Showing papers by "Miami University published in 2000"

Inverting the Classroom: A Gateway to Creating an Inclusive Learning Environment

Abstract: (2000). Inverting the Classroom: A Gateway to Creating an Inclusive Learning Environment. The Journal of Economic Education: Vol. 31, No. 1, pp. 30-43.

The Teacher-Student Relationship as an Interpersonal Relationship.

Abstract: Communication skills, as defined by Burleson and Samter (1990), were examined in the teacher‐student relationship. Three questions guided this investigation: (a) with regard to effective teaching, what are students’ perceptions of the importance of communication skills and immediacy behaviors? (b) what is the relationship between students’ perceptions of teachers’ use of communication skills, immediacy behaviors, motivation and learning? and (c) do male and female students differ in their perceptions of communication skill and immediacy behaviors in regard to importance, motivation, and learning? Two studies were conducted. Study one found that students reported referential skill, ego support, and conflict management as being most important to effective teaching. Study two found referential skill, ego support, and immediacy to have a strong relationship with student learning and motivation. Some sex differences also were found and explored in both study one and two.

Generation of reactive oxygen species after exhaustive aerobic and isometric exercise

Abstract: ALESSIO, H. M., A. E. HAGERMAN, B. K. FULKERSON, J. AMBROSE, R. E. RICE, and R. L. WILEY. Generation of reactive oxygen species after exhaustive aerobic and isometric exercise. Med. Sci. Sports Exerc., Vol. 32, No. 9, pp. 1576–1581, 2000. Many studies have implicated elevated oxygen consumption (VO

Linking operational and environmental improvement through employee involvement

Abstract: This paper uses data from 349 employee involvement (EI) team projects to explore the relationships between process type, operational performance, employee involvement, and environmental performance. We investigate the stated goals and outcomes of EI team projects and relationships among these. For repetitive manufacturing processes in particular, we find strong relationships between the operational goals and outcomes of teams and the positive environmental impact outcome. To the extent that environmental performance results from operational systems, this paper suggests that the continuous improvement efforts of operations managers, including EI team projects, can be a key source of environmental improvements. Managers who understand this will take overt steps to leverage their operational improvement systems for environmental gains. From a theory development standpoint, questions are raised regarding the areas of potential synergy between operational and environmental improvement.

A New Set of Arabidopsis Expressed Sequence Tags from Developing Seeds. The Metabolic Pathway from Carbohydrates to Seed Oil

Abstract: Large-scale single-pass sequencing of cDNAs from different plants has provided an extensive reservoir for the cloning of genes, the evaluation of tissue-specific gene expression, markers for map-based cloning, and the annotation of genomic sequences. Although as of January 2000 GenBank contained over 220,000 entries of expressed sequence tags (ESTs) from plants, most publicly available plant ESTs are derived from vegetative tissues and relatively few ESTs are specifically derived from developing seeds. However, important morphogenetic processes are exclusively associated with seed and embryo development and the metabolism of seeds is tailored toward the accumulation of economically valuable storage compounds such as oil. Here we describe a new set of ESTs from Arabidopsis, which has been derived from 5- to 13-d-old immature seeds. Close to 28,000 cDNAs have been screened by DNA/DNA hybridization and approximately 10,500 new Arabidopsis ESTs have been generated and analyzed using different bioinformatics tools. Approximately 40% of the ESTs currently have no match in dbEST, suggesting many represent mRNAs derived from genes that are specifically expressed in seeds. Although these data can be mined with many different biological questions in mind, this study emphasizes the import of photosynthate into developing embryos, its conversion into seed oil, and the regulation of this pathway.

Effects of the Exotic Invasive Shrub Lonicera maackii on the Survival and Fecundity of Three Species of Native Annuals

Abstract: Negative effects on native plant populations are often attributed to invasions by exotic plants, but experimental evidence is lacking to support many of these claims. Lonicera maackii, an exotic shrub with long leaf phenology, has become naturalized throughout the eastern United States. This study investigated the effects of L. maackii on demography of Galium aparine, Impatiens pallida and Pilea pumila, native annual herbs in differing phenological categories. These interactions were examined in two Ohio forest stands. One stand has a history of logging, burning and grazing and a higher L. maackii density, whereas the other stand has little anthropogenic disturbance and a lower L. maackii density. Three types of experimental plots were established: L. maackii removal, L. maackii present and, at the less disturbed stand, L. maackii absent. Seedlings of the annuals were transplanted and monitored for 1 y for survival to reproductive age and fecundity. In the more disturbed stand, survival of Galium...

