John Anderson - US grants

This project examines the transport of polymer chains within porous media focusing on systems where the mean chain dimension is comparable to or exceeds the pore size. A solution of high molecular weight polymer is forced by pressure through microporous membranes; polymer is larger than the pores and hence will not pass through the membrane at low throughputs. However, at higher solvent flowrates the polymer chains can deform and some of them will enter the pores. The dependence of polymer rejection on solvent flow rate will be measured and these results will be correlated with molecular properties of the polymer. Successful completion of this work may contribute to an understanding of the deformation of polymer chains in converging solvent flow fields, as well as provide insight into separation of polymeric materials by ultrafiltration. Additionally, adsorption of a polyelectrolyte onto the surfaces of a porous membrane will be studied and transport rates of solvent and other small molecules through the partially blocked pores will be measured. This work also explores the feasibility of creating membranes, modified by adsorbed polymer, whose permeability can be controlled by selectively changing solution properties.

The objective of this project is to study how the enzymes of the cytoplasmic membrane of Micrococcus luteus, a gram positive bacterium, effect the biosynthesis of teichuronic acid which is covalently linked to the peptidoglycan. A series of intermediates containing undecaprenyl phosphate as carrier lipid effect teichuronic acid biosynthesis by sequential elongation of the carbohydrate chain of teichuronic acid. Modified cell preparations will be used to determine if some of the intermediates can transfer the putative teichuronic acid chain to peptidoglycan. Concomitant peptidoglycan synthesis may also be required. Another objective is to isolate and chemically characterize the unique linkage region oligosaccharide which joins teichuronic acid to peptidoglycan. An enzymatic and chemical degradation scheme based on the presumed structure of the linkage region will be followed by purification. Methylation analysis, mass spectrometry and nuclear magnetic resonance spectroscopy will be used for characterization. The glycosyltransferase which is involved in teichuronic acid chain elongation will be purified so that the mechanism can be determined by which glucosyl residues are incorporated into the polymer with retention of anomeric configuration while the alternate residues of the polymer are incorporated with inversion of configuration. Teichuronidase, an enzyme which degrades teichuronic acid, will be isolated from an organism which can utilize teichuronic acid as growth substrate. Characterization of the enzyme will follow. Immunoelectron microscopy utilizing antibodies directed against teichuronic acid will be used to evaluate the location of teichuronic acid in the cell wall and sites of synthesis in the cytoplasmic membrane. Proteus myxofaciens, a gram negative bacterium, produces an extracellular gel which will be isolated and characterized by methylation analysis, mass spectrometry and nuclear magnetic resonance spectroscopy.

Transport of colloidal particles by phoretic mechanisms such as diffusiophoresis, electrophoresis, and osmophoresis will be studied using both experimental and theoretical methods. The experiments involve measurement of particle migration by two separate phenomena: "diffusiophoresis," where a concentration gradient of a simple electrolyte drives the motion of charged colloids, and "ospmophoresis," where vesicles move in response to a gradient of osmotic pressure in the surrounding fluid. The data will be used to test the theoretical models which have been published and to show that these mechanisms of colloidal transport are significant from an engineering, and perhaps biological, point of view. Theoretical work is also anticipated for modeling the influence of proximal boundaries and nearby particles on the diffusiophoretic or electrophoretic velocity of a particle and for modeling the effects of non-uniform surface properties on the phoretic response of particles. Attempts will be made to develop models based on phoretic mechanisms for the locomotion (self-propulsion using chemical energy) of biological cells.

Successful uses of the recent and emerging developments in biotechnology and biochemical engineering require dependable and efficient techniques for separating valuable products such as proteins from process streams. Because of the deficiencies of the present separation methods, there is a critical need for novel techniques that are capable of singling out specific proteins (i.e., capable of high selectivity) and separating them at sufficiently high rates to make the overall process economical. An exploratory experimental research program is conducted to investigate the performance of a novel separation technique.

This is a combined experimental and theoretical research effort to study transport phenomena of polymer solutions in microporous media. In all experiments, well-characterized porous membranes and polymeric molecules are used so that results will be amenable to theoretical analysis. the theoretical aspects of this research focus on relating a microscopic description of polymer dynamics to the observable macroscopic phenomena. Models are sought that allow interpretation of the experimental results in terms of molecular characteristics of the polymer molecules. Of primary interest is the extent to which molecular deformation caused by solvent flow and confining boundaries (pore wall) affects transport of polymers in porous media.

