What kind of disclosure would be a problem for our patent application?

"Disclosure" means, in effect, "public disclosure" - so if you disclose your invention to third parties, it is a disclosure. A disclosure to investors can probably effectively be negated by having them sign non-disclosure agreements, but a presentation to a group of scientists or university members is probably pushing the boundaries of disclosure, even if you had them all sign non-disclosure agreements. I would check further with your patent professional in order to ascertain, for example, specific case law that has adjudicated such matters.