CINXE.COM

Just a moment...

<!DOCTYPE html><html lang="en-US"><head><title>Just a moment...</title><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><meta http-equiv="X-UA-Compatible" content="IE=Edge"><meta name="robots" content="noindex,nofollow"><meta name="viewport" content="width=device-width,initial-scale=1"><style>*{box-sizing:border-box;margin:0;padding:0}html{line-height:1.15;-webkit-text-size-adjust:100%;color:#313131;font-family:system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,Noto Sans,sans-serif,Apple Color Emoji,Segoe UI Emoji,Segoe UI Symbol,Noto Color Emoji}body{display:flex;flex-direction:column;height:100vh;min-height:100vh}.main-content{margin:8rem auto;max-width:60rem;padding-left:1.5rem}@media (width <= 720px){.main-content{margin-top:4rem}}.h2{font-size:1.5rem;font-weight:500;line-height:2.25rem}@media (width <= 720px){.h2{font-size:1.25rem;line-height:1.5rem}}#challenge-error-text{background-image:url(data:image/svg+xml;base64,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);background-repeat:no-repeat;background-size:contain;padding-left:34px}@media (prefers-color-scheme:dark){body{background-color:#222;color:#d9d9d9}}</style><meta http-equiv="refresh" content="390"></head><body class="no-js"><div class="main-wrapper" role="main"><div class="main-content"><noscript><div class="h2"><span id="challenge-error-text">Enable JavaScript and cookies to continue</span></div></noscript></div></div><script>(function(){window._cf_chl_opt={cvId: '3',cZone: "www.columbia.edu",cType: 'managed',cRay: '917bc9adb8f84963',cH: '5kF2WGdosCRDA_zUe_Ar6UoQF64ljG9RGwWViUQSR3M-1740529420-1.2.1.1-S7XHynea3hj9OVh9yRkSib7T7Ew_JMI2n..NahObJLzzwsS4CmtuxJjhyxFEyygh',cUPMDTk: "\/cu\/libraries\/indiv\/oral\/offsite.html?__cf_chl_tk=4cILdEtI7DM8dD.ejUSCiU06j0sDdHr0A9zkh0FQqkc-1740529420-1.0.1.1-VdusyC40Blh9C.7lhSlNQWu3FcmM1cfDGgsCcWjTXEk",cFPWv: 'b',cITimeS: '1740529420',cTTimeMs: '1000',cMTimeMs: '390000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/cu\/libraries\/indiv\/oral\/offsite.html?