THISWEEKcould bedetected in the implanttrapenoughcellstoworkas anCatch cancer asitwhileitwasstillinplace,viaa newanticancertherapy,saysShea,butscanning system called opticalthe implant could boost people'scoherence tomography (OCT)chances of survival by identifyingspreads with a trapThis technique, which canearlyon that cancer cells are onpenetrate livingtissuebyafewthemove-allowingthepatienttomillimetres,involvesmeasuringbegin chemotherapyrightaway.CCL22.This attracts certainthe way light is scatteredofflargeThemain challenge, says Shea,Clare Wilsonimmunecells,whichencouragesmoleculesandstructuresinsidewillbegettingtheOCTscannertoTHEtroublewithcanceris itcancercellstofollow suit.cells.Cancer cells can be detectedpenetrate human skin, whichisspreads-sometimesevenbeforethickerthan rodent skin.Theyimplantedthedevicebecause theyaredensersomeoneknowstheyare ill.underthe skinofmicewithainternally.VariousfirmsareOthergroups areinvestigatingAsmall implantthattraps cancerdeveloping devices that would lettumourtrapsthat attractcertainversionofbreastcancer,andcells as they migrate through thefoundtumourcells in itafter twoOCT bedone with a smartphone.types of cancer cells via different,bloodcould makea lifesavingweeks (NatureCommunications,In mice,the implants cutthemore specific, chemical signals.early-detection system.doi.org/7js).numberoftumourcellsthatThenewimplantshouldintheory"This could be thecanary intheInexperimentsonothermice,migrated to secondary sites likeattracta widerangeofcancercoal mine,"says Lonnie Shea oftheteamshowedthatcancercellsthe lungs. They probably wouldn'tcells-althoughsofartheteamthe University of Michigan at Annhaveonly shownitworksforoneArbor,oneofthedevelopers.tumourtypeotherthanbreastSofartheidea has beentestedcancer,in unpublished workinmice.if ittranslatestopeople,Theyenvisagefirst using thethen the implantcouldbetrapin womenatahigh risk ofscanned for cancer cells while stillbreastcancer,suchasthosewhoinside the body-either by doctors,have already had surgery toorone dayperhaps just witharemoveatumourandmightsmartphone."That'sthefantasy."experiencearecurrence.Ifasays Shea.scanrevealsthatcancercellsareShea devisedtheapproachpresent,theimplantcouldevenalong with Jacqueline Jeruss,aberemoved andthe cells analysedbreast cancer surgeon. Jeruss hadto see which drugs they are mostnoticedhowcommonitwasforsusceptible to.Gerhardt Attard of the Instituteherpatientsfirstsymptomtobebreathlessness-as the cancerofCancerResearchin Londonhad already spread to their lungs.says there is growing interest inThey and their colleaguespersonalisingtreatmentsbydevisedanimplantmadefromantesting cancercells in theblood.inert porous materialalreadyused"Thiscouldbea verypowerfulin medical devices,andloaded itway ofrisk stratifyingpatients forwitha signallingmolecule calledFind wandering cells earlier treatment,"he says.Buttheprocesshasbeenhardtosmoking gun as've seen so far," saysoxygen as elsewhere in theseSpidergalaxiesobserve in practice. Most galaxiesastronomer Chris Churchill of Newgalaxies. This was a sign of newlyguzzle gas fromnear us, and our own Milky way,Mexico State University in Las Cruces.arrived gas powering star formation,are flled with hot gas that warmsTo find the fresh gas, Almeida'sthey concluded:it had to be recentlythe cosmic webapproaching material,preventinggroup lookedata setofsmall,faintadded because any old gas would loseitfromcollapsingintostars.AndgalaxieswithalowproportionofitsdistinctivechemicalsignatureLIKE cosmic spiders,dwarf galaxiesbecause clumps of cold gas inwithina few hundred million yearselementsthatareheavierthanhavebeencaughtfeasting onblobsofintergalacticspacedonotemithydrogenand helium.Theywereasitmingledwithothergases.gas spread across a hidden web.Blobs of gasmoving along themuch light,theyarehard to spot.abletoinferhowoxygenlevelsTheideathatgalaxiesgrewfatbyTheclincherwouldbetowatchavariedacrossthesegalaxies'discs.cosmic web could explain theveryblob of freshgastriggering aburstofThey found that the star-formingeatingfromthecosmicweb-agiantexistence of these galaxies,saysmeshofdark matterbeadedwithstarformation in asmall galaxythat isregions had about one-tenthas muchAlmeida. They might be normal dwarfclouds of cold gas - has been aroundgalaxies that have been spurred tonot building many stars on its own."The ideathatgalaxiesfor a while. Simulations suggestNow a team led by Jorge Sanchezmakenewstarsbyfreshgas,thegrewfatbyeatingfromthethat as the gas clouds fallinto theAlmeida of the Astrophysics Instituterecent arrivalof which diluted theircosmicwebhasbeenhardgravitational clutches of a galaxy.of the Canary Islands in Spain hasheavy elementcontent(Astrophysicalto observein practice"they spark bursts of star formation.donejustthat."it's as close toaJournal,doi.org/7hp).Joshua Sokol14|NewScientist/12September 2015
