I like the inversion of the motif. The dynamics are well used, but almost too contrasting in measures nine and forty-four. The mp at measure thirty-six and seventy-nine seemed right to me, even with the pp following 79. For 9 and 44, perhaps decrescendo from a measure before for the violins, or mp; p just seemed too soft after ff for the violins. The pizzicato came through about perfect at that part, though, and I think pizz. goes quite well with the piece. Anyways, the presentation and development seems logical and to-the-point, at least to me; I like that. The use of rhythm and dynamics provides great contrast, especially when used together; it really adds to the building and releasing of urgency and suspense. After measure 44, you do a good job of releasing the constant tension, but I feel you could change it up by using the violins more "gently", and emphasizing on harmony and possibly do something more interesting with the cello pizz. Just and idea. =p You seem to have put a good deal of effort and thought into it. Good job. =)