This research is concerned with developing and testing a theory of human cognition. That theory sees human cognition as operating according to a set of production rules. Each production rule specifies that a mental act should take place when a particular type of mental state occurs. The research will continue the development of the PUPS computer simulation program, begun under Anderson's prior NSF support, which enables one to trace out the interactions of these production rules. An effort will be made to make the PUPS simulation available to other interested researchers in the cognitive science community. Part of the effort will be devoted to the writing of a research monograph that will describe the support for Anderson's production system theory. Empirical research will be devoted to analyzing the distinction between procedural and declarative knowledge which is central to the theory. Procedural knowledge is knowledge about how to perform various cognitive skills and is encoded as production rules. Declarative knowledge is factual knowledge about the world which can be used by the production rules. The research will try to establish that these are separate types of knowledge, by showing that there is little transfer between learning procedural and learning declarative knowledge, that declarative knowledge is more readily interfered with by performing a concurrent task which involves similar information, and that people have more conscious control over expression of declarative knowledge. The research will also compare the basic parameters associated with acquisition and retention of the two types of knowledge. The theory is of general applied significance, because it is concerned with the processes by which complex cognitive skills (like doing a proof in logic) are acquired. In particular, in examining the relationship between declarative and procedural knowledge, the research is laying the foundation for understanding how people make the transition from reading written instruction in a technical domain to solving problems fluently in that domain. Anderson is following up this applied challenge in other projects with other funding.

This research uses the Geometry Tutor computer assisted instruction system as an environment to study skill acquisition. A particular model of skill learning, called ACT*, is investigated in detail in three ways. 1) Student performance data with the Geometry Tutor are examined and analysed. 2) Variations of the Geometry Tutor and their effects on learning are studied. 3) A computer simulator of the ACT* theory is interfaced to the Geometry Tutor and used to model a human student's learning process. The importance of this research is that computer supported environments for learning are vital to future science and engineering education. These computer teaching systems must be rationally designed from solid experience and theoretical modeling of how student performance can be optimized.

"Intelligent Tutors in Algebra and Geometry" Currently we have developed a technology for effectively producing intelligent tutors that produce about a one standard deviation improvement on high school mathematics achievement. The goal of this research is to develop and demonstrate intelligent tutoring techniques that will yield a dramatic increase in the effectiveness of intelligent tutoring to a three standard deviation effect. This effort will advance in four fronts. We will develop deeper cognitive models that get at the planning behind mathematics problem solving. We will extend our model-tracing techniques to deal with a word-problem-oriented curriculum. We will identify which features of human and computer pedagogical strategy are effective. We will identify develop interface features for delivering speech, for instructing declarative structures, and for graphically reifying abstract mathematical concepts. The first two years of this proposal will be devoted to exploring these directions. Effort in the third and fourth years will also be directed towards demonstration of this technology and towards dissemination of the technology. We will develop and integrated algebra and geometry tutor that will cover in one year the material that is normally covered in two. We will create a general tutoring architecture that can be used by others to develop mathematics curriculum.

The research deals with protein separations by a new phenomenon, "ligand-induced transport." The protein diffusion across a porous membrane is enhanced by the concentration gradient of a ligand to which the protein binds. The high but different fluxes of different proteins provide the basis for an efficient separation process. In this research six enzymes will be studied, each with two- three ligands. The fluxes will be measured by a new fluorescence spectroscopy technique. The expected results of the research are twofold: (a) to provide a fundamental understanding of protein/ligand interactions; and (b) possibly leads to a new, efficient technique for separation and purification of proteins.

This award supports cooperative research on communication and information theory by William Pearlman and John B. Anderson of Rensselaer Polytechnic Institute and Weiler A. Finamore of the Pontifical Catholic University in Rio de Janeiro. The proposed research will advance our knowledge in areas of data compression and bandwidth-efficient modulation. The work will be divided between efficient digital representation of information generated by analog sources and the development of modems which use continuous-phase modulation. The latter is one the latest innovations in digital information transmission. This work brings together two leading research groups in the two countries. Dr. Pearlman is well-known for his work on quantization and new structures for optimal source codes and Dr. Finamore has contributed to the subjects of coded modulation and source coding. The collaboration should benefit the scientific efforts of both countries leading to advancements in theoretical knowledge and practical applications as well.