14 | NewScientist | 12 September 2015 THIS WEEK Clare Wilson THE trouble with cancer is it spreads – sometimes even before someone knows they are ill. A small implant that traps cancer cells as they migrate through the blood could make a lifesaving early-detection system. “This could be the canary in the coal mine,” says Lonnie Shea of the University of Michigan at Ann Arbor, one of the developers. So far the idea has been tested in mice. If it translates to people, then the implant could be scanned for cancer cells while still inside the body – either by doctors, or one day perhaps just with a smartphone. “That’s the fantasy,” says Shea. Shea devised the approach along with Jacqueline Jeruss, a breast cancer surgeon. Jeruss had noticed how common it was for her patients’ first symptom to be breathlessness – as the cancer had already spread to their lungs. They and their colleagues devised an implant made from an inert porous material already used in medical devices, and loaded it with a signalling molecule called CCL22. This attracts certain immune cells, which encourages cancer cells to follow suit. They implanted the device under the skin of mice with a version of breast cancer, and found tumour cells in it after two weeks (Nature Communications, doi.org/7js). In experiments on other mice, the team showed that cancer cells could be detected in the implant while it was still in place, via a new scanning system called optical coherence tomography (OCT). This technique, which can penetrate living tissue by a few millimetres, involves measuring the way light is scattered off large molecules and structures inside cells. Cancer cells can be detected because they are denser internally. Various firms are developing devices that would let OCT be done with a smartphone. In mice, the implants cut the number of tumour cells that migrated to secondary sites like the lungs. They probably wouldn’t trap enough cells to work as an anticancer therapy, says Shea, but the implant could boost people’s chances of survival by identifying early on that cancer cells are on the move – allowing the patient to begin chemotherapy right away. The main challenge, says Shea, will be getting the OCT scanner to penetrate human skin, which is thicker than rodent skin. Other groups are investigating tumour traps that attract certain types of cancer cells via different, more specific, chemical signals. The new implant should in theory attract a wide range of cancer cells – although so far the team have only shown it works for one tumour type other than breast cancer, in unpublished work. They envisage first using the trap in women at a high risk of breast cancer, such as those who have already had surgery to remove a tumour and might experience a recurrence. If a scan reveals that cancer cells are present, the implant could even be removed and the cells analysed to see which drugs they are most susceptible to. Gerhardt Attard of the Institute of Cancer Research in London says there is growing interest in personalising treatments by testing cancer cells in the blood. “This could be a very powerful way of risk stratifying patients for treatment,” he says. ■ Catch cancer as it spreads with a trap STEVE GSCHMEISSNER/SCIENCE PHOTO LIBRARY “The idea that galaxies grew fat by eating from the cosmic web has been hard to observe in practice” –Find wandering cells earlier– LIKE cosmic spiders, dwarf galaxies have been caught feasting on blobs of gas spread across a hidden web. The idea that galaxies grew fat by eating from the cosmic web – a giant mesh of dark matter beaded with clouds of cold gas – has been around for a while. Simulations suggest that as the gas clouds fall into the gravitational clutches of a galaxy, they spark bursts of star formation. Spider galaxies guzzle gas from the cosmic web But the process has been hard to observe in practice. Most galaxies near us, and our own Milky Way, are filled with hot gas that warms approaching material, preventing it from collapsing into stars. And because clumps of cold gas in intergalactic space do not emit much light, they are hard to spot. The clincher would be to watch a blob of fresh gas triggering a burst of star formation in a small galaxy that is not building many stars on its own. Now a team led by Jorge Sánchez Almeida of the Astrophysics Institute of the Canary Islands in Spain has done just that. “It’s as close to a smoking gun as I’ve seen so far,” says astronomer Chris Churchill of New Mexico State University in Las Cruces. To find the fresh gas, Almeida’s group looked at a set of small, faint galaxies with a low proportion