Given a question and a context passage, generate the answer having the word or phrase from the context passage. Here, the answer should be a shortest continous span from the passage.

Q: Context: A machine is any device that makes work easier by changing a force. When you use a machine, you apply force to the machine. This force is called the input force. The machine, in turn, applies force to an object. This force is called the output force. Recall that work equals force multiplied by distance: Work = Force Distance The force you apply to a machine is applied over a given distance, called the input distance. The force applied by the machine to the object is also applied over a distance, called the output distance. The output distance may or may not be the same as the input distance. Machines make work easier by increasing the amount of force that is applied, increasing the distance over which the force is applied, or changing the direction in which the force is applied. Contrary to popular belief, machines do not increase the amount of work that is done. They just change how the work is done. So if a machine increases the force applied, it must apply the force over a shorter distance. Similarly, if a machine increases the distance over which the force is applied, it must apply less force. Examples of machines that increase force are doorknobs and nutcrackers. Figure 16.8 explains how these machines work. In each case, the force applied by the user is less than the force applied by the machine, but the machine applies the force over a shorter distance. Examples of machines that increase the distance over which force is applied are paddles and hammers. Figure 16.9 explains how these machines work. In each case, the machine increases the distance over which the force is applied, but it reduces the strength of the applied force. Some machines change the direction of the force applied by the user. They may or may not also change the strength of the force or the distance over which it is applied. Two examples of machines that work in this way are claw hammers and the rope systems (pulleys) that raise or lower flags on flagpoles. Figure 16.10 explains how these machines work. In each case, the direction of the force applied by the user is reversed by the machine. How does this make it easier to do the job? An exoskeleton suit may seem like science fiction, turning ordinary humans into super heroes. But wearable robots are moving forward into reality. And for paraplegics, the ability to stand and walk that these machines provide is a super power. QUEST meets Austin Whitney and Tamara Mena, two "Exoskeleton Test Pilots" who are now putting this new technology through its paces. For more information on exoskeleton suits, see [Link] MEDIA Click image to the left or use the URL below. URL: You read above that machines do not increase the work done on an object. In other words, you cant get more work out of a machine than you put into it. In fact, machines always do less work on the object than the user does on the machine. Thats because all machines must use some of the work put into them to overcome friction. How much work? It depends on the efficiency of the machine. Efficiency is the percent of input work that becomes output work. It is a measure of how well a machine reduces friction. Consider the ramp in Figure 16.11. Its easier to push the heavy piece of furniture up the ramp to the truck than to lift it straight up off the ground. However, pushing the furniture over the surface of the ramp creates a lot of friction. Some of the force applied to moving the furniture must be used to overcome the friction. It would be more efficient to use a dolly on wheels to roll the furniture up the ramp. Thats because rolling friction is much less than sliding friction. As a result, the efficiency of the ramp would be greater with a dolly. Efficiency can be calculated with the equation: Efficiency = Output work 100% Input work Consider a machine that puts out 6000 joules of work. To produce that much work from the machine requires the user to put in 8000 joules of work. To find the efficiency of the machine, 
 Question: force applied by a machine

A: output force
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Q: Context: Three isoforms of human plasma apolipoprotein E (apoE) are ligands to lipoprotein receptors and influence in different manner the synthesis and catabolism of pro-atherogenic triglyceride-rich lipoproteins. Among three isoforms, the apoE4 isoform is associated with increased frequency of atherosclerosis and Alzheimer's disease (AD). The conformational transitions of beta-amyloid (Abeta) influenced by apoE and serum amyloid P (SAP) component are key events in AD development, the accumulation of intermediate diffusible and soluble oligomers of Abeta being of particular significance. SAP and apoE, in a different manner for the three isoforms, serve as "pathological" chaperones during the aggregation of Abeta considered as a conformation-prone process. In turn, apoE consisting of two domains self-associates in solution and intermediate structures differently populated for the three isoforms exist. The different structures of the three isoforms determine their different distribution among various plasma lipoproteins. The structural and metabolic consideration of the common apoE pathway(s) in two pathologies assumes four molecular targets for AD correction: (i) inhibition of the accumulation of diffusible soluble Abeta oligomers; (ii) inhibition of apoE synthesis and secretion by astrocytes, in particular, under lipid-lowering therapy; (iii) inhibition of the binding of apoE and/or SAP to Abeta; (iv) stimulation of the expression of cholesterol transporter ABCA1. 
 Question: Which ApoE isoform is associated with atherosclerosis and Alzheimer's disease?

