Showing papers by "Northern Illinois University published in 1994"

Disparate rates of molecular evolution in cospeciating hosts and parasites

Abstract: DNA sequences for the gene encoding mitochondrial cytochrome oxidase I in a group of rodents (pocket gophers) and their ectoparasites (chewing lice) provide evidence for cospeciation and reveal different rates of molecular evolution in the hosts and their parasites. The overall rate of nucleotide substitution (both silent and replacement changes) is approximately three times higher in lice, and the rate of synonymous substitution (based on analysis of fourfold degenerate sites) is approximately an order of magnitude greater in lice. The difference in synonymous substitution rate between lice and gophers correlates with a difference of similar magnitude in generation times.

Individualism-Collectivism, Social-Network Orientation, and Acculturation as Predictors of Attitudes Toward Seeking Professional Psychological Help Among Chinese Americans

Abstract: Several culturally based variables were used to predict the patterns of help-seeking attitudes among a sample of Chinese-American students (TV = 219) in a large midwestern university. Cultural values operationalized by H. C. Triandis, R. Bontempo, M. J. Villareal, M. Asai, and N. Lucca's (1988) Individualism-Collectivism Scale, social support attitudes operationalized by A. Vaux's (1985) Network Orientation Scale, and the continuous variable of acculturation operationalized by the Suinn-Lew Asian Self-Identity Acculturation Scale (R. M. Suinn, K. Rickard-Figueroa, S. Lew, & P. Vigil, 1987) were selected as predictors of attitudes as measured by E. H. Fischer and J. L. Turner's (1970) Attitudes Toward Seeking Professional Psychological Help Scale. Each of the 4 independent variables were found to be significant predictors of attitudes towards seeking professional psychological help. The counseling and research implications of the results are discussed. Research on cross-cultural issues that have an impact on counseling and psychotherapy has gained an impetus only since the 1970s (Atkinson, 1985). Atkinson (1985) examined reviews that had critically summarized studies dealing with the relationship between cultural and counseling variables (Atkinson, 1983; Harrison, 1975; Sattler, 1977). Three important characteristics of the studies conducted before 1985 stood out. First, most of the research had focused on relations between African Americans and Caucasians and had not examined other racial and ethnic groups. Second, the settings in which a large proportion of the studies had been conducted were mental health outpatient clinics or psychiatric hospital inpatient units, not college counseling centers. Third, either a survey or an archival research design had been used in a majority of the studies. These observations can also be made about a large number of studies that have examined the role of ethnic and racial variables in areas of psychology other than those of counseling and psychotherapy. Atkinson (1985) recommended that researchers study a number of different ethnic and racial groups, investigate within-group variables, such as self-designated identity and cultural commitment, and do more research in college settings. These recommendations are valuable for studies on a number of psychological issues and processes. Some of these issues include attitudes, values, experiences, expectations, beliefs, and social-support systems of members of different ethnic groups (Root, 1985). These factors affect a number of behaviors, one of which is the act of seeking professional psychological help. Research has shown that members of non-Caucasian ethnic groups

Numerical methods for linear control systems

Abstract: The design and analysis of linear control systems: $$\dot x(t) = Ax(t) + Bu(t),\,\,\,\,\,\,\,\,\,\,y = Cx(t)$$ (1.1) and $$x_{k + 1} = Ax_k + Bu_k ,\,\,\,\,\,yk = Cx_k$$ (1.2) give rise to many interesting linear algebra problems. Some of the important ones are: controllability and observability problems, the problem of computing the exponential matrix e At ,the matrix equations problems: (Lyapunov equations, Sylvester equations, the algebraic Riccati equations), the pole-placement problems, stability problems, and frequency response problems. These problems have been very widely studied in the literature. There exists a voluminous work both on theory and computations. Theory is very rich. Unfortunately, the same can not be remarked about computations. Many of the earlier methods were developed before the computer era, and are not based on numerically sound techniques. Fortunately, in the last twenty years or so, numerically effective techniques have been developed for most of these problems, and numerical analysis aspects of these methods (e.g. study of stability by round-off error analysis) and of the problems themselves (e.g. study of sensitivity) have been studied.