The principle methodology of this research has been to develop computer simulations of the representations and mechanisms of human cognition. My research has taken a new direction which is characterized as being focused on how the mechanisms of the human mind are adapted to structure of the environment. I am currently pursuing a thesis called "The principle of rationality" which proposed that the mechanisms of the mind are optimized to the environment. A book is being completed (Anderson, in press) that develops this thesis successfully for relatively simple areas of human cognition such as basic memory and simple concept formation. The purpose of this award is to allow sufficient time to acquire the training required to effectively pursue this analysis for the more complex areas of problem solving and language. The first three years will be spent acquiring a sophisticated background in Bayesian decision theory. The last three years (overlapping in one year) will be spent retraining myself as to the current state of linguistics. In parallel with this, a rational theory of problem solving will be developed. This theory will combine an analysis of the probability of causal extrapolations involved in problem solving with the cost of various paths of problem solving. It will attempt to explain both the logic and control of problem solving as an optimization that responds to the combined consideration of probability and cost.

The PUPS Tutoring Architecure enables exploration of new issues involving the tutoring of introductory programming courses. Its unique features are that it allows one to tutor any programming language and its performance is not significantly affected by the complexity of the program that is being tutored. The proposal is concerned with three different applications of the PUPS Tutoring Architecture. The first concerns increasing the low level of transfer from a first programming course to other programming languages. The effectiveness of simultaneous instruction in multiple languages and the use of data-flow representations to plan algorithms will be explored. Research under this topic will explore issues of how to get students to represent knowledge in a transferrable way. Thus, this research has implications well beyond transfer across programming languages. The second topic concerns use of the architecture to tutor larger programs. Here the concern is both with transfer between a subject domain like mathematics and programming and with issues intrinsic to larger programs such as data structures and algorithm efficiency. The goal here is to begin to understand the relationship between an introductory course and other intellectual activities it is supposed to facilitate. The third application concerns developing training material and utilities to facilitate use of the tutoring architecture by non-Al specialists. A tutor will be developed for use of the production system core of the tutor and a set of authoring aides. This system will be tested with local teachers of introductory programming courses.//

A study of the electrophoretic mobility of complex colloidal systems is proposed. Two model systems will be considered: The first consists of single, nonspherical particles having a nonuniform charge density that leads to a distribution of zeta potential (for example, clay particles); and secondly, aggregates of differently charged spherical particles, (a dumbbell of two particles and chains of three or more particles). Experiments will be performed in a specially designed electrophoresis chamber mounted under a fluorescence microscope. While a theory exists for nonuniformly charged spheroids, it does not account for polarization of the double layer, which occurs at high zeta potentials. It is, thus, proposed to extend the theory to account for polarization effects. There is presently no model for the motion of linear chains of alternately charged particles. Part of this research will therefore, involve development of such a model for the case where the Debye screening length of the solution is very small relative to the diameter of the particles comprising the chain.

Membrane science and separations are two areas highlighted recently by the Amundson report as worthy of special attention in chemical engineering research. The goal of this Gordon Conference, which has been held every other year since 1974, is to bring together researchers working at the leading edge of membrane science and technology for one week so that they may present the most recent research findings and discuss the impact of these findings on the use of membranes in separation methods. In the spirit of Gordon Conference in general, we have organized the 1990 Synthetic Membrane Conference to allow considerable time for active discussion of each paper. This Conference will draw participants from the fields of engineering, chemistry and physics for the purpose of discussing the most recent research progress in membrane science and technology. It is important that we enable a significant number of graduate students to attend so that 1) future leaders of membrane technology are exposed to pioneering work done in the field; 2) the conference benefits from the fresh input provided by younger researchers; and 3) current students in the field of membrane science and separations are stimulated toward a research career and possibly toward a faculty position.

This research will explore the degree to which the basic cognitive functions of memory and categorization are adapted to the structure of the environment. It is based on the hypotheses that human memory functions to make most available that information which is most likely to be needed in the current context and that we form categories of objects to maximize our ability to make predictions about new objects. In the case of memory, the research will explore how the need for information varies with the pattern of past use of that information and the cues available in the environment. The environments to be explored will be both linguistic environments such as newspapers and biological environments as recorded in animal counts. Experiments will determine whether availability of information in memory varies in the same way as need for that information varies in the environment. In the case of categorization, the research will explore how features cluster across objects in our environment. The environments to be explored will be various data sets that have been gathered in the machine learning research on categorization. Experiments will determine if human predictions of object features show sensitivity to the same variables that are predictive in these environments. The theory to be developed will tie the two domains of memory and categorization together as two manifestations of cognition's effort to come up with accurate models of its environment. This research, with its adaptive focus, should allow us to better understanding function and disfunction of human memory.

