Diamonds that oncelay more than 435miles beneath the

earth’s surface have pro-vided researchers with anunexpected window intothe planet’s history. Thediamonds, during theirformation, captured evi-dence that slabs of theocean floors descend deepbeneath the earth’s sur-face, recycling carbonbetween the oceans andthe earth’s mantle, theshell of rock, about 1,800miles thick, that liesdirectly beneath theearth’s surface.

Understanding the fateof the slabs will help sci-entists better understandthe earth’s carbon cycleand all the processes thatdepend on it, from the car-bon dioxide in the atmos-phere to the carbon com-pounds in living organ-isms and the formation ofhydrocarbons in oil andgas. Objects that resembleocean slabs can be seen inseismic recordings, butthey lie far too deep forany drill to sample.Impurities in the dia-

monds contain chemicalsignatures of the extinctocean floor, evidence thatthe slabs have been cycleddeep into the earth’s man-tle, says a research teamled by Michael J. Walterof the University ofBristol in England.

These microscopicimpurities, derived fromrock and from organicmaterial in creatures thatonce lived on an ancientocean floor, have under-gone an amazing journey.The ocean floor rock,basalt, along with the sed-iment that built up on topof it, was drawn down atthe edge of an ocean aspart of the conveyor-beltmechanism that movesthe continents.

When the slab of oceanfloor had plunged 435miles beneath the surface,minerals from the basaltwere encapsulated insidethe diamonds that formedat these depths.

The diamonds contin-ued to descend with theslab of ocean floor untilthey experienced two ele-vator rides back to the

surface. A rising mass ofsolid rock known as amantle plume carriedthem slowly back towardthe upper mantle, and theheat of the plume thenpropelled to the surfacean explosive jet of moltenkimberlite, a volcanicrock that preserves dia-monds.

Eons later, the dia-monds were mined by theRio Tinto Group fromJuina in Brazil. The com-pany allowed members ofthe research team to siftthrough stones notdeemed to be of gem qual-ity. After examining thou-

sands of diamonds, theresearchers found just sixthat seemed to be ofsuperdeep origin.

Despite their deep ori-gin, the Juina diamondsare comparatively youngas diamonds go. Theywere formed only 100 mil-lion years ago. Most gem-quality diamonds are 1billion to 3.5 billion yearsold, and originate at shal-lower depths, in the keelsbeneath the cratons, theancient blocks of rockthat form the hearts of theearth’s continental mass-es. The impurities thatmake the superdeep dia-monds useless to the jew-eller are invaluable to thescientist. From the inclu-sions in the six Juina dia-monds, Dr Walter’s teamwas able to infer the exis-tence of two minerals thatform only in conditionsthat exist 435 miles or

deeper below the earth’ssurface. The compositionof the two mineralsmatched the basalt ofwhich the ocean floor ismade, showing that slabsof ocean floor had reachedthis depth, theresearchers reportedonline on Thursday in thejournal Science.

In another test, theyshowed that the carbon inthe impurities containedless than usual of the iso-tope known as carbon 13,a signature of organic car-bon at the surface of theearth that has beenprocessed by living organ-isms. Researchers aredelighted that so muchinformation about majorgeological processes canbe gleaned from themicroscopic impurities inthe superdeep diamonds.“The superdeeps willprobably emerge in thenext 10 years as some ofthe strongest evidence fordeep movements andpathways in the earth’smantle,” said Steven B.Shirey of the CarnegieInstitution ofWashington, a member ofDr Walter’s team.

Thomas Stachel, anexpert on diamond geo-chemistry at theUniversity of Alberta inCanada, said, “Here youhave a beautiful demon-stration that the oceanicplate cycle is not relative-ly shallow, as many peo-

ple assume, but that thesubducted plate makes itdown to the deep mantleand is brought back to thesurface by a mantleplume.”

In Dr Walter’s laborato-ry, the superdeep dia-monds are polished with ajeweller’s polishing wheeluntil the precious impuri-ties within them areexposed. With a variety ofspectroscopic tests, theresearchers then measurethe composition of theminerals within theimpurities.

The discovery that car-bon from the ocean floorcan be mixed so deepwithin the mantle raisesthe larger question of howmuch of the ocean floorand sediments are carriedto the deep mantle. Giventhe importance of carbonto life, scientists seek tounderstand the majorreservoirs of carbon inthe earth and theexchanges between them,both in space and in time.“The mantle is the biggestreservoir of carbon, andwe know very little aboutit,” Dr Walter said.