Adaptive signal processing algorithms: stability and performance

Abstract: PART I. 1. Introduction. 2. Offline Analysis. 3. Iterative Minimization. 4. Algorithm Construction. 5. Algorithm Analysis: Gaussian White Noise Setting. 6. Algorithm Analysis: Deterministic Global Theory. PART II. 7. Deterministic Averaging: Single Time Scale. 8. Deterministic Averaging: Mixed Time Scale. PART III. 9. Stochastic Averaging: Single Time Scale. 10. Stochastic Averaging: Mixed Time Scale. APPENDICES. A. Matrix Analysis Review. B. Stochastic Signals and Systems Review. C. Deterministic Signals and Systems Review. D. Mathematical Analysis Review. E. Probability Review. Bibliography. Index.

The DØ detector

Abstract: The DO detector is a large general purpose detector for the study of short-distance phenomena in high energy antiproton-proton collisions, now in operation at the Fermilab Tevatron collider. The detector focusses upon the detection of electrons, muons, jets and missing transverse momentum. We describe the design and performance of the major elements of the detector, including the tracking chambers, transition radiation detector, liquid argon calorimetry and muon detection. The associated electronics, triggering systems and data acquisition systems are presented. The global mechanical, high voltage, and experiment monitoring and control systems which support the detector are described. We also discuss the design and implementation of software and software support systems that are specific to DO.

Rat posterior parietal cortex: topography of corticocortical and thalamic connections.

Abstract: Anatomical and functional findings support the contention that there is a distinct posterior parietal cortical area (PPC) in the rat, situated between the rostrally adjacent hindlimb sensorimotor area and the caudally adjacent secondary visual areas. The PPC is distinguished from these areas by receiving thalamic afferents from the lateral dorsal (LD), lateral posterior (LP), and posterior (Po) nuclei, in the absence of input from the ventrobasal complex (VB) or dorsal lateral geniculate (DLG) nuclei. Behavioral studies have demonstrated that PPC is involved in spatial orientation and directed attention. In the present study we used fluorescent retrograde axonal tracers primarily to investigate the cortical connections of PPC, in order to determine the organization of the circuitry by which PPC is likely to participate in these functions, and also to determine how the topography of its thalamic connections differs from that of neighboring cortical areas. The cortical connections of PPC involve the ventrolateral (VLO) and medial (MO) orbital areas, medial agranular cortex (area Fr2), portions of somatic sensory areas Par1 and Par2, secondary visual areas Oc2M and Oc2L, auditory area Tel, and retrosplenial cortex. The secondary visual areas Oc2L and Oc2M have cortical connections which are similar to those of PPC, but are restricted within orbital cortex to area VLO, and within area Fr2 to its caudal portion, and do not involve auditory area Te1. The cortical connections of hindlimb cortex are largely restricted to somatic sensory and motor areas. Retrosplenial cortex, which is medially adjacent to PPC, has cortical connections that are prominent with visual cortex, do not involve somatic sensory or auditory cortex, and include the presubiculum. We conclude that PPC is distinguished by its pattern of cortical connections with the somatic sensory, auditory and visual areas, and with areas Fr2, and VLO/MO, in addition to its exclusive thalamic connectivity with LD, LP and Po. Because recent behavioral studies indicate that PPC, Fr2 and VLO are involved in directed attention and spatial learning, we suggest that the interconnections among these three cortical areas represent a major component of the circuitry for these functions in rats.

Micromotion of femoral stems in total hip arthroplasty. A randomized study of cemented, hydroxyapatite-coated, and porous-coated stems with roentgen stereophotogrammetric analysis.