of elements that are heavier than hydrogen and helium. They were able to infer how oxygen levels varied across these galaxies’ discs. They found that the star-forming regions had about one-tenth as much oxygen as elsewhere in these galaxies. This was a sign of newly arrived gas powering star formation, they concluded: it had to be recently added because any old gas would lose its distinctive chemical signature within a few hundred million years as it mingled with other gases. Blobs of gas moving along the cosmic web could explain the very existence of these galaxies, says Almeida. They might be normal dwarf galaxies that have been spurred to make new stars by fresh gas, the recent arrival of which diluted their heavy element content (Astrophysical Journal, doi.org/7hp). Joshua Sokol ■
AA career in science,it's not alwayswhat you thinkFrommovieadvisortosciencefestivaldirector,wherewillyoursciencecareertakeyou?DRADC=20xl=(6.09 NewScientist Jobsnewscientist.com/jobs
A career in science, it’s not always what you think From movie advisor to science festival director, where will your science career take you? newscientist.com/jobs
INBRIEFHIV'pump'killswithruthlessefficiencyAFTER all these years, HIV can stilltake usby surpriseUntil recently,we thought HIVlargely spread through the bodyasfree-floating particles.Nowweknowthat thevirus can infectimmunecellsbybeingpumpeddirectlyfromonecellintoanother,during briefconnectionsbetween thetwo.Research using newer tissueculture methods suggest thatcrucial whitecells called CD4T-cells are killed by this cell-to-celltransmissionupto95percentofthetime (Cell Reports, doi.org/7fw).Thismodeofinfectioncouldbethousandsoftimesmoreefficient than single virusesinfecting cells from theblood.This may help explain whyefforts to develop HIV vaccineshave sofarprovedfruitlessWhen viruses are inside cells,conical zonefanningoutfromthe12hawk nests ontheymaybe more likelyto escapeHawk'sinvisibleforcefieldtreetops they observed. This, they say, is because of thedestructionbyantibodies,andtoprotectshummingbirdnestsevolveresistancetothem.wayhawkshunt,swoopingonpreyincludingjaysfromhigherup.ThiseffectivelyenvelopsthehummingbirdWHEN you'retiny,it's good tohavebigfriendsinnestsinacone-shapedforcefieldavoidedbythejays.high places.Living in theshadow of hawksmeansHowever,when hawks abandonedtheir nestsSupernovaforgehummingbirds can protect their eggs and chicksfollowing raids by coatis,tree-climbing raccoon-liketestedinthelabfrombeingeaten by voraciousjays.mammals,thejays became much bolder.They visited"Thejaysarefoodforthehawks,andthehummingbirdwhathadbeenno-flyzonesandtookmorehummingbirdDON'Ttrythis at home.Fortheeggsarejusttoo small andtaketoo longforapredatoreggs andchicksthan whenthe hawkswere aroundfirsttime,alabexperimenthaslikeahawktofind,"saysHarold GreeneyattheYanayacu(ScienceAdvances,doi.orq/7hn)BiologicalStation inCosanga,Ecuador.Greeneydoesn'tthinkthehummingbirds consciouslyprobed the nuclear physics insideGreeney'steamstudiedthebirds intheChiricahuaseekouttheprotection."Theysimplyreturntositesadying star.mountainsof Arizona over three years and found thatWhenastarexplodes,trillionswherethey'vepreviouslyhadgoodbreedingsuccess,of tonnes of gas collapse inwardsjaysavoidedraidinghummingbirdnestsfoundineachandthishappenstobeunderthehawk nests,hesays.before bursting into a supernova.Asthis happens,elementsfusetoSuccessforoff-the-shelfstemcellsoff-the-shelf-the stem cellsfromformheavierelements-buttheasinglepersoncouldbeusedtodetailsoftheprocessareunclear.IT'S a quiet revolution.Simplechances of healingsuch woundstreat 2500people.AteambasedatGoethestemcell therapies arefinallyby5opercent-andapparentlyBy contrast, the only stem-cell-University in Frankfurt,Germany,making their waytowards thewith noadverse sideeffects.based medicinal productthat issimulated theeventbyconfiningclinic,andatreatmentforwoundsThe therapy uses stem cellscurrently approvedfor use in the100,000rutheniumionsinacausedbyCrohn'sdiseasecouldderivedfromdonatedliposuctionEU-acorneatreatment-involvesdevice calleda particlestoragebethefirstoff-the-shelftherapytissue,whichhaveextremelylowring,where the ions interactedremoving cells fromeachlevels ofthe proteins thattriggerwith hydrogen. Sometimes theytogetEuropeanUnionapproval.individual'seyeand growingHard-to-treat wounds neartheimmune reactions, says TiGenixthem outside the bodyfor weeks.picked upa protonto becomethehead Eduardo Bravo.This meansheavierrhodium (Physical Reviewanusafflictaround5o,ooopeopleAndbone-marrowtransplants,in Europeeveryyear.In aphase IIIthatthetreatment,shoulditbewhich also involve stem cells andC,doi.org/7f8).Theexperimenttrial,atreatmentdevelopedbyapprovedafterthefullresults arehavebeenperformedfordecadescanhelptoupdatemodelsofhowTiGenix in Belgium improvedthepublished next year,can be givenrequirea matched donor.heavyelements areforged.16/NewScientist/12September2015