“This won’t affect cli-mate tomorrow, but whatour results tell you is thatcarbon from the surfacecan go all the way into thelower mantle, which maybe a long-term sink forcarbon.”

By arrangement with the New York Times

Before the CFDA FashionAwards in June, theNew York-based fashiondesigner Phillip Lim,who’d been travelling

frequently and working hard, wasfeeling a bit puffy. “I heard ofmodels and other designers takingarnica before big events or photoshoots, so I thought I’d try it out,”he said recently, referring to thehomeopathic supplement arnicamontana. “It’s supposed to slimyou down because it flushes youout. And it clears up your skin.”Mr Lim tried a three-day oral reg-imen of arnica before walking thered carpet, and was pleased withthe results. “I did feel like my skinglowed afterwards,” he said.

Available in pellets, topical gels,creams and even massage oil,arnica is the latest of many herbalremedies to invigorate, if notintoxicate, the fashion crowd.Linda Fargo, the fashion directorof Bergdorf Goodman, counts thepellet form as one of her fashionweek survival must-haves, andthe stylist Isabel Dupré has longbeen a fan.

“I know it for its healing quali-ty,” Ms Dupre said. “It’s an oldfamily remedy.”

Wende Zomnir, the executivecreative director of Urban Decaycosmetics, who uses arnica in sev-eral forms instead of nonsteroidalanti-inflammatory drugs, said: “Ithink it’s amazing. I take it myself,give it to my kids and hand it outat the Crossfit gym I work out at. Iuse it after a tough workout to pre-vent muscle soreness, if myself ormy kids have gotten bumpedaround and might be bruised, or ifI’ve strained a muscle.”

Derived from a yellow mountaindaisy that grows in Europe and isalso known as leopard’s bane,arnica has traditionally been usedto treat bruising. It reputedlyincreases circulation by stimulat-ing white blood cell activity,thereby decreasing the amount ofhealing time and reducing inflam-mation. If taken internally, itmust be diluted with water; arnicacontains the toxin helenalin and ispoisonous if consumed in largequantities.

Dr Macrene Alexiades-Armenakas, a Manhattan derma-tologist and an assistant clinicalprofessor at Yale, said that, “takenorally, arnica has been reported tocause irritation and toxicity forboth the gastrointestinal systemand the kidneys”.

Still, even before the style settook it up, sports figures wereshowing interest in the substance.Pierre Barrieu, a former head fit-ness coach for the United StatesMen’s National Soccer Team, hadbeen treating players with arnicapellets and topical formulationssince 2002.

“Basically, it was to relieve theeffects of blows and bruises (i.e.,prevent swelling and bleeding)when applied in a timely man-ner,” he wrote in an email. “It’sbest to apply as early as possibleafter the traumatic event. We alsoused it to accelerate the recovery,because arnica decreases theinflammation. And finally, it wasused to prevent cramps.”

Orthopaedic surgeons have also“prescribed” arnica, which is soldin places like Duane Reade andWhole Foods, as a pre- and post-operative measure. And some der-matologists have recommended itafter plastic surgery and injecta-bles like Botox and Restylane.

When the fashion designerDiane Von Furstenberg wasinjured in a ski accident inJanuary, she tweeted duringrecovery: “Arnica gel is the bestthing you can do for bruises... Icannot say it enough...,” prompt-ing rumours that the accident wasa foil for plastic surgery (whichshe quickly batted away).

In the hands of natural-beautybuffs, arnica has recently becomesomething of a medicine-cabinetand vanity catch-all. According toSprayology, a company featuredon Teen Vogue’s website that sellsvitamin and homeopathic mouthsprays, arnica treats confusionand feelings of vertigo. That’s theclaim, anyway, for including theherb in its “Brain Power” formu-lation.

On online forums, especially ofthe ayurvedic and homeopathicvariety, arnica oil has been touted

as a remedy for alopecia, or hairloss. Ms Zomnir of Urban Decayused it for pain and soreness afternatural delivery. “My midwifegave me arnica after the births ofmy boys,” she said. “I had themboth at home, so no drugs avail-able. Arnica did the trick.”

Still others say it clears up acneand other skin inflammations.Nelsons Pure and Clear Acne Gellists arnica as one of four activeingredients. In an Elle magazineinterview, the model GiseleBundchen touted Nelson’s gel as agentle way to clear up blemishes.

