Learn English – Do I need to use “from” after “graduated”

• It is not acceptable in formal or academic writing. (Typically.)

  There are exceptions. @oosterwal, @tcovo, and @wooble give good examples of perfectly valid constructions starting with especially (or in wooble's case, starting with because).

  An example with because :

Because of the necessity of lowering their their baskets to the cave floor daily, the Pitifoo began to develop ingenious mechanisms to deploy the baskets with greater speed and less effort.

An example with especially:

Especially during the depression in the seventeenth century, when money was scarce in many countries, transactions frequently reverted to payments in kind. ^{The Cambridge economic history of Europe edited by Sir John Harold Clapham, Eileen Power, Michael Moïssey Postan, Edwin Ernest Rich}

Another :

Especially during the years of conflict between these powers, 264-248 B.C., the Jews must have suffered severely. ^{An Introduction to the Old Testament: Chronologically Arranged By Harlan Creelman}

• It's probably acceptable in email correspondence at work, but you have to be aware of the informal tone it gives.

  Sometimes deliberate informality can be a good thing, as it gives or creates the sense of or the illusion of a closer relationship. It is more casual as well as being more informal, and this relaxation of 'formal' rules can give the correspondence the same relaxed feel.

  'But wait,' I hear you saying, 'aren't you just deliberately and strategically making a mistake if you use it like that? '

  "Especially if you use it like that?" I ask.

  'No,' you say, 'you're just mocking me. I mean that it isn't just an ugly cousin of the correct sentence structure, which you can choose to use as you please. It's actually broken. It's a solecism."

  "Absolutely not," I insist. "Definitely not." I shake my virtual head. "The machinery of language is far more flexible than you think. The rules are beaten into your noggin so that you know how sentences function. One you know these rules and how they operate, the actual syntactic and semantic mechanisms you use to communicate your thoughts can twist, bend, and stretch to fit the shape of current circumstance."

• Among friends, it's fine, as long as one of you isn't a grammar absolutist.

• It's certainly an acceptable formation in fiction writing, as it mirrors the actual practice that occurs in spoken English.

No, it is not correct. A grammatically correct alternative that I'd suggest is:

statistically significant with respect to

See these references.