Showing papers by "Hampshire College published in 2005"

An investigation of moral judgement in frontotemporal dementia.

Abstract: Objective:To investigate the basis of disturbed moral judgment in patients with frontotemporal dementia (FTD).Background:FTD is characterized by difficulty in modulating social behavior. Patients lack social propriety and may perform sociopathic acts. In addition, FTD patients often lack empathy for

The Push3 execution stack and the evolution of control

Abstract: The Push programming language was developed for use in genetic and evolutionary computation systems, as the representation within which evolving programs are expressed. It has been used in the production of several significant results, including results that were awarded a gold medal in the Human Competitive Results competition at GECCO-2004. One of Push's attractive features in this context is its transparent support for the expression and evolution of modular architectures and complex control structures, achieved through explicit code self-manipulation. The latest version of Push, Push3, enhances this feature by permitting explicit manipulation of an execution stack that contains the expressions that are queued for execution in the interpreter. This paper provides a brief introduction to Push and to execution stack manipulation in Push3. It then presents a series of examples in which Push3 was used with a simple genetic programming system (PushGP) to evolve programs with non-trivial control structures.

Operating Systems Design and Implementation (3rd Edition)

Abstract: ion is the key to managing complexity. Good abstractions turn a nearly impossible task into two manageable ones. The first one of these is defining and^aglementing the abstractions. The second one is using these abstractions to sol^He problem at hand. One abstraction that almost every computer user understands is the file. It is a useful piece of information, such as a digital photo, SEC. 1.1 WHAT IS AN OPERATING SYSTEM? 5 saved e-mail message, or Web page. Dealing with photos, e-mails, and Web pages is easier than the details of disks, such as the floppy disk described above. The job of the operating system is to create good abstractions and then implement and manage the abstract objects thus created. In this book, we will talk a lot about abstractions. They are one of the keys to understanding operating systems. This point is so important that it is worth repeating in different words. With all due respect to the industrial engineers who designed the Macintosh, hardware is ugly. Real processors, memories, disks, and other devices are very complicated and present difficult, awkward, idiosyncratic, and inconsistent interfaces to the people who have to write software to use them. Sometimes this is due to the need for backward compatibility with older hardware, sometimes due to a desire to save money, but sometimes the hardware designers do not realize (or care) how much trouble they are causing for the software. One of the major tasks of the operating system is to hide the hardware and present programs (and their programmers) with nice, clean, elegant, consistent, abstractions to work with instead. Operating systems turn the ugly into the beautiful, as shown in Fig. 1-2. Application programs

Emergence of Collective Behavior in Evolving Populations of Flying Agents

Abstract: We demonstrate the emergence of collective behavior in two evolutionary computation systems, one an evolutionary extension of a classic (highly constrained) flocking algorithm and the other a relatively un-constrained system in which the behavior of agents is governed by evolved computer programs. The first system demonstrates the evolution of a form of multicellular organization, while the second demonstrates the evolution of a form of altruistic food sharing. In this article we describe both systems in detail, document the emergence of collective behavior, and argue that these systems present new opportunities for the study of group dynamics in an evolutionary context. We also provide a brief overview of the breve simulation environment in which the systems were produced, and of breve's facilities for the rapid, exploratory development of visualization strategies for artificial life.

Variation in elemental intensities among teeth and between pre- and postnatal regions of enamel.

