Scientific American 60 Second Science.docx

Scientific American 60 Second Science.docx

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ScientificAmerican60SecondScience

December1,2008

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Aseaslugcancarryonphotosynthesisformonthsatatimebyeatingalgaeandsavingthetinyorganellesthatthesingle-celledorganismusestoconvertsunlighttoenergy.CynthiaGraberreports

Itmaylooklikejustanotheranimal.Butonekindoflowlyseaslugactuallyhasthesolarpowerabilitiesofaplant.Bizarrebuttrue,theseaslugcarriesoutphotosynthesis.ThisfindingwaspublishedintheProceedingsoftheNationalAcademyofSciences.

Usually,plantsperformphotosynthesisbywayoftinyorganellescalledplastids.Plastidsconvertsunlight,waterandcarbondioxideintousablenutrients.Thenanimalseattheplants.Buttheseasluggoesaboutitslightlydifferently.

Ithasatleastonegenenecessaryforphotosynthesis—sofarit’stheonlyanimalknownwiththisability.Butitneedssomehelp,thegeneitselfisn’tenough.Soseaslugseatalgae.Theyslitopentheorganismsandsuckoutthecytoplasm.Theslugsdigestmostofthealgae,butthoseplastidsremainwholeandundigested.Andthentheplastidskeepondoingwhattheydo,whichisconvertsunlighttousableenergy.Oncetheseaslughaseatenenoughalgae,andgainedenoughplastids,itcanliveoffjustsunlightforuptoninemonths.Whenitcomestoenergy,thisslugneedsnoplug.

—CynthiaGraber

December2,2008

RobotClamAchievesFeatwithFoot

M.I.T.researchershaveinventedaroboticclam--whichmeansthey'vereallydevelopedasmartanchorforsmallvessels.CynthiaGraberreports

M.I.T.scientistshavedesignedanewrobot.You’llprobablyneverseeitthough—it’smeanttobehidden.Becauseit’sarobotclam.Engineerswantedtodesignalightweightanchorthatcouldbeeasilysetandthenpickedup.That’snotpossiblewithconventionalanchors.Amoretalentedanchorwouldbegreatfor,say,smallsubmarinesthatmovearoundconstantlytotestoceantemperaturesandcurrents.

Razorclamspresentedtheidealbiologicalmodel.Theycanburrowacentimeterpersecondmorethantwofeetdownintothesoil,wheretheycananchorthemselvestightlytotheoceanfloor.Scientistssetupaglassboxwithwaterandbeadsandstuckalivingrazorclaminside.Theyfilmedwhathappenednext.Theanimal’sfootwiggledintothebeads.Therestoftheclamfollowedbymovingquicklyupanddownandrapidlyopeningandclosingitsshell.Bycarefullyanalyzingthefilm,thescientistsdiscoveredsomethingsurprising.Theclam’smovementsturnthesandaroundthecreatureintomoreofafluid—basicallyquicksand.Bycopyingthissystem,M.I.T.researcherscreatedatinyRoboClam.It’sthesizeofacigarettelighter.Iftheyaddartificialintelligence,wecanfindoutifthedeviceishappyasaclam.

—CynthiaGraber

December3,2008

UsingRadartoMonitorBabyBreathing

UniversityofFloridaengineershavecreatedaprototypebabymonitorthatusesDopplerradartotrackthemovementsofababy'schest,indicatingbreathingstatus.SteveMirskyreports

[Radiosound:

]“Northeast480youareclearedforlanding,Northeast480youareclearedforlanding.”

Thatsameradartechnologythatguidesaircraftandtrackshurricanescouldinthefuturekeeptrackofababy’sbreathing.EngineersfromtheUniversityofFloridahavebuiltaprototyperadarbabymonitor.Thecrib-mountedmonitordetectsmovementoftheinfant’schestusingDopplerradar.Ifbreathingstops,movementstopsandthemonitorsoundsanalarm.Suchasystemshouldbesuperiortothosethatjustsendsoundorvideototheparents.TheresearchwillappearintheFebruaryissueofIEEEMicrowaveMagazine.IEEEistheInstituteofElectricalandElectronicsEngineers.

Theradarmonitorthattheresearcherscreatedisaboutthesizeofsmallbook.Thereceiverindicatesthebaby’sbreathing,aswellasthestateofthewirelessconnectionwiththemonitorandthebatterystatus.Futureversionscouldalsodetectheartbeatthroughahigherfrequencysignal.

[Radiosound:

]“Mrs.WatsononMapleDrive,yourbabyisbreathingnormally,thebabyisbreathingnormally.”

—SteveMirsky

December4,2008

BraheBurstBroughttoLight

Astronomershavecollectedlightbouncingaroundsincea1572supernova,witnessedbyTychoBrahehimself,tofigureoutexactlywhatkindofexplosionitwas.CynthiaGraberreports

It’snoteverydaywegetachancetotimetravel.Otherthanintothefutureattherateofonesecondpersecond.Butastronomerssaythey’vedonealittletravelingintothepast.InNovemberof1572,legendaryastronomerTychoBrahepeeredupatthenightsky.HesawwhatlookedlikeastrangelybrightstarintheconstellationCassiopeia.ItwasbrightereventhanthenearbyplanetVenus.Hestudiedthatbrightnewstarforfivemonths,untilitfadedaway.ButwhatBrahesawwasn’tanewstar.Itwasactuallyanoldstarundergoingthebrilliantlybrightdeathofasupernova.