The goal of this research is to develop the methodology for using model-tracing tutors to deliver useable classroom instruction. The context of this effort will be to develop an Algebra I tutor that will be used in the Pittsburgh Public Schools. As the consequence of past NSF support we have developed a software system for building such tutors, had extensive experience with building tutors for algebra, and have an established research laboratory in the schools. This grant will explore how this can be used to deliver a Algebra I tutor that will be used in the schools. We will try to adapt the expert system development methodology for tutor development. Our experts will be a master teacher in the school system and the mathematics faculty in a local high school. We will work with them on codifying the curriculum (consistent with the standards of the NCTM) that they want to to teach and on making the classroom adjustments to profitably employ the tutor. This project will serve as a general test of our tutoring methodology and serve as a model for adapting it for other school systems and for other topics.

ABSTRACT This proposal is for travel funds to help support a workshop designed to bring chemists and chemical engineers together for the purpose of defining research horizons for "Environmentally benign chemistry". The intended audience is academic chemists and chemical engineers. The workshop will be sponsored by the National Science Foundation (CTS and Chemistry Divisions), Council for Chemical Research, National Institute of Standards and Technology, and Center for Waste Reduction Technology (AIChE). The program committee consists of chemists and chemical engineers from industry, and make decisions on financial support of the academics who attend. We anticipate a total attendance of less than 100. The main goals of the workshop are to develop areas of focus for research into chemical synthesis and process engineering as they relate to environmental concerns; interest the academics, especially the chemists, in these research areas; and provoke brainstorming on environmentally relevant basic research in the chemical sciences at universities.

The goal of this project is to provide a detailed test of the ACT-R theory. The ACT-R theory is a production system theory of human cognition that concerns itself with how cognitive problem solving skills (for example, algebra equation solving) are organized and acquired. It is a computer simulation program which is capable of modeling in detail the steps of problem solving. The experiments in this project will test three new aspects that augment the ACT-R theory. These are: (1) a detailed theory of how people scan visual information and how this relates to higher-level processing; (2) a theory of how attentional limitations affect success in retrieving information needed to solve problems from memory; and (3) a theory of how new problem-solving skills are learned by analogy. The ACT-R theory has played a major role in translating psychological research into educational applications. For instance, computer-based tutors, which incorporate ACT-R models, have been developed for teaching mathematics. While such applications are already successful in improving educational achievement they could be even more successful if they were based on a more detailed interpretation of student behavior. The new theoretical developments that the present experiments will test provide the requisite level of detail in the ACT-R theory; the present research will determine the accuracy of these theoretical extensions.

CTS-9814064
J. Anderson and Y. Solmentsev
Carnegie Mellon University


It is proposed to investigate electrophoretic deposition of particles as a selfassembling coating approach on a flat surface. The proposed model will include a pair of hydrodynamic interaction. Video experiments will be conducted to verify the model, obtain data for multiparticle aggregation and study the differences between direct current and alternating current in the dynamics of selfassembly process. The authors suggests that hydrodynamical forces acting at particle scale play an important role on selfassembling.

If successful, the proposed selfassembling process of particles on a surface may lead to high quality single or multiple layer particle coatings for electronic and optical applications, as well as improved understanding of the dynamics of charged colloidal particles deposited on electrically polarized surfaces.

ACT-R is a theory that tries to model the microstructure of human cognition in time increments of less than a second. According to the ACT-R theory, during each step of cognition some information is retrieved from the environment or memory in response to a goal and this information is used to transform the goal. The research will apply the theory to three domains. Part of the methodology in this research will be to monitor and interpret eye movements to get information about the temporal dynamics of problem solving. The first domain of study will be equation solving, a task of immediate educational significance. The research addresses the question of how fluency in retrieval of arithmetic facts and basic algebraic transformations determines fluency in an advanced mathematical skill. It will measure the duration of eye fixations in reading equations and study how these reflect retrieval processes. These studies will lay the foundation for using eye movements to inform computer-based instruction. The second domain, planning in the Tower of Hanoi laboratory task, is concerned with how planning is guided in complex problem solving. The research tests basic assumptions in the theory about how goals are remembered to organize moment-by-moment problem solving. The timing of individual steps in the solution will be measured and we will look at those that are associated with retrieval of goals. The third domain, research on the psychological refractory period, is concerned with how perception, cognition, and action are intertwined to determine the flow of behavior. The experiments look at when and how doing one task interferes with doing a second task. The ACT-R theory claims that central cognition can only do one thing at a time but that central cognition can run in parallel with perceptual and motor processes. Understanding the timing dependencies in such tasks is important for identifying the critical factors in use of artifacts like computer applications. The research and theory will be extended to studies of how people coordinate eye movements and mouse movements while using a computer.