16 | NewScientist | 12 September 2015 IT’S a quiet revolution. Simple stem cell therapies are finally making their way towards the clinic, and a treatment for wounds caused by Crohn’s disease could be the first off-the-shelf therapy to get European Union approval. Hard-to-treat wounds near the anus afflict around 50,000 people in Europe every year. In a phase III trial, a treatment developed by TiGenix in Belgium improved the chances of healing such wounds by 50 per cent – and apparently with no adverse side effects. The therapy uses stem cells derived from donated liposuction tissue, which have extremely low levels of the proteins that trigger immune reactions, says TiGenix head Eduardo Bravo. This means that the treatment, should it be approved after the full results are published next year, can be given off-the-shelf – the stem cells from a single person could be used to treat 2500 people. By contrast, the only stem-cellbased medicinal product that is currently approved for use in the EU – a cornea treatment – involves removing cells from each individual’s eye and growing them outside the body for weeks. And bone-marrow transplants, which also involve stem cells and have been performed for decades, require a matched donor. HAROLD F. GREENEY, YANAYACU BIOLOGICAL STATION Hawk’s invisible force field protects hummingbird nests WHEN you’re tiny, it’s good to have big friends in high places. Living in the shadow of hawks means hummingbirds can protect their eggs and chicks from being eaten by voracious jays. “The jays are food for the hawks, and the hummingbird eggs are just too small and take too long for a predator like a hawk to find,” says Harold Greeney at the Yanayacu Biological Station in Cosanga, Ecuador. Greeney’s team studied the birds in the Chiricahua mountains of Arizona over three years and found that jays avoided raiding hummingbird nests found in each conical zone fanning out from the 12 hawk nests on treetops they observed. This, they say, is because of the way hawks hunt, swooping on prey including jays from higher up. This effectively envelops the hummingbird nests in a cone-shaped force field avoided by the jays. However, when hawks abandoned their nests following raids by coatis, tree-climbing raccoon-like mammals, the jays became much bolder. They visited what had been no-fly zones and took more hummingbird eggs and chicks than when the hawks were around (Science Advances, doi.org/7hn). Greeney doesn’t think the hummingbirds consciously seek out the protection. “They simply return to sites where they’ve previously had good breeding success, and this happens to be under the hawk nests,” he says. Success for off-the-shelf stem cells HIV ‘pump’ kills with ruthless efficiency AFTER all these years, HIV can still take us by surprise. Until recently, we thought HIV largely spread through the body as free-floating particles. Now we know that the virus can infect immune cells by being pumped directly from one cell into another, during brief connections between the two. Research using newer tissue culture methods suggest that crucial white cells called CD4 T-cells are killed by this cell-to-cell transmission up to 95 per cent of the time (Cell Reports, doi. org/7fw). This mode of infection could be thousands of times more efficient than single viruses infecting cells from the blood. This may help explain why efforts to develop HIV vaccines have so far proved fruitless. When viruses are inside cells, they may be more likely to escape destruction by antibodies, and to evolve resistance to them. Supernova forge tested in the lab DON’T try this at home. For the first time, a lab experiment has probed the nuclear physics inside a dying star. When a star explodes, trillions of tonnes of gas collapse inwards before bursting into a supernova. As this happens, elements fuse to form heavier elements – but the details of the process are unclear. A team based at Goethe University in Frankfurt, Germany, simulated the event by confining 100,000 ruthenium ions in a device called a particle storage ring, where the ions interacted with hydrogen. Sometimes they picked up a proton to become the heavier rhodium (Physical Review C, doi.org/7f8). The experiment can help to update models of how heavy elements are forged. IN BRIEF
