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="120"></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: "publications.waset.org",cType: 'non-interactive',cRay: '91351e8cfed3d4a5',cH: 'P7TdJHF9En6OUWlmWLWn8ywbrsMNNhWGz9WWpHMR1H4-1739788407-1.2.1.1-ONxXsk0WeTQM29UX1pzVK3YlGwhTxyvX179xFKeZOINotTW74BifiSVqGhwAfT1L',cUPMDTk: "\/abstracts\/search?q=Northern%20Nigeria&__cf_chl_tk=o6OvvoxMFmvgX50B05KAnKXvVPLpoFgav4HDt.g7gwU-1739788407-1.0.1.1-i990rW90eW5iYE8nJjjx5n88P0giwMmbFNeLFHYC1g8",cFPWv: 'b',cITimeS: '1739788407',cTTimeMs: '1000',cMTimeMs: '120000',cTplC: 0,cTplV: 5,cTplB: 'cf',cK: "",fa: "\/abstracts\/search?q=Northern%20Nigeria&__cf_chl_f_tk=o6OvvoxMFmvgX50B05KAnKXvVPLpoFgav4HDt.g7gwU-1739788407-1.0.1.1-i990rW90eW5iYE8nJjjx5n88P0giwMmbFNeLFHYC1g8",md: "wonX1ukK0TVkFKU1ceM7GwxKv86P1onpQUrzNUEjNis-1739788407-1.2.1.1-rvBjmoqtV7mS.9emK09G_LM9nGA1BNnpTyd_Ki0PRpYHZVYH0Mf_i1P6nfe7V0JVkJhghBOivEjRTAtjbShztwC_rP.QWddfyAwQlnWwj2PHOcQR3O8oNh7K0s8gowRsmM06XdVHCJRv0_mi5BZez4yJBdi93krWCofolDNDy72DxFDY_Tlddgl.Jn.nRMl33OGn1bt9hwIjLh.RmxCXFhWyDYJrVgmhZgVX4WaUOWqwDCFqNx0qkPET3KL.OeF3B6aPiup2g8HTAmYgiCu8DmmN0_AY480Vr6E4dGzLxL6lECrZU48jIpw0SvozhUNUXBVtqdW3koNr_iQAwLx3zXQcIZtg44iywLx0o0OA.fmkLMTCizyTHfO6MfUQajF6plJ4f8BB5Q0baUhkHE3JH3w8DFbytMYMi9Na95TxtpGYqNGJqETiB7EZdT4anbeCi.d9JdyD9P8wWBMbMKTkF3DWDPSu60hFfkDjVP9_VQV0ZJ1M3dDTwNEbtCszV3Gu1obpMam8MCpTZ.jGvGJa8VtgumeEVmofhK_D6nVk_N77oWnyLY6qBa3JgxJjNZHdTbw2j33WjA_W.fh.NmZM82j7p6DGDH05UOSsLxcJQuzutkzb52CmOec0UcONWQ0HtKnV3AcMXf5zas6vSq_S3CMddt7.bx_UO6hmVpu8N947ae5VC0SimLNFBIvJ9GsZbMM3yrP.7vSxY66eD_TjtorZcx.KgJ64ckuLilpegkYgPuCB_9gNLHduzHI5DwuR1R.zNzgBg8ZKOva8qOVndHPhXe42kQcISonYGthG1eXODpXVMAXPfY1H_1bL8L7ydQb3zPcL4iHgkmg.FrTlu1LuXaByvQ9gvuLl.b1d80KWsI4gJmXCU2FUMNDEBzpzvzqz0yRWaNVog3kNpMdGuTfN9vAWIZNxhCRqXaabqIHPdwB1YOKzGF3R9Fp2dh4