When combined with the 副助詞（ふくじょし） (adverbial particle) は, 以上（いじょう） is frequently translated as ‘since (A), (B)’, ‘now that (A), (B)’, or ‘as long as (A), (B)’. This is a formal structure that is rarely found in daily speech.
This construction may be used with verbs and い-Adjectives in their standard forms, and な-Adjectives or nouns followed by である以上（いじょう）は.

• 猫（ねこ）を飼（か）うと決（き）めた以上（いじょう）は、最後（さいご）まで責任（せきにん）を持（も）って育（そだ）てないといけないと思（おも）います。
  Now that I have decided to keep a cat, I think that I have the responsibility to raise it until the end.
• 体調（たいちょう）が悪（わる）い以上（いじょう）は、会社（かいしゃ）に来（こ）ないでください。
  As long as you are sick, please don’t come into work.
• 有名（ゆうめい）である以上（いじょう）は、テレビではもちろん、SNSでも発言（はつげん）に気（き）をつけなければいけません。
  As long as you are famous, you will have to watch what you say, not only on television but also on social networks.
• この地域（ちいき）の住民（じゅうみん）である以上（いじょう）は、この地域（ちいき）のルールをしっかりと守（まも）ってもらわないと困（こま）ります。
  As long as you are a resident of this community, we need you to properly follow the rules of this community.

As with many other grammar points, the particle is often dropped, leaving 以上（いじょう） by itself.

• キャプテンに選（えら）ばれた以上（いじょう）、結果（けっか）を残（のこ）すために精一杯（せいいっぱい）頑張（かんば）ります！
  Now that I have been chosen as captain, I will do my best to achieve results!
• どんなに気（き）を付（つ）けていても、人間（にんげん）である以上（いじょう）、ミスは防（ふせ）げないよ。
  No matter how careful you are, as long as you are a human, you can’t avoid making mistakes.

Due to である以上（いじょう）は often presenting something which is being acted upon, the (B) part of sentences that include this grammar structure will frequently include the resolutions or intentions of the speaker, and can be thought of as either obvious or necessary once considering (A). This usually appears in the form of べきだ, つもりだ, はずだ, たい, ほうがいい, and similar patterns.