Protective spines

Rubber-based adhesives provide softness and good low temperature flexibility (see Table 8). These properties make them the primary choice for the hinge application, which are two thin glue beads applied to the sides of the book block adjacent to the spine. These adhesive beads allow the book to open with the cover and help to protect the spine glue from stresses. Hinge glues have low if any wax, and are pressure sensitive. When used for the spine application, rubber-based adhesives require a water-based emulsion primer due to their short open time and thus low penetration of paper substrates. 

An overall osteoprotective effect is associated with soy diets, the major active component being the isoflavones although the contribution (if any) of soy protein has to be clarified. The spine, rather than the femur, appears to be the most consistently protected bone site. The average daily intake in Japanese women is around 50 mg/day and appears to be sufficient to have a long-term protective effect on the spine. In non-Asian, postmenopausal women, the demonstrated effective dose is 80-90 mg/day. In future clinical studies, investigating the effect of isoflavones on bone metabolism, larger scale, randomized, controlled, intervention trials for longer time periods (1-3 years) will be necessary with a standardized source of soy protein/isoflavones and... 

A one-page essay in which it is suggested that evolution in plankton is driven by a watery arms race has attracted much attention (Smetacek 2001). Smetacek discusses the concept that defence of phytoplankton by mechanical protection, increased cell size, formation of spines, or production of noxious chemicals leads to the adaptation of zooplankton to these measures. This process resulted in the shape and properties of phyto- and zooplankton that we observe today. In the years following that essay several candidate molecules were discovered and intensely studied. The concept that chemical signals and defence metabolites are important factors in plankton ecology has now become widely accepted. 

An intact CNS is critical to the well-being of a person. Nature has gone to a good deal of trouble to protect the CNS from damage, both external and internal. The brain is protected from external trauma by the bony structure we call the skull. The spine is similarly protected by the bony spinal column. The CNS is also protected by the blood-brain barrier against penetration by molecules that might prove a problem. There are special facilitated transport mechanisms for specific molecules required by the CNS but which cannot penetrate the blood-brain barrier. 

Poisons are primarily defensive, designed as protection against predators. Poisons are often sprayed or delivered with a stinger to penetrate the skin. Some fishes, for example, have poisonous spines. Toxins can also be on the skin or be part of the meat of the animal, thus making them poisonous to touch or eat. Some poisonous animals develop very colorful markings to advertise their undesirable qualities. 

The spinal column houses the spinal cord and a blow here can cause derangement of the column, re> suiting in paralysis or death. If you succeed in knocking your opponent down, a blow with your knee, your elbow, the heel of your shoe, or a toe kick can easily kill or seriously injure him (fig. 20). The best place to strike tliis blow is three or four inches above the belt line where the spine is least protected. 

Seaweed is the favorite food of the purple sea urchin (Arbacia punctulata), whose body is covered in 1-inch (2.5-cm) purple spines. During low tide, sea urchins use their tough spines to carve out holes in the rocks. Once inside their caves, they are protected from desiccation during low tide as... 

Shallow-water inhabitants are subject to a variety of predators but protect themselves with an arsenal of defense mechanisms. Sea urchins are covered in sharp spines, and anemones are armed with stinging cells. Sponges wage chemical warfare on their foes by producing toxins, and mobile animals simply... 

Chapters 3 and 4 investigate representatives of the invertebrate groups in the intertidal zone, the small animals. These organisms include sponges, cnidarians, worms, mollusks, crustaceans, and echinoderms. In the coastal food chain, these invertebrates feed on plants and animals and serve as food for larger organisms. Most are protected by structures such as shells or spines or by toxic chemicals. 

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