Mechanisms of the early phases of plant gravitropism.

Abstract: Gravitropism is directed growth of a plant or plant organ in response to gravity and can be divided into the following temporal sequence: perception, transduction, and response. This article is a review of the research on the early events of gravitropism (i.e., phenomena associated with the perception and transduction phases). The two major hypotheses for graviperception are the protoplast-pressure and starch-statolith models. While most researchers support the concept of statoliths, there are suggestions that plants have multiple mechanisms of perception. Evidence supports the hypothesis that the actin cytoskeleton is involved in graviperception/transduction, but the details of these mechanisms remain elusive. A number of recent developments, such as increased use of the molecular genetic approach, magnetophoresis, and laser ablation, have facilitated research in graviperception and have allowed for refinement of the current models. In addition, the entire continuum of acceleration forces from hypo- to hyper-gravity have been useful in studying perception mechanisms. Future interdisciplinary molecular approaches and the availability of sophisticated laboratories on the International Space Station should help to develop new insights into mechanisms of gravitropism in plants.

Computer simulation of surfactant solutions

Abstract: Major advances have been made at several levels of computer simulation of surfactant solutions. Atomistic level studies of preassembled surfactant structures have become fairly routine. The development of structure in surfactant solutions has now been studied using atomistic, coarse grain and mesoscopic models. Coarse grain and mesoscopic simulations have been used to determine phase diagrams. The challenges involved in treating complex surfactant solutions will continue to drive this field forward.

Ethanol, memory, and hippocampal function: a review of recent findings.

Abstract: For well over a century, ethanol was believed to exert its effects on cognition and behavior by producing a ubiquitous depression of central nervous system activity. A general disruption in brain function was consistent with the belief that ethanol's effects on cognition and behavior were also quite general. Substantial evidence now indicates that ethanol produces a host of selective effects on neural activity, resulting in regional differences in ethanol's effects in the brain. Consistent with such evidence, recent research suggests that ethanol's effects on cognition and behavior are not as global as previously assumed. The present paper discusses evidence that many of ethanol's effects on learning and memory stem from altered cellular activity in the hippocampus and related structures. Potential mechanisms for ethanol's disruption of hippocampal function are reviewed. Evidence suggests that ethanol disrupts activity in the hippocampus by interacting directly with hippocampal neurons and by interacting with critical hippocampal afferents. Hippocampus 2000;10:88–93. © 2000 Wiley-Liss, Inc.

A new method for the extraction of fetal ECG from the composite abdominal signal

Abstract: We developed a wavelet transform-based method to extract the fetal electrocardiogram (ECG) from the composite abdominal signal. This is based on the detection of the singularities obtained from the composite abdominal signal, using the modulus maxima in the wavelet domain. Modulus maxima locations of the abdominal signal are used to discriminate between maternal and fetal ECG signals. Two different approaches have been considered, In the first approach, at least one thoracic signal is used as the a prior to perform the classification whereas in the second approach no thoracic signal is needed, A reconstruction method is utilized to obtain the fetal ECG signal from the detected fetal modulus maxima. The proposed technique is different from the classical time-domain methods, in that we exploit the most distinct features of the signal, leading to more robustness with respect to signal perturbations. Results of experiments with both synthetic and real ECG data have been presented to demonstrate the efficacy of the proposed method.

Postural instability and motion sickness in a fixed-base flight simulator

Abstract: We evaluated the prediction that postural instability would precede the subjective symptoms of motion sickness in a fixed-base flight simulator Participants sat in a cockpit in a video projection dome and were exposed to optical flow that oscillated in the roll axis with exposure durations typical of flight simulation The frequencies of oscillation were those that characterize spontaneous postural sway during stance Head motion was measured prior to and during exposure to imposed optical flow Of 14 participants, 6 were classified as motion sick, either during or after exposure to the optical oscillation Prior to the onset of subjective symptoms, head motion among participants who later became sick was significantly greater than among participants who did not become motion sick We argue that the results support the postural instability theory of motion sickness Actual or potential applications include the prevention or mitigation of motion sickness in virtual environments

Urban african-american middle school science students : Does standards-based teaching make a difference?