Fornewstories everyday,visitnewscientist.com/newsCrappyfashionKeyenzymemakesfarmkidshealthierkeepsspideraliveDIRTis good for you. Kids onimportantfordampingdownexperiment was repeated withfarms areless likelytodevelopoveractiveimmunesystems.mice that had been geneticallyTHIS spider has gonetotown inallergiesandasthmathan urbanChildren withgenemutationsengineeredtolackAzo (Science)making itselflook likecrap-literally.children.Butthe protectivethatdisruptthefunctioningofandoi.org/7hf).Lambrecht andhiseffectsoffriendlymicrobesalsoenzymecalled A2o aremore likelyteamthenturnedtohuman lungBird-dungcrabspidersspendalotof timesittingmotionlessonseemtodependonaperson'sto haveasthma and allergies,socells andfound thatA20was lessleaves,usingtheirgrosslookstogeneticmake-up.BartLambrechtofGhentactiveinadultswhohadasthmaattract fliesfordinner.Their trickThehygiene hypothesis says"it's important because it showsUniversity in Belgium and hisistomimicbirddroppingsincolourthatalackofexposuretodirtandteamwonderedwhetherA2omaythatendotoxincan'tworkonitsmicrobes istoblameforincreasesbe involved in helpingendotoxinsshape,sizeandsmell,deceivingown,saysErikavonMutiusofthein allergies and asthma.OneLudwig Maximilian University inpredatorsandpreyalike."Birdstrainourimmunesystems.almostall withgoodeyesight,willexplanation is thatchildrentodayFirsttheyexposed micetoMunich,Germany,a proponentofnotgo forwhatappears to betheirencounterlessendotoxin,aendotoxin,and sawtheythe hygiene hypothesis.bacterial proteinfoundon thedeveloped fewerallergies whenIt is thought that about5perownturdforfood"saysosephK.HKohoftheLeeKongChianNaturalsurfaceofmany common species,laterexposedtodustmites.Butcentof peoplehaveafaultyHistoryMuseuminSingaporeincludingE.coli,thatmaybethiseffectwasn'tseenwhentheversionoftheA2oenzyme.Thespider's body has a glossysurfacethatgivesitthe"wet"lookoffreshfaeces."ThenodulesonthePalaeolithicpeoplebody and rough-edges of the legsate carbs as wellfurtherreinforcethe'shitty'look-pardon the rudeness,"Koh says.Long Yu of Hubei University inGOING on the palaeo diet? Don'tChina and histeam exposed theputdownyourporridgejustyet.Hunter-gatherers ate oats as farspidertooneof itspredators-backas32,oooyearsago-wayjumpingspiders.Theyalsoaddedhouseflies as prey.The team foundbefore farming took root.that thecamouflagehelps theseThisistheearliestknownhumanconsumptionofoats,crabspiders(Phrynarachneceylonica)repelmorejumpingsay Marta Mariotti Lippi at theUniversity of Florence in Italyspidersandattractmorefliesthanthose withoutcamouflage.Theyand her colleagues, who made thediscovery after analysing starchpresentedtheirfindingsattheBehaviour2015meeting in Cairns,grains on an ancientstonegrindingtoolfromsouthernAustralia,lastmonthItaly (PNAS, DOI:10.1073/Other spiders,such as orbweaversinthegenusCelaeniapnas.1505213112).alsolooklikebirddroppings,butthThePalaeolithicpeoplegroundSpeediertrainscanslowdownroadsupthewildoatstoformflour,foul smellmakesbird-dungcrabwhichtheymayhaveboiled orspidersunique.baked intoa simpleflatbread,READING this while stuckin traffic?morepeopleontheoutskirtswillusesays Mariotti Lippi.Fasttrainsmaybetoblame.Slowingtrains.ButthesecommutersoftenThey also seem to have heatedtheLondon Underground could cuthavetotravelbyroadtodoso,asHEthe grains before grindingthem,overall congestion in thecity.suburbanstationsarethinlyspreadperhaps to drythemout intheMarcBarthelemyoftheFrenchTheresultismorecongestionoverall,colderclimateofthetime.AtomicEnergy and AlternativeasincreasedtrafficattheoutskirtsMariottiLippinotesthatthisEnergies Commission in Gif-sur-outweighssmootherflowintheYvetteandcolleaguesmappedoutwouldalsohavemadethegraincentre(arxiv.org/abs/1508.07265)easiertogrind and longer-lasting.theroadandsubwaynetworks in"if youwantto givemoreaccessThismulti-stage processLondonandNewYorkCityandtomorepeople,thenincreasingthesimulated travelatdifferentspeeds.speedofthe subwayisnotthebestwouldhavebeen time consuming,but beneficial. The grain isTheyfoundthattheratioofthesolution,"says Barthelemy-packingnutritionally valuable,andstationsmorecloselyis oftenbetter.averageroadandrail speedscanturning it intoflour would havehaveacriticalimpactoncongestion.NewYorkCityisanexception,beenagood waytotransportit,If thesubwayspeedsupwhilehowever:congestionhereissobadwhichwasimportantforroadspeed staysfixed,forexample,that speeding up trains does help.Palaeolithic nomads, she says.12September 2015|NewScientist/17
