Constitutive structural defenses

The innate immune system constitutes the front line of defense against disease and has three structural components ... 

Chemistry, like any discipline, has a social structure. It relies on the interactions, behaviors, and expectations of individuals in order to function. Every social structure has a code of practices that constitutes its behavioral norms, that is, a set of rules governing what are acceptable and unacceptable behaviors. These rules are the moral philosophy of that social structure. When people find themselves in a situation in which there is a conflict or dilemma, the decision-making processes that they use to make the behavioral choices that follow are called ethical decision-making skills. Ethics, then, is the process whereby an individual, faced with a moral dilemma, arrives at a morally defensible decision. 

PAs are found widely in the families Asteraceae, Boraginaceae, Fabaceae, and Apocynaceae. About 360 diverse structures have been characterized,23 and these widespread alkaloids are produced by at least 3% of all flowering plants. It is remarkable that one group of animals-the insects-have broken through the formidable alkaloidal defenses represented by the highly toxic pyrrolizidine alkaloids. This evolutionary adaptation has provided a large resource for these insects that is not available to PA-intolerant species, which constitute most of the herbivores. 

Increased resistance to necrotrophs also could result from changes that increase antibiotic efficiency. Other approaches for these pathogens should aim at increasing constitutive defenses. Such things as higher tannin and lignin concentration, thicker cuticle structure, and increased suberization would be expected to improve resistance. 

The terpenoids, which are composed of the five-carbon isoprenoids, constitute the largest family of natural products with over 22,000 individual compounds in this class having been described. The terpenoids (hemiterpenes, monoterpenes, sesquiterpenes, diterpenes, triterpenes, tetraterpenes, polyterpenes, and the like) play diverse functional roles in plants as hormones, photosynthetic pigments, electron carriers, mediators of polysaccharide assembly, structural components of membranes, and defense compounds. Many compounds used by man including resins, latex, waxes, and oils contain plant terpenoids. 

Proteins constitute a universally essential class of macromolecules which perform a wide range of specialized functions in living systems. Examples of these functions include the enzymatic catalysis of metabolic pathways, hormonal signaling in the endocrine system, and antibody mediated defense in the immune system. Proteins also perform critical structural roles, for example as the muscle proteins actin and myosin. The study of protein structure and function is therefore essential to our understanding of life and the advancement of medicine [1]. 

The main subject of this chapter is one of these remaining stalwart defenses, an antibiotic known as vancomycin (1), which constitutes the only agent presently capable of combating deadly methicillin-resistant strains of Staphylococcus aureus This structurally com-... 

The SCBs, and the floor, walls, and ceiling of the Zone 2A canyon and Room 109 constitute the structures designed to serve a radioactive material confinement function under all normal, abnormal, and accident conditions (refer to Appendix 3E, Section 3E.7 for design basis earthquake accident analysis assumptions). By reducing the likelihood of a radioactive material release these structures provide both defense in depth and worker safety functions. 

Criterion 2 applies to the Zone 1 and Zone 2A canyon/Room 109 confinement structures, the Zone 1 and Zone 2A ventilation exhaust ducting and charcoal filters, and HCF stack HEPA filters. These SSCs constitute the physical barriers that function to prevent the uncontrolled release of radioactive materials from the HCF during normal and abnormal (transient) operating conditions. Thus, these items provide a defense in depth function. 

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