Abstract: The fixation of the femoral stem in a total hip arthroplasty was studied in sixty patients (sixty-four hips) with use of roentgen stereophotogrammetric analysis. The hips were randomly stratified on the basis of the age, sex, and weight of the patient; the roentgenographic quality of the bone; and the reason for the operation (primary or secondary osteoarthrosis). The hips were then randomly assigned to one of three types of fixation of the femoral component: insertion with cement, hydroxyapatite coating, or porous coating. Examinations with roentgen stereophotogrammetry were done as long as two years after the operation. Micromotion of the prostheses was evaluated in terms of subsidence or proximal migration and rotations and translations of the proximal-lateral (shoulder) and distal (tip) parts of the prostheses. The clinical results at the two-year follow-up evaluation did not differ significantly between the groups with regard to the Harris hip score or the pain score (p > 0.05 for both; Wilcoxon rank-sum test). There were small or no differences in rotations and micromotions of the shoulder and the tip of the prostheses. Increased subsidence of 0.1 to 0.2 millimeter was recorded for the cemented and the porous-coated prostheses (p = 0.002 and p = 0.02, respectively; Wilcoxon rank-sum test). Thus, proximal hydroxyapatite coating seems to enhance the early fixation of the stem. Conventional roentgenography revealed an increased number of radiodense lines surrounding the porous-coated prostheses. Distal hypertrophy of the femoral cortex was found mainly around the hydroxyapatite-coated prostheses. Proximal resorption of bone and heterotopic ossification occurred to approximately the same extent regardless of the type of fixation used.

Feedback repression of polyamine transport is mediated by antizyme in mammalian tissue-culture cells.

Abstract: Antizyme, a spermidine-induced protein that binds and stimulates ornithine decarboxylase degradation, is now shown also to mediate the rapid feedback inhibition of polyamine uptake into mammalian cells. Using a cell line (HZ7) transfected with truncated antizyme cDNA, and mutant ornithine decarboxylase cell lines, we demonstrate that this newly discovered action of antizyme is distinct from its role in modulating polyamine biosynthesis.

Correcting the 16pf for faking: effects on criterion-related validity and individual hiring decisions

Abstract: The effects of correcting a personality measure for faking were evaluated within an organizational context. Two possible repercussions of score correction were studied using the 16PF personality inventory: the effect on criterion-related validity and the effect on individual hiring decisions (i.e., which applicants would or would not be hired). Results indicated that correction for faking had little effect on criterion-related validity. However, depending on the selection ratio, correction of scores would have resulted in different hiring decisions than those that would have been made on the basis of uncorrected scores. Implications for organizations using personality measures for selection and recommendations regarding the use of faking corrections are discussed.

PI and fuzzy estimators for tuning the stator resistance in direct torque control of induction machines

Abstract: Direct torque control (DTC) of induction machines uses the stator resistance of the machine for estimation of the stator flux. Variations of stator resistance due to changes in temperature or frequency make the operation of DTC difficult at low speeds. A method for the estimation of changes in stator resistance during the operation of the machine is presented. The estimation method is implemented using proportional-integral (PI) control and fuzzy logic control schemes. The estimators observe the machine stator current vector to detect the changes in stator resistance. The performance of the two methods are compared using simulation and experimental results. Results obtained have shown improvement in DTC at low speeds.

Prime time for Bacillus megaterium.

Abstract: It is evident that B megaterium is an intriguing organism because of its biochemical versatility, its wide distribution ecologically, its ability to undergo sporulation, and its usefulness as an industrial production strain and expression host With the progress in genetics and the availability of molecular tools such as new transposons, vectors and efficient transformation, an understanding of some of the organization and regulation of many genes is increasing rapidly Such recent discoveries as the ability of oxetanocin to combat some medically significant, recalcitrant viruses further demonstrates that there is much to be learned and much to benefit from continued study of B megaterium