The goal of this project is to improve our ability to track how students solve mathematical problems. This research will use eye tracking to make real-time inferences about what the student is thinking and fMRI imaging to make inferences about different styles of problem solving. This research is done in the context of both the ACT-R theory of human cognition, which allows us to produce computational models of cognition, and a series of cognitive tutors for mathematics education, which are based on the ACT-R theory. The ACT-R theory is a theory of how the cognitive system adaptively uses procedural and declarative knowledge to achieve its goals. The research will focus on the algebra tutor that is currently in use in high schools and is being adapted for use in middle schools. The research will be concerned with the effect of different mathematical representations on problem solving and with different strategies for mathematical problem solving. There will be three lines of research. One, involving eye movements, will document the instructional opportunities associated with eye movements in the context of the cognitive tutors. It will particularly focus on the eye movements associated with competent use of graphical, tabular, and symbolic representations of functions. The second line of research, involving fMRI brain imaging, will study brain activation markers of the course of mathematical problem solving. It will particularly focus on distinguishing between students who use an informal, verbal form of reasoning with students who use a symbolic, visual form of reasoning. This line will also look at how we can merge information from imaging and eye scanning to make both methodologies more effective. The third line of research will study how one can use the information from fMRI scanning and eye tracking to produce more effective instruction. The three lines of research will converge on a culminating study that attempts to improve the effectiveness of the middle school tutor. It will first use fMRI imaging to identify the learning strategies of individual students and then collect real-time eye movement to guide instruction as students are learning. This will demonstrate how we can use some of the new emerging sensing technology to improve mathematics education.

This Small Business Innovation Research Phase I project is designed to demonstrate the feasibility of building giant-magnetoresistive (GMR) bridge sensors that exhibit tenfold and greater improvement in hysteresis over existing bridge sensors. Unique processing enables edge pinning in GMR sandwich resistor elements that leads to increased stability and significant reduction in hysteresis. Technical objectives required to develop the low hysteresis bridge sensors are: (1) determine the edge hardening mechanism; (2) develop a single-step edge hardening process protocol; (3) develop a two-step edge hardening process protocol; (4) design sensor prototypes utilizing low hysteresis; and (5) build and characterize hard-edge bridge sensors. The research will focus on first gaining an understanding and control of the hard edge treatment. This effort will produce a basic low hysteresis bridge sensor. That knowledge will then be applied to processing variable degrees of hard edge profiles within a given device. The result of this effort will be a self-biased full-output bride sensor and a fully symmetric bridge sensor. In addition to addressing the need for low hysteresis in magnetic bridge sensors, the processes developed can be applied to integrated linear and digital output sensors and signal isolation devices.

Abstract
CTS-0089875
J. L. Anderson, Carnegie Mellon University

Electrophoretic deposition is the procress where charged colloid particles are driven by an applied
electrical field towards the surface of an electrode and deposited there. Under certain conditions, the particles will still be mobile and self assemble before being depositedat a fixed surface location. There is a variety of desirable applications for this procedure, depending on the colloids, the electrodes and also the applied electrical field; in particular, the results obtained differ radically for direct currents and for alternating ones. The goal of this proposal is first to assess the currentlyavailable theoretical models (e.g. electrohydrodynamic, electrokinetic) and their limitaions. It is then to develop a theory and perform experiments which would include all the aspects of self-ordered aggregation for the alternating current case (e.g. Brownian motion, electrokinetice, colloid forces). Specifically, the expected to increase accuracy substantially above what has been obtained elsewhere with layer-averaged modeling.

This Small Business Innovation Research (SBIR) Phase II project will develop giant-magnetoresistive (GMR) sensing devices that yield superior hysteresis performance over existing bridge sensors and GMR signal isolators and provide intrinsic self-biasing without using affixed magnets or power consuming coils. Phase I demonstrated that edge pinning techniques can be used to fabricate low hysteresis push-pull and shielded bridge sensors with designed bias points. Before the technology can be commercialized, Phase II research must: (1) develop hard edge resistor elements that minimize hysteresis and maximize signal; (2) optimize hard edge processing and implementation; (3) determine the viability of alternate pinning strategies; (4) develop specification, architecture, and physical designs for prototype sensor or isolator products; (5) fabricate target devices; and (6) characterize devices for magnetic and electrical responses. A fully developed magnetic field sensor and/or signal isolator is expected, one that is ready for commercialization.

Potential commercial applications are discrete low hysteresis bridge sensors and isolators, improved digital magnetic switches, and ultra-low field sensors employing integrated circuit (IC) based feedback amplifiers.

