

Green Patches

SCIENCE REPORTER, SEPTEMBER 201411

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SECRET OF WAKING-UP FRESH!

at the end of REM – right aE er the last episode of our dream comes to an end.

Now, how can we use this piece of scien� fi c evidence to make our lives easy? How to wake up fresh and full of energy? It’s all about � ming our bed � me in order to wake up at the end of the sleep-cycle, not in between. Suppose you would like to wake up by 7 AM, the perfect � me to sleep can be calculated by subtrac� ng in mul� ples of 90 minutes, keeping in view 5-6 sleep cycles that we minimally need. Therefore, it is either 10 PM (6 cycles), or 11:30 PM (5 cycles). We usually need 15-20 minutes to fall asleep, which needs to be factored to calculate the perfect bed-� me. So, the perfect bed-� me for waking up at 7 AM is around 9:45 PM or 11:15 PM.

Wish you had a smart alarm clock that wakes you up every morning at your op� mum � me? Here’s the fi nest example of how innovators pick up ideas from primary research papers and make

the idea work in real life. A number of smartphone apps are now available in the market (for example, “Sleep-Cycle” for android/iPhone) that can wake you up at the op� mal � me based on this principle and the � me you fall asleep.

These apps make use of the accelerometer (mo� on-sensor) which is available in most smartphones. You keep the phone in the ma1 ress while sleeping. We tend to move around a while before we fall asleep and these apps look at the moment we stop these movements. So, instead of waking you up at the exact � me you specify, the algorithm calculates the ideal � me based on the � me you fall asleep and wakes you up at or before the � me you specify!

The principle of sleep cycle applies for naps too; an ideal aE ernoon siesta should last for at least 90 minutes. Coming to naps, there are a number of scien� fi c studies that associate taking naps with increased memory reten� on and crea� vity. Maybe it is high � me for employers and HR departments to inculcate napping prac� ce in their workforce.

Contributed by Dr Felix Bast, Assistant Professor at Center for Biosciences, Central University of Punjab, City Campus, Mansa Road, Bathinda, Punjab-151001. Email: felix.bast@gmail.com Sleep cycles illustrating stages (top-left) and ideal times to sleep/wake-up (bottom).

Brain

Acti

vity

1 sleep cycle

NREM REM Wakeup fresh in rhese phases of sleep cycle

Time11:30 1:00 2:30 4:00 5:30 7:00

HAVE you ever wondered how much sleep we should get every night in order to stay healthy and wake up fresh? An adage says “eight hours of sleep a day” keeps you fresh. Now, some� mes even aE er that perfect eight hours of sleep (or even longer!), why do we wake up at � mes sleepy, exhausted, listless and lazy? And once in a while you wake up earlier than your usual � me, yet you feel fresh and full of energy.

Here’s what science reveals, aE er rigorous experiments with night-long EEG scans on sleep volunteers done four decades ago. We sleep in the so called “sleep cycles”, each las� ng about 90 minutes, passing through four stages of NREM (Non-Rapid Eye Movement) and the last stage of REM (Rapid Eye Movement). This 90-minute sleep cycle is well known since the 1960s, yet using this informa� on to make our sleep be1 er is a compara� vely recent phenomenon.

When we fall asleep, we begin with a light sleep – the fi rst stage of NREM. As we progress, sleep gets increasingly deeper with decreased brain ac� vity, and by the fourth stage of NREM we are almost en� rely in deep sleep, which con� nues � ll REM, the fi nal stage when brain ac� vity is again increased and it’s when we start dreaming.

An adult needs fi ve to six sleep cycles, while infants need more. It is extremely unpleasing if we wake up during the last two stages. Ideally, the most pleasing � me to wake up is right

There are a number of scientifi c studies that associate taking naps with increased memory retention and creativity.

This 90-minute sleep cycle is well known since the 1960s, yet using this information to make our sleep better is a comparatively recent phenomenon.