Abstract: The current reform movement in science education promotes standards-based teaching, including the use of inquiry, problem solving, and open-ended questioning, to improve student achievement. This study examines the influence of standards-based teaching practices on the achievement of urban, African-American, middle school science students. Science classes of teachers who had participated in the professional development (n = 8) of Ohio's statewide systemic initiative (SSI) were matched with classes of teachers (n = 10) who had not participated. Data were gathered using group-administered questionnaires and achievement tests that were specifically designed for Ohio's SSI. Analyses indicate that teachers who frequently used standards-based teaching practices positively influenced urban, African-American students' science achievement and attitudes, especially for boys. Additionally, teachers' involvement in the SSI's professional development was positively related to the reported use of standards-based teaching practices in the classroom. The findings support the efficacy of high-quality professional development to change teaching practices and to enhance student learning. © 2000 John Wiley & Sons, Inc. J Res Sci Teach 37: 1019–1041, 2000

Habitat selection in a large orb-weaving spider: vegetational complexity determines site selection and distribution.

Abstract: Summary 1. The distribution of the large orb-weaving spider Argiope trifasciata in old field habitats of North America and the habitat selection process this species used was studied for 2 years. 2. Because web spiders have limited dispersal abilities and an energetically costly prey capture device, they do not have the ability to sample potential foraging sites. Structural complexity of the vegetation to which the web must be attached is relatively easy to assess. The hypothesis that the structural complexity is a primary factor in determining initial web site selection was tested both by relating the natural distribution of the spiders across habitats to vegetational complexity and by manipulating the complexity of the habitats in a series of experiments. 3. Argiope trifasciata was not distributed evenly among three old field vegetation types. Habitat complexity was related to spider density in both years although no measure of insect activity, prey capture, or prey consumption was correlated with spider distribution. 4. Three experimental manipulations were conducted to test the impact of habitat structure on spider establishment: (1) the amount of natural vegetation was reduced, (2) structures were added to a simple habitat, and (3) the complexity of the structures added was varied. In each case, spiders were introduced and establishment of webs was monitored. In all manipulations, spider establishment was related to the complexity of the substrate available. 5. These results are important for understanding the cues that influence foraging site selection and therefore provide insight into the distribution of species with limited dispersal abilities and high site investment requirements.

The Internet and the Inverted Classroom

Abstract: (2000). The Internet and the Inverted Classroom. The Journal of Economic Education: Vol. 31, No. 1, pp. 11-11.

Motivation for youth participation in sport and physical activity: relationships to culture, self-reported activity levels, and gender.

Abstract: The purpose of the present investigation was to compare participation motives of youth in competitive sport versus physical activity using culture, self-reported physical activity levels, and gender as independent variables. Participants were 1,472 boys (n=822) and girls (n=650) from the United States, Australia, and New Zealand. Three self-report inventories were administered to all participants to determine the amount and frequency of participation as well as participation motives for competitive sport and physical activity. Results from principal component factor analyses revealed stability across cultures in the four factors describing competitive motives (i.e., competition, social/energy, fitness/fun, teamwork) as well as from the four factors describing physical activity motives (i.e., intrinsic, extrinsic, fitness, energy release) accounting for 44% and 51% of the variance, respectively. Results from the 3 x 2 x 3 (Physical Activity Frequency x Gender x Culture) MANOVA's on the competitive sport and physical activity questionnaires revealed significant multivariate main effects for all three independent variables for both questionnaires. Post hoc tests indicated that all four factors were related to these main effects across competitive and physical activity motives. Results are discussed in terms of the differing motives for sport and physical activity and the importance of understanding the particular social milieu in which these activities occur.