__cf_chl_f_tk=4cILdEtI7DM8dD.ejUSCiU06j0sDdHr0A9zkh0FQqkc-1740529420-1.0.1.1-VdusyC40Blh9C.7lhSlNQWu3FcmM1cfDGgsCcWjTXEk",md: "wsOpaGXZqvRIrOgH0NPV6lVwDInIY2u19KVYDlmT4tY-1740529420-1.2.1.1-fJCOwIviJPfEBEnEhtpAenLyx7_2gN_YQ5BtFBytzje.uph7Sr01AkNMl7D1vrPJ_.GMZQOhnn1TFg4wMrWD3ZdwVKklp6K6Ki.nDReMyvXiPX6F93IflsFO0rtxZ7JLM0ddphSmB9f1xSZEu46VIYDKg09f32sYow516_4EpZES9_5W71sFNWsDEleuNCs367NDS4zFScdRP48.RaaJpssfUsgUjm6aCdD7dVJod.JM.TMeDHo0TjQqPLyEq3ICineTaTDllOtHW9UXsOLdUByhKecFjonCDByeRR_4wT8rVYm9NcfiqP_Sdf3ZQE1YTzeKUFLtYuKmHzOfUCNkcQFgdqNkOLFluECGYs.xs3I.7W7.vlPrX7cGFcjieuLDCtjBw8mI2S_1852QORyLeAmfscdMMsAke7SPLIEjXs4AiPXBqJPWIsgjH53mecT8EAD1OCyJ3jLDfn_PHeBjPgpBBNFwNf0RRk9mcb5Ld...9XFX._YqpFX0AQjuQ_QNoUduW0vQ1ZbYYp.NH7WeAmrcbTRswuISz_P7UASJkTWtQ3ZRivOSHTjAAKqpbmNhvt6rAmoF43LLyHkRd9Cd4HrEjFX2zww6uZ.Omko9p8h1eosZx4e7R9GYgpuXN0jIMehfAJblSDXJyndsaIPuA5oMX8L5LdvDwN4BjCKZTEnCve74VOOtxzm_uckF4B6RZXL7fkHgt4RhUv4gXscxsDc1_1NRzsuOBlbzBCEfs421b1ElnZcNwBBfH_8LCxIUVLuVCQg5xAvKIiUnR5MUnPC_5LkfC.kavb6zCoW.U1zps7hBl2FEzD8x5it5BpEVWTZocaKXs.oO7xXYyRsPFDb9F.rEiS.UzHPmAPhyJ6cPLNcNVo7L6b.Omakb977mTg5Xvmrhl8karbBaJhoWyTkIzm_gRrJb_80VtujXsfEIgLRwvbrBmuFErHS2.SPbJ4elOMn8QqxiryvDisHxZLXKBedBgtX913R9lhdzf.chntpXk4.jY.piXKNHA2SjjpZ3di_uALSoSwKqLklzkD77exTP7e8nWzKPeSnroOBB9il1AVzYh9_0_U_TehGVzpyyZzHsBvPmd1ENV4BOLT4YbxTkhu__euiI9XdGnHlYP8Snw0Tmv2hMwguZIXQMzK5udXMwD.GizoZQq27q2nVdI3EwNImDKzcRwonbQzU8E57eG_.UJhzr1qQN.KzypAKtHxHV9t9bBtD0741U3M18FjQ9mMa.ep_NpW6h45YidHwGUPeFGp5oaqj_mNebtqE2UwAs1Lm28nLBQCdAcSgnsZUJbnAKLBQMyhZk5IEZ_cbdyM3JjuS.fSrEYJzD1AIhEBFbAOb.WXLIYPke4HSf.vaECF2cIKQe.kPrYgeUhJtjCMX79TprNdlZxB9h6fu0O7jUla8iDKayOmHAFUksx2IF7dG9koCRyyRTQMjKkxEZzWNkOhyfTzWYIJPoIyt3qshtbYxJD1z.zJs9bTvrGH2Zvphg8foXKijcdruviHHD.3fb9JjAULdl1BxrOrvvZ4G1jBlkg2nUhXGzWjaCld1ipj5z8AtTvrVotE7j5rMqUp_bmAfLW6zl14eh_cF9zJDv9rxyba2OmpN6M2goCIeccJFI6ydCocDONw6sEJDD9XxFHfW76azjLsVOY6rrmWc.4CRXLYNTYa4Q1LsLDA6FOVuaVcmgaEW0oOpux8vWF_VK4DWSv_Ck8y9SlmZC9Q7wbaED5ZNPCtcWAy_TLAt0i7JFutAdglU4IDYbWm1q.rktEYu6iRrxXF80OiBSmB.pFIbJ1Ibp5RqXaHKd4IBMLYGO5ysUFUTvmC6dDrUzmRRXIq65a1MNx7fDQhbhCjnXyrANwpK5cBHNIahSpZTSK8MAPly.IiryHTp4HLT914lCwNUCX23.Ia6l0DhRKQe7JJ.x5YPtC7x5XCZErR2tRN8FM73U.DmV2tEeEPMtWrPsSy3NBw9mUT.DH8AvujVmjmh657iKTNAJ4HeI2Ug7av