CINXE.COM

<!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: "academic.oup.com",cType: 'managed',cRay: '913617fee9f2402f',cH: '82qyXB5WEsmj9UvsmOVwBZCBACk7JmmlRsZwHydeWJ0-1739798625-1.2.1.1-l5mVLqg2ewtJ8p1JvBzdUvGrUYMZUiGyDs_.mSDgBJR0bP4OIKZracmUiQAIOFur',cUPMDTk: "\/oup\/backfile\/Content_public\/Journal\/sp\/31\/2\/10.1093_sp_jxae001\/1\/jxae001.pdf?resultClick=1&__cf_chl_tk=PDt165dNJhqmyFwdP39D_nEqgaeLVQq65qblAZB6mvQ-1739798625-1.0.1.1-r9mu8ZzL6CyUOdDa_xMy9H4bYpY7a1VUDRdzz71hyZo",cFPWv: 'g',cITimeS: '1739798625',cTTimeMs: '1000',cMTimeMs: '390000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/oup\/backfile\/Content_public\/Journal\/sp\/31\/2\/10.1093_sp_jxae001\/1\/jxae001.pdf?resultClick=1&__cf_chl_f_tk=PDt165dNJhqmyFwdP39D_nEqgaeLVQq65qblAZB6mvQ-1739798625-1.0.1.1-r9mu8ZzL6CyUOdDa_xMy9H4bYpY7a1VUDRdzz71hyZo",md: "Wx_67a15uVaem4JTlAk7jvzuIjP8BBiuegmEJilOlSU-1739798625-1.2.1.1-9z8FnDQmVbIUkR2CGJLnxPSFklNFgB2i8HVAySzApt.3kCXSoutp6hJvU2smVRilFnN6dFXjBvM8ygSCjuxOv6o190h3ClBSUPMJtbKIx0Leu6WVspcid5ucdTDPkLjvkYd829DXO202yL6UPyrnmpdpvY_Ka.Rf1PavN_rBwG5M8OmiA1KDs7FM.bN3BBRcVL_tEFZmgdY1t1tXj8Rv44fNpPaV.7NcUd4jt3Fi04ZVSv20_mSNw_GAEheKXRY9SoOzG3.udluXtj8Oy7CjP4pcdQgcmk0CxsDJPB66YZiFhVvrX8bwVS3jFUVIeuZsH.WNMLDtEEcGZU2udpDuvDvLA6RJnBHqDyrASHEUhdXABAb0hDVuMw3__rqj0GpYe376k.OLA_JQww6JVWEOYc0gXrnRCy1itDsI7qYc0W_qUwiahVPVqAnFS0.bYmpZXKlcUjbmHo0QAO6IqKFOkRoXkbTamHiExAAz.._MyEReJAkyVRdX1xwb0nx0QeFf98MFqgj6vL9Mh_f7d5ODp9PWzC8HRGzAIWYPkVMbXetvoCYtai8ewNMSa0selqIe59koKnF..T.OXptRYyHSzmN3Do.HdtNOn1KhMdCnGMh6h0nStS6Iug5z_iR2lqn8x2iiKXrAHDEZtVsxwFLdpEqZLIXvaAArp0FG2qhTyTeQU00swMh6aEHlMruPqS3qJZAe6hP2QrCHqdhIsoP4lMTCgsdHW34HKTrgUQ8HMgsCCPbhM3vXdUHaQuYc8suvStBnGZiEqZC2cI8U0kCBjH7WiRC8Fz4QvfHf4Zsdf8Ixiqetj7IMtQYOUWyE2vzbh2gUJj5u1v1BaGOZJ6Vr9IISnuVAS89uZsxvKbpUT466tW7Wt1TPjDny5WF7NROFhOVUEZMv1Z5EVRpbCfPE5se.o4BKI_aL8DKpfiEuJc9Gph67N12kWe9UPkfYe.L5oixnawq4ZGWyuQkQVhvSVecbgycJguo8GR7Y4WrnWDYdzIJK.5jeRhOLXIgFQf_OkSbTQccupLNlrv2n28JJTaMQlbOO_6jn2cVOIG680ZPaJ6FThcKb54OSxD7u8rB0l2Zs2j1bEYXbsFqfIsp97du64kRVDlzbb5FOO0JPev.eO4UZpx_Gw_y5mwtm8cbPo8pj7Lmn2Gx9kW3a4PmgH.SLawm_JQdpWd6E3aFWNgmXcxrnYAzT.tmCmBFXDqtU3f7As9Jv.9rR51A.SXEGuTUYbbR.Kb.lYqR1FJ_0HCM3w48gymkCLugkGBs9J0R76flrXaw0FEGVRsvgiOxXy1HjpkxlN0NrLfm88bi5mAGmppvv7QebrIBLdo7dnOEQ45VZeQ7LPAd_GA0OE_iniS1e4FH9u30uI449A_ug_UcsD3TT1hwT4qnNOFs.VoK2q5eEsaZAADQjdgv88Qtx.Zo6OcZ37_NHcymDOhLab9pka2S9FgC9ZNP6QDH90O0OkRrk5pMI2glovVBXLIc3iTUiBWlAuAREez9AuWVd7AQBnYUjDt69D6UE5oNgRvZJDZGTvHYae4Nleslxny4k8JBylj7aWEW4wreUBXYDha9Sz7_xIHQEcW6wfOyJ9k3wNP5QzronW6sqirNiwa5VK4_HXOFfYivURXyCzsFWNldKhbii96Oa6SGrk4uPk8oICsFYnvkLn2JSWS.GgMmBhjKad_lIcL_rZWWRSA8whJFWU7o2d4w5QNAibETGR7y6WYEdjrHXlXzfTXrF3CmA9D0HAemZ08X5Rmwfi.lt91Q.z_ofWIA.d9v794FObvvVsvy3ppvCx5o9XThLpMS2KaDZlN4ZCCIqa5A7q5LPol97DtofhUhnu9.nsMmKRmm8LGMjRk2A2d6U3wCPfTpZaCuK9WLSi7npM7DHQ.ERjlUHL5wyxPM3PdDiCUw7GDVFm2bcBOwuGusQP7h25etux2xza8uvzGBRW.yuLGQmf5Gf0gFxYnVVhLUUjQeNoQdVaCKfirVK7LDvzc5vR5fVG5shaFZqaaRs2yPO2aClENzIfQTKNfshj8Ob3P0jM2HSqwPoB8ZLGPXAirjNhQlHtjILE3o1TvHIJeslutTY6SwAu2R.QAWULYtHh_x8cMDuyHp47vlT1kuPY4MHjKMZ2y7.ZNd1H6CoD6cuFwadksccPgIXyMwoVC110MUAZ2gKY6BjE3xYyIw8ySubVGt6B5suMJyobxCmWhe0vLof9SGTobawB9j7gAXYG.rfBlEfuHvGbIni_fz9HrJTIPEFj0wHr9DtjJRaGp30iGRzWbia8Jc8gdlJLgX1vizRXbVHBMmaBckcjcM6on9AI6p6eYGS.6EDa7RqrDiJoVY6yDNpIdhxx4ysru02B8EsGpllITWO3dF3cjOEdrz0XjRuCQw_1xG5yzweZ9gKyzMpVay1e7ggohukx6_DS0P9Sd_6Q8qxK2x17.pfO4RCSFwVRRSaFXBhsDigcpX4XQXLIQZiViObM09fF4LXEO1IEI12nclAl2RH9KKJzLhH1pbveC4ouGY7K9DXZDLaQV6ACM15mHrKksyUInrHE60VnMsQZR8x_qpl5fAx5ZdlC_Ylf_Kk9wfq9EFzX0TtmyxuK_iTJ52Un_UeIwigcUAm6NsZm0A9xd2t1qu__0fZxbFRNJLRkfSEoL_h5PkXFlErTOAt_mx44KFGTtm9HkdSTOrvBb3GboeaNmMdT0n_DW27m5.6MIokEgCKCnsuUG4nKOxYHAeiTkL39gSCC3cLIvH_",mdrd: "0k.fBx9u7zmt1YIJXYuT3t8PYcj2oWtT8N3jemZCWok-1739798625-1.2.1.1-IFX8_ruyC3Q4qEIgrOt_vI6YIxwfufBI9FF9v6Osq0hK8nJkpaJlxbbZ3RJRG.L5FyyDF.yCkPNEgEKAJpx_fhnUA5uUopmcHTCovXwN.U2ynwSP8tqdzH7ZllI_v8v9UcGy4IImuXa7kDPRexccXi9K4KmSzt8Np1C_eYSY3tA4Ur7xMWbgo125UbleEG4dA166uWPMo..xxD5L7TwISsLIorBmfTMpx0edC4gkqLQBulBAb1bRUxX3lesSqJk.ICoVelR5YKI5qYNI4QbSAfVqoYzhlQ7yu8QBnm6AHDpQnlPJKA6TY6m5LjxTthHckj.jqtMivNxsNKpPqz98kiBMd8V4tYJMSiKxhtcItzluDHeGP3_