A: apoe4 isoform
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Q: Context: The movie begins in the year 1967 with a pregnant woman being admitted to a hospital, bleeding from the neck. Paramedics think she was attacked by some type of animal. Doctors perform an emergency C-Section, and her baby (a boy) is born alive just as she dies.Thirty years later a young man named Dennis (Kenny Johnson) is riding in a car with an attractive redhead named Racquel (Traci Lords) heading to an underground nightclub (located, oddly, in a slaughterhouse) somewhere in Los Angeles. After addressing the doorman in Russian, Racquel brings the young man into the club. The man is confused and trying to understand the rules of the club. Some of the regulars indifferently push him aside. Saying he needs a drink, the sprinkler suddenly system activates, raining blood down on everyone inside. It is then that he (and the audience) realizes that everyone in the club is a vampire.Dennis desperately tries to get away and winds up at the feet of a menacing figure in a black-leather trenchcoat. The vampires look on this figure with awe, mumbling the words: "it's the Daywalker!" This is our first look at Blade (Wesley Snipes), the vampire killer.Blade pulls out a shotgun and opens fire on the vampires, who instantly burn to ashes when killed. When the gun is knocked out of his hands by Racquel, Blade uses a set of silver stakes to kill Racquel and more vampires, including the disk jockey. Soon all the vamps are either dead or have fled except for one; a heavyset vamp named Quinn (Donal Logue), whom Blade has apparently run into before. Blade pins Quinn to the wall, and then sets him on fire before confronting the last member in the club (the human man from the beginning). Finding no vampire bite marks on Dennis, Blade lets him live and makes his escape as the police arrive.Quinn is extinguished and taken to the local hospital. A morgue technician examines his blood and shows the results to Dr. Karen Jenson (N'Bushe Wright), who finds a number of irregularities, including abnormally developed jaw muscles. As they are discussing the test results, Quinn springs back to life and bites both doctors. Before he can finish Dr. Jenson, Blade shows up and saves her, cutting off one of Quinn's arms.Blade brings Karen to his hideout and asks for help from his mentor, an elderly man named named Whistler (Kris Kristofferson). Whistler injects Dr. Jenson with a solution of garlic essence and silver nitrate and remarks that she has a 50/50 chance of recovering.Meanwhile, a group of vampires are discussing Blade's latest attack on their members. Apparently this club (and to an extent, Quinn) is the property of a vampire named Deacon Frost (Stephen Dorff). Frost wants the vampires to outright rule the humans and use them as a food source while the others (particularly an older vampire named Dragonetti) prefer to maintain a peaceful co-existance. Dragonetti (Udo Kier) in particular does not like Frost because Frost is not a "pure-blood" (ie: was not born a vampire, merely became one through the bite of another). Frost is also arrogant and his & the actions of his followers draw unnecessary attention to the vampire underworld.The next morning, Jenson awakens and sees Whistler injecting Blade with some type of serum. She tries to run away but Whistler confronts her and tells her that he and Blade are hunting vampires. Karen of course is skeptical, but Whistler goes on to talk about what they use to hunt- explaining that vampires are severely allergic to silver & garlic while also being vulnerable to sunlight (ultraviolet rays in particular). Whistler fuels up Blade's car and gives him a new UV flashlight to use when hunting that night. Whistler also gives Karen a type of "vampire mace" (garlic & silver nitrate in a liquid form).Blade drops Karen off at her apartment and she tries to pack up and get out of town. A police officer, identifying himself as Officer Krieger (Kevin Patrick Walls), arrives and questions her about the events 
 Question: What are the weapons made out of?

A:
silver
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