Showing papers by "Purdue University published in 1989"

The Competitive Ethos and Democratic Education

Abstract: Young children and even infants work hard at mastering various kills and show spontaneous pleasure at their own accomplishment. John Nicholls explores the conditions that cause students to lose their unselfconscious involvement in a game or task and become concerned with how they are stacking up against others. Charting the development of children s concepts of luck, effort, and ability, he argues that with age they are increasingly prone to take superiority over others as the definition of success. An emphasis on interpersonal competition, which permeates Western society, exacerbates this egotistical tendency and results in diminished accomplishment and alienation from school.To overcome these problems, Nicholls argues, we must become as little children for whom absorption in exploration and accomplishment come naturally, even when those around them are more competent. This ideal is unlikely to be promoted through technical approaches to education, or by the current emphasis on the role of education in economic development. Instead, Nicholls calls for a progressive approach to education. Difficult though it is to implement, this approach is most likely to increase equality of motivation for intellectual development, substantial accomplishment, satisfaction in work, and more productive relations with others. These are important ideas for anyone interested in achievement motivation, for those professionally involved in education, and for nonspecialists interested in, or worried about, how we educate our children."

Social Cognitive Theory and Self-Regulated Learning

Abstract: Current theoretical accounts of learning view students as active seekers and processors of information (Bandura, 1986; Pintrich, Cross, Kozma, & McKeachie, 1986). Learners’ cognitions can influence the instigation, direction, and persistence of achievement-related behaviors (Brophy, 1983; Corno & Snow, 1986; Schunk, 1989; Weiner, 1985; Winne, 1985). Research conducted within various theoretical traditions places particular emphasis on students’ beliefs concerning their capabilities to exercise control over important aspects of their lives (Bandura, 1982; Corno & Man-dinach, 1983; Covington & Omelich, 1979; Rotter, 1966; Weiner, 1979).

Identification of MRF4: a new member of the muscle regulatory factor gene family.

Abstract: We have identified a rat cDNA encoding MRF4, a new member of the muscle regulatory factor gene family that includes MyoD1, myogenin, and Myf-5. MRF4 encodes a predicted 27-kD protein that contains a conserved helix-loop-helix motif, which is a common feature of this gene family. Northern analyses indicate that MRF4 is expressed solely in skeletal muscle tissue but is not detected in most embryonic muscle cell lines. Transfection of MRF4 into C3H10T1/2 fibroblasts produces stable myogenic lineages at frequencies that are equal to or greater than those obtained when MyoD1 or myogenin are introduced into these cells. Expression of the MRF4 cDNA leads to expression of the endogenous MyoD1 and myogenin genes, although C3H10T1/2 cells expressing MyoD1 or myogenin cDNAs do not express MRF4. Interestingly, the endogenous MyoD1 and myogenin genes are negatively regulated by serum and by purified growth factors since MRF4-transfected C3H10T1/2 cells activate MyoD1 and myogenin expression only in mitogen-depleted, differentiation-induced muscle cultures. The myofiber-specific expression pattern of MyoD1 and myogenin in these cells suggests that the primary role for this muscle regulatory factor gene family may be in regulating specific terminal differentiation events that are crucial for normal skeletal muscle development.

Wave Propagation in Structures

Abstract: The present chapter is the culmination of the procedures developed thus far: It allows the analysis of complicated connected structures. In the previous chapters, the systems of equations were set up on an ad hoc basis. This is reasonable and efficient for simple connectivities but can begin to get unwieldy even in the straightforward example of the elastic joint. The only way to efficiently handle problems with complicated boundaries and discontinuities is to develop a matrix methodology. That is the purpose of this chapter.