ScientistsattheSubaruTelescopeinJapanrecentlyanalyzedwhatcouldbecalledechoesofthismorethan400-year-oldevent.TheypublishedtheirresearchintheDecember4thissueofthejournalNature.Lightfromtheoriginalsupernovabouncedoffdustparticlesintheinterstellarcloudsandeventuallyreachedushereonearthmorethanfourcenturieslater.ScientistsusedtheseechoestodeterminethatBrahewitnessedatypeIasupernova.

—CynthiaGraber

December5,2008

HappinessIsContagious

Ahappypersonwithinasocialcirclequicklyinfluencesthosearoundhimorhertobehappy,extendingtothreedegreesofseparation.AdamHinterthuerreports

Wanttoliveahappierlife?

Trysurroundingyourselfwithhappyfriendsoratleastfindfriendswithhappyfriends.AstudypublishedonlineDecember4thintheBritishMedicalJournalsayshappinesscanquicklygoviralwithinyoursocialnetwork.

Researcherslookedattwentyyears'worthofdataonmorethan5,000individualsandfoundthatwhenanyonepersonwashappy,theirfriendsbecamemorelikelytosharethatjoy.Benefitsspreadouttothreedegreesofseparation,meaningabetterchanceathappinessfornotonlytheirfriends'friends,butalsotheirfriends'friends'friends.

Butdon'tgothinkingyourtenthousandbuddiesonFacebookwillbringyouhappiness.Theresearchersfoundthatthestrengthoftheeffectdissipatesoverphysicaldistance,withnext-doorneighborsandfriendslivingnearbygettingthebiggestboost.Surprisingly,sadnessmadeverylittleheadwaywithinsocialnetworks,palingincomparisontothecommunaleffectsofhappiness.Justintimefortheholidayseason,scientificproofthatit'snotthegiftthatcounts—it’sthesmileonthefaceofthefriendgivingit.

—AdamHinterthuer

December8,2008

WarmClimatesSupportLongerLimbs

Astudywithmicefindsthatthosekeptinwarmerenvironmentsdeveloplongerlimbsthantheirchilliercousins,thankstoenhancedcartilagegrowth.KarenHopkinreports

Animalsthatliveincoldclimatestendtohavestubbylimbs—shorterarmsandlegs—evensmallerearsandtails.Pictureapenguinandyou’llseewhatImean.Biologistshavelongassumedthatthesestumpyappendagesareanevolutionaryadaptation.Shorterextremitiesminimizeheatloss,soanimalsthataremorecompactarebettersuitedtothecold.

ButscientistsfromOhiosaythattemperaturemayhaveamoredirecteffectonthelengthofananimal’slimbs.Becausetheyfindthatturninguptheheathelpscartilagegrow—resultsthatwerepublishedintheProceedingsoftheNationalAcademyofSciences.

Theresearchersraisedmiceatseveraldifferenttemperatures,andtheyconfirmedthatthosekeptatabalmy80degreeswerelongerlimbedthanthosewholivedatamorechill45.Buthowdoesalittleheatmakemicemoreleggy?

Theanswer,theyfind,liesinthecartilage.Longbonesgrowfromthecartilagefoundateitherend.Andthewarmeritis,themorethatcartilagegrows,evenwhenit’sjustsittinginatesttube.WhichIguessmeansit’spossiblethatthedogdaysofsummerleadtolonger-leggeddogs.

—KarenHopkin

December9,2008

TraditionalTreatmentsShowPromiseforHIV,Psoriasis

TraditionalChinesemedicine'sastragalusrootshowspromiseinHIVtreatment,andtheplantextract,indigonaturalis,mayhelpcalmtheskinconditionpsoriasis.CynthiaGraberreports

Chinesemedicinehasbeengettingsomepropslately.Acoupleofrecentstudieshavedemonstratedthemedicalpotentialoftraditionaltreatments.

PartofthechallengeofAIDSisthatimmunecellslosetheirabilitytodivideandthustheirdiseasefightingpower.Partlybecausethetelomeres—asortofprotectivecapontheendsofchromosomes—becomeprogressivelyshorter.Entertherootastragalus.It’susedfrequentlyinChineseherbalremedies.ResearchersfocusedonachemicalcalledTAT2,whichwasidentifiedinastragalus.TheytesteditoncellsandbloodfromHIVinfectedindividuals.ThecompoundslowedtheshorteningoftelomeresandgenerallyimprovedtheabilityofcellstofightHIV.（TheJournalofImmunology）

Anotherstudyfocusedonpsoriasis.There’snocureforthatchronicskindisease.ButinChinaandTaiwan,peoplewithpsoriasisfrequentlyapplyadarkblueplant-basedpowdercalledindigonaturalis.Inarandomizedstudy[intheArchivesofDermatology],indigopowdersignificantlyreducedskinscaling,rednessandhardness.TheTaiwanesescientistssaythenextstepistodetermineindigo’spharmacologyandperhapsextractthespecificchemicalcompoundsthatcouldbringpsoriasissuffererssomerelief.

—CynthiaGraber

December10,2008

ImmigrantElephantsStickTogether

Whenelephantsaretransportedtonewhabitats,theimmigrantstendtosticktogether,onlyslowlyassimilatingintotheexisting