12 September 2015 | NewScientist | 17 Crappy fashion keeps spider alive THIS spider has gone to town in making itself look like crap – literally. Bird-dung crab spiders spend a lot of time sitting motionless on leaves, using their gross looks to attract flies for dinner. Their trick is to mimic bird droppings in colour, shape, size and smell, deceiving predators and prey alike. “Birds, almost all with good eyesight, will not go for what appears to be their own turd for food,” says Joseph K. H. Koh of the Lee Kong Chian Natural History Museum in Singapore. The spider’s body has a glossy surface that gives it the “wet” look of fresh faeces. “The nodules on the body and rough-edges of the legs further reinforce the ‘shitty’ look – pardon the rudeness,” Koh says. Long Yu of Hubei University in China and his team exposed the spider to one of its predators – jumping spiders. They also added houseflies as prey. The team found that the camouflage helps these crab spiders (Phrynarachne ceylonica) repel more jumping spiders and attract more flies than those without camouflage. They presented their findings at the Behaviour 2015 meeting in Cairns, Australia, last month. Other spiders, such as orb weavers in the genus Celaenia, also look like bird droppings, but the foul smell makes bird-dung crab spiders unique. Speedier trains can slow down roads READING this while stuck in traffic? Fast trains may be to blame. Slowing the London Underground could cut overall congestion in the city. Marc Barthelemy of the French Atomic Energy and Alternative Energies Commission in Gif-surYvette and colleagues mapped out the road and subway networks in London and New York City and simulated travel at different speeds. They found that the ratio of the average road and rail speeds can have a critical impact on congestion. If the subway speeds up while road speed stays fixed, for example, more people on the outskirts will use trains. But these commuters often have to travel by road to do so, as suburban stations are thinly spread. The result is more congestion overall, as increased traffic at the outskirts outweighs smoother flow in the centre (arxiv.org/abs/1508.07265). “If you want to give more access to more people, then increasing the speed of the subway is not the best solution,” says Barthelemy – packing stations more closely is often better. New York City is an exception, however: congestion here is so bad that speeding up trains does help. DIRT is good for you. Kids on farms are less likely to develop allergies and asthma than urban children. But the protective effects of friendly microbes also seem to depend on a person’s genetic make-up. The hygiene hypothesis says that a lack of exposure to dirt and microbes is to blame for increases in allergies and asthma. One explanation is that children today encounter less endotoxin, a bacterial protein found on the surface of many common species, including E. coli, that may be important for damping down overactive immune systems. Children with gene mutations that disrupt the functioning of an enzyme called A20 are more likely to have asthma and allergies, so Bart Lambrecht of Ghent University in Belgium and his team wondered whether A20 may be involved in helping endotoxins train our immune systems. First they exposed mice to endotoxin, and saw they developed fewer allergies when later exposed to dust mites. But this effect wasn’t seen when the experiment was repeated with mice that had been genetically engineered to lack A20 (Science, doi.org/7hf). Lambrecht and his team then turned to human lung cells and found that A20 was less active in adults who had asthma. “It’s important because it shows that endotoxin can’t work on its own,” says Erika von Mutius of the Ludwig Maximilian University in Munich, Germany, a proponent of the hygiene hypothesis. It is thought that about 5 per cent of people have a faulty version of the A20 enzyme. Key enzyme makes farm kids healthier Palaeolithic people ate carbs as well GOING on the palaeo diet? Don’t put down your porridge just yet. Hunter-gatherers ate oats as far back as 32,000 years ago – way before farming took root. This is the earliest known human consumption of oats, say Marta Mariotti Lippi at the University of Florence in Italy and her colleagues, who made the discovery after analysing starch grains on an ancient stone grinding tool from southern Italy (PNAS, DOI: 10.1073/ pnas.1505213112). The Palaeolithic people ground up the wild oats to form flour, which they may have boiled or baked into a simple flatbread, says Mariotti Lippi. They also seem to have heated the grains before grinding them, perhaps to dry them out in the colder climate of the time. Mariotti Lippi notes that this would also have made the grain easier to grind and longer-lasting. This multi-stage process would have been time consuming, but beneficial. The grain is nutritionally valuable, and turning it into flour would have been a good way to transport it, which was important for Palaeolithic nomads, she says. JOSEPH K H KOH ALEX SEGRE / ALAMY STOCK PHOTO For new stories every day, visit newscientist.com/news