Rapid Stimulation of an Oxidative Burst during Elicitation of Cultured Plant Cells: Role in Defense and Signal Transduction

Abstract: Stimulation of cultured plant cells with elicitors of the defense response leads to the rapid destruction of a variety of water-soluble compounds including indoleacetic acid and certain fluorescent dyes. This destructive activity, which is often vigorously manifested within 5 minutes of elicitor addition, is shown to derive from the rapid production of H2O2 and its use by extracellular peroxidases. Because of its speed of appearance, this oxidative burst may qualify as the first induced line of defense against invading pathogens. Since H2O2 has been implicated as a second messenger of hormone-stimulated metabolic changes in some animal cells, its possible role in transduction of the defense signal in plants was also examined. Not only did exogenous H2O2 alone stimulate phytoalexin production in the plant cell suspension, but inhibition of elicitor-stimulated phytoalexin production was observed upon addition of catalase and other inhibitors of the oxidative burst. Furthermore, for inhibition to occur, the presence of catalase was required during elicitor addition, since if introduction of the enzyme was delayed until 1 hour after addition of the elicitor, no inhibition resulted. These results suggest that H2O2 also plays an important role in inducing subsequent defense responses such as phytoalexin production.

Gender Stereotypes and Attitudes Toward Women and Men

Abstract: Attitude theory is used to provide a conceptual analysis of how attitudes toward men and women relate to gender stereotypes. Consistent with this analysis, attitudes toward the sexes related positively to the evaluative meaning of the corresponding gender stereo-types. In addition, attitudes and stereotypes about women were extremely favorable - in fact, more favorable than those about men. The findings also demonstrated that the Attitudes Toward Women Scale assesses attitudes toward equal rights for women not attitudes toward women, and therefore did not relate to the evaluative meaning of subjects' stereotypes about women.

Phase relations and vitrification in saccharide-water solutions and the trehalose anomaly

Abstract: Glass transition temperatures and phase relations for several saccharide-water systems are reported. The trehalose-water system is distinguished from the others by a significantly higher T g at all water contents with a particularly large advantage near the stoichiometry of one water molecule per glucose ring. We relate this to the observation that desert insects, which survive dehydration and can exist in suspended animation for decades, produce trehalose intracellularly during desiccation

Correlation between mesh size and equilibrium degree of swelling of polymeric networks

Abstract: A correlation is established between the mesh size of a swollen cross-linked network and its equilibrium polymer volume fraction, for hydrogels isothermally swollen up to semidilute, dilute, or concentrated conditions. The exponent of this correlation decreases as the water concentration of the hydrogel decreases. Experimental results with hydrogels of poly(vinyl alcohol) and poly(2-hydroxy ethyl methacrylate) are used to verify the new scaling laws.

Calibration of wrist-mounted robotic sensors by solving homogeneous transform equations of the form AX=XB

Abstract: To use a wrist-mounted sensor (such as a camera) for a robot task, the position and orientation of the sensor with respect to the robot wrist frame must be known. The sensor mounting position can be found by moving the robot and observing the resulting motion of the sensor. This yields a homogeneous transform equation of the form AX=XB, where A is the change in the robot wrist position, B is the resulting sensor displacement, and X is the sensor position relative to the robot wrist. The solution to an equation of this form has one degree of rotational freedom and one degree of translation freedom if the angle of rotation of A is neither 0 nor pi radians. To solve for X uniquely, it is necessary to make two arm movements and form a system of two equations of the form: A/sub 1/X=XB/sub 1/ and A/sub 2/X=XB/sub 2/. A closed-form solution to this system of equations is developed and the necessary conditions for uniqueness are stated. >

Tissue graft composition

Abstract: This invention relates to a method for preparation of a tissue graft composition from a segment of small intestine. A tissue graft composition is described which comprises the tunica submucosa of a segment of small intestine of a warm-blooded vertebrate wherein the tunica submucosa is deliminated from the tunica muscularis and at least the luminal portion of the tunica mucosa. The tissue graft composition has been shown to have excellent mechanical characteristics, as well as non-allergenicity and non-thrombogenicity in applications as vascular autografts, vascular allografts, and vascular heterografts.

Neutrino Oscillations in Matter

Abstract: Nonzero neutrino masses would provide new, unique information on particle physics beyond the standard model. Neutrino flavor oscillations provide the most sensitive method for directly testing for small neutrino masses. When the oscillations occur in matter, a resonance can occur that dramatically enhances the flavor mixing and can lead to conversion from one neutrino flavor to another. This is an attractive solution to the long-standing "solar neutrino problem." The phenomenon of neutrino oscillations in matter is reviewed. Analytic descriptions of the neutrino flavor survival probability in matter are considered in detail. A discussion is given for applications of neutrino oscillations in matter for the sun, Earth, supernovae, and the early universe.

