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Through our work to examine mathematical and computational learning in authentic and convivial contexts that requires creativity, imagination, reasoning, and discourse, we have theorized an experiential learning cycle that attends to the development of voice, agency, and identity needed in young people for an earned insurgency—the right to demand change. Our work underscores how the current situation that many students face in classrooms amounts to a type of cognitive segregation that denies these students access to authentic and empowering intellectual agency. By facilitating a process whereby students, using their own creative and imaginative means, intentionally develop a type of ownership over the exploration and application of the mathematical concepts they are being taught, we help students move from simple surface level, syntactic understandings, to deeper semantic learning that is more personally significant and meaningful., Através do nosso trabalho para examinar a aprendizagem matemática e computacional em contextos autênticos e conviviais que requerem criatividade, imaginação, raciocínio e discurso, teorizamos um ciclo de aprendizagem experiencial que atende ao desenvolvimento da voz, agência e identidade necessários nos jovens para uma insurgência conquistada—o direito de exigir mudanças. Nosso trabalho ressalta como a situação atual que muitos alunos enfrentam nas salas de aula equivale a um tipo de segregação cognitiva que nega a esses alunos o acesso a uma agência intelectual autêntica e capacitadora. Ao facilitar um processo pelo qual os alunos, usando seus próprios meios criativos e imaginativos, desenvolvem intencionalmente um tipo de propriedade sobre a exploração e aplicação dos conceitos matemáticos que estão sendo ensinados, ajudamos os alunos a passar de um nível de superfície simples, entendimentos sintáticos, para um entendimento semântico mais profundo. aprendizagem que é mais pessoalmente significativa., A través de nuestro trabajo para examinar el aprendizaje matemático y computacional en contextos auténticos y agradables que requieren creatividad, imaginación, razonamiento y discurso, hemos teorizado un ciclo de aprendizaje experiencial que atiende al desarrollo de la voz, la agencia y la identidad necesarias en los jóvenes para un insurgencia ganada—el derecho a exigir cambios. Nuestro trabajo subraya cómo la situación actual que enfrentan muchos estudiantes en las aulas equivale a un tipo de segregación cognitiva que niega a estos estudiantes el acceso a una agencia intelectual auténtica y empoderadora. Al facilitar un proceso mediante el cual los estudiantes, usando sus propios medios creativos e imaginativos, desarrollan intencionalmente un tipo de propiedad sobre la exploración y aplicación de los conceptos matemáticos que se les están enseñando, ayudamos a los estudiantes a pasar de un nivel superficial simple, comprensión sintáctica, a una comprensión semántica más profunda. aprendizaje que es más personalmente significativo y significativo.

Theoretical and experimental observations that catalysis enhances the diffusion of enzymes have generated exciting implications about nanoscale energy flow, molecular chemotaxis, and self-powered nanomachines. However, contradictory claims on the origin, magnitude, and consequence of this phenomenon continue to arise. To date, experimental observations of catalysis-enhanced enzyme diffusion have relied almost exclusively on fluorescence correlation spectroscopy (FCS), a technique that provides only indirect, ensemble-averaged measurements of diffusion behavior. Here, using an anti-Brownian electrokinetic (ABEL) trap and in-solution single-particle tracking, we show that catalysis does not increase the diffusion of alkaline phosphatase (ALP) at the single-molecule level, in sharp contrast to the ∼20% enhancement seen in parallel FCS experiments using p-nitrophenyl phosphate (pNPP) as substrate. Combining comprehensive FCS controls, ABEL trap, surface-based single-molecule fluorescence, and Monte Carlo simulations, we establish that pNPP-induced dye blinking at the ∼10-ms timescale is responsible for the apparent diffusion enhancement seen in FCS. Our observations urge a crucial revisit of various experimental findings and theoretical models--including those of our own--in the field, and indicate that in-solution single-particle tracking and ABEL trap are more reliable means to investigate diffusion phenomena at the nanoscale.

