Hi Pey! No, you can't use ''just as''. ''With'' as a preposition has a lot of different meanings and one of them is ''because of''. For example: With exams approaching, it's a good idea to brush up on your grammar. (Because exams are approaching...) With average home prices down over eight percent in 2008...(Because average home prices were down....) ''Just as'' can mean exactly or in the same way. For example: Things turned out just as I had expected. He's signing his name just as he's always done it. I hope this helps :)

"With" phrases like this one explain a factor which is relevant to the main clause. In context, it may be the only factor, in which case it is a simple reason clause (like using "because"). We use this kind of expression to add variety, especially in journalistic writing, and/or sometimes when we want to make a connection between two ideas which is not quite as strong or clear as simple cause and effect. A similar expression is "in the light of...."

No. Why? They simply don’t mean the same. Examples of use of “just as”: "I am just as tall as you are." "It was just as you described it." "Just as we were going, it started to rain."