Abstract: Microspatial analyses of the trace element composition of dental enamel are made possible using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). Fine spatial resolution, multielement capabilities, and minimal sample destruction make this technique particularly well-suited for documenting the distribution of elements in sequentially calcifying layers of enamel. Because deciduous enamel forms from week 13 in utero up to 9 months postnatally (thereafter essentially becoming inert), the application of LA-ICP-MS allows for the retrospective measurement of prenatal and early postnatal trace-element uptake during a critical period of child development. In this study, we compared intra- and intertooth intensities of 25Mg, 57Fe, 66Zn, 68Zn, 88Sr, 138Ba, and 208Pb via LA-ICP-MS of 38 exfoliated deciduous incisors and canines donated by 36 participants in the Solis Valley Mexico Nutrition Collaborative Research Support Program (NCRSP). Pre- and postnatal comparisons within teeth showed significant increases (P < 0.001) and greater variation in the abundance of all isotopes in postnatal enamel, with the exception of a decrease in 25Mg (P < 0.001) and constant values for 88Sr (P = 0.681). Conversely, comparisons by tooth type and mouth quadrant revealed few significant differences between teeth of the same individual. We argue that more variation in the trace element composition of teeth occurs across developmental areas within a tooth than among different teeth of the same person. This study further demonstrates that sequentially calcifying areas of enamel have different chemical concentrations. The results support the use of microspatial analyses of enamel for understanding changes in nutrition, pollution, and residence.

The shape of development

Abstract: This project examines the shape of conceptual development from early childhood through adulthood. To do so we model the attainment of developmental complexity levels in the moral reasoning of a large sample (n = 747) of 5- to 86-year-olds. Employing a novel application of the Rasch model to investigate patterns of performance in these data, we show that the acquisition of successive complexity levels proceeds in a pattern suggestive of a series of spurts and plateaus. We also show that there are six complexity levels represented in performance between the ages of 5 and 86; that patterns of performance are consistent with the specified sequence; that these findings apply to both childhood and adulthood levels; that sex is not an important predictor of complexity level once educational attainment has been taken into account; and that both age and educational attainment predict complexity level well during childhood, but educational attainment is a better predictor in late adolescence and adulthood.

Molecular visualization in chemistry education: The role of multidisciplinary collaboration

Abstract: Visualization tools and high performance computing have changed the nature of chemistry research and have the promise to transform chemistry instruction. However, the images central to chemistry research can pose difficulties for beginning chemistry students. In order for molecular visualization tools to be useful in education, students must be able to interpret the images they produce. Cognitive scientists can provide valuable insight into how novices perceive and ascribe meaning to molecular visualizations. Further insights from educators, computer scientists and developers, and graphic artists are important for chemistry educators who want to help students learn with molecular visualizations. A diverse group of scientists, educators, developers, and cognitive psychologists have begun a series of international collaborations to address this issue. The effort was initiated at the National Science Foundation supported Molecular Visualization in Science Education Workshop held in 2001 and has continued through a series of mini-grants. These groups are investigating characteristics of molecular representations and visualizations that enhance learning, interactions with molecular visualizations that best help students learn about molecular structure and dynamics, roles of molecular modeling in chemistry instruction, and fruitful directions for research on molecular visualization in the learning of chemistry. This article summarizes the value of collaboration identified by participants in the workshop and subsequent collaborations. [Chem. Educ. Res. Pract., 2005, 6 (3), 136-149]

Strategy use, the development of automaticity, and working memory involvement in complex multiplication.

Abstract: Participants practiced a set of complex multiplication problems (e.g., 3 × 18) in a pre-/postpractice design. Before, during, and after practice, the participants gave self-reports of problem-solving strategies. At prepractice, the most common strategy was a mental version of the standard multidigit algorithm, and dual tasks revealed that working memory load was high and heavier for problems solved via nonretrieval strategies. After practice, retrieval was used almost exclusively, and participant variability, automaticity level of problems (proportion of trials on which retrieval was used over the entire experiment), and error rates were significant predictors of problem-solving latencies. Practice reduced working memory involvement to minimal levels, and there was no relationship between automaticity level and working memory load. The commonalities between the present findings and findings related to automaticity development in simple arithmetic are discussed.