Teacher attitudes toward mainstreaming: a cross‐cultural study in six nations

Abstract: Attitudes of teachers toward the educational mainstreaming of special needs students in six nations ‐ the United States, Germany, Israel, Ghana, Taiwan, and the Philippines ‐ were compared Also investigated were teacher background variables associated with attitudes toward integration Findings revealed that the most supportive views were expressed by teachers in the United States followed by educators in Germany Attitudes of teachers in the other nations represented mainly a neutral disposition toward mainstreaming The lowest attitude scores were obtained for Israeli non‐kibbutz educators Several variables were associated with attitudes: training in special education, grade level, age, teaching experience, and experience with individuals who are disabled The role that teacher preparation programs and effective mainstreaming practices have in the development of teacher support for integration are discussed

Terrestrial adaptations in the postcranial skeletons of guenons

Abstract: Arboreal and semiterrestrial guenons show similar osteological features of the limbs across a wide range of species, environments, and geography, while the more terrestrially committed guenons exhibit greater morphological divergence. An ecomorphological comparison of two sympatric guenons living in Kibale Forest, Uganda, reveals an array of anatomical adaptations for terrestriality in the limbs of Cercopithecus lhoesti similar to those found in Erythrocebus patas. In contrast, Cercopithecus aethiops, although also frequent users of the terrestrial environment, generally exhibit fewer morphological adaptations characteristic of a terrestrial lifestyle. It appears that significant morphological modification for terrestriality has occurred twice within the diverse radiation of living guenons with C. aethiops perhaps representing a third group in the making.

C-axis response of yba2cu4o8 : a pseudogap and possibility of josephson coupling of cuo2 planes

Abstract: We report on the temperature dependence of the far-infrared conductivity of YBa[sub 2]Cu[sub 4]O[sub 8] single crystals for [bold E][parallel][ital c]. With decreasing temperature, the conductivity shows a transition from a Drude-like behavior to a pseudogap at 180 cm[sup [minus]1] which grows deeper below 180 K without any abrupt changes at the superconducting transition at [ital T][sub [ital c]]=80 K. In the superconducting state the formation of the superfluid condensate can be seen. We show that in a variety of high-[ital T][sub [ital c]] superconductors the value of the London penetration depth for [bold E][parallel][ital c] correlates with the conductivity along the [ital c] direction. With respect to this correlation we discuss the possibility of Josephson coupling between the CuO[sub 2] layers.

Gender, ethnic, and body type biases: The generality of prejudice in childhood.

Abstract: From a very young age, children show signs of prejudice. However, it is not clear whether those who are the most biased in one domain (e.g., gender) are also the most biased in other domains (e.g., ethnicity). This study addressed the issue using multiple measures of prejudice (negative bias) in 3 domains: gender (male, female), ethnicity-language (French Canadian, English Canadian), and body type (overweight, normal weight). The flexibility of attitudes (i.e., the belief that people from different categories can possess similar traits) was also assessed. A total of 254 children (127 boys, 127 girls) in kindergarten to Grade 6 participated. Children demonstrated clear biases against groups to which they did not belong, although attitudes became more flexible and prejudice declined somewhat with age. There was little predictive power across domains; that is, there was no evidence that prejudice represents a general characteristic that differentiates children.

An adaptive estimation of periodic signals using a Fourier linear combiner

Abstract: Presents an adaptive algorithm for estimating from noisy observations, periodic signals of known period subject to transient disturbances. The estimator is based on the LMS algorithm and works by tracking the Fourier coefficients of the data. The estimator is analyzed for convergence, noise misadjustment and lag misadjustment for signals with both time invariant and time variant parameters. The analysis is greatly facilitated by a change of variable that results in a time invariant difference equation. At sufficiently small values of the LMS step size, the system is shown to exhibit decoupling with each Fourier component converging independently and uniformly. Detection of rapid transients in data with low signal to noise ratio can be improved by using larger step sizes for more prominent components of the estimated signal. An application of the Fourier estimator to estimation of brain evoked responses is included. >

Young Measure‐Valued Solutions for Non-Newtonian Incompressible Fluids1

Abstract: For the model of a nonlinear bipolar fluid, in which the highest order viscosity vanishes, and the viscous part of the stress tensor satisfies a growth condition of the form the rate of strain tensor, we demonstrate the existence of Young-measure valued solutions for these solutions are proven to be weak solutions for and for and unique regular weak solutions for

Behavioral assessment of feeding problems of individuals with severe disabilities.