[unreadable] DESCRIPTION (provided by applicant): The goal of this project is to use brain imaging and cognitive architectures to mutually inform one another. A framework has been developed to map the processes in a cognitive architecture onto the BOLD function obtained in fMRI imaging. Given an assignment of processes to brain regions it is possible to make a priori predictions about the exact form of the BOLD function obtained in these regions across a range of tasks. This can serve as the link that enables fMRI imaging to provide novel tests of any well specified theory of cognitive processing theory and to direct the future development of that theory. More specifically, the research will look at predictions of the ACT-R theory for four general cognitive domains. The first involves algebraic string manipulation tasks for which the theory has already been substantially tested with respect to its simultaneous predictions for a motor area, a posterior parietal imagery area, and a prefrontal retrieval area. The second involves various goal-manipulation tasks for which the expectation is that dorsolateral prefrontal regions will be active during subgoaling. The third involves a set of retrieval tasks involving the fan effect for which the expectation is that the results will elaborate the mapping of the ACT-R theory onto prefrontal retrieval regions. In addition to directing the development of the ACT-R theory this research will serve to develop the conceptual tools for using fMRI research to study higher-level cognitive functioning. Advancing the mapping of brain imaging to higher-level cognitive function is important for many applications including health-related efforts such as understanding the basis of cognitive dysfunctions. [unreadable] [unreadable]

The goal of this project is to improve our ability to track how students learn to solve mathematical problems and how better to instruct mathematics in the context of intelligent tutoring systems. The underlying model of cognition informing the research program is Anderson's ACT-R. The researchers will look both at the potential of eye tracking and of brain imaging to improve the tracking of learning. It will focus on a computer-based algebra tutor that is currently in use in high school and is being adapted for use in middle schools. Past research has shown that instructional interventions based on eye movements can improve learning by detecting when students are having problems and by disambiguating the nature of their confusions. The current research will focus on developing interventions based on using a practical web-based camera that might be deployed in the classroom. The goal is to devise a system that will respond to the course of learning in the individual. They propose three project lines: The first project, involving fMRI brain imaging, will identity brain correlates of critical aspects of mathematics learning (e.g., whether there is a different pattern of activiation when students have simply made a computational error as opposed to when are they confused). The second project will conduct brain imaging studies during tutorial interactions. The research team will attempt to confirm that the Regions of Interest identified in the first line will generalize to learning with the tutor. They will also attempt contingent tutoring in which they branch instructional decisions depending on the brain signal. The third project will focus on advancing eye tracking methodology to the point where it can be used for instruction in the classroom by means of a web-cam.

(58) This project is bringing representatives from industry and education together to address training and education needs for today and the future. The principal issues that are being addressed are: (1) identifing parties who will validate the required competencies of the manufacturing technicians; (2) developing information about previous and ongoing efforts in aerospace manufacturing; (3) benchmarking existing educational models; (4) establishing linkages with other related programs, associations, and organizations; and (5) developing a definitive plan is needed to attract and retain individuals from underrepresented groups. Principal project participants include Boeing and Northrop Grumman, representing the customers for the training process; El Camino College, Oregon Institute of Technology, and Purdue University, as the education providers; and the Society of Manufacturing Engineers as a provider of continuing education, training and certification. The results of the project are being disseminated through a variety of media including workshops, conferences publications and expositions.

This Small Business Innovation Research Phase I project addresses the need for low-cost, portable, and fast analysis biosensors for the detection of biological and chemical pathogens in consumer and point-of-care diagnostic test kits. Magnetic biosensors fuse spintronics and biosensing technologies to improve bioassay
analysis over current fluorescent and chemical-luminescent systems. This program incorporates a high-density form of magnetoresistive random access memory, called VMRAM, with current magnetic biosensing approaches in order to maximize sensor density and resolution by facilitating single-tag detection. Performance goals for the program are sensitivity to 1-10 magnetic tags and a signal level of 100uV per tag.

The technology proposed addresses the need for hand-held bioassay detectors that can be sold cheaper and provide fast analysis in response to the need to prevent the dissemination of biological and chemical pathogens worldwide. Aside from the first responder community, commercial markets for advanced integrated magnetic bioassay sensors include single-test, disposable consumer test kit and point-of-care multi-pathogen test platforms.