5X6IF5jHXdj0YdeAoLjlJ8.J5LadC9uec6OBV_I91ZzG8w.Txj0932R3wtO4CJdolLOfyXz3tnpGqYBWRZYB3hLZ_SdQ4t6S1aLQQJ7RkXwpavh4PLVCh57bPoai13foNv6ArwC8pOfAE47xNRggl.TbOXySxtgWkSDbLG8aliFq8u6MQ34SEcq8lDtMuQqGQ9M79uv87g46U_QArohCzSLF.ZZWUVkmIxUTgLEVNGAlhIlVGmA9Enwa4pUh1Qy01qt4ifdqDZVC4KOQWue2apUWW8KAuSul_BhpWLZJk2K3YPF0Td3Q4ihBs.O_vFtjexFTirD6pXy.69NMeULSY_TRa8lyMGAl8vjQExmeleEBsnj4d_vNVjVhyN5wiuTP1605PbkibVdE983rsleXSw7a_hPaaT8RNyl0exhQ9N0gHkqsFZlXoRB9TRlHM9MmSN.z4nFRNVpiU_ibXEXqUtI2z472WURA3Lywp5g_0jDWDwWEl0irJcTKaJ6nMd_fDw.6jlJSJ783ZRGeixgdHU7576Nl3t16NzJIgdD0nNWuyGeSZNLtAJkrh6UJXcS5UN0F3z2f4JUdk",mdrd: "ZQiiIgDYunWuoQu9lAaf9S_D8qqRbjaiMXza4WMH1RI-1740529420-1.2.1.1-kbcezd2ZD7kCChzVeBnSjfgmw8hW6FWV4KZ8EGcu6tWRm5Hs474QvXAqTHYLc4igRwZYE3DysLjbyNgSJvAF4_DJHghHhzXsiTxbp5NJYHOVSVbPfFtokME4MYrjyWEilwGQykDANO4KbSO_iFV6_F4vV3A2dTSZPWC3ZEMD.zKKuge5vsl8b8c8_bsnl9fHy9mEBHLEih6aqM9403G2yJBkWGU7uNkroiX1gM_sJdEqQp6JvAG4Th34HxFHKHoJlZfS2AGP_x4ty3QBS.Lho75SMf4GZNPbmo69R8B1gRmlwEmV_o9wrZlw.m.I0ZXTEHBdYxppJ1JbJpQlkRLtCpQnUWKc88Op0IHm3UWV4T4nJBJksEybLzu1P752jRFXC6VZTqpz_sxa7fcYdFxw_qc9fs5YXtW4iFe0g.tsCTLnLeBCcQpHbpZnr7BUq7Eqvv7AHvLo012tJWBBlnDaBTq04JBiKiTpIZ5mr3e0JSXCbFsEe0MC5mdtPib0bnD_.QhhoT52HaNX52VPDmNS_Y7Fv3TQ_6_N2FfbdbWH0n5zM.9vjlWMu2bpna7pLQ_8EUw.r5VuTz6_dOoc_sVGYZT7hiDjai6dyj_aUnsT320Im..G.2iOw9Z5VvPvmyEnCCLriGIk9rMSGwhReCgUMOYpBReO7iGKJpJowTCSRlnhK1LmxdAElF7ZKR3eoL4L"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=917bc9adb8f84963';window._cf_chl_opt.cOgUHash = location.hash === '' && location.href.indexOf('#') !== -1 ? '#' : location.hash;window._cf_chl_opt.cOgUQuery = location.search === '' && location.href.slice(0, location.href.length - window._cf_chl_opt.cOgUHash.length).indexOf('?') !== -1 ? '?' : location.search;if (window.history && window.history.replaceState) {var ogU = location.pathname + window._cf_chl_opt.cOgUQuery + window._cf_chl_opt.cOgUHash;history.replaceState(null, null, "\/cu\/libraries\/indiv\/oral\/offsite.html?__cf_chl_rt_tk=4cILdEtI7DM8dD.ejUSCiU06j0sDdHr0A9zkh0FQqkc-1740529420-1.0.1.1-VdusyC40Blh9C.7lhSlNQWu3FcmM1cfDGgsCcWjTXEk" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>