2) (25 points)   Consider downloading a file of size F bits from a server S to a client C. The server has an access link with transmission bit rate RS = 2R bit/s to the backbone of the Internet, while the client has access transmission bit rate RC = R. We model the backbone of the Internet with two links with transmission bit rates RB1 = 5R and RB2 = 10R that are interconnected with a router. Thus, there are total of two hosts (i.e., server, client), three routers (i.e., router between server access link and first backbone link, router between the two backbone links, and router between second backbone link and client access link),  and four links in the considered network architecture and the file is transmitted from the server to the client as indicated by the direction of the arrows: Server => Access link RS = 2R bit/s => Backbone link RB1 = 5 R  => Backbone link RB2 = 10 R  => Access link RC = R  => Client. The distances (lengths) of the access links of client and server are the same and are denoted by dA meters, the backbone links have length dB, dB > dA. Let s meters/second denote the propagation speed on the links. Assume that the routers interconnecting the links have unlimited buffer capacity and negligible nodal processing delay. There are no other traffic flows in the considered network. Drawing a labeled separate space-time diagram for each of the following parts a), b), and c) is required in order to receive credit. a) Suppose message switching is used, i.e., the entire file is treated as one large packet. How long does it take to download the file? b) Suppose the file is broken up into packets, each packet with P information bits (with F/P an integer), and packet switching is used. Header bits are negligible. How long does it take to download the file? c) Suppose circuit switching is used. The circuit that we set up across all the network links has a circuit transmission bit rate of R/2 bit/s. Assuming ts seconds set up time, how long does it take to download the file?

Why does Nagel say that “it seems that even if our choices are not determined in advance, it is still hard to understand in what way we can do what we don’t do?

All four types of macromolecules essential to life are assembled from their simpler building blocks by removal of water.

Match the statement with the photosynthetic pathway it describes. a. The most common photosynthetic pathway. b. Spatially separates CO2 fixation from the Calvin cycle. c. Stomata are closed during the day time. d. CO2 is fixed at night. e. Yields the highest photosynthetic rates at temperatures above 25 degrees C. f. Is most likely to be affected by photorespiration. g. One important plant that utilizes this pathway is corn.

What type of protein fiber, commonly found in the extracellular matrix, is extensible (can be stretched or extended)?

Select all of the properties of water that result from its polarity.

Problem 3 Part B Find the probability that it will be cloudy on Wednesday given that it was not cloudy on Sunday or Monday.

This tissue is found lining the:  

A 5-year-old child is brought into your clinic for immunizations and physical exam. The mother states her child is a little “under the weather.” as he was recently sent home due to a fever a couple of days ago. He does not have a fever today but does appear fatigued.  Which of the following is a contraindication to vaccinating this child?

Match each term with it’s definition