The dynamic link between the nanoscale spatial distribution of biomolecules and their functional impact on cellular and downstream biological behaviors has been hypothesized, but only supported by limited evidences. This is mostly due to the lack to methods to fabricate well-defined patterns of biomolecules. In this thesis, we utilized the DNA origami method to create protein ligand and antigen patterns with high precision, and applied it to study cell signaling events in a cancer cell line and complex antibody-antigen interactions. In addition, to achieve quality fabrication of our protein and antigen functionalized DNA origami nanostructures we developed and adapted several DNA and protein purification methods. Finally, we employed the versatility of the DNA origami method to create anticancer drug carriers with tunable drug release kinetics.

The spatial organization of membrane-bound ligands is thought to regulate receptor-mediated signaling. However, direct regulation of receptor function by nanoscale distribution of ligands has not yet been demonstrated, to our knowledge. We developed rationally designed DNA origami nanostructures modified with ligands at well-defined positions. Using these 'nanocalipers' to present ephrin ligands, we showed that the nanoscale spacing of ephrin-A5 directs the levels of EphA2 receptor activation in human breast cancer cells. Furthermore, we found that the nanoscale distribution of ephrin-A5 regulates the invasive properties of breast cancer cells. Our ligand nanocaliper approach has the potential to provide insight into the roles of ligand nanoscale spatial distribution in membrane receptor mediated signaling.

Since the height of the Vietnam War in 1968, the defense budget has gone through two complete 20 year cycles of decline and recovery, during which the budget topline fell by more than one third in constant dollars. Declines fell disproportionately on the acquisition budget which lost about half of its value in the course of each downturn. This paper examines these cycles, underlying conditions, and measures taken in anticipation of and response to the budget declines, and it observes that the defense budget could be entering another period of decline. Based on history and current conditions, it analyzes the potential effects on the acquisition budget of several different possible defense budget evolutions over the coming decade, notes the potential for severe consequences for acquisition, and suggests possible measures to avoid or ameliorate those consequences., The original document contains color images.

by Alan Clinton Shaw., Thesis (Ph. D.)--Massachusetts Institute of Technology, Program in Media Arts & Sciences, 1995., Includes bibliographical references (leaves 196-199).

A nuclear attack using unconventional means of delivery within the United States remains a very low probability, very high consequence event that is extremely difficult to defend against. In the absence of effective countermeasures, the probability is likely to increase over time, as the technology for making nuclear weapons becomes more accessible. Two other elements of the threat -- access to nuclear materials and expertise, and motivations to attack -- are amenable to influence. Studies have concluded that there are no individual measures that could be conceived and developed that could provide a highly effective defense. In the absence of a vastly increased public perception of the threat of attack, significantly increased funding is unlikely to become available to solve this problem. A reasonable approach is to construct a system of systems (i.e., a coherent array of existing, improved, and new measures that address all elements of all threat paths). The system would be designed to deter through likely denial of success of a very costly operation, coupled with the imposition of retribution and other consequences. This approach makes sense only as long as nuclear weapons remain extremely rare and costly items to potential attackers. The system can be thought of as having three dimensions: (1) basic design and system elements; (2) overall plan for management and organization; and (3) plans for evolution of the system, including identification of needs, research, development, and acquisition. This report concentrates on the first. The general structure of the system should mirror the threat paths, which consist of three basic elements: obtaining a weapon, bringing it to the United States, and using it to cause great damage. System elements will generally consist of the following: (1) controlling the supply side, (2) impeding transportation, and (3) reducing vulnerabilities to attack and freedom of perpetrators to move weapons within the United States.

The goal was to further develop a methodology, language, and tools, based on state machines, for describing, analyzing, and executing requirements and designs for concurrent and distributed real time systems. Using our communicating real time state machine (CRSM) notation , we showed how specifications in the large could be obtained with simple mechanisms for composing CRSMs into subsystems and larger systems, and how assertion checking can be employed to monitor systems changes. Events and data messages that are communicated among distributed components are often time stamped as a way to handle timing constraints, ordering, and causality; the idea of time stamped event histories, i.e., sequences of time stamped events ordered by time, was developed as a new real time programming object and supported by an implementation extension of our CRSM simulator. Our current work is focused on real time communication models that fit naturally into a state machine framework and that can be applied to the many and diverse forms of distributed communication that exist.