And at the Upper East Side Kiehl’sflagship and spa, which opened onJuly 19, jars of arnica flowers linethe treatment rooms so aestheti-cians can customise services onthe spot. It’s visually attractivefrom a naturist’s standpoint, butnot the most contemporarymethod.

“Arnica has evolved,” said DrAlexiades-Armenakas. “Eventhough it has a long history, it’snever been terribly effective. Fastforward to the present, and we’vehad a good amount of labs analysethe active ingredients in arnica.They’ve identified a number ofingredients that account for anti-bruising, and among them are caf-feine derivatives.”

Dr Alexiades-Armenakas hasincluded these derivatives alongwith cacao extract in her 37Extreme Actives facial cream,sold at Neiman Marcus for $295 fora 1.7-ounce pot. “The idea is tocombat puffiness because caffeinehas a constrictive ability on bloodvessels and lymphatic vessels,”she said.

Dr Charles Passler, a Manhattanchiropractor and nutritionist whohas worked with the Estée Laudermodel Carolyn Murphy and withDylan Lauren, recommends bothoral and topical forms of arnica,mainly for bruising and inflam-mation.

“As far as using arnica as a toolfor changing body composition,I’m not aware of it,” he said. Fortemporary de-bloating, though, DrPassler conceded, “It will helpdecrease any puffiness in the bodycaused by inflammation.”

Despite her use of arnica in a top-ical product, Dr Alexiades-Armenakas remains concernedabout long-term oral use. “I wouldbe OK if they did it for a few daysfor a photo shoot once a month,”she said of the fashionable pill-poppers.

“But if they’re having a photoshoot every week, and they’re reg-ularly on it, I would be very wor-ried. Especially for models,they’re very thin, and it’s easier toget toxicity.”

By arrangement with the New York Times

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Low-fat curd intake in pregnancy could trigger

asthma in children

Drug eluting balloon technology is a new way to treat heart blockages

In diamonds’ flaws, findingclues to earth’s carbon cycle

! Gemstonesthat once lay

more than 435miles beneath

the earth’s sur-face and that

include chemi-cal signaturesof the extinct

ocean floorare shedding

light on theplanet’s car-

bon cycle

diaryAashima Dogra

meanwhileNicholas Wade

! Derived froma flower, arnica

is used to promote many

kinds of healing.It is available

in pellets, topi-cal gels, creams

and even massage oil

New scientifictrends are hardlyunfounded at the

British Science festival.It is here that the term“scientist” was coinedand the word “dinosaur”was first used. Brandnew research showcasedat this years festival:

PPOOPPUULLAARR CCOOSSMMOOLLOOGGYYMMOODDEELL NNEEEEDDSS RREEVVIISSIIOONN

Our view of the cosmosmight need correction.Four per cent of our uni-verse is formed of matter,21 per cent is dark-matterand the rest is dark ener-gy. All experiments look-ing for direct evidence ofdark matter are based onthe standard model ofcosmology. This modeldoesn’t stick in the simu-lation of dwarf galaxyformation (believed to bemade up of dark matter)created by Durham sci-entists. Announcing theresults of their study,Prof. Carlos Frenkexpressed his concernover inconsistency of thestandard model and indi-cated it needed revisionbefore any dark matterwas to be found.

RRAARREE EELLEEMMEENNTTSS GGRROOWWIINNGG SSPPAARRSSEE

Rare earth elements usedin manufacture of mobilegadgets will soon be inshort supply. To meetfuture demands these ele-ments will need to bemined at undiscoveredlocations or recycledfrom electronic waste.China supplies 97 percent of the world’s rareearth elements.

TTEECCHHNNOOLLOOGGYY NNEEEEDDSSSSPPOORRTT

The gradual fall in per-formance times of ath-

letes can be directlyattributed to use of tech-nology in sportingevents. Prof. Steve Haakeof Sheffield HallamUniversity warned sport-governing authorities ofstagnation in world sportrecords as a result of ban-ning new technology. Hiswork reveals the lack ofany new records sincethe ban on the hydrody-namic swimsuits afterthe Beijing Olympics. Ifthe ban persists andrecords are not re-set,these records couldremain “untouched fordecades”.

WWAARR OONN TTEERRRROORR WWAASS AA MMIISSTTAAKKEE

The outcome of the over-militarised reaction after9/11 has been radicallydifferent than expected.Prof. Paul Rogers fromBradford University pre-sented results of hisstudy on post-9/11events.