Modular Habitat Refugia Enhance Generalist Predators and Lower Plant Damage in Soybeans

Abstract: Promoting generalist predators in agriculture via habitat manipulation has gained much interest in biocontrol research. Straw shelters have been used by Chinese farmers for .2,000 yr to provide temporary spider refugia during cyclic farming disturbances. This method, however, has not been systematically investigated on larger scales in western-style agriculture. Our prelim- inary observations indicated a significant decrease in the abundance of spiders (76%) and their egg sacs (75%), after conventional tillage of soybeans (Glycine max (L.) Merr.). We hypothesized that providing alternative habitats in tilled fields could conserve predatory assemblages following this major disturbance. We used modular habitat refugia constructed of chicken wire loosely filled with bedding straw to provide temporary habitats for epigeic predators in a soybean field. Refugia held 5—36 times the spider density compared with open field, and the production of spider egg sacs was enhanced 18—87 times. Almost 60% more spider species were found in refugia than in open field. Abundance of harvestmen, carabids, and staphylinid beetles also significantly increased in habitat refugia. Increased habitat cover and provision of alternative prey in habitat refugia may have caused this dramatic predator increase. Soybean seedlings grown withi n1mo fhabitat refugia suffered 33% less insect damage compared with plants at control locations. Decrease in seedling damage, however, did not significantly increase soybean seed production. Applications of discrete habitat refugia may provide an alternative to habitat manipulation techniques to conserve and augment arthropod predators in agroecosystems.

Effects of gizzard shad on phytoplankton and nutrient dynamics: role of sediment feeding and fish size

Abstract: We examined the role of the omnivorous fish, gizzard shad (Dorosoma cepedianum), in transporting nutrients from sediments into the water column and their subsequent impacts on phytoplankton. We manipulated sediment access and fish size during two mesocosm experiments to determine how these factors could alter the effects of gizzard shad on phytoplankton. In the first experiment, gizzard shad stimulated phytoplankton only when they could feed directly on lake sediments and not when benthic feeding was prevented by a mesh netting. In the second experiment, small gizzard shad stimulated phytoplankton to a greater extent than did an equivalent biomass of large gizzard shad. In the absence of gizzard shad, zooplankton became more abundant, and phytoplankton were less P limited, compared to treatments with gizzard shad present. This suggests a shift from grazer limitation in the absence of gizzard shad to direct limitation by nutrients in the presence of gizzard shad. Gizzard shad stimulated total N and P, suggesting an important nutrient transport effect. Thus, gizzard shad impact phytoplankton through an interaction of top-down and bottom-up effects, which are facilitated by a large detrital subsidy to this system.

Triggering Events, Corporate Entrepreneurship and the Marketing Function

Abstract: The interface between entrepreneurship and marketing in established companies is explored. It is argued that the conventional role of marketing varies with the type of entrepreneurship, but that the role tends to be reactive or adaptive. An entrepreneurial perspective on marketing is introduced. Factors that initiate entrepreneurial events are examined, and ways for categorizing these triggers are proposed. Four general roles for marketing in entrepreneurial efforts are derived, and the appropriateness of each role is related to the category of trigger. Specific characteristics of marketing’s involvement, such as the pattern, timing, and scope of inputs, are linked to types of triggers. Implications are drawn for theory and practice.

Self-Management and Peer-Monitoring within a Group Contingency To Decrease Uncontrolled Verbalizations of Children with Attention-Deficit/Hyperactivity Disorder.

Abstract: This study examines the efficacy of an intervention designed to improve the classroom behavior of children identified with Attention-Deficit/Hyperactivity Disorder (ADHD). The intervention entailed training a class of third-grade students, including four students diagnosed with ADHD, to use self-management and peer-monitoring strategies embedded within a group contingency to decrease inappropriate verbalizations during class time. Findings indicated that the self-monitoring/group contingency intervention substantially decreased inappropriate talking-out behavior in all four subjects along with their matched controls. Implications as well as limitations within the study are discussed. © 2000 John Wiley & Sons, Inc.