TECHNOLOGYAutomatic worldThetechnologybehindbitcoin is creeping out intothe real worldsaysJacobAron.ThepossibilitiescouldchangethewaysocietyisrunTHEcentre cannot hold.TheriseUS presidentialelection in 2016.devices(see"Ourblockchainofbitcointook therighttoissueThesekinds of predictionfuture",below),andbankssuchmoney,once the sole preserve ofmarkets already exist-Betfair isas Citi, UBS and Barclays, havinggovernments,andplaced itinthethe largest-but they areseen therise ofbitcoin,arehands ofeveryone.Now a spin-offcentralised,meaningthatfirmsexploring the technology."Theevolutionofthetechnologycould dothe sameformusthandlemoneyandruleonblockchain is perhaps thegreatestothercoreconceptsofsociety:outcomes.Augurautomatesthis,identity,ownership,reputationusingsmartcontractstogatheradvancementofcomputerandeven theruleof law.science sincethe invention of"Anythingthat requiresThistechnologyis thethe internet,"says Barclaysproofofownershipblockchain, and it has thechief design officer Derek White.potentialtoenabletheultimatecanbereplacedbytheThebank has partnered withablockchain"workers'cooperatives, or perhapsnumber of start-ups and currentlyan ultra-libertarian parallelhas45 internalblockchainconsensus oncompletedsociety,beyond governmentalexperiments."Anything thatcontrolpredictions and pay winners.requiresproofofownershipBitcoin's blockchain is a"At no point is a human beingthroughpapertodaycan be-TSA8Ecryptographicallysecured listofever touching anybody's moneyreplaced by the blockchain."everybitcointransactioneverit's controlled by an algorithmBTIVO/ATmade.Thelistisstoredoneveryandstoredontheblockchain,Parallellawmachinerunningbitcoin softwaresays Peronet Despeignes ofAugur.TheblockchainstorestheSmartcontractscouldevengoandis continuouslyupdatedaseachtransactioniscompleted.beyond ordinary businessesreputationofusers,ensuringthatNo central authority is in control:givingrise to autonomousentitiesindividuals. Once set up, it willanyone trying to cheat the systemthemachinesessentially monitorisswiftlybooted out.The servicethat live on the blockchain.Forkeepgoing even afterthe initialeachotherto stopfraud.will launch fully in the comingexample, Etherplan is workingcustomer has died, says founderBut blockchains can beusedformonths.on softwarethat isdesigned toDonald McIntyre."if a customermorethanfinancialtransactionsExistingfirms also seethereplace wealthmanagersbydisappears,andwedisappear,theautomaticallyinvestingaccordingLastvearsawtheintroductionofblockchain'spotential.SamsungsmartinvestmentplansaregoingEthereum,ablockchainplatformandIBMareexperimentingwithtoacustomer's desired portfolio,to continueexecuting theirthatenables"smartcontracts"Ethereumtocontrolsmartinvestmentstrategyandthenpayingout tonominatedwhichautomaticallyenforcedistributingto beneficiaries."agreements betweentwo parties.But howwill these smartOURBLOCKCHAINFUTUREYou can thinkofabitcoincontracts interactwith lawin thepayment as a specialised kind ofTherangeofapplicationsbuiltonthetransparency,saysfounderreal world?IfI sell you myhousesmart contract, in which oneNickDodsonbytransferring ownershipon theblockchainisorowingallthetimeblockchain,butrefusetoactuallypersonagreestopayanotheraHereare justafewoftheup-andEverledgerisworkingwithBarclavstotracktheownershipotmove out and hand overthekeys,certainsum;butsmartcontractscomingconceptscangovernanyagreementADEPTisajointIBM-Samsungdiamondsandcombatfraud.Therewill the courts recognise thatlthat can be digitised.areplansto expand intoothergoods.havebrokenouragreement?AtexperimentforputtingdevicesonEthereum wasfullylaunchedtheblockchain.Yourwashingthe moment, no one is quite sure.Provenancewillrevealsuppllastmonthwithdevelopertoolsto"It's not recognised by lawmarhinecouldusesmartcontractschainsbyrecordingthetransterbuilddistributedapps,ordapps,to orderitself detergent.ofqoodsthroughbusinessesbecauseit ismeanttobea parallellaw,"says StephanTualofonitsblockchain,andahostofBoardRoomwillletneonlerunFinallv.SlockitnrovideEthereum-powered services areinterneet-enabledphysicallocksonEthereum.But if people startorganisationsonthebiockchainspringingup.One ofthe mosttheblockchain,soyoucouldemailcontrollingsecurevotesandbudgetsmanaging their affairs usingdeveloped is Augur, in whichblockchain law,governments willfromanvwhere.Charitiesandyourkeystosomeoneandrevokeusers betontheoutcomeofgovernmentscoulduseitforultimatethematanytime.haveto accommodateit,he says,events,suchaswho will win thejustas themusicindustryhadto18/NewScientist/12September2015