Relationship between Task and Ego Orientation and the Perceived Purpose of Sport among High School Athletes

Abstract: This study examined the relationship between an athlete's goal perspective (i.e., task or ego orientation) and the perceived purpose of sport among male and female high school athletes. The sport-specific measure of task and ego orientation was found to have a stable factor structure and high internal consistency. Factor analysis of the Purpose of Sport Questionnaire revealed seven factors: sport should (a) teach the value of mastery and cooperation, (b) show people how to be physically active for life, (c) make good citizens, (d) make people competitive, (e) help individuals obtain a high status career, (f) enhance self-esteem, and (g) show people how to get ahead and increase their social status. Results indicated that the importance placed on skill mastery and personal improvement in sport (task orientation) positively related to the beliefs that sport should enhance self-esteem and teach people to try their test, cooperate, and be good citizens. Ego orientation was a positive predictor of the view tha...

Research opportunities on clusters and cluster-assembled materials—A Department of Energy, Council on Materials Science Panel Report

Abstract: The Panel was charged with assessing the present scientific understanding of the size-dependent physical and chemical properties of clusters, the methods of synthesis of macroscopic amounts of size-selected clusters with desired properties, and most importantly, the possibility of their controlled assembly into new materials with novel properties. The Panel was composed of both academic and industrial scientists from the physics, chemistry, and materials science communities, and met in January 1988.In materials (insulators, semiconductors, and metals) with strong chemical bonding, there is extensive spatial delocalization of valence electrons, and therefore the bulk physical properties which depend upon these electrons develop only gradually with cluster size. Recent research using supersonic-jet, gas-aggregation, colloidal, and chemical-synthetic methods indeed clearly establishes that intermediate size clusters have novel and hybrid properties, between the molecular and bulk solid-state limits. A scientific understanding of these transitions in properties has only been partially achieved, and the Panel believes that this interdisciplinary area of science is at the very heart of the basic nature of materials. In Sec. V (Future Challenges and Opportunities), a series of basic questions for future research are detailed. Each question has an obvious impact on our potential ability to create new materials.Present methods for the synthesis of useful amounts of size-selected clusters, with surface chemical properties purposefully controlled and/or modified, are almost nonexistent, and these fundamentally limit our ability to explore the assembly of clusters into potentially novel materials. While elegant spectroscopic and chemisorption studies of size-selected clusters have been carried out using molecular-beam technologies, there are no demonstrated methods for recovery and accumulation of such samples. Within the past year, the first reports of the chemical synthesis of clusters with surfaces chemically modified have been reported for limited classes of materials. Apparatus for the accumulation and consolidation of nanophase materials have been developed, and the first promising studies of their physical properties are appearing. In both the chemical and nanophase synthesis areas, clusters with a distribution of sizes and shapes are being studied. Progress on macroscopic synthetic methods for size-selected clusters of controlled surface properties is the most important immediate goal recognized by the Panel. Simultaneous improvement in physical characterization will be necessary to guide synthesis research.Assuming such progress will occur, the Panel suggests that self-assembly of clusters into new elemental polymorphs and new types of nanoscale heterogeneous materials offers an area of intriguing technological promise. The electrical and optical properties of such heterogeneous materials could be tailored in very specific ways. Such ideas are quite speculative at this time; their implementation critically depends upon controlled modification of cluster surfaces, and upon development of characterization and theoretical tools to guide experiments.The Panel concluded that a number of genuinely novel ideas had been enunciated, and that in its opinion some would surely lead to exciting new science and important new materials.

A Simple Flow Rule for Characterizing Nonlinear Behavior of Fiber Composites

Abstract: A one-parameter flow rule for orthotropic plasticity was developed to describe nonlinear behavior of fiber composites. Since most fiber composites exhibit in significant plasticity in the longitudi...