DESCRIPTION (provided by applicant): The goal of this project is to use fMRI brain imaging to understand the organization and acquisition of complex cognitive abilities. Components of the ACT-R cognitive architecture, which is capable of modeling complex cognitive abilities, have been mapped on different brain regions. A methodology has been developed for taking the activities of these components and making predictions for the BOLD response obtained in these areas from fMRI imaging. Recent developments have also enabled such tests to be applied in the face of high variability in the timing of individual components. The proposed research is intended to further develop the mapping between components of the ACT-R theory and to extend the work to understand the structure of complex tasks. Three classes of experiments are proposed. First, experiments will be performed to test predictions about a prefrontal region associated with declarative retrieval, a parietal region associated with mental representation, and an anterior cingulate region associated with control. The second group of experiments are designed to extend and modify the ACT-R theory. They will examine whether the response of an anterior prefrontal region can guide the development of a metacognitive component in ACT-R and whether the ACT-T theory of the dorsal caudate should be amended to include effects of reinforcement learning. The third class of experiments will test the decomposition hypothesis -- that the processes in large task consist of the same components as are revealed in smaller tasks. A complex radar-screen task will be investigated to see if the activation patterns in this task can be predicted from the behavior of individual components of the ACT-R theory. It will also be studied to identify further directions for the development of the cognitive architecture. In addition to advancing understanding of complex cognition this research will serve to develop the methodology for using fMRI research to study higher-level cognitive functioning. Advancing the mapping of fMRI brain imaging to higher-level cognitive function is important for many applications including health-related efforts such as understanding the basis of cognitive dysfunctions. For instance, many theories of autism relate it to the coordination of different brain regions in service of intellectual goals. PUBLIC HEALTH RELEVANCE Advancing the mapping of fMRI brain imaging to higher-level cognitive function is important for many applications including health-related efforts such as understanding the basis of cognitive dysfunctions. For instance, many theories of autism relate it to the coordination of different brain regions in service of intellectual goals.

Mathematics is a tool humans invented to help deal with commerce, navigation, agriculture, and government, and other real-world applications. They often require that we extend our mathematical knowledge beyond the exact procedures that we have been taught. Many people have mastered the mathematical knowledge they have been taught in school, but they still display serious difficulties when challenged to extend that knowledge to new situations and often produce nonsensical answers. This research will study adolescents and college students who have mastered middle-school mathematics including fractions and negative numbers, and challenge them to extend this knowledge to deal with a novel mathematical concept.

This research will focus on a little-known class of mathematical problems, called pyramid problems or trapezoidal numbers, that have a natural geometrical interpretation to help guide their understanding. Their novelty to the general public makes them ideal for study and they require no calculations that go beyond middle school mathematics. Participants will be taught to solve pyramid problems that involve small positive integers and then they will be challenged to extend the relationships to deal with large numbers, fractional numbers, and negative numbers. To understand developmental trends, adolescents will be compared with college students. The data to be collected will involve a combination of performance measures, verbal protocols, and fMRI brain imaging patterns. Separate studies will investigate the basis of individual differences in successful knowledge extension, the effect of metacognitive engagement on success, and the role of the geometric interpretation in guiding inferences about the mathematical relationships. This research will take place within the theoretical framework of the ACT-R theory, a computational model of mathematical problem solving. The critical test of this theory will be its ability to predict the rich pattern of data collected. Having such a theoretical framework will be important for generalizing the results from pyramid problems to helping students extend their mathematical knowledge more generally.

The critical contribution of this research is that it goes beyond the question of how to teach a specific mathematical competence and addresses the question of how to prepare students to extend their mathematical knowledge and discover new mathematical relationships. Placed in the context of a formal computational model of cognition, it would make a major contribution to cognitive science and neuroscience by moving theory beyond the learning of well-defined procedures to the mechanisms responsible for the generation of new knowledge. This research will take place within the context of the Cognitive Tutors, which are currently deployed in many American classrooms, reaching over 500,000 students. The computational model developed in the project can be transitioned to these tutors and would enable a major enhancement in the kinds of competences that these tutors teach.

This project, to be conducted at Carnegie-Mellon University in Pittsburgh, Pennsylvania, will study algebra learning and problem-solving by college students and children age 12-14. The project will use behavioral and brain imaging methods to examine when problems are solved using symbols versus images. The results will be used to develop a computational model of mathematical reasoning, and to inform practices for teaching math. This project will advance the work of the REAL (Research on Education and Learning) program in studying the cognitive and neural basis of STEM (science, technology, engineering, and mathematics) learning.

The project will use fMRI (functional magnetic resonance imaging) to study brain activity, focusing on brain regions including the RLPFC (rostrolateral prefrontal cortex) and AG (angular gyrus). The computational modeling will take place using the ACT-R (Adaptive Control of Thought-Rational) model. The main theoretical focus will be how symbolic and visuospatial processes are used and integrated during math learning and problem-solving.