Global Prescriptions: Gendering Health and Human Rights

Abstract: Global Prescriptions: Gendering Health and Human Rights. By Rosalind Pollack Petchesky. New York: Zed Books, 2003. 320p. $75.00 cloth, $25.00 paper. In her book, Rosalind Petchesky sets herself the ambitious task of analyzing the development and impact of transnational movements for women's health in the last two decades of the twentieth century. She examines them not only in relation to the changing concepts of human rights and major United Nations conferences, but within the broader political and economic context of the spread of neoliberalism, religious fundamentalisms, the HIV/AIDS pandemic, and militarism. Originally commissioned by the United Nations Research Institute for Social Development for a five-year review of the World Summit for Social Development, the book assumes a fair degree of sophistication in regard to transnational politics although the text is punctuated by short boxes that give readers a useful introduction to key policy developments.

A Path Worth Taking: The Development of Social Justice in Outdoor Experiential Education.

Abstract: This article examines the influences promoting social justice in the field of outdoor experiential education. The philosophical foundations of outdoor adventure including the work of John Dewey and Kurt Hahn are considered in light of social justice education. The historical evolution of social justice activism within the professional community is analyzed. Other influential trends including the development of outdoor programs sensitive to social justice concerns, the cross fertilization from other related fields, and the demographic and economic imperatives to transform the field are described. The methodological fit between outdoor experiential education and social justice education is the final influence presented. The article concludes that potentials for social justice education within the outdoor experiential education field create an imperative for inclusion.

Automatic Sign Detection and Recognition in Natural Scenes

Abstract: Visually impaired individuals are unable to utilize the significant amount of information in signs. VIDI is a system for detecting and recognizing signs in the environment and voice synthesizing their contents. The wide variety of signs and unconstrained imaging conditions make the problem challenging. We detect signs using local color and texture features to classify image regions with a conditional maximum entropy model. Detected sign regions are then recognized by matching them against a known database of signs. A support vector machine classifier uses color to focus the search, and a match is found based on the correspondences of corners and their associated shape contexts. Our dataset includes images of downtown scenes with several signs exhibiting both illumination differences and projective distortions. A wide range of signs are detected and recognized including both text and symbolic information. The detection and the recognition components each perform well on their respective tasks, and initial evaluations of a complete detection and recognition system are promising.

Robusticity and osteoarthritis at the trapeziometacarpal joint in a Bronze Age population from Tell Abraq, United Arab Emirates.

Abstract: Osteoarthritis (OA) is a progressive disease of the joints and can cause pain, reduced range of motion and strength, and ultimately loss of function at affected joints. Osteoarthritis often occurs at sites where biomechanical stress is acutely severe or moderate but habitual over the course of a lifetime. Skeletal remains from an Umm an-Nar tomb at Tell Abraq, United Arab Emirates (ca. 2300 BC), were recovered and represented over 300 individuals of all ages. The remains were disarticulated, commingled, and mostly fragmented. An analysis of 650 well-preserved adult metacarpal and carpal bones, from the tomb's western chamber, revealed that over 53% of the trapeziometacarpal joint facets showed signs of OA varying from mild to severe. The first and second metacarpals and trapezium bones were sided and evaluated for OA at the trapeziometacarpal joint articulations. Osteoarthritis was detected on 53% of the first metacarpals, 40% of the second metacarpals, and 57% of the trapezium bones. All specimens appeared enlarged, and the first metacarpals were assessed for sexual identification and robusticity. Eighty-five percent of the bones were probable males, and more than 80% of them had a robusticity index of 60 or higher. A strong correlation was found between OA, sex, and robusticity. High levels of OA and robusticity at the thumb suggest that the people of Tell Abraq were habitually involved in biomechanically challenging work with their hands.

Critical Thinking Environments for Science Education

Abstract: We have developed a range of critical thinking environments for science education that span several academic content areas, including human biology, geology and forestry. All environments share a methodology, infrastructure and sets of assumptions and tools, which allows them to leverage from the accomplishments and intuitions of the others. These tutors support a student on the Web to be active and engaged, track that student's critical thinking and reason about her knowledge and its own teaching strategies. An Inquiry Notebook provides a way to sort, filter and categorize data and justifications and an Argument Editor supports argument formation. Students drag and drop evidence to support or refute each argument. A Coach provides helpful feedback guided by a database of expert rules, which create the basis for the content-specific analysis of the student's argument.