“The analysis of thefirst ten years of the ‘waron terror’ after 9/11examines the expectedoutcomes of the war,including a defeated AlQaeda movement, stableand pro-western states inIraq and Afghanistan,and a diminished Iran. Itcontrasts these with theactual outcomes, includ-ing over 2000,000 peoplekilled, over seven millionrefugees, and an unstableIraq, a more influentialIran and a war in

Afghanistan about toenter its second decade.”He suggested 9/11 shouldhave been treated as anevent of “transnationalcriminality” and dealtwith action by a strongerInterpol and a decisiveinternational justice sys-tem.

Superdeeps willemerge in 10years as some ofthe strongest evidence fordeep movementsin earth’s mantle

–––– SStteevveenn BB.. SShhiirreeyyCarnegie Institution

New trends makea splash at UK fest

A search for relief

through ArnicafocusBee-Shyuan Chang

MONDAY 19 | SEPTEMBER 2011NEW DELHI

WWaasshhiinnggttoonn:: The cata-strophic meteor strike thatkilled dinosaurs on earthsome 65 million years agomay also have wiped outancient birds, scientists say.

Palaeontologists whoexamined fossils of ancientbirds found that many of thearchaic birds died off at theend of the Age of Dinosaurs.According to the research-ers, nearly all the modernbird groups, from owls topenguins and so on, beganto emerge within 15 millionyears after all the dinosaurswent extinct. These birdsare subtly but significantlydifferent from many of theancient lineages that existedbefore a cosmic impact thatwreaked havoc around theglobe at the end of theCretaceous period about 65million years ago, they said.“These archaic birds superfi-cially looked very similar tomodern birds, but under-neath their feathers theywere completely different,”study researcher NicholasLongrich, said. — PTI

ooddddss

UN CHIEF DIES INPLANE ACCIDENT NNddoollaa ((NNoorrtthh RRhhooddeessiiaa)),, SSeepptt..1188:: Dag Hammarskjoeld waskilled when his plane crashedseen and a half miles fromNdola today. The U.N.Secretary-General’s body wasamong the six found in thewreckage.

Another person who was notimmediately identified wasfound seriously injured. MrHammarskjoeld’s plane a DC-6 airliner, crashed in the bushseven and a half miles fromNdola. The wreckage wasspotted by a Royal RhodesianAir Force provost aircraft.

A Northern RhodesiaGovernment spokesman con-firmed that the wreckagefound was that of MrHammarskjoeld’s plane. Healso confirmed that MrHammarskjoeld’s body hadbeen identified. Thespokesman said the wreckagewas first seen by an Africancharcoal burner and thenlater spotted by a provost air-craft of the Royal RhodesianAir Force. The spokesmansaid that when a search partyreached the wreckage at 3.15pm today it was still smolder-ing. Six bodies, including thatof Mr Hammarskjoeld, werefound near the aircraft.

The spokesman said that itappeared that the aircraft hadstruck the ground at speedand with considerable force.

DINO-KILLINGASTEROID WIPEDOUT BIRDS: STUDY

WWaasshhiinnggttoonn:: Scientists havefigured out a new way to killcancer cells by disabling aprotein known as fortilin,which promotes their unbri-dled growth. Fortilin doesso by neutering (removing)protein p53, which actuallysuppresses cancer.

This finding potentiallypaves the way for treating arange of tumours and ather-osclerosis (hardening ofarteries, with plaque build-up), which p53 also helpsprevent.

“The p53 protein is a criti-cal defence against cancerbecause it activates genesthat induce apoptosis, orthe death of cells,” said KenFujise, director cardiologydivision, University of TexasMedical Branch, who led thestudy.

Fujise and his team usedanimal models to demon-strate that fortilin inhibitsp53 from activating genes,such as BAX and Noxa, thatfacilitate cell death. Thus,cells that would be killedare allowed to proliferate,the Journal of BiologicalChemistry reports.

“When normal cellsbecome cancer cells, ourbodies’ natural biologicalresponse is to activate p53,which eliminates the hope-lessly damaged cells,” saidFujise, according to a Texasstatement. — IANS

NEW WAY TO KILLCANCER CELLSDISCOVERED

50 YEARS AGO INDECCAN CHRONICLE

Derived from a yellow mountain daisy that grows inEurope and is alsoknown as leopard’sbane, arnica has traditionally beenused to treat bruising

SCIENCE+HEALTH

Wende Zomnir of Urban Decayuses arnica to prevent soreness.

