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Responses were sought to the following questions: (1) Are there differences between self concepts of disadvantaged and nondisadvantaged students? (2) Do these differences, if any, occur within and/or among different types of communities? A total of 373 students were selected from Maine communities designated "rural depressed,""rural nondepressed,""affluent suburban," and "typical urban." The Tennessee Self Concept Scale and an Individual Data Sheet were administered. Each subject was categorized from the data as "disadvantaged" or "nondisadvantaged," and also according to community status, sex and grade level. Factorial analysis of variance revealed that the disadvantaged feel less adequate in social interaction than did the nondisadvantaged. On seven other aspects of self concept no class differences existed. "Rural depressed" subjects had a more positive self concept than "affluent suburban." The disadvantaged "rural nondepressed" experienced the greatest negative self concept. In general, it is very difficult to generalize on self concepts of the disadvantaged, and suggestions for further research include the need to treat the group as heterogeneous rather than homogeneous. (CJ)

The hollow fiber membrane bundle is the functional component of artificial lungs, transferring oxygen and carbon dioxide to and from the blood. It is also the primary location of blood clot formation and propagation in these devices. The geometric design of fiber bundles is defined by a narrow range of parameters that determine gas exchange efficiency and blood flow resistance, such as fiber packing density, path length, and frontal area. However, these parameters also affect thrombosis. This study investigated the effect of these parameters on clot formation using 3-D printed flow chambers that mimic the geometry and blood flow patterns of fiber bundles. Hollow fibers were represented by an array of vertical micro-rods (380 micron diameter) arranged with varying packing densities (40, 50, and 60%) and path lengths (2 and 4 cm). Blood was pumped through the device corresponding to three mean blood flow velocities (16, 20, and 25 cm/min). Results showed that (1) clot formation decreases dramatically with decreasing packing density and increasing blood flow velocity, (2) clot formation at the outlet of fiber bundle enhances deposition upstream, and consequently (3) greater path length provides more clot-free fiber surface area for gas exchange than a shorter path length. These results can be used to create less thrombogenic, more efficient artificial lung designs., Translational Impact Sentence: Fiber bundle parameters, such as decreased packing density, increased blood flow velocity, and a longer path length, can be used to design a less thrombogenic, more efficient artificial lung to extend functionality.