Project Abstract This proposed research involves the investigation of distal anion effects on the properties of transition metal oxo complexes. Transition metal oxo species are invoked as central intermediates in a wide variety of enzymatic oxidations. This centrality has motivated substantial efforts at understanding their structure and function. Molecular model complexes have provided significant insights into oxo complexes by providing systems where hypotheses can be rationally and systematically studied. Nevertheless, it is becoming increasingly apparent that classic systems used to model oxo intermediates, which typically feature strongly donating anionic ligand sets, do not mimic the electronic structures or reactivities of some of the most interesting enzymatic active sites. Against this backdrop, recent results have underscored the importance of secondary coordination sphere effects in the function of oxo species. These studies have primarily focused on hydrogen bonding interactions. In this research program, we aim to investigate an alternative secondary coordination sphere influence, namely that of distal anionic charges. Enzymatic active sites can be highly charged and this effect can strongly influence the reactivity of different oxo species. However, the effect of the incorporation of distal charges has not been systematically investigated. We aim to rationally incorporate distal anions onto model oxo complexes in order to study the effect of anionic charge on the reactivity and properties of transition metal oxo species. By incorporating distal anion charges that are not in conjugation with transition metal centers we will be able to tune the redox potential of transition metal oxo complexes independent of the electronic structure of the M-O unit. This will allow us to modulate parameters such as O-H BDE's which should directly influence C-H abstraction capabilities. Furthermore, we anticipate that the incorporation of distal anions will enable the isolation and study of high-valent oxo complexes with comparatively weak ligand fields. These weak ligand fields should enable unusual electronic structures, such as high spin states, that have been proposed as important for crucial intermediates but have little to no synthetic precedent. As a final point, we will also target oxo complexes that have no structural precedent, particularly Cu oxo species. This broad strategy will enable fundamental insights into processes such as C-H activation/hydroxylation and oxygen evolution. The importance of charge on enzymatic function is well-established, but has not been investigated in the context of oxo intermediates. As such, our approach offers a great deal of promise in understanding the function of oxo complexes and rationally controlling their properties and reactivity.

Project Abstract This is a request for a diversity supplement to the existing grant R35GM133470 to hire Jorge Martinez as a post-doctoral scholar. Jorge Martinez is an outstanding Ph.D. candidate in the laboratory of Jeremy Smith. When he joins our group, Jorge will work on studying the fundamental effects of anionic charges on coordination complexes, particularly oxo complexes. This proposed research involves the investigation of distal anion effects on the properties of transition metal oxo complexes. Transition metal oxo species are invoked as central intermediates in a wide variety of enzymatic oxidations. This centrality has motivated substantial efforts at understanding their structure and function. Molecular model complexes have provided significant insights into oxo complexes by providing systems where hypotheses can be rationally and systematically studied. Nevertheless, it is becoming increasingly apparent that classic systems used to model oxo intermediates, which typically feature strongly donating anionic ligand sets, do not mimic the electronic structures or reactivities of some of the most interesting enzymatic active sites. Against this backdrop, recent results have underscored the importance of secondary coordination sphere effects in the function of oxo species. These studies have primarily focused on hydrogen bonding interactions. In this research program, we aim to investigate an alternative secondary coordination sphere influence, namely that of distal anionic charges. Enzymatic active sites can be highly charged and this effect can strongly influence the reactivity of different oxo species. However, the effect of the incorporation of distal charges has not been systematically investigated. We aim to rationally incorporate distal anions onto model oxo complexes in order to study the effect of anionic charge on the reactivity and properties of transition metal oxo species. Jorge's project will involve a fac-chelating ligand where the number and position of negative charges can be systematically controlled. Furthermore, the system that Jorge will synthesize will enable tuning of the dipole or electric field of systems while also changing the overall charge of the system. Jorge will investigate how these variable affect fundamental properties such as redox-potential, backbonding, basicity, as well as more exotic phenomena such as O-centered radical character. Jorge will then be able to link these properties and the effects of anionic charges to important reactions such as C?H activation and oxygen evolution. In parallel with this research effort, there will be a comprehensive and curated training program to prepare Jorge for a career as a PI at a major research institution. This will involve training in communication, both written and verbal, as well as new instrumental and analytical techniques. Furthermore, there is a multi-component plan aimed at networking interactions for Jorge with the community more broadly and with other faculty at UChicago and other institutions in particular.