— NYT

x

c m y k c m y k

PAGE 14

US approves first mechanical cardiac

assist device for kids

Depressed teen girls are twice as likely to startbinge eating: Study SCIENCE+HEALTHMONDAY 19 | DECEMBER 2011

NEW DELHI

LLoonnddoonn:: A daily dose ofVitamin B can radicallycombat memory loss in oldage and even help protectagainst Alzheimer’s dis-ease, a new study hasfound. More than 250 peo-ple took part in the study,at Oxford University,including people with mildcognitive impairment whowere aged 70 years orolder.

They were given VitaminB, found naturally in foodsuch as beans, meat, whole-grains and bananas, or aplacebo over a two-yearperiod. Taking the foodsupplement appeared tohelp maintain mentalprocesses, such as plan-ning, organising andrecalling information.

The researchers foundthat people taking the pillhad lower levels of a brainprotein known to lead to arise in the risk of demen-tia.

They found that it alsoslowed mental decline inolder people who haveslight problems with theirmemory. — ANI

ooddddss

INDIAN FORCES ENCIRCLE PANJIMBBeellggaauumm:: India’s defenceforces had reached the verygates of Panjim, capital of Goaand were poised for a formalentry into Panjim tomorrowmorning, according to latestreports received here aroundmidnight tonight. India’sdefence forces moved into Goaearly this morning afterPortuguese has rejected everyeffort of PM JawaharlalNehru for the last 15 years andmore to settle the issue peace-fully. The Portuguese whohad been subjecting the peo-ple of Goa to tyranny all theseyears fled in panic as defenceforces closed in on Panjim byusing the minimum force.

As the Indian defence forcesadvanced towards the capitalon a three-pronged drive fromthe north, south, and east,town after town fell in a mili-tary sense, but actually thetowns’ people received thetroops from the motherlandwith open arms amidst scenesof jubilation and rejoicing bythe local people, while thePortuguese fled in panic aban-doning their positions evenbefore they were attacked,reports from the front said.

Cooperating with the Indianforces in every possible way,the local people pointed out tothe Indian troops the placeswhere mines had been laid,provided them with boats andferried them across the riversand waterways.

VITAMIN B CANHELP BEAT MEMORYLOSS, ALZHEIMER’S

SSyyddnneeyy:: Adenoviruses thatcan cause respiratory, eye,and intestinal tract infec-tions, must adopt the cellu-lar machinery of infectedorganisms to produce moreof their own, scientists sug-gest. Scientists fromChinese and Australianuniversities have found away to disrupt the hijack-ing process by using plas-ma to damage the virusesbefore they come into con-tact with host cells.

The research led by Z.Xiong and X. Lu (HuaZ-hong University of Scienceand Technology, China)and K. Ostrikov (Univers-ity of Sydney, Australia),prepared solutions con-taining adenoviruses.They then subjected thesamples with a low-temper-ature plasma, a highlyenergised state of matterwhich is created by apply-ing a voltage to a gaseousmixture in a syringe, thejournal Applied PhysicsLetters reported. The plas-ma damaged the viralDNA. When the virus solu-tions were later added tocolonies of embryonic kid-ney cells, plasma-treatedsamples showed much lessviral activity, a universitystatement said. — IANS

PLASMA CAN HELPKNOCK OUT DEADLY VIRUSES: RESEARCH

AAbubble rosethrough a holein the surface ofa frozen lake. Itpopped, fol-

lowed by another, andanother, as if a pot weresomehow boiling in the icydepths. Every burstingbubble sent up a puff ofmethane, a powerful green-house gas generatedbeneath the lake from thedecay of plant debris.These plants last saw thelight of day 30,000 yearsago and have been lockedin a deep freeze — untilnow. “That’s a hot spot,”declared Katey M. WalterAnthony, a leading scien-tist in studying the escapeof methane. A few minuteslater, she leaned perilouslyover the edge of the ice,plunging a bottle into thewater to grab a gas sample.

It was another small cluefor scientists struggling tounderstand one of thebiggest looming mysteriesabout the future of theearth. Experts have longknown that northern landswere a storehouse of frozencarbon, locked up in theform of leaves, roots andother organic mattertrapped in icy soil — a mixthat, when thawed, canproduce methane and car-bon dioxide, gases thattrap heat and warm theplanet. But they have beenstunned in recent years torealise just how muchorganic debris is there.