RxhNRTgy01Ud3XZbUaAnhJFSfZkxNtRMRInY6B6JwAz2AhpzaloZl5zY1Ak5DwKPU.wU2YQyWOxkjJo..NTGmC9VmRxtghroozEZauvF2jtJetS4QlZqu5U9uQTJaICYjqS8XrKxqj_h2V.yVJftbOW984u1OvbSuD7JLPT4qDywPSzBvZCfhFrp1Qb9v9FWUt1FSu5xF4ig_mDy1XR01680NL1jpzUeh1AZzM27i_X1qzcLB.sRpycyBTw1Ia6VXp.PYldNzhxP6eZTxiAYLlpLJRoMaaP_ZPHVk_a5.8O47JhnseMNfhBERqw8BvOigN2BYJsAwGzyYJe2vUbmlN5DwOfPC9tlQeIcv.hFkSI17pXHPszw4X.d_TbgAbAnR5eJYPdWDpC2NQ_CMvllq6ds_yjdw3t3FPcI8yPSlnGfHZm9UXio7rRddJn6kvJE8t7vj8uSbEv.UtT7_cO2blqnmmYzRw6YMS_CzTEtkUSabQjBnKMQAjfjrdYRx2BVx_xKmKidJLGzAWQ_WDV.U0S6McMzoFqO4zvn6dPJwSamA7TSlGZvPg6snv5GIHidizd5aBuLuv.mEtJjvNvYjOI7DJKHNDIi.GOocr_FKU497OupLzEWh3CBMoFwwh9nXiu63qU9vvAx4zcPm6FPc9vTKL2taRLdfgbzOH94KgM.P0byI5aYpn7p72Hx2cRDQe5IatDWzz8ybOvyz9dhCpcSrTQRL.1UtUj3CpaWDpHeBu1LJQTqbdcm6vXhLswzibgp1yN.MtiBKL11vUwUbuASbOJ1IJUhHLpTfGOf1ObUpp9F0qU.HclgAYorlUJfBFII5USYycbjvu02yC3MOIZKG7g5emSqd0khDQps9M5.3F_AdcIr74locMfD7_8bYfrU5sOhZPcuT.myAaQdOt3i3WOHcR6FgPZ2q.A4VxkirNB85X0d3OCmFgNH6lpIf.apDOA._pd8N0obucu.SKA66umea.G5H9t4oB_Rpu5Q7uA1jpnii3jKFeUrt5jqjwRLWBhFJGdDQhYjI5CFvFByCbgrkXuKhat0oCfdXpJqJ8UiA4fJpNm08jn8DSwMN1LrxCdnahpi8l85arRahSx4Uf2QvFiggLw6ARcNmVeK.ofqxVcWfMS47uFM5U_SWOoNk.bw1CV.wx1KP1UO.tgxufhQVHFgfHIy1oi_H5jsJCQfidTaYwsVxLhT9sBdXysxI7ZuVHRoI.8ikp_sxFuvRAdwlTrLo2_LqOVx1Y9TvB371otTw81i0O6KK2OJxkl5IELamz85U0pa4EY8bpVAOh7hg.d0MZ7Z_0prsdL.PxjB59wHEiI01z5kZQCs5aGBWdFl1jGWHMae5LBinC7sRgCHVEV0tAcXdS2jTAvretXIwP9nbIVCHHbE6WOYE.TUi97Xog73Kdpd5yR2PIfh2Wpb9xSkIF.dfQglUUheDD7knPfH2QyHlP7_mbKt2P.d9D2b_q9mSBIx6A719QZcwa_UOGNqjNJ6KISvuIGgnv2UZ0ZyAtFSAIKWRNzoHmqSnaZITYMfVBIWt5cdhRQM4xoT8nDqT7uGyKncGoNLYqvdResIPjNrL.2m_LDpuT3ClM4xnE1hc"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/g/orchestrate/chl_page/v1?ray=913617fee9f2402f';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, "\/oup\/backfile\/Content_public\/Journal\/sp\/31\/2\/10.1093_sp_jxae001\/1\/jxae001.pdf?resultClick=1&__cf_chl_rt_tk=PDt165dNJhqmyFwdP39D_nEqgaeLVQq65qblAZB6mvQ-1739798625-1.0.1.1-r9mu8ZzL6CyUOdDa_xMy9H4bYpY7a1VUDRdzz71hyZo" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>