Abstract: As many as 80% of the individuals with severe or profound mental retardation exhibit feeding problems Although behavioral interventions have been used to treat these problems, no assessment procedure for determining a functional relationship between a person's acceptance of food and the type and texture of that food has been reported The purpose of this study was to test a behavioral assessment procedure for a feeding problem of limited intake Five individuals with severe or profound mental retardation were fed 10 to 12 types of foods with one or more textures Behavioral categories of acceptance, rejection, expulsion, and other negative behavior were recorded Results indicated that each subject fit into one of four categories of feeding problems: (a) total refusal, (b) type selectivity, (c) texture selectivity, or (d) type and texture selectivity Thus, although all 5 subjects exhibited limited intake, the food characteristics correlated with the problem were different for each individual Results suggest that treatments for limited intake may be based on assessments that show the association of food type or texture to a person's rejection or expulsion of food

Global patterns of plant diversity

Abstract: Using 94 data sets from across the globe, we explored patterns of mean community species richness, landscape species richness, mean similarity among communities and mosaic diversity. Climate affected community species richness primarily through productivity while other climatic factors were secondary. Climatic equability affected species richness only in temperate regions where richness was greatest at high levels of temperature variability and low levels of precipitation variability. Landscape species richness correlated positively with community species richness. A global gradient in mean similarity existed but was uncorrelated with community species richness. Mean similarity was least and mosaic diversity was greatest between 25 and 30° latitude. The most diverse landscapes (low mean similarity) correlated with warm temperatures, high elevations, large areas and large seasonal temperature fluctuations. The most complex landscapes (high mosaic diversity) correlated with large areas, high productivity and warm winters. We compared diversity measures among continents and found only one significant difference: Australian landscapes have greater mosaic diversity than African landscapes. Based on our analyses we propose two hypotheses: (1) for plants, biotic interactions are more important in structuring landscapes in warmer climates and (2) longer isolated landscapes have more clearly differentiated ecological subunits.

Preparing High School Students with Learning Disabilities for the Transition to Postsecondary Education Teaching the Skills of Self-Determination

Abstract: Increasing numbers of students with learning disabilities (LD) are looking to postsecondary education and training to help them achieve success in career development and eventual job placement. Unfortunately, research suggests that many of these students are having difficulty staying in and completing postsecondary programs. A number of self-determination skills have been identified that are related to students' making a successful transition to postsecondary education. These include stating one's disability and its impact on school performance, and identifying instructional accommodations and strategies for arranging those accommodations with their regular classroom teachers. The purpose of this study was to examine whether these self-determination skills could be acquired through direct instruction, and subsequently generalized to general education classrooms. The results of the effectiveness of this self-determination training are reported and their implications for teachers, parents, and students discussed.

Hypothesis-based interventions for tantrum behaviors of persons with developmental disabilities in school settings.

Abstract: We conducted a functional assessment of problem behaviors of 2 students with developmental disabilities in their classroom environments. Results of the assessments showed that although there were more tantrums in demand than in no-demand conditions, the function of the behavior was to gain attention (positive reinforcement) rather than to avoid or escape demands (negative reinforcement); demand conditions apparently served a discriminative function for the availability of attention. Therefore, intervention was based on the positive reinforcement hypothesis, resulting in a substantial reduction of tantrums for both subjects.

Prepulse inhibition of the startle response in mice: relationship to hearing loss and auditory system plasticity.