KSpK4Tx25.bADgvQYN4s3M9gOw6tpLLhX_ucfSN4XSVImHYELIOTaHSt95aYlC50_xUj3Wtv4C6Tl5RL9cQQiFKogvrjOmTGBVXq0ZtiGx1MahgtkkOfC.HR_4FpFWQh8yQjmh7RHx2LlBj9WIjJccWwlCMlecuFwjxnuX4ofxNQiuLeH.Rwdg4_GkW7XFAdhTVjFhcElFId01iwo9nN4XO05OmG5TLZnnG3YKLAjYwrx57VaUnhsanW8cEQ9jUilXDi9p2W4qOqsFJl9DRdaTDNKJEV7f0bbG_5TlbTs_WpX8aFNRULlvq8bB5fBxU6LbcwuAwln_GzMu4poiaMlxaBWsgopwFwijguN2Ik68YSYo4cTaiciYLmsOeVvdrmIJtZjC4V0BQwuBSRx16bqYnh6THu3B1pK.B_Bf1N5jB2XnnREEoTVsygBHOh7PBRa4LT1X5r0Zu5EeZ8m7LZrZr64JN4H4zgjtaSgo5AuNvqNQUMi6ivLXPe3Qa.wvSci_Hq87b8YYy3f8YPM5QkEDat26R92n2HnFzgSUvBQBnO0DRcXhBIaGnfA87lHe.7w1UABBqVLmCEyTO5ywHgUuT583cZjZ9j632n18pkRVjCi5yAtj_NY29X8YebZ3xG5UzHD02FO2O8nOUYG.NIv307SvQbGp77qFrswRO7uHxFpluUuKNCcPScnbmOMQanO8HRUAFWsx5eYm2Jbtf4WQFhFWnBLv83qqA43lPc2EsKbQv_kHQWpR5w0dhDLOA6xU..KJ6Kf9dMdNG8WRzcg4sY48JVLXbiL10SlI5cz2fS_JMtm6X204RXLcPsx7dFit4ukpJ0p0.4648WI83seOF0UQ1OPjxLKRO5it_4z1C9bOsnpGyFgmDBEH3naGQuegkO2N5sSUZLGgwZWx6STVPWT8PlveM.QktmGxpovjq_iXL79dmEn8QWzy3mBl_qpxkB5pKnd8n3ClKByIhgnUB21TEjHi_wGMT8NXpl9sQo",mdrd: "UCR77CocM6jEePu2E67OjKmHYSsvDc1kPLlQUiYiXiE-1739788407-1.2.1.1-efBNa8GLiiUA38TzXVgs5AefV2piAIRIpgKstWfqMtAa62VeCbpfEyBy.kQk_qScUmsC1YZ6p_Z33QmqApF95BZ12WIU0iqzkt4gorOUachyy172Rg9Bdjr9h4fG_90rv0up2ELIvyUsTUTBoxhLBcuoGLCVlQgywkJ0jkyN96liLJopHFuCLI9xkAIDJdrgS9e8SyLcQh9DEt4AMvkBALQIe7tpBJK5pzAA8d7EC24AsroxLh4MR5QRRnFl5LRDyhFrXBGq2C1wAGH5k8ymy7VDpBA7742oWZavQ_0SEuoqAbHa3.lm3gjNjP6KnaUL.dYky71vCsl3.9.dRiNeB9BRf2QME3ct7_NXJk9Un2hlbq5siSd8tWOphgx8ajA3rn44GRhhRlJc8VBwJa1VUYc3mzz.1XvhykmfGVH2C60K6kbd8qMBJBUBltfD_P.tSM8YXZZZrRczoDc51WuRzo45kIGiQceiWkgoejbhUbAMFxdXRXOpxEh0OtQioJbiB.ibsgirbzpgT3kTWaQgxVVJUY9ArD0y1Vb5_xdNQRfslgX6iD7ZSc3vE00bgzndTrErtxigvO3ney82JzyLOSuuBANTEOqQuTI5V6VynZCtZsrYtcxXmaH5jZEUfjjStAa0DxLoMooY2AXC8Ynn2DyO1rGtm2jqDGEAKflc.R1eOW0gPnX8RllnJXmdVi8na0SiFU3743a5I_V.biiMcSscgx8Vc1XjQikHOQVfKio2vW7Qhc8K2GWz5_Zt6VjrGB3j0cLfG.xjphzQjAw0sSBqZnh3WBtoM2VLzUGInAC9LOgcmxvHF16fX7V_G13yq_7BdIERqCQ_fO7uYHby6WctLZzg0SHLOrmoyDsJSlRj_CqwWUC.JoCNm.dlcDTRnz0.2LF.8tMRmJBIUXQbZ1VGiD6HqiFhrIAqAkY.8ca_vl7THm5Npg3B6lmk7y3O1bztTHT4WweE.AcP57OM.h5th11o5Z_iiBTjGOETg9AfnsTJFbIb4aLKePAZk.EV4Bzc4lBkOBe60A1uRbs1wVzObYPAOY9mOJuHyfa437PGq25bhUwof8SH4YNmct0uqA3c8JkfRF_eUJZQxMP8M.CCTqckH4j87VTnuwx4o8LmMAMl.2R6oe04Mb8OdYtxvNmYoYasGb2FdtHIRcxmsXTFYvS1Xm_d0g2eRiw.m0epL4aa2nSaIAswu4N8YXs2LeJODXwD63cEyyflw1pk_Fgw91b066MrLYnNEswHedPRlo1x5kTQaOjMcZdr4pJDnbrwZZRbWmE2ph0nUNK8tVQQb9LD60zL7LClrK6jbGabFxb2G1EVoSZ0RwQT7bR_nsdyLrZUSMDjkE8RG_oTi.bp.3LLgkSM2M9z_MpOSf3nQWLcsQcfIPWM6jGw4vCQjbXtNiLBNyEnueUicpYS.y7h9PNv7jR8pdcxKo6Uwwt1qbMFSb8OECXqhdTPDLv4bx5B08Zpphxo.CTSB5Y4JoTP3FcsxJt3aR6rAIvMbCekZhAuYscp2vlX8OrGpNrwxQLX_4wkXq2KkRe6jI9nllI2orT76iso8mFsdp9bF99uxXVafoByUTFHpb482hLkrpekbuL8JDLHPWILyOhoj_uZs05LFyVYEPVEmDNnAJgVvDRNNUb6UqBh11D4hWh294xN_cnX4bNDmS9DvezUQ2MOtzEbTISPjgsVcpEOKRuPTo38sf4UCNck98HRiJv1SzdFZ3X2NlX9A0Z.X5sTKYhp7pcbiDU.wHpQflEME9f4sGeDW.kQCpykmTRDgIzevlQtyP3rNOAtkwVcYJ653ON6W_aTqiJ_npbJxq3tHsILS.3vjfMcqIikuw.a0YdzzirSDDHJhDk4MqSIy_mgM08kaWgo_BL7nm7sDewSlQVCIiMg0jxMqcDFC9292Da2PD5q_PVQZM2X7eGmFvGLtBxeshxyQ.7yqX2qtNnsr8EcJsPdFTMV64nDOXdnShey"};var cpo = document.createElement('script');cpo.src = '/cdn-cgi/challenge-platform/h/b/orchestrate/chl_page/v1?ray=91351e8cfed3d4a5';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, "\/abstracts\/search?q=Northern%20Nigeria&__cf_chl_rt_tk=o6OvvoxMFmvgX50B05KAnKXvVPLpoFgav4HDt.g7gwU-1739788407-1.0.1.1-i990rW90eW5iYE8nJjjx5n88P0giwMmbFNeLFHYC1g8" + window._cf_chl_opt.cOgUHash);cpo.onload = function() {history.replaceState(null, null, ogU);}}document.getElementsByTagName('head')[0].appendChild(cpo);}());</script></body></html>