Epithelial cells serve as a frontline defense in innate immunity by forming physical barriers and producing soluble mediators that influence immune responses. (A)  Propose one strategy to enhance epithelial cell-mediated innate immunity against a respiratory bacterial infection. Justify your approach based on known epithelial innate immune functions. (3 points) (B)  Design an experiment, assuming unlimited resources, to test the efficacy of your strategy from Part A. Briefly describe your methodology, controls, and expected results. (5 points)

Which is the most obvious sign of fire cause?

A bump test is performed to:

An advantage of using thermal imagers during search and rescue operations is:

In which situation would firefighters likely use an air monitoring device?

Which extinguisher would be effective for use on a burning puddle of gasoline at a vehicle incident?

The closet hook is a tool that matches which category:

Antibody & TCR Diversity (A)  Diversification of the T cell receptor (TCR) primary repertoire is generated using the same mechanisms as for immunoglobulin genes.  Briefly define each of the four genetic mechanisms involved in generating Ab and TCR diversity:  Germline; Combinatorial; Junctional; and Association.  (4 points)  (B)  Why is it that the junctional diversity produced by addition of “P” and “N” nucleotides occurs in the CDR3 region and not the other two CDRs?  (2 points) (C)  Briefly define why a VH segment cannot join directly with a JH segment in heavy-chain gene rearrangement.  (2 points) (D)  Briefly define one advantage and one disadvantage of junctional diversity during the rearrangement of immunoglobulin gene segments.  (2 points)

If air monitoring indicates that the oxygen level in the atmosphere is below 19.5 percent,:

In order to conduct an effective search operation, firefighters must know the: