Showing papers by "University of Oregon published in 2005"

The Use of Single-Subject Research to Identify Evidence-Based Practice in Special Education:

Abstract: Slnglesubject research plays an important role in the development of evidence-based practice in special education. The defining features of single-subject research are presented, the con- tributions oj single-subject research for special education are reviewed, and a specific proposal is of- fered for using single-subject research to document evidence-based practice. This article allows readers to determine if a specific study is a credible example of single-subject research and if a spe- cific practice or procedure has been validated as "evidence-based" via single-subject research.

Development and testing of a short form of the patient activation measure.

Abstract: Objective The Patient Activation Measure (PAM) is a 22-item measure that assesses patient knowledge, skill, and confidence for self-management. The measure was developed using Rasch analyses and is an interval level, unidimensional, Guttman-like measure. The current analysis is aimed at reducing the number of items in the measure while maintaining adequate precision. Study methods We relied on an iterative use of Rasch analysis to identify items that could be eliminated without loss of significant precision and reliability. With each item deletion, the item scale locations were recalibrated and the person reliability evaluated to check if and how much of a decline in precision of measurement resulted from the deletion of the item. Data sources The data used in the analysis were the same data used in the development of the original 22-item measure. These data were collected in 2003 via a telephone survey of 1,515 randomly selected adults. Principal Findings. The analysis yielded a 13-item measure that has psychometric properties similar to the original 22-item version. The scores for the 13-item measure range in value from 38.6 to 53.0 (on a theoretical 0-100 point scale). The range of values is essentially unchanged from the original 22-item version. Subgroup analysis suggests that there is a slight loss of precision with some subgroups. Conclusions The results of the analysis indicate that the shortened 13-item version is both reliable and valid.

Sequencing of Aspergillus nidulans and comparative analysis with A. fumigatus and A. oryzae

Abstract: The aspergilli comprise a diverse group of filamentous fungi spanning over 200 million years of evolution. Here we report the genome sequence of the model organism Aspergillus nidulans, and a comparative study with Aspergillus fumigatus, a serious human pathogen, and Aspergillus oryzae, used in the production of sake, miso and soy sauce. Our analysis of genome structure provided a quantitative evaluation of forces driving long-term eukaryotic genome evolution. It also led to an experimentally validated model of mating-type locus evolution, suggesting the potential for sexual reproduction in A. fumigatus and A. oryzae. Our analysis of sequence conservation revealed over 5,000 non-coding regions actively conserved across all three species. Within these regions, we identified potential functional elements including a previously uncharacterized TPP riboswitch and motifs suggesting regulation in filamentous fungi by Puf family genes. We further obtained comparative and experimental evidence indicating widespread translational regulation by upstream open reading frames. These results enhance our understanding of these widely studied fungi as well as provide new insight into eukaryotic genome evolution and gene regulation.

Neural measures reveal individual differences in controlling access to working memory.

Abstract: The capacity of visual short-term memory is highly limited, maintaining only three to four objects simultaneously. This extreme limitation necessitates efficient mechanisms to select only the most relevant objects from the immediate environment to be represented in memory and to restrict irrelevant items from consuming capacity. Here we report a neurophysiological measure of this memory selection mechanism in humans that gauges an individual's efficiency at excluding irrelevant items from being stored in memory. By examining the moment-by-moment contents of visual memory, we observe that selection efficiency varies substantially across individuals and is strongly predicted by the particular memory capacity of each person. Specifically, high capacity individuals are much more efficient at representing only the relevant items than are low capacity individuals, who inefficiently encode and maintain information about the irrelevant items present in the display. These results provide evidence that under many circumstances low capacity individuals may actually store more information in memory than high capacity individuals. Indeed, this ancillary allocation of memory capacity to irrelevant objects may be a primary source of putative differences in overall storage capacity.

Training, maturation, and genetic influences on the development of executive attention

Abstract: A neural network underlying attentional control involves the anterior cingulate in addition to lateral prefrontal areas. An important development of this network occurs between 3 and 7 years of age. We have examined the efficiency of attentional networks across age and after 5 days of attention training (experimental group) compared with different types of no training (control groups) in 4-year-old and 6-year-old children. Strong improvement in executive attention and intelligence was found from ages 4 to 6 years. Both 4- and 6-year-olds showed more mature performance after the training than did the control groups. This finding applies to behavioral scores of the executive attention network as measured by the attention network test, event-related potentials recorded from the scalp during attention network test performance, and intelligence test scores. We also documented the role of the temperamental factor of effortful control and the DAT1 gene in individual differences in attention. Overall, our data suggest that the executive attention network appears to develop under strong genetic control, but that it is subject to educational interventions during development.

4.4 billion years of crustal maturation: oxygen isotope ratios of magmatic zircon

Abstract: Analysis of δ18O in igneous zircons of known age traces the evolution of intracrustal recycling and crust-mantle interaction through time. This record is especially sensitive because oxygen isotope ratios of igneous rocks are strongly affected by incorporation of supracrustal materials into melts, which commonly have δ18O values higher than in primitive mantle magmas. This study summarizes data for δ18O in zircons that have been analyzed from 1,200 dated rocks ranging over 96% of the age of Earth. Uniformly primitive to mildly evolved magmatic δ18O values are found from the first half of Earth history, but much more varied values are seen for younger magmas. The similarity of values throughout the Archean, and comparison to the composition of the “modern” mantle indicate that δ18O of primitive mantle melts have remained constant (±0.2‰) for the past 4.4 billion years. The range and variability of δ18O in all Archean zircon samples is subdued (δ18O(Zrc)=5–7.5‰) ranging from values in high temperature equilibrium with the mantle (5.3± 0.3‰) to slightly higher, more evolved compositions (6.5–7.5‰) including samples from: the Jack Hills (4.4–3.3 Ga), the Beartooth Mountains (4.0–2.9 Ga), Barberton (3.5–2.7 Ga), the Superior and Slave Provinces (3.0 to 2.7 Ga), and the Lewisian (2.7 Ga). No zircons from the Archean have been analyzed with magmatic δ18O above 7.5‰. The mildly evolved, higher Archean values (6.5–7.5‰) are interpreted to result from exchange of protoliths with surface waters at low temperature followed by melting or contamination to create mildly elevated magmas that host the zircons. During the Proterozoic, the range of δ18O(Zrc) and the highest values gradually increased in a secular change that documents maturation of the crust. After ∼1.5 Ga, high δ18O zircons (8 to >10‰) became common in many Proterozoic and Phanerozoic terranes reflecting δ18O(whole rock) values from 9 to over 12‰. The appearance of high δ18O magmas on Earth reflects nonuniformitarian changes in the composition of sediments, and rate and style of recycling of surface-derived material into magmas within the crust.

Research in Special Education: Scientific Methods and Evidence-Based Practices

Abstract: This article sets the context for the development of research quality indicators and guidelines for evidence of effective practices provided by different methodologies. The current conceptualization of scientific research in education and the complexity of conducting research in special education settings underlie the development of quality indicators. Programs of research in special education may be viewed as occurring in stages: moving from initial descriptive research, to experimental causal research, to finally research that examines the processes that might affect wide-scale adoption and use of a practice. At each stage, different research questions are relevant, and different research methodologies to address the research questions are needed.

On fusion categories

Abstract: Using a variety of methods developed in the literature (in particular, the theory of weak Hopf algebras), we prove a number of general results about fusion categories in characteristic zero. We show that the global dimension of a fusion category is always positive, and that the S-matrix of any (not necessarily hermitian) modular category is unitary. We also show that the category of module functors between two module categories over a fusion category is semisimple, and that fusion categories and tensor functors between them are undeformable (generalized Ocneanu rigidity). In particular the number of such categories (functors) realizing a given fusion datum is finite. Finally, we develop the theory of Frobenius-Perron dimensions in an arbitrary fusion category. At the end of the paper we generalize some of these results to positive characteristic.

Network thinking in ecology and evolution.

Abstract: Although pairwise interactions have always had a key role in ecology and evolutionary biology, the recent increase in the amount and availability of biological data has placed a new focus on the complex networks embedded in biological systems. The increased availability of computational tools to store and retrieve biological data has facilitated wide access to these data, not just by biologists but also by specialists from the social sciences, computer science, physics and mathematics. This fusion of interests has led to a burst of research on the properties and consequences of network structure in biological systems. Although traditional measures of network structure and function have started us off on the right foot, an important next step is to create biologically realistic models of network formation, evolution, and function. Here, we review recent applications of network thinking to the evolution of networks at the gene and protein level and to the dynamics and stability of communities. These studies have provided new insights into the organization and function of biological systems by applying existing techniques of network analysis. The current challenge is to recognize the commonalities in evolutionary and ecological applications of network thinking to create a predictive science of biological networks.

Affect, Risk, and Decision Making

Abstract: Risk is perceived and acted on in 2 fundamental ways. Risk as feelings refers to individuals' fast, instinctive, and intuitive reactions to danger. Risk as analysis brings logic, reason, and scientific deliberation to bear on risk management. Reliance on risk as feelings is described with "the affect heuristic." The authors trace the development of this heuristic across a variety of research paths. The authors also discuss some of the important practical implications resulting from ways that this heuristic impacts how people perceive and evaluate risk, and, more generally, how it influences all human decision making. Finally, some important implications of the affect heuristic for communication and decision making pertaining to cancer prevention and treatment are briefly discussed.

Early Identification and Interventions for Students With Mathematics Difficulties

Abstract: This article highlights key findings from the small body of research on mathematics difficulties (MD) relevant to early identification and early intervention. The research demonstrates that (a) for many children, mathematics difficulties are not stable over time; (b) the presence of reading difficulties seems related to slower progress in many aspects of mathematics; (c) almost all students with MD demonstrate problems with accurate and automatic retrieval of basic arithmetic combinations, such as 6 + 3. The following measures appear to be valid and reliable indicators of potential MD in kindergartners: (a) magnitude comparison (i.e., knowing which digit in a pair is larger), (b) sophistication of counting strategies, (c) fluent identification of numbers, and (d) working memory (as evidenced by reverse digit span). These are discussed in terms of the components of number sense. Implications for early intervention strategies are explored.

Nanoscaffold Mediates Hydrogen Release and the Reactivity of Ammonia Borane

Abstract: One of the imposing barriers to realizing the promise of an energy economy based on hydrogen is onboard hydrogen storage for fuel-cell-powered vehicles. New materials that enable the release of dense, plentiful and pure hydrogen at temperatures less than 85 oC are necessary to move the world from an oil-based economy to a hydrogen economy. We report a novel approach in which we deposit a hydrogen-rich material into a nanoporous scaffold. The role of the scaffold is to impose a nano-phase structure on the hydrogen-rich material thus providing an additional handle on the kinetics and thermodynamics of hydrogen release. We demonstrate on the example of ammonia borane infused in the nanoporous silica that the kinetics of hydrogen release is improved while the purity of hydrogen is increased in comparison with the release from bulk ammonia borane. These findings suggest that hydrogen rich materials infused in nanoscaffolds offer the most promising approach to date for onboard hydrogen storage

The development of executive attention: contributions to the emergence of self-regulation.

Abstract: Over the past decade, developmental studies have established connections between executive attention, as studied in neurocognitive models, and effortful control, a temperament system supporting the emergence of self-regulation. Functions associated with the executive attention network overlap with the more general domain of executive function in childhood, which also includes working memory, planning, switching, and inhibitory control (Welch, 2001). Cognitive tasks used with adults to study executive attention can be adapted to children and used with questionnaires to trace the role of attention and effortful control in the development of self-regulation. In this article we focus on the monitoring and control functions of attention and discuss its contributions to self-regulation from cognitive, temperamental, and biological perspectives.

Life stress, the "kindling" hypothesis, and the recurrence of depression: considerations from a life stress perspective.

Abstract: Major depression is frequently characterized by recurrent episodes over the life course. First lifetime episodes of depression, however, are typically more strongly associated with major life stress than are successive recurrences. A key theoretical issue involves how the role of major life stress changes from an initial episode over subsequent recurrences. The primary conceptual framework for research on life stress and recurrence of depression is the "kindling" hypothesis (R. M. Post, 1992). Despite the strengths of the kindling hypothesis, a review of the research literature reveals inconsistencies and confusion about life stress and its implications for the recurrence of depression. Adopting a life stress perspective, the authors introduce 3 major themes that resolve the inconsistencies in the current literature. They integrate these themes and extrapolate the ideas with available data to develop a preliminary framework for evaluating competing explanatory models and to guide research on life stress and the recurrence of depression.

Cluster algebras III: Upper bounds and double Bruhat cells

Abstract: We develop a new approach to cluster algebras, based on the notion of an upper cluster algebra defined as an intersection of Laurent polynomial rings. Strengthening the Laurent phenomenon established in [7], we show that under an assumption of ``acyclicity,'' a cluster algebra coincides with its upper counterpart and is finitely generated; in this case, we also describe its defining ideal and construct a standard monomial basis. We prove that the coordinate ring of any double Bruhat cell in a semisimple complex Lie group is naturally isomorphic to an upper cluster algebra explicitly defined in terms of relevant combinatorial data.

Fluency: Bridge Between Decoding and Reading Comprehension

Abstract: A deep, developmental construct and definition of fluency, in which fluency and reading comprehension have a reciprocal relationship, is explicated and contrasted with superficial approaches to that construct. The historical development of fluency is outlined, along with conclusions of the U.S. National Reading Panel, to explore why fluency has moved from being “the neglected aspect of reading” to a popular topic in the field. A practical, developmental instructional program based largely on the theoretical framework and research findings of Linnea Ehri is delineated. The nine essential components of that program include building the graphophonic foundations for fluency; building and extending vocabulary and oral language skills; providing expert instruction and practice in the recognition of high-frequency vocabulary; teaching common word parts and spelling patterns; teaching, modeling, and providing practice in the application of a decoding strategy; using appropriate texts to coach strategic behaviors and to build reading speed; using repeated reading procedures as an intervention approach for struggling readers; extending growing fluency through wide independent reading; and monitoring fluency development through appropriate assessment procedures. The position is taken throughout that teaching, developing, and assessing fluency must always be done in the context of reading comprehension.

A Distributed Left Hemisphere Network Active During Planning of Everyday Tool Use Skills

Abstract: Determiningtherelationshipbetweenmechanismsinvolvedinaction planning and/or execution is critical to understanding the neural basesofskilledbehaviors,includingtooluse.Herewereportfindings from two fMRI studies of healthy, right-handed adults in which an event-related design was used to distinguish regions involved in planning (i.e. identifying, retrieving and preparing actions associated with a familiar tools’ uses) versus executing tool use gestures withthedominantright(experiment1)andnon-dominantleft(experiment 2) hands. For either limb, planning tool use actions activates a distributed network in the left cerebral hemisphere consisting of: (i) posterior superior temporal sulcus, along with proximal regions of the middle and superior temporal gyri; (ii) inferior frontal and ventral premotor cortices; (iii) two distinct parietal areas, one located in the anterior supramarginal gyrus (SMG) and another in posterior SMG and angular gyrus; and (iv) dorsolateral prefrontal cortex (DLFPC). With the exception of left DLFPC, adjacent and partially overlapping sub-regions of left parietal, frontal and temporal cortex are also engagedduringactionexecution.Wesuggestthatthisleftlateralized networkconstitutesaneuralsubstratefortheinteractionofsemantic and motoric representations upon which meaningful skills depend.

Physical discipline and children's adjustment: Cultural normativeness as a moderator

Abstract: Interviews were conducted with 336 mother-child dyads (children's ages ranged from 6 to 17 years; mothers' ages ranged from 20 to 59 years) in China, India, Italy, Kenya, the Philippines, and Thailand to examine whether normativeness of physical discipline moderates the link between mothers' use of physical discipline and children's adjustment. Multilevel regression analyses revealed that physical discipline was less strongly associated with adverse child outcomes in conditions of greater perceived normativeness, but physical discipline was also associated with more adverse outcomes regardless of its perceived normativeness. Countries with the lowest use of physical discipline showed the strongest association between mothers' use and children's behavior problems, but in all countries higher use of physical discipline was associated with more aggression and anxiety.

Political ecology: where is the ecology?

Abstract: © 2005 Edward Arnold (Publishers) Ltd 10.1191/0309132505ph530pr

The Mitochondrial Inner Membrane Protein Mitofilin Controls Cristae Morphology

Abstract: Mitochondria are complex organelles with a highly dynamic distribution and internal organization. Here, we demonstrate that mitofilin, a previously identified mitochondrial protein of unknown function, controls mitochondrial cristae morphology. Mitofilin is enriched in the narrow space between the inner boundary and the outer membranes, where it forms a homotypic interaction and assembles into a large multimeric protein complex. Down-regulation of mitofilin in HeLa cells by using specific small interfering RNA lead to decreased cellular proliferation and increased apoptosis, suggesting abnormal mitochondrial function. Although gross mitochondrial fission and fusion seemed normal, ultrastructural studies revealed disorganized mitochondrial inner membrane. Inner membranes failed to form tubular or vesicular cristae and showed as closely packed stacks of membrane sheets that fused intermittently, resulting in a complex maze of membranous network. Electron microscopic tomography estimated a substantial increase in inner:outer membrane ratio, whereas no cristae junctions were detected. In addition, mitochondria subsequently exhibited increased reactive oxygen species production and membrane potential. Although metabolic flux increased due to mitofilin deficiency, mitochondrial oxidative phosphorylation was not increased accordingly. We propose that mitofilin is a critical organizer of the mitochondrial cristae morphology and thus indispensable for normal mitochondrial function.