A recent estimate sug-gests that the perenniallyfrozen ground known as

permafrost, which under-lies nearly a quarter of theNorthern Hemisphere,contains twice as muchcarbon as the entire atmos-phere. Temperatures arewarming across much ofthat region, primarily, sci-entists believe, because ofthe rapid human release ofgreenhouse gases.Permafrost is warming,too. Some has alreadythawed, and other signsare emerging that thefrozen carbon may bebecoming unstable.

“It’s like broccoli in yourfreezer,” said KevinSchaefer, a scientist at theNational Snow and IceData Center in Boulder,Colorado. “As long as thebroccoli stays in the freez-er, it’s going to be OK. Butonce you take it out of thefreezer and put it in thefridge, it will thaw out andeventually decay.”

If a substantial amount ofthe carbon should enterthe atmosphere, it wouldintensify the planetarywarming. An especiallyworrisome possibility isthat a significant propor-tion will emerge not as car-bon dioxide, the gas thatusually forms when organ-ic material breaks down,but as methane, producedwhen the breakdownoccurs in lakes or wet-lands. Methane is especial-ly potent at trapping thesun’s heat, and the poten-tial for large new methaneemissions in the Arctic isone of the biggest wildcards in climate science.

Scientists have declaredthat understanding theproblem is a major priori-ty. The United Statesdepartment of energy andthe European Unionrecently committed to newprojects aimed at doing so,and Nasa is considering asimilar plan. Butresearchers say the moneyand people devoted to theissue are still minimalcompared with the risk.

For now, scientists havemany more questions thananswers. Preliminary com-puter analyses, made onlyrecently, suggest that theArctic and sub-Arcticregions could eventuallybecome an annual sourceof carbon equal to 15 percent or so of today’s yearlyemissions from humanactivities.

But those calculationswere deliberately cautious.A recent survey drew onthe expertise of 41 per-mafrost scientists to offermore informal projections.They estimated that ifhuman fossil-fuel burningremained high and theplanet warmed sharply,the gases from permafrostcould eventually equal 35per cent of today’s annualhuman emissions.

The experts also said thatif humanity began gettingits own emissions undercontrol soon, the green-house gases emerging frompermafrost could be kept toa much lower level, per-haps equivalent to 10 percent of today’s humanemissions.

Even at the low end, thesenumbers mean that thelong-running internationalnegotiations over green-house gases are likely tobecome more difficult,with less room for coun-tries to continue burninglarge amounts of fossilfuels. In the minds of mostexperts, the chief worry isnot that the carbon in thepermafrost will breakdown quickly — typicalestimates say that will takemore than a century, per-haps several — but thatonce the decompositionstarts, it will be impossibleto stop.

“Even if it’s 5 or 10 percent of today’s emissions,it’s exceptionally worry-ing, and 30 per cent ishumongous,” said Josep G.Canadell, a scientist inAustralia who runs a glob-al programme to monitorgreenhouse gases. “It willbe a chronic source ofemissions that will lasthundreds of years.”

A troubling trend hasemerged recently:Wildfires are increasingacross much of the north,and early research sug-gests that extensive burn-ing could lead to a morerapid thaw of permafrost.

RISE AND FALL OF PERMAFROST

Standing on a bluff theother day, overlooking animmense river valley, A.David McGuire, a scientistfrom the University of

Alaska, Fairbanks,sketched out two millionyears of the region’s histo-ry. It was the peculiar geol-ogy of western NorthAmerica and easternSiberia, he said, thatcaused so much plantdebris to get locked in anice box there. These areaswere not covered in glaci-ers during the last ice age,but the climate was frigid,with powerful winds. Thewinds and rivers carriedimmense volumes of siltand dust that settled in thelowlands of Alaska andSiberia.

A thin layer of this soilthawed on top during thesummers and grassesgrew, capturing carbondioxide. In the bitter win-ters, grass roots, leavesand even animal partsfroze before they coulddecompose. Layer afterlayer of permafrost builtup. At the peak of the iceage, 20,000 years ago, thefrozen ground was moreextensive than today,stretching deep into partsof the lower 48 states thatwere not covered by icesheets. Climate-changecontrarians like to point tothat history, contendingthat any melting of per-mafrost and ice sheetstoday is simply the tail endof the ice age.

Citing permafrost tem-peratures for northernAlaska — which, thoughrising rapidly, remain wellbelow freezing — anOrganization called theCenter for the Study of

Carbon Dioxide and GlobalChange claimed that per-mafrost is in “no more dan-ger of being wiped out anytime soon than it was inthe days of our great-grandparents.”

