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'); document.write('

'); } function MM_preloadImages() { //v3.0 var d=document; if(d.images){ if(!d.MM_p) d.MM_p=new Array(); var i,j=d.MM_p.length,a=MM_preloadImages.arguments; for(i=0; i0&&parent.frames.length) { d=parent.frames[n.substring(p+1)].document; n=n.substring(0,p);} if(!(x=d[n])&&d.all) x=d.all[n]; for (i=0;!x&&i 2) { if ((img = MM_findObj(args[2])) != null && !img.MM_init) { img.MM_init = true; img.MM_up = args[3]; img.MM_dn = img.src; if ((nbArr = document[grpName]) == null) nbArr = document[grpName] = new Array(); nbArr[nbArr.length] = img; for (i=4; i < args.length-1; i+=2) if ((img = MM_findObj(args[i])) != null) { if (!img.MM_up) img.MM_up = img.src; img.src = img.MM_dn = args[i+1]; nbArr[nbArr.length] = img; } } } else if (event == "over") { document.MM_nbOver = nbArr = new Array(); for (i=1; i < args.length-1; i+=3) if ((img = MM_findObj(args[i])) != null) { if (!img.MM_up) img.MM_up = img.src; img.src = (img.MM_dn && args[i+2]) ? args[i+2] : ((args[i+1])? args[i+1] : img.MM_up); nbArr[nbArr.length] = img; } } else if (event == "out" ) { for (i=0; i < document.MM_nbOver.length; i++) { img = document.MM_nbOver[i]; img.src = (img.MM_dn) ? img.MM_dn : img.MM_up; } } else if (event == "down") { nbArr = document[grpName]; if (nbArr) for (i=0; i < nbArr.length; i++) { img=nbArr[i]; img.src = img.MM_up; img.MM_dn = 0; } document[grpName] = nbArr = new Array(); for (i=2; i < args.length-1; i+=2) if ((img = MM_findObj(args[i])) != null) { if (!img.MM_up) img.MM_up = img.src; img.src = img.MM_dn = (args[i+1])? args[i+1] : img.MM_up; nbArr[nbArr.length] = img; } } } //-->

Uses - Medicine

Vaccines

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Safer vaccines can be produced through genetic engineering. First, scientists need to identify the gene in a pathogenic (disease-causing) virus that stimulates the body to produce antibodies, which provides protective immunity. That portion of DNA is then isolated and incorporated into an established harmless virus such as vaccinia, the virus used in the vaccination of smallpox. This new recombinant virus is used as a vaccine. These vaccines are much safer since they do not expose the patients to the actual virus and do not risk inadvertent infection, a risk that is very important to consider in vaccines for AIDS, for example. This method may be useful in vaccines against malaria and schistosomiasis.