Thiol-Functionalized, 1.5-nm Gold Nanoparticles through Ligand Exchange Reactions: Scope and Mechanism of Ligand Exchange

Abstract: Ligand exchange reactions of 1.5-nm triphenylphosphine-stabilized nanoparticles with omega-functionalized thiols provides a versatile approach to functionalized, 1.5-nm gold nanoparticles from a single precursor. We describe the broad scope of this method and the first mechanistic investigation of thiol-for-phosphine ligand exchanges. The method is convenient and practical and tolerates a surprisingly wide variety of technologically important functional groups while producing very stable nanoparticles that essentially preserve the small core size and size dispersity of the precursor particle. The mechanistic studies reveal a novel three-stage mechanism that can be used to control the extent of ligand exchange. During the first stage of the exchange, AuCl(PPh3) is liberated, followed by replacement of the remaining phosphine ligands as PPh3 (assisted by gold complexes in solution). The final stage involves completion and reorganization of the thiol-based ligand shell.

Organizing Far from Equilibrium: Nonlinear Change in Organizational Fields

Abstract: Organizational fields undergo upheavals. Shifting industry boundaries, new network forms, emerging sectors, and volatile ecosystems have become the stuff of everyday organizational life. Curiously, profound changes of this sort receive scant attention in organization theory and research. Researchers acknowledge fieldwide flux, emergence, convergence, and collapse, but sidestep direct investigations of the causes and dynamic processes, leaving these efforts to political scientists and institutional economists. We attribute this neglect to our field's philosophical, theoretical, and methodological fealty to the precepts of equilibrium and linearity. We argue that ingrained assumptions and habituated methodologies dissuade organizational scientists from grappling with problems to which these ideas and tools do not apply. Nevertheless, equilibrium and linearity are assumptions of social theory, not facts of social life. Drawing on four empirical studies of organizational fields in flux, we suggest new intellectual perspectives and methodological heuristics that may facilitate investigation of fields that are far from equilibrium. We urge our colleagues to transcend the general linear model, and embrace ideas like field configuration, complex adaptive systems, self-organizing networks, and autocatalytic feedback. We recommend conducting natural histories of organizational fields, and paying especially close attention to turning points when fields are away from equilibrium and discontinuous changes are afoot.

Peer influence in children and adolescents: crossing the bridge from developmental to intervention science.

Abstract: Considerable evidence supports the hypothesis that peer relationships influence the growth of problem behavior in youth. Developmental research consistently documents the high levels of covariation between peer and youth deviance, even controlling for selection effects. Ironically, the most common public interventions for deviant youth involve segregation from mainstream peers and aggregation into settings with other deviant youth. Developmental research on peer influence suggests that desired positive effects of group interventions in education, mental health, juvenile justice, and community programming may be offset by deviant peer influences in these settings. Given the public health policy issues raised by these findings, there is a need to better understand the conditions under which these peer contagion effects are most pronounced with respect to intervention foci and context, the child's developmental level, and specific strategies for managing youth behavior in groups.

Virtual lesions of the anterior intraparietal area disrupt goal-dependent on-line adjustments of grasp

Abstract: Adaptive motor behavior requires efficient error detection and correction. The posterior parietal cortex is critical for on-line control of reach-to-grasp movements. Here we show a causal relationship between disruption of cortical activity within the anterior intraparietal sulcus (aIPS) by transcranial magnetic stimulation (TMS) and disruption of goal-directed prehensile actions (either grip size or forearm rotation, depending on the task goal, with reaching preserved in either case). Deficits were elicited by applying TMS within 65 ms after object perturbation, which attributes a rapid control process on the basis of visual feedback to aIPS. No aperture deficits were produced when TMS was applied to a more caudal region within the intraparietal sulcus, to the parieto-occipital complex (putative V6, V6A) or to the hand area of primary motor cortex. We contend that aIPS is critical for dynamic error detection during goal-dependent reach-to-grasp action that is visually guided.