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ScienceShot: The Secret of the Frozen Frogs

first_imgTo call wood frogs hardy would be an understatement. The species (Rana sylvatica) can survive winter temperatures that freeze up to two-thirds of the water in their bodies. They endure this annual popsicle phase with help from cryoprotectants, substances circulating in their blood that lower the freezing point of their body fluids. New research shows that frogs at the northern limits of the species’ range are uniquely adapted to freezing. A team of zoologists collected wood frogs near Fairbanks, Alaska, and froze them to -16°C—a temperature that would kill frogs of the same species living in the midwestern United States. When the creatures still managed to reanimate after thawing, the team looked for physical qualities that might explain this superior resilience. It found that the Alaskan frogs stockpile astonishing amounts of a complex sugar called glycogen in their livers, which grow 1.5-fold relative to body mass as the amphibians prepare for winter. “This frog is like a walking liver,” says zoologist Jon Costanzo of Miami University in Oxford, Ohio, who led the research. The liver later converts this glycogen to glucose, a known cryoprotectant that quickly gets distributed to all the cells in the body when temperatures drop. The Alaskan frogs also accumulated about three times as much of the cryoprotectant urea in their blood plasma compared with  frogs collected in Ohio, the team reports online today in The Journal of Experimental Biology. A third substance, whose identity is still mysterious, was present in Alaskan frogs, but not Ohioan ones. Costanzo and his team are on the case.See more ScienceShots. Sign up for our daily newsletterGet more great content like this delivered right to you!Country *AfghanistanAland IslandsAlbaniaAlgeriaAndorraAngolaAnguillaAntarcticaAntigua and BarbudaArgentinaArmeniaArubaAustraliaAustriaAzerbaijanBahamasBahrainBangladeshBarbadosBelarusBelgiumBelizeBeninBermudaBhutanBolivia, Plurinational State ofBonaire, Sint Eustatius and SabaBosnia and HerzegovinaBotswanaBouvet IslandBrazilBritish Indian Ocean TerritoryBrunei DarussalamBulgariaBurkina FasoBurundiCambodiaCameroonCanadaCape VerdeCayman IslandsCentral African RepublicChadChileChinaChristmas IslandCocos (Keeling) IslandsColombiaComorosCongoCongo, The Democratic Republic of theCook IslandsCosta RicaCote D’IvoireCroatiaCubaCuraçaoCyprusCzech RepublicDenmarkDjiboutiDominicaDominican RepublicEcuadorEgyptEl SalvadorEquatorial GuineaEritreaEstoniaEthiopiaFalkland Islands (Malvinas)Faroe IslandsFijiFinlandFranceFrench GuianaFrench PolynesiaFrench Southern TerritoriesGabonGambiaGeorgiaGermanyGhanaGibraltarGreeceGreenlandGrenadaGuadeloupeGuatemalaGuernseyGuineaGuinea-BissauGuyanaHaitiHeard Island and Mcdonald IslandsHoly See (Vatican City State)HondurasHong KongHungaryIcelandIndiaIndonesiaIran, Islamic Republic ofIraqIrelandIsle of ManIsraelItalyJamaicaJapanJerseyJordanKazakhstanKenyaKiribatiKorea, Democratic People’s Republic ofKorea, Republic ofKuwaitKyrgyzstanLao People’s Democratic RepublicLatviaLebanonLesothoLiberiaLibyan Arab JamahiriyaLiechtensteinLithuaniaLuxembourgMacaoMacedonia, The Former Yugoslav Republic ofMadagascarMalawiMalaysiaMaldivesMaliMaltaMartiniqueMauritaniaMauritiusMayotteMexicoMoldova, Republic ofMonacoMongoliaMontenegroMontserratMoroccoMozambiqueMyanmarNamibiaNauruNepalNetherlandsNew CaledoniaNew ZealandNicaraguaNigerNigeriaNiueNorfolk IslandNorwayOmanPakistanPalestinianPanamaPapua New GuineaParaguayPeruPhilippinesPitcairnPolandPortugalQatarReunionRomaniaRussian FederationRWANDASaint Barthélemy Saint Helena, Ascension and Tristan da CunhaSaint Kitts and NevisSaint LuciaSaint Martin (French part)Saint Pierre and MiquelonSaint Vincent and the GrenadinesSamoaSan MarinoSao Tome and PrincipeSaudi ArabiaSenegalSerbiaSeychellesSierra LeoneSingaporeSint Maarten (Dutch part)SlovakiaSloveniaSolomon IslandsSomaliaSouth AfricaSouth Georgia and the South Sandwich IslandsSouth SudanSpainSri LankaSudanSurinameSvalbard and Jan MayenSwazilandSwedenSwitzerlandSyrian Arab RepublicTaiwanTajikistanTanzania, United Republic ofThailandTimor-LesteTogoTokelauTongaTrinidad and TobagoTunisiaTurkeyTurkmenistanTurks and Caicos IslandsTuvaluUgandaUkraineUnited Arab EmiratesUnited KingdomUnited StatesUruguayUzbekistanVanuatuVenezuela, Bolivarian Republic ofVietnamVirgin Islands, BritishWallis and FutunaWestern SaharaYemenZambiaZimbabweI also wish to receive emails from AAAS/Science and Science advertisers, including information on products, services and special offers which may include but are not limited to news, careers information & upcoming events.Required fields are included by an asterisk(*)last_img read more

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Go back to the enewsletter A group of Infinity

first_imgGo back to the e-newsletter >A group of Infinity wholesale consultants from around Australia ‘discovered what matters’ on a trade trip to Vanuatu last week.Hosted by Vanuatu Tourism Office (VTO) the trip ran from 6 to 11 November, 2015 and took in the islands of Efate and Espiritu Santo.The wholesalers were given the chance to experience the contrast of this South Pacific island destination to its neighbours, which they found was much more than simply a ‘fly and flop’ holiday location.From getting down and dirty with some off road buggy rides, racing along beaches, marvelling at the breathtaking blue holes of Espiritu Santo to snorkelling and canoeing scenic rivers, the group were given the opportunity to discover the many different sides of Vanuatu.The group was hosted at The Grand Hotel & Casino, Warwick Le Lagon and Breakas Beach Resort in Port Vila and Aore Island Resort on Espiritu Santo.The Infinity wholesale consultants sampled a variety of Vanuatu’s restaurants as well as Port Vila’s nightlife by stopping by the newly opened, chic Lava Lounge.Vanuatu is gearing up for a strong 2016, with new accommodation, restaurants/bars and tourism offerings making this destination even more tempting for Australian holidaymakers.Go back to the e-newsletter >last_img read more