Bit-to-bit error dependence in slotted DS/SSMA packet systems with random signature sequences

Abstract: A technique is developed to find an accurate approximation to the probability of data bit error and the probability of packet success in a direct-sequence spread-spectrum multiple-access (DS/SSMA) packet radio system with random signature sequences. An improved Gaussian approximation to the probability of data bit error is performed. Packet performance is analyzed by using the theory of moment spaces to gain insight into the effect of bit-to-bit error dependence caused by interfering signal relative delays and phases which are assumed constant over the duration of a desired packet. Numerical results show that if no error control exists in the desired packet or if block error control is used when multiple-access interference is high, the error dependence increases the average probability of packet success beyond that predicted by models which use independent bit errors. However, when block error control is used and the multiple-access interference is low, the bit error dependencies cause a reduction in packet error performance. >

Characterization of the glycinin gene family in soybean.

Abstract: We characterized the structure, organization, and expression of genes that encode the soybean glycinins, a family of storage proteins synthesized exclusively in seeds during embryogenesis. Five genes encode the predominant glycinin subunits found in soybeans, and they have each been cloned, sequenced, and compared. The five genes have diverged into two subfamilies that are designated as Group-I and Group-II glycinin genes. Each glycinin gene contains four exons and three introns like genes that encode related proteins in other legumes. Two other genes have been identified and designated as "glycinin-related" because they hybridize weakly with the five glycinin genes. Although not yet characterized, glycinin-related genes could encode other glycinin subunit families whose members accumulate in minor amounts in seeds. The three Group-I glycinin genes are organized into two chromosomal domains, each about 45 kilobase pairs in length. The two domains have a high degree of homology, and contain at least five genes each that are expressed either in embryos or in mature plant leaves. Gel blot studies with embryo mRNA, as well as transcription studies with 32P-RNA synthesized in vitro from purified embryo nuclei, indicate that glycinin and glycinin-related genes become transcriptionally activated in a coordinated fashion early in embryogenesis, and are repressed coordinately late in seed development. In addition to transcriptional control processes, posttranscriptional events also are involved in regulating glycinin and glycinin-related mRNA levels during embryogenesis.

A neural network methodology for process fault diagnosis

Abstract: The ability of knowledge-based expert systems to facilitate the automation of difficult problems in process engineering that require symbolic reasoning and an efficient manipulation of diverse knowledge has generated considerable interest recently. Rapid deployment of these systems, however, has been difficult because of the tedious nature of knowledge acquisition, the inability of the system to learn or dynamically improve its performance, and the unpredictability of the system outside its domain of expertise. This paper proposes a neural-network-based methodology for providing a potential solution to the preceding problems in the area of process fault diagnosis. The potential of this approach is demonstrated with the aid of an oil refinery case study of the fluidized catalytic cracking process. The neural-network-based system successfully diagnoses the faults it is trained upon. It is able to generalize its knowledge to successfully diagnose novel fault combinations it is not explicitly trained upon. Furthermore, the network can also handle incomplete and uncertain data. In addition, this approach is compared with the knowledge-based approach.

Antecedents and consequences of role stress: A covariance structure analysis

Abstract: An earlier model of the consequences of role conflict and role ambiguity is expanded to incorporate antecedent job conditions and the outcome of organizational commitment. This newer model clarifies the impact of role stressors on commitment and other established outcomes (i.e. tension, job dissatisfaction, and turnover intention). The antecedent job conditions are added in consideration of research indicating that role conflict and ambiguity do not directly influence affective and behavioral reactions when other perceptions of the work environment are included in the analysis. A LISREL analysis of this model with cross-validation on an independent sample indicated that the direct effects of participation and co-worker social support on job satisfaction may account for the direct effects of role conflict and role ambiguity on satisfaction and turnover intention observed in previous studies. In addition, organizational commitment appeared to mediate the effects of other variables on turnover intention. Implications for theories of role-related variables and directions for future research are discussed.