Plastid position in Arabidopsis columella cells is similar in microgravity and on a random positioning machine

Abstract: In order to study gravity effects on plant structure and function, it may become necessary to remove the g-stimulus On Earth, various instruments such as clinostats have been used by biologists in an attempt to neutralize the effects of gravity In this study, the position of amyloplasts was assayed in columella cells in the roots of Arabidopsis thaliana (L) Heynh seedlings grown in the following conditions: on Earth, on a two-dimensional clinostat at 1 rpm, on a three-dimensional clinostat (also called a random-positioning machine, or an RPM), and in space (true microgravity) In addition, the effects of these gravity treatments on columella cell area and plastid area also were measured In terms of the parameters measured, only amyloplast position was affected by the gravity treatments Plastid position was not significantly different between spaceflight and RPM conditions but was significantly different between spaceflight and the classical two-dimensional clinostat treatments Flanking columella cells showed a greater susceptibility to changes in gravity compared to the central columella cells In addition, columella cells of seedlings that were grown on the RPM did not exhibit deleterious effects in terms of their ultrastructure as has been reported previously for seedlings grown on a two-dimensional clinostat This study supports the hypothesis that the RPM provides a useful simulation of weightlessness

STRONTIUM IN THE APATITE STRUCTURE: STRONTIAN FLUORAPATITE AND BELOVITE-(Ce)

Abstract: Strontium is one of the most common substituents in apatite; the presence and behavior of Sr in apatite-group phases are of considerable significance in geology, materials science and biology. The atomic arrangements in strontian fluorapatite (1.18 Sr atoms per 10 Ca sites) and belovite-(Ce) [ideally Sr 6(REE2Na2)(PO4)6F2] have been refined to R values of 0.016 and 0.014, respectively, in order to examine the incorporation of Sr in apatite and apatite-group minerals. In strontian fluorapatite, Sr is ordered at the Ca(2) site, and no dissymmetrization from P63/m results from the substitution; expansion of the Ca(2) site accom

Optimization of site occupancies in minerals using quadratic programming

Abstract: Atomic sites with multiple substituents are common in minerals, and correct site assignment of substituents in structure refinement is of fundamental importance. Substituents must be assigned to particular sites to fit the observed site scattering and chemical analysis, but the assignments are rarely made with mathematical rigor. We propose a quadratic programming approach to calculating optimal site assignments, thereby providing crystallographers with a mathematically robust starting point for the determination of site occupancies. Our program, O CCQP, implements this approach within the widely used MATLAB programming environment. User-defined weights may be assigned to the structural formula, site scattering, and bond-valence sums. The program is useful for evaluation of site occupancies in newly refined structures and re-evaluation of previously published structures with ad hoc site assignments. For larger problems, mineralogists incorporate additional information (e.g., spectroscopic analyses) and adjust site occupancies in an attempt to mimic observed bond lengths, sitescattering values, and quantitative chemical data. Rarely, however, are these adjustments made with mathematical rigor. They invariably incorporate simplifying assumptions based on crystal-chemical reasoning. Examples of such simplifications include substituting only species of like-valence at a site, assuming certain species cannot even be considered at a site, assuming only two species may occupy a site, and assuming certain sites are fully occupied. We present a model for optimizing the occupancies of multiply occupied sites of crystals. The approach is based on crystal-structure data and chemical analyses of the compound, without making prior assumptions. Furthermore, this method provides a flexible means of evaluating the trade-off inherent in assigning occupancies on the basis of a single criterion, such as satisfying the observed structural formula exactly. Multiple criteria may be used and their relative importance adjusted interactively. The optimized occupancies obtained by this method provide a rigorous starting point for evaluation by crystallographers; the optimization yields excellent results from minimal assumptions.

Mutational Analysis of Metallo-β-lactamase CcrA from Bacteroides fragilis†

Abstract: In an effort to evaluate the roles of Lys184, Asn193, and Asp103 in the binding and catalysis of metallo-β-lactamase CcrA from Bacteroides fragilis, site-directed mutants of CcrA were generated and characterized using metal analyses, CD spectroscopy, and kinetic studies. Three Lys184 mutants were generated where the lysine was replaced with alanine, leucine, and glutamate, and the analysis of these mutants indicates that Lys184 is not greatly involved in binding of cephalosporins to CcrA; however, this residue does have a significant role in binding of penicillin G. Three Asn193 mutants were generated where the asparagine was replaced with alanine, leucine, and aspartate, and these mutants exhibited <4-fold decrease in kcat, suggesting that Asn193 does not play a large role in catalysis. However, stopped-flow visible kinetic studies showed that the Asn193 mutants exhibit a slower substrate decay rate and no change in the product formation rate as compared with wild-type CcrA. These results support the pro...