But mainstream scien-tists, while hoping thebreakdown of permafrostwill indeed be slow, rejectthat argument. They saythe climate was reasonablystable for the past 10,000years or so, during theperiod when human civili-sation arose. Now, as peo-ple burn immense amountsof carbon in the form of fos-sil fuels, the planet’s tem-perature is rising, and theArctic is warming twice asfast. That, scientists say,puts the remaining per-mafrost deposits at risk.

For several decades,researchers have beenmonitoring permafrosttemperatures in hundredsof boreholes across thenorth. The temperatureshave occasionallydecreased in some regionsfor periods as long as adecade, but the overalltrend has been a relentlessrise, with temperaturesnow increasing fastest inthe most northerly areas.

Thawing has been mostnotable at the southernmargins. Across hugeareas, including much ofcentral Alaska, permafrostis hovering just below thefreezing point, and isexpected to start thawingin earnest as soon as the2020s.

In northern Alaska andnorthern Siberia, wherepermafrost is at least 12degrees Fahrenheit belowfreezing, experts say itshould take longer. “Evenin a greenhouse-warmedworld, it will still get coldand dark in the Arctic inthe winter,” said MarkSerreze, director of thesnow and ice data center inBoulder.

Scientists need betterinventories of the ancientcarbon. The best estimateso far was published in2009 by a Canadian scien-tist, Charles Tarnocai, and

some colleagues. They cal-culated that there wasabout 1.7 trillion tons ofcarbon in soils of thenorthern regions, about 88per cent of it locked in per-mafrost. That is about twoand a half times theamount of carbon in theatmosphere. PhilippeCiais, a leading French sci-entist, wrote at the timethat he was “stunned” bythe estimate, a largeupward revision from pre-vious calculations. “If, in awarmer world, bacteriadecompose organic soilmatter faster, releasingcarbon dioxide,” Dr Ciaiswrote, “this will set up apositive feedback loop,speeding up global warm-ing.”

PLUMES OF METHANEKatey Walter Anthony hadbeen told to hunt formethane, and she could notfind it. As a youngresearcher at theUniversity of Alaska,Fairbanks, she wanted tofigure out how much ofthat gas was escaping fromlakes in areas of per-mafrost thaw. She wasdoing field work in Siberiain 2000, scattering bubbletraps around various lakesin the summer, but she gotalmost nothing.

Then, that October, thelakes froze over. Plumes ofmethane that had beenhard to spot on a choppylake surface in summersuddenly became more vis-ible. “I went out on the ice,this black ice, and it lookedlike the starry night sky,”Dr Walter Anthony said.“You could see these bub-ble clusters everywhere. Irealised — ‘aha!’ — this iswhere all the methane is.”

When organic materialcomes out of the deepfreeze, it is consumed bybacteria. If the material iswell-aerated, bacteria thatbreathe oxygen will per-form the breakdown, andthe carbon will enter theair as carbon dioxide, theprimary greenhouse gas.But in areas where oxygenis limited, like the bottomof a lake or wetland, agroup of bacteria calledmethanogens will breakdown the organic material,and the carbon will emergeas methane.

Scientists are worriedabout both gases. Theybelieve that most of thecarbon will emerge as car-bon dioxide, with only afew percent of it being con-verted to methane.

By arrangement with the New York Times

! Expertsworry that ifthe permafr-ost thaws inthe NorthernHemisphere,huge amoun-ts of carbonwill be relea-sed into theair, greatly in-tensifying gl-obal warming

As permafrost thaws,scientists study risks

BBack before comput-ers moved into ourexam rooms, I tend-

ed paper growth charts rit-ually at every checkup.Pink for girls, blue forboys. Age on the X-axis,weight on the Y-axis. Ipaid particular attentionto the charts of infants,plotting weight and length

and head circumferencewith my pen month bymonth to show parentshow their babies weregrowing, to reassure themwhen they worried thatthere wasn’t enoughbreast milk or becausetheir babies were spittingup a little.

It’s a primal impulse toworry about an infant’sgrowth. But experts onchild nutrition, mostlyenlisted nowadays in thebattle against childhoodobesity, point out thatsome of our standardinfant feeding practicesand attitudes may needrevising, including someof those encouraged bypediatricians like me. Mygrandmother’s attitude —stuff food into the baby, beproud of a “good eater” —may not make sense in anenvironment of abundantfood and rising obesity.