Language learnability and specific language impairment in children

Abstract: Theories of language learnability have focused on “normal” language development, but there is a group of children, termed “specifically language-impaired,” for whom these theories are also appropriate. These children present an interesting learnability problem because they develop language slowly, the intermediate points in their development differ in certain respects from the usual developmental stages, and they do not always achieve the adult level of language functioning. In this article, specifically language-impaired children are treated as normal learners dealing with an input that is distorted in principled ways. When the children are viewed from this perspective, Pinker's (1984) theory can account for many of the features of their language.

Least significant differences for combined analyses of experiments with two- or three-factor treatment designs

Abstract: (...) Emphasis is given to combined analyses of series of experiments in which the effects of experiments are considered to be random; individual experiments are assumed to have complete factorial treatment designs involving either two or three factors of which at least one is qualitative. All treatments effects, including main effects and interactions, are considered to be fixed effects. Formulae applicable to commonly used experimental designs are presented for the estimation of variances for the five categories of pairwise mean differences in two-factor treatment designs and the 19 categories of pairwise mean differences in three-factor treatment designs (...)

Method and apparatus for thermally destroying a layer of an organ

Abstract: Method and apparatus are disclosed for thermally destroying a layer of an organ such as the mucosal layer of the gallbladder. The apparatus includes a catheter having an elongated member having a plurality of lumens therein. At the distal end of the elongated member is an electrode for emitting radiofrequency current to the mucosal layer. Also at the distal end is a capacitive balloon electrode surrounding the current-emitting electrode for containing an electrolyte solution and for distributing the radiofrequency current to the mucosal layer. The balloon electrode is expanded with the electrolyte solution to conform and make contact with the mucosal layer. The electrolyte solution has a resistivity significantly less than the resistivity of the gallbladder wall, as well as the gallbladder bile, to cause a concentrated power deposition in the mucosal layer. The distal end of the catheter is endoscopically inserted into the body of the gallbladder by a retrograde route through the duodenum, common bile duct and cystic duct. While the balloon electrode is being expanded, the bile present in the gallbladder is drained through one of the lumens in the elongated member. The apparatus also includes a radiofrequency generator for supplying radiofrequency current to the current-emitting electrode. The current-emitting electrode is energized for a period of time to cause the mucosal layer to be heated for a predetermined period of time to thermally coagulate the mucosal layer of the gallbladder and cystic duct. A dispersive electrode is positioned on the skin of the patient's body to facilitate a complete circuit back to the generator without causing trauma to the patient.

Changes in the zein composition of protein bodies during maize endosperm development.

Abstract: Zeins, the seed storage proteins of maize, are synthesized during endosperm development by membrane-bound polyribosomes and transported into the lumen of the endoplasmic reticulum, where they assemble into protein bodies. To better understand the distribution of the various zeins throughout the endosperm, and within protein bodies, we used immunolocalization techniques with light and electron microscopy to study endosperm tissue at 14 days and 18 days after pollination. Protein bodies increase in size with distance from the aleurone layer of the developing endosperm; this reflects a process of cell maturation. The protein bodies within the subaleurone cell layer are the smallest and contain little or no alpha-zein; beta-zein and gamma-zein are distributed throughout these small protein bodies. The protein bodies in cells farther away from the aleurone layer are progressively larger, and immunostaining for alpha-zein occurs over locules in the central region of these protein bodies. In the interior of the largest protein bodies, the locules of alpha-zein are fused. Concomitant with the appearance of alpha-zein in the central regions of the protein bodies, most of the beta- and gamma-zeins become peripheral. These observations are consistent with a model in which specific zeins interact to assemble the storage proteins into a protein body.

Effects of sample size in classifier design

Abstract: The effect of finite sample-size on parameter estimates and their subsequent use in a family of functions are discussed. General and parameter-specific expressions for the expected bias and variance of the functions are derived. These expressions are then applied to the Bhattacharyya distance and the analysis of the linear and quadratic classifiers, providing insight into the relationship between the number of features and the number of training samples. Because of the functional form of the expressions, an empirical approach is presented to enable asymptotic performance to be accurately estimated using a very small number of samples. Results were experimentally verified using artificial data in controlled cases and using real, high-dimensional data. >