var newIdAtual = -1;
function startNews(){
	newIdAtual = 0;
	setInterval(showNextNews, 4000);
}
function showNextNews() {
	/*
	//hide anterior
	$("#list_not ul li:eq("+newIdAtual+")").hide("slow");
	//show next
	newIdAtual++;
	var numLis = document.getElementById("list_not").getElementsByTagName("li").length;
	if (newIdAtual > (numLis-1)) {
		newIdAtual = 0;
	}
	$("#list_not ul li:eq("+newIdAtual+")").show("slow");
	*/
	
	var nextId = newIdAtual+1;
	var numLis = document.getElementById("list_not").getElementsByTagName("li").length;
	if (nextId > (numLis-1)) nextId = 0;
	$("#list_not ul li:eq("+newIdAtual+")").fadeOut(1000, function () {
		newIdAtual = nextId;
		$("#list_not ul li:eq("+nextId+")").fadeIn(1000);
	});
}
$(document).ready(startNews);
<!-- /noticias -->