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One-color light is well suited for traffic lights and signals, exit signs, emergency vehicle lighting, ships' navigation lights or lanterns (chromacity and luminance standards being set under the Convention on the International Regulations for Preventing Collisions at Sea 1972, Annex I and the CIE) and LED-based Christmas lights. In cold climates, LED traffic lights may remain snow-covered. Red or yellow LEDs are used in indicator and alphanumeric displays in environments where night vision must be retained: aircraft cockpits, submarine and ship bridges, astronomy observatories, and in the field, e.g. night time animal watching and military field use.
What color LEDs are used when night vision is important?
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The answer: Red or yellow

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The Boulton Paul Defiant, despite its poor performance during daylight engagements, was a much better night fighter. It was faster, able to catch the bombers and its configuration of four machine guns in a turret could (much like German night fighters in 19431945 with Schrage Musik) engage the unsuspecting German bomber from beneath. Attacks from below offered a larger target, compared to attacking tail-on, as well as a better chance of not being seen by the bomber (so less chance of evasion), as well as greater likelihood of detonating its bombload. In subsequent months a steady number of German bombers would fall to night fighters.
How could aircraft engage bombers when fitted with a turret?
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The answer: engage the unsuspecting German bomber from beneath

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Though Jehovah's Witnesses do not accept blood transfusions of whole blood, they may accept some blood plasma fractions at their own discretion. The Watch Tower Society provides pre-formatted durable power of attorney documents prohibiting major blood components, in which members can specify which allowable fractions and treatments they will personally accept. Jehovah's Witnesses have established Hospital Liaison Committees as a cooperative arrangement between individual Jehovah's Witnesses and medical professionals and hospitals.
The Hospital Liaison Committees serve to bridge between hospitals, medical professionals and who?
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The answer: individual Jehovah's Witnesses

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Humanism is a philosophical and ethical stance that emphasizes the value and agency of human beings, individually and collectively, and generally prefers critical thinking and evidence (rationalism, empiricism) over acceptance of dogma or superstition. The meaning of the term humanism has fluctuated according to the successive intellectual movements which have identified with it. Generally, however, humanism refers to a perspective that affirms some notion of human freedom and progress. In modern times, humanist movements are typically aligned with secularism, and today humanism typically refers to a non-theistic life stance centred on human agency and looking to science rather than revelation from a supernatural source to understand the world.
What can be credited for the changes in the definition of humanism?
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The answer:
intellectual movements