Abstract: Prepulse inhibition was used with C57BL/6J (C57) mice to assess behavioral-perceptual correlates of previously demonstrated physiological changes in the central auditory system associated with age-related hearing loss. Normal-hearing CBA/CaJ (CBA) mice and DBA/2J (DBA) mice, which exhibit extremely rapid hearing loss, were also tested. Tone prepulse stimuli (S1s) were presented 100 ms prior to a startle-evoking noise stimulus (S2), and a decrease in startle amplitude served as the measure of startle modification. As high-frequency hearing declined in C57 mice between 1 and 12 months of age, the efficacy of lower-frequency S1s was significantly enhanced. CBA mice exhibited no age-related changes in startle modification. DBA mice exhibited changes similar to those observed in C57s but at an accelerated rate. The enhanced behavioral saliency of low and middle frequencies in C57 and DBA mice appears to be a consequence of neural plasticity in the central auditory system.

Mutagenesis of the hairpin ribozyme

Abstract: Extensive In vitro mutagenesis studies have been performed on the hairpin ribozyme and substrate in an effort to refine the overall secondary structure of the molecule and provide further insight Into what elements are essential for activity. A secondary structure consisting of four helices and five loop regions remains the basic model as originally proposed. Two helices, helix 1 and 2, form between the substrate and ribozyme while helices 3 and 4 are within the ribozyme itself. Our results suggest that helices 3 and 4 are smaller than previously proposed, consisting of four base pairs and three base pairs respectively. Helix 4 can be extended without loss of activity and loop 3 at the closed end of the hairpin model can be varied in sequence with retention of activity. There is an unpaired nucleotide between helices 2 and 3 consisting of a single A base, suggesting the opportunity for flexibility within the tertiary structure at this point. Comparisons are made between the new data and previously published mutagenesis and phylogenetic data. Substrate targeting rules require base pairing between helices 1 and 2 with cleavage (*) occurring in a preferred 5'(g/c/u)n*guc3' sequence of the substrate.

A Cross-Validation Study of the Trauma Symptom Checklist: The Role of Mediating Variables

Abstract: The study examines the responses to the Trauma Symptom Checklist (TSC) of college women (n = 654) sexually abused as children, sexually assaulted as adults, sexually assaulted as children and adults, and nonabused. Also investigated was the role of mediating variables: parental support, attributional style, and coping. Subjects completed a series of self-report measures in small groups. Sexual abuse was associated with more symptoms and more recent assaults, and revictimized women reported the most symptoms. The hypothesized mediating variables were predictive of scores on the Dissociation, Anxiety, Depression, Sexual Abuse Trauma Index, and Sexual Problems subscales. The interaction of low levels of parental support and a nonexpressive coping style was predictive of Anxiety and Depression scores. The results support the validity of the TSC as a measure of sexual abuse trauma and point to family patterns associated with prolonged symptomatology.

Attempts to Improve English L2 Pronunciation: The Variable Effects of Different Types of Instruction

Abstract: This study compared the pronunciation of targeted vocabulary items in spontaneous speech by 23 adult Chinese L1 learners of L2 English grouped into four different conditions reflecting current pedagogical practices: (a) traditional drilling activities, (b) self-study with tape recordings, (c) interactive activities, and (d) a no-intervention control condition. One hundred and twenty native-speaking listeners judged whether there was improvement or deterioration in pronunciation before and at two separate times subsequent to each of the four conditions. Because none of the results appeared to overwhelmingly favor one teaching technique, we included a discussion of the range of patterns of change brought about by the four input types. We also present arguments for a more serious consideration of the complex effects potentially involved when setting out to modify a learner's L2 pronunciation.

A Predictive Approach to the Analysis of Designed Experiments

Abstract: Viewing the analysis of designed experiments as a model selection problem, we introduce the use of a predictive Bayesian criterion in this context based on the predictive density of a replicate experiment (PDRE). A calibration of the criterion is provided to assist in the model choice. The relationships of the proposed criterion to other prevalent criteria, such as AIC, BIC, and Mallows's C p , are given. An information theoretic criterion based on the PDRE's of two competing models is also introduced and compared with the usual F statistic for two nested models. Examples are given to illustrate the proposed methodology.