But it gets medically con-troversial, and emotional-ly sticky, when doctorsstart talking about obesityin babies. Is there an epi-demic of infant obesity?Are fat babies at greaterrisk of turning into fatchildren at higher risk formedical consequenceslater on in life? And what

can doctors advise parentsabout feeding a baby —which ought, after all, tobe one of the basic joys ofparenthood?

The answers to thosequestions aren’t alwaysclear. Scientists do knowthat the number of obesechildren has been on theincrease. But not the pro-portion of those under age2 whose weight-for-lengthcurve is at the 95th per-centile or above — thathas held pretty steadysince 1999.

Perhaps more important,no one wants to see babieson diets, no one wants tosee hungry babies notgiven food. Dr Elsie M.Taveras, a paediatricianon the faculty at HarvardMedical School and a lead-ing expert on obesity riskfactors in children, saysthat the evidence indicates

that when parents tooseverely restrict a child’sfood intake, that child is athigher risk for obesity.

“When we are overlycontrolling, either overlyrestrictive or we overlypressure a child to eat,that doesn’t allow thechild to respond to theirown hunger and satiety,”she said.

Satiety cues (spitting outthe bottle or the breast,turning the head away,closing the mouth) are thesignals that infants sendwhen they’ve had enoughto eat. One promising lineof research involves help-ing parents recognizebabies’ hunger signals(rooting, putting a hand tothe mouth, sucking mouthmovements) and whenthey’re saying that they’vehad enough.

Decades ago, “we reallywere more worried, andneeded to be more wor-ried, about failure tothrive,” said Leann L.Birch, director of theCentre for ChildhoodObesity Research at PennState. “Overfeeding seemsto be more dangerousthese days.”

By arrangement with the New York Times

Joy of feeding, withoutall the parental angst

focusJustin Gillis

meanwhilePerri Klass

In an Alaskan lake, bubbles of methane, a potent greenhouse gas, collect beneath the ice. — NYT

If humanity begangetting its ownemissions undercontrol soon, thegreenhouse gasesemerging frompermafrost couldbe kept to a muchlower level

50 YEARS AGO IN

! While thenumber ofobese babiesis not on therise, some ofour standardinfant feed-ing practicesand attitudesmay needrevising

TThe tsunami-destroyednuclear reactors atFukushima, Japan

have reached a “cold shut-down”. This means the tem-perature in each of thethree vessels is now wellbelow a 100 degrees. Fromhere on, the operators havemore control and safety canbe easily maintained.Despite the cold shutdownannouncement, recircula-tion of water will continueto cool the reactor core;environmental concernshave been raised regardingminor leakages of this nowradioactive water.Eventually, the fuel, cool-ing water, debris etc will bemoved to another locationwhere it can decay over theyears without causingmore harm. The area willthen be decontaminated byremoving the topsoil layerbefore the residents canmove in. The entire processwill take years, if notdecades.

FAILED MARS-MOON PROBETO FALL BACK TO EARTH

The Russian Phobos-Gruntprobe was designed to trav-el to the larger of the twoMartian moons, Phobos,collect a soil sample andbring it to earth. It took offearly November this year,only to fall back twomonths later. Roscosmos,the Russian space agency

announced last week thatafter losing contact withthe 13.2 tonne probe, it willstart crash landing nextmonth; and most of it willdisintegrate on its waydown including the 11 kg oftoxic fuel that is expected toburn 60 miles above thesurface. Two hundred kg ofrandom scrap from theprobe might survive the re-entry, crashing into anunknown location any-where on earth — the exactcoordinates can be calcu-lates only 2-3 days beforethe descend. What was to bechina’s first Mars satellite,Yinghuo-1, that piggy-backed on the probe, willalso descend into its doomwith the stranded probe.

COCAINE IN THE AIRA group of Italian scientistscollected air from differentsites and tested it for illicitdrugs and the usual air pol-

lutants. They found thatthe airborne concentrationof cocaine was linked to thenumber of drug seizuresmy the police in the area.This might form the basisof detecting comparabledrug use prevalence incities or communities.

LOVEJOY SURVIVES SUN’S WRATH

A seemingly suicidal cometsurvived a close encounterwith our star. Comet love-joy, named after the ama-teur observer who identi-fied it only a few weeks ago,was expected to bedestroyed by the sun’s heat-ed outer atmosphere wheretemperature go up to 6000degrees and its powerfulmagnetic field. Lovejoy didnot pass the sun unscathed,only 10 per cent of it sur-vived the encounter and ithas lost its tail.

Symbolic coolingof Fukushima

diaryAashima Dogra