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: To investigate whether gender is an independent factor associated with disease expression in early rheumatoid arthritis (RA) patients. 438 patients with early RA (disease duration less than one year) were studied. They all were patients with early RA who presented at the Rheumatology Clinic of the University Hospital of Ioannina during the period 1991-2000. All patients fulfilled the American College of Rheumatology criteria for RA. The demographic, clinical, laboratory, radiological and therapeutic characteristics of the disease at diagnosis, and at the last follow-up were analyzed according to gender. We studied 312 women and 126 men with early RA. The female to male ratio was 2.5:1 and the mean age at diagnosis was 49.4 +/- 14.9 years for women and 55.3 +/-15.6 years for men (P < 0.0003). Women had a longer duration of follow-up (P < 0.0003). There were no differences between genders in the general symptoms or the simmetricity of joint involvement at at disease onset. However at disease onset women had a higher erythrocyte sedimentation rate (ESR) (> 30 mm/1st hour), although there were no significant differences between the two groups concerninig the rest of the clinical, laboratory and radiological findings. At the last follow-up women still had a higher ESR (>30 min/1st hour), but no significant differences were found between the two groups concerning the rest of the parameters investigated independently of the follow-up duration. Finally, women and men showed the same degree of radiological changes and functional ability and were treated similarly except for the more frequent use of hydroxychloroquine in women. It seems that gender does not signficantly influence the expression of RA. 
 Question: Is Rheumatoid Arthritis more common in men or women?

A: women
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Q: Context: We show that overexpression of Polo-like kinase 4 (Plk4) in human cells induces centrosome amplification through the simultaneous generation of multiple procentrioles adjoining each parental centriole. This provided an opportunity for dissecting centriole assembly and characterizing assembly intermediates. Critical components were identified and ordered into an assembly pathway through siRNA and localized through immunoelectron microscopy. Plk4, hSas-6, CPAP, Cep135, gamma-tubulin, and CP110 were required at different stages of procentriole formation and in association with different centriolar structures. Remarkably, hSas-6 associated only transiently with nascent procentrioles, whereas Cep135 and CPAP formed a core structure within the proximal lumen of both parental and nascent centrioles. Finally, CP110 was recruited early and then associated with the growing distal tips, indicating that centrioles elongate through insertion of alpha-/beta-tubulin underneath a CP110 cap. Collectively, these data afford a comprehensive view of the assembly pathway underlying centriole biogenesis in human cells. 
 Question: Where in the cell do we find the protein Cep135?

A: centrosome
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Q: Context: Newtons third law of motion states that every action has an equal and opposite reaction. This means that forces always act in pairs. First an action occurs, such as the skateboarders pushing together. Then a reaction occurs that is equal in strength to the action but in the opposite direction. In the case of the skateboarders, they move apart, and the distance they move depends on how hard they first pushed together. You can see other examples of actions and reactions in Figure 14.9. You can watch a video about actions and reactions at this URL: You might think that actions and reactions would cancel each other out like balanced forces do. Balanced forces, which are also equal and opposite, cancel each other out because they act on the same object. Action and reaction forces, in contrast, act on different objects, so they dont cancel each other out and, in fact, often result in motion. For example, in Figure 14.9, the kangaroos action acts on the ground, but the grounds reaction acts on the kangaroo. As a result, the kangaroo jumps away from the ground. One of the action-reaction examples in the Figure 14.9 does not result in motion. Do you know which one it is? What if a friend asked you to play catch with a bowling ball, like the one pictured in Figure 14.10? Hopefully, you would refuse to play! A bowling ball would be too heavy to catch without risk of injury assuming you could even throw it. Thats because a bowling ball has a lot of mass. This gives it a great deal of momentum. Momentum is a property of a moving object that makes the object hard to stop. It equals the objects mass times its velocity. It can be represented by the equation: Momentum = Mass Velocity This equation shows that momentum is directly related to both mass and velocity. An object has greater momentum if it has greater mass, greater velocity, or both. For example, a bowling ball has greater momentum than a softball when both are moving at the same velocity because the bowling ball has greater mass. However, a softball moving at a very high velocity say, 100 miles an hour would have greater momentum than a slow-rolling bowling ball. If an object isnt moving at all, it has no momentum. Thats because its velocity is zero, and zero times anything is zero. Momentum can be calculated by multiplying an objects mass in kilograms (kg) by its velocity in meters per second (m/s). For example, assume that a golf ball has a mass of 0.05 kg. If the ball is traveling at a velocity of 50 m/s, its momentum is: Momentum = 0.05 kg 50 m/s = 2.5 kg m/s Note that the SI unit for momentum is kgm/s. Problem Solving Problem: What is the momentum of a 40-kg child who is running straight ahead with a velocity of 2 m/s? Solution: The child has momentum of: 40 kg 2 m/s = 80 kgm/s. You Try It! Problem: Which football player has greater momentum? Player A: mass = 60 kg; velocity = 2.5 m/s Player B: mass = 65 kg; velocity = 2.0 m/s When an action and reaction occur, momentum is transferred from one object to the other. However, the com- bined momentum of the objects remains the same. In other words, momentum is conserved. This is the law of conservation of momentum. Consider the example of a truck colliding with a car, which is illustrated in Figure 14.11. Both vehicles are moving in the same direction before and after the collision, but the truck is moving faster than the car before the collision occurs. During the collision, the truck transfers some of its momentum to the car. After the collision, the truck is moving slower and the car is moving faster than before the collision occurred. Nonetheless, their combined momentum is the same both before and after the collision. You can see an animation showing how momentum is conserved in a head- 
 Question: equal and opposite forces that act on the same object

A:
balanced forces
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