The major research accomplishments supported by the grant were: (1) predicting the Deterministic Timing Behavior of Programs. Much work was done in developing concepts and techniques to predict the deterministic execution times of sequential and parallel programs. This also included substantial experimental work and the construction of software tools to validate our ideas and methodology, especially for sequential programs. The basis for this work was our notion of source program timing schema that provided a machine-independent timing semantics for higher-level language software. (2) Specifying Requirements and Designs for Real-Time Systems. A new specification method, called communicating real-time state machines, was invented for describing requirements and designs of distributed real-time systems. (3) Other Research - We designed a methodology for the software engineering of real-time operating systems, based on a straightforward process/abstract-data-type (object) model, and built an operating system kernel using our scheme.

University of Michigan., Vol. 1, no. 2- issued as the University of Michigan official publication, v. 63, no. 74, Electronic serial mode of access: World Wide Web., Michigan quarterly review, Michigan quarterly review. : Vol XXIII : Issue 3, (dlps) volume: act2080.0023.003, (dlps) article: act2080.0023.003:17, These pages may freely searched and displayed. Permission must be received for subsequent distribution in print or electronically. Please contact spo-help@umich.edu for more information.

University of Michigan., Vol. 1, no. 2- issued as the University of Michigan official publication, v. 63, no. 74, Electronic serial mode of access: World Wide Web., Michigan quarterly review, Michigan quarterly review. : Vol XXV : Issue 4, (dlps) volume: act2080.0025.004, (dlps) article: act2080.0025.004:18, These pages may freely searched and displayed. Permission must be received for subsequent distribution in print or electronically. Please contact spo-help@umich.edu for more information.

University of Michigan., Vol. 1, no. 2- issued as the University of Michigan official publication, v. 63, no. 74, Electronic serial mode of access: World Wide Web., Michigan quarterly review, Michigan quarterly review. : Vol XXIV : Issue 3, (dlps) volume: act2080.0024.003, (dlps) article: act2080.0024.003:21, These pages may freely searched and displayed. Permission must be received for subsequent distribution in print or electronically. Please contact spo-help@umich.edu for more information.

University of Michigan., Vol. 1, no. 2- issued as the University of Michigan official publication, v. 63, no. 74, Electronic serial mode of access: World Wide Web., Michigan quarterly review, Michigan quarterly review. : Vol XXV : Issue 4, (dlps) volume: act2080.0025.004, (dlps) article: act2080.0025.004:18, These pages may freely searched and displayed. Permission must be received for subsequent distribution in print or electronically. Please contact spo-help@umich.edu for more information.

University of Michigan., Vol. 1, no. 2- issued as the University of Michigan official publication, v. 63, no. 74, Electronic serial mode of access: World Wide Web., Michigan quarterly review, Michigan quarterly review. : Vol XXIII : Issue 3, (dlps) volume: act2080.0023.003, (dlps) article: act2080.0023.003:17, These pages may freely searched and displayed. Permission must be received for subsequent distribution in print or electronically. Please contact spo-help@umich.edu for more information.

University of Michigan., Vol. 1, no. 2- issued as the University of Michigan official publication, v. 63, no. 74, Electronic serial mode of access: World Wide Web., Michigan quarterly review, Michigan quarterly review. : Vol XXIV : Issue 3, (dlps) volume: act2080.0024.003, (dlps) article: act2080.0024.003:21, These pages may freely searched and displayed. Permission must be received for subsequent distribution in print or electronically. Please contact spo-help@umich.edu for more information.