18| NewScientist | 12 September 2015 individuals. Once set up, it will keep going even after the initial customer has died, says founder Donald McIntyre. “If a customer disappears, and we disappear, the smart investment plans are going to continue executing their investment strategy and distributing to beneficiaries.” But how will these smart contracts interact with law in the real world? If I sell you my house by transferring ownership on the blockchain, but refuse to actually move out and hand over the keys, will the courts recognise that I have broken our agreement? At the moment, no one is quite sure. “It’s not recognised by law because it is meant to be a parallel law,” says Stephan Tual of Ethereum. But if people start managing their affairs using blockchain law, governments will have to accommodate it, he says, just as the music industry had to TECHNOLOGY TOM SIBLEY/GALLERYSTOCK Automatic world The technology behind bitcoin is creeping out into the real world, says Jacob Aron. The possibilities could change the way society is run THE centre cannot hold. The rise of bitcoin took the right to issue money, once the sole preserve of governments, and placed it in the hands of everyone. Now a spin-off technology could do the same for other core concepts of society: identity, ownership, reputation and even the rule of law. This technology is the blockchain, and it has the potential to enable the ultimate workers’ cooperatives, or perhaps an ultra-libertarian parallel society, beyond governmental control. Bitcoin’s blockchain is a cryptographically secured list of every bitcoin transaction ever made. The list is stored on every machine running bitcoin software and is continuously updated as each transaction is completed. No central authority is in control: the machines essentially monitor each other to stop fraud. But blockchains can be used for more than financial transactions. Last year saw the introduction of Ethereum, a blockchain platform that enables “smart contracts”, which automatically enforce agreements between two parties. You can think of a bitcoin payment as a specialised kind of smart contract, in which one person agrees to pay another a certain sum; but smart contracts can govern any agreement that can be digitised. Ethereum was fully launched last month with developer tools to build distributed apps, or dapps, on its blockchain, and a host of Ethereum-powered services are springing up. One of the most developed is Augur, in which users bet on the outcome of events, such as who will win the US presidential election in 2016. These kinds of prediction markets already exist – Betfair is the largest – but they are centralised, meaning that firms must handle money and rule on outcomes. Augur automates this, using smart contracts to gather consensus on completed predictions and pay winners. “At no point is a human being ever touching anybody’s money, it’s controlled by an algorithm and stored on the blockchain,” says Peronet Despeignes of Augur. The blockchain stores the reputation of users, ensuring that anyone trying to cheat the system is swiftly booted out. The service will launch fully in the coming months. Existing firms also see the blockchain’s potential. Samsung and IBM are experimenting with Ethereum to control smart devices (see “Our blockchain future”, below), and banks such as Citi, UBS and Barclays, having seen the rise of bitcoin, are exploring the technology. “The evolution of the blockchain is perhaps the greatest advancement of computer science since the invention of the internet,” says Barclays’ chief design officer Derek White. The bank has partnered with a number of start-ups and currently has 45 internal blockchain experiments. “Anything that requires proof of ownership through paper today can be replaced by the blockchain.” Parallel law Smart contracts could even go beyond ordinary businesses, giving rise to autonomous entities that live on the blockchain. For example, Etherplan is working on software that is designed to replace wealth managers by automatically investing according to a customer’s desired portfolio, then paying out to nominated The range of applications built on the blockchain is growing all the time. Here are just a few of the up-andcoming concepts. ADEPT is a joint IBM–Samsung experiment for putting devices on the blockchain. Your washing machine could use smart contracts to order itself detergent. BoardRoom will let people run organisations on the blockchain, controlling secure votes and budgets from anywhere. Charities and governments could use it for ultimate transparency, says founder Nick Dodson. Everledger is working with Barclays to track the ownership of diamonds and combat fraud. There are plans to expand into other goods. Provenance will reveal supply chains by recording the transfer of goods through businesses. Finally, Slock.it provides internet-enabled physical locks on the blockchain, so you could email your keys to someone and revoke them at any time. OUR BLOCKCHAIN FUTURE “Anything that requires proof of ownership can be replaced by the blockchain