A Hierarchical Approach to Sign Recognition

Abstract: Sighted individuals draw a significant amount of information from signs but this information is denied to the visually impaired. VIDI is an evolving system for detecting and recognizing signs in the environment and voice synthesizing their textual contents. The wide variety of signs commonly encountered and the uncontrolled nature of the real world add significant complexity to the problem. VIDI treats the recognition problem as one of matching an unknown sign image, obtained from the detection component as a hypothesized sign, to a database of known signs. A color based support vector machine classifier coarsely picks a group of sign classes that are the most likely matches to the query. A finer retrieval technique employing corners and shape contexts ranks the hypothesized sign classes and verifies whether or not the top ranked class is the true class of the query. The database includes a set of real images with a wide variety of sign classes, each containing multiple signs exhibiting not only illumination differences, but also rotational variations. Tested on over 1,200 images, our system correctly recognizes and identifies the sign class of a query, achieving a 94.75% accuracy.

Evaluating Inquiry Learning Through Recognition-Based Tasks

Abstract: The Rashi inquiry learning environment for human biology was evaluated using a new instrument for assessing gains in scientific inquiry skills. The instrument was designed to be sensitive to the small pre-post skill gains that are hypothesized for short learning interventions. It is also designed to be scored with less effort than the verbal protocol analysis methods most often used to asses higher order skills. To achieve these ends the instrument is “item-based”, “recognition-based” and “difference-based.” We describe our assessment design method and results of its first use.

Validation of evolutionary activity metrics for long-term evolutionary dynamics

Abstract: As artificial life systems grow in number and sophistication, it is becoming increasingly important that the field agree on principled metrics for evaluating them. This report describes a series of experiments validating the evolutionary activity statistics developed by Bedau and his colleagues [2, 3, 4]. The work described herein was motivated by a feeling that the 'null hypothesis'---that is, that the evolutionary activity statistics fail to exclude intuitively unlifelike systems from Class 3 dynamics [3]---had not been sufficiently disproved in the existing literature. We conducted a series of experiments applying the statistics to such systems, attempting to 'break' the scheme by measuring Class 3 dynamics in an intuitively unlifelike system. The evolutionary activity measurement scheme has so far proved robust to our attempts to break it, but we believe that this work is still valuable in advancing the validity of the scheme, and that this does not mean the scheme is without shortcomings.

Teaching the evolution of behavior with SuperDuperWalker

Abstract: SuperDuperWalker is a software-based framework for experiments on the evolution of locomotion. It simulates the behavior of evolving agents in a 3D physical simulation environment and displays this behavior graphically in real time. A genetic algorithm controls the evolution of the agents. Students manipulate parameters with a graphical user interface and plot outputs using standard utilities. The software supports an inquiry cycle that has been piloted in CS193T: Biocomputational Developmental Ecology at Hampshire College.

Spectroscopic Characterization of Fulvic Acid Under Different Cover Crop Systems

Abstract: Fulvic acids (FAs) are an important dynamic component of soils that may be affected by soil management. Carbon‐13 cross‐polarization total sideband suppression nuclear magnetic resonance (CP‐TOSS 13C NMR) was used to examine the effect of cover crop systems on the characteristics of fulvic acid fractions. FA was isolated from soils with the following treatments: 1) vetch/rye, 2) rye alone, and 3) check (no cover crops) with varying nitrogen fertilizers. Preliminary NMR results indicate that FA from the rye alone system both with and without nitrogen fertilizers contains less aliphatic carbon (0–108 ppm) than that from the other two treatments. Based on the elemental composition analysis result, C∶N ratio of FA from rye alone cover with or without nitrogen fertilizer is lower than FA from vetch/rye cover system. These data suggest that farming systems affect the FA compositions.