Technological superiority has been a cornerstone of U.S. security and industry since World War II. That cornerstone is not crumbling, but over the past decade it has weathered significantly. Foreign companies have made deep inroads into high-technology markets that had been more or less the exclusive domain of U.S. industry. In addition to causing economic problems, this has fostered dependence on foreign sources for defense equipment at a time when the technology in defense systems comes increasingly from the civilian sector. At the same time, the Department of Defense reports that Soviet defense technology is catching up with ours, and sophisticated Western military equipment is routinely sold to third world nations. These trends, and others, have prompted the Senate Committee on Armed Services to ask what needs to be done to maintain the base of high technology on which U.S. national security depends. This report, the second of the Office of Technology Assessments's (OTA) "Maintaining the Defense Technology Base," looks into that question in some depth. An earlier report, "The Defense Technology Base: Introduction and Overview" (OTA-ISC-374, March 1988), provided a broad view of the defense technology base and the concerns regarding its health. This report develops some of the ideas introduced in the first report. It examines the management of DoD technology base programs and laboratories. It also analyzes the process through which technology is introduced into defense systems to understand why it takes so long and what might be done to speed up the process. Finally, the report examines the exploitation of civilian commercial sector technology for defense needs. It concentrates on the dual questions of expediting military access to civilian technology and keeping the necessary base of technology alive and well in the United States. Volume 2 of this report contains extensive appendices and will be published in the summer of 1989.

This document describes general requirements for the WIS Test Processing System prototype project. The objective for this effort is the development of a complete Ada-based document management system with capabilities for, but not limited to, word processing, providing output with multiple type fonts, and user-oriented help messages tailored to the operations being performed and user expertise. In general, critical design issues include the following: a) The provision for compatibility with multiple subsystems that may or may not have been completely defined and/or developed; b) The ability to use a variety of input/output devices; c) The capability of using textual syntax/ semantics to provide assistance in document preparation; d) The ability to provide user-oriented help based on analyses of operations being performed (e.g. , code being executed) and user history/expertise. Two specifications have been generated and support the stated objective of developing software in Ada to support WIS communications functionality in the 1990's: a) Specification for Structure Generator Editor for Documents, Programs and Other Structured Data; b) Specification for a Writer's Workbench. This work is the result of the identification of the functionality requirements and research of the technology base., See also Volume 5, ADA178436.

Various applications require triangulations, or polyhedral representations, of surfaces which are represented as serial sections. Heuristic methods are in common use to triangulate such data. These methods work well on segments of generalized cylinder, i.e., runs of sections containing single loops, but they often fail when attempting to process highly convoluted surfaces. This is because the topology of the sections changes when a critical point of the surface is encountered. This paper uses the equivalent of the full adjacency graph of the surface, provided by a voxel model, to classify the changes in topology of the sections of the surface, and thereby guide the triangulation process. For a voxel surface which is a discrete sampling of a smooth manifold in general position, we are able to exhaustively classify the small set of possible topological changes in the sections of the surface; we then deal with these cases exhaustively. To the best of our knowledge, this is the first description of an algorithm which can in theory and practice triangulate surfaces as complex as that of a brain, from serial sections, without human interaction. Keywords: Computer graphs; Computer aided design; Numerical analysis; Biomedical applications.

To counter the growing threat of the Soviet navy, the Administration has announced its intention to reverse the long-term decline in the size of the U.S. Navy and otherwise improve Navy capabilities. It proposes to expand the U.S. fleet from the current 535 ships to roughly 600 and to increase the number of carrier-based air wings from 12 to 14. In addition to expanding, the Navy plans to modernize the existing carrier air forces, replacing 360 aircraft with more recent types, notably the F/A-18. This paper estimates the cost of the Navy's plan to expand and modernize its carrier air forces and examines alternatives to parts of that plan, while a companion Congressional Budget Office paper analyzes the shipbuilding issue.

Copies of company documents and research notes for APPM history., 110366 Acquisition: [2006.0004] "SHAW, ALAN GEORGE LEWERS (PROFESSOR)"

Recently, auroral observations have indicated the strong enhancement of certain infrared bands during periods of auroral activity. A theoretical model has been created in order to study the infrared processes associated with the aurora. The quantitative results of this study depend upon a thorough knowledge of the rates of all processes involved. Some of the rate constants are well known while for others only the crudest approximation is made. Qualitatively, however, results indicate that certain infrared bands of CO2, N2O, NO, and NO+ are strongly enhanced during periods of auroral activity. This is primarily the result of two basic energy exchange mechanisms. The energy deposited by the primary auroral electron flux goes into increasing the internal energy of N2, O2, and O. In addition to energetic auroral particles as an energy source, electric fields are also considered. Qualitatively the results are similar except that the energy tends to be deposited at altitudes somewhat higher than in direct precipitation processes.