A Case for Geology

Geology suffers from two enduring stereotypes. The first stereotype is that geology is about rocks and minerals, period. It is true that the materials, the configurations of matter, studied in geology are largely rocks and minerals, but the study of geology goes much further than this simple intention. It has a lot more to say about the world in which we live than just a study of earth materials. The second stereotype concerns the reasons one should study geology. Many persons, including not a few professional geologists, regard geology\u27s role in society as limited to the finding and producing of raw materials to feed the economic system. This is a vitally important role for geology to play, and it is one which provides employment for many geologists, but the purposes of geology transcend its economic utility. If the purpose of teaching geology were only to include the study of a larger array of natural objects (rocks and minerals and such) or to provide vocational training for those engaged in resource-gathering, the case for the subject would be much weaker. Geology, however, provides insights and intellectual experiences unique to this field of science. Why should we study the earth? Why should we teach about the Earth

Embedded Training for Complex Information Systems

One approach to providing affordable operator training in the workplace is to augment applications with intelligent embedded training systems (ETS). Intelligent embedded training is highly interactive: trainees practice realistic problem-solving tasks on the prime application with guidance and feedback from the training system. This article makes three contributions to the theory and technology of ETS design. First, we describe a framework based on Norman’s “stages of user activity” model for defining the instructional objectives of an ETS. Second, we demonstrate a non-invasive approach to instrumenting software applications, thereby enabling them to collaborate with an ETS. Third, we describe a method for interpreting observed user behavior during problem solving, and using that information to provide task-oriented hints on demand

The Architecture of a Cooperative Respondent

If natural language question-answering (NLQA) systems are to be truly effective and useful, they must respond to queries cooperatively, recognizing and accommodating in their replies a questioner\u27s goals, plans, and needs. Transcripts of natural dialogue demonstrate that cooperative responses typically combine several communicative acts: a question may be answered, a misconception identified, an alternative course of action described and justified. This project concerns the design of cooperative response generation systems, NLQA systems that are able to provide integrated cooperative responses. Two questions must be answered before a cooperative NLQA system can be built. First, what are the reasoning mechanisms that underlie cooperative response generation? In partial reply, I argue that plan evaluation is an important step in the process of selecting a cooperative response, and describe several tests that may usefully be applied to inferred plans. The second question is this: what is an appropriate architecture for cooperative NLQA (CNLQA) systems? I propose a four-level decomposition of the cooperative response generation process and then present a suitable CNLQA system architecture based on the blackboard model of problem solving

Mother--First Room

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Degradation of Algal Palynomorphs on 34-yr-old Microscope Slides

Reexamination of 34-yr-old microscope slides of palynological preparations reveals the loss and degradation of algal palynomorphs, in particular the green alga Pediastrum and the desmid Pleurotaenium. Results from this study suggest that great caution should be used when referring co archived palynological slides

THE NEW RADIOBIOLOGY: RETURNING TO OUR ROOTS

In 2005, two expert advisory bodies examined the evidence on the effects of low doses of ionizing radiation. The U.S. National Research Council concluded that current scientific evidence is consistent with the linear no-threshold dose-response relationship (NRCNA 2005) while the French National Academies of Science and Medicine concluded the opposite (Aurengo et al. 2005). These contradictory conclusions may stem in part from an emphasis on epidemiological data (a “top down” approach) versus an emphasis on biological mechanisms (a “bottom up” approach). In this paper, the strengths and limitations of the top down and bottom up approaches are discussed, and proposals for strengthening and reconciling them are suggested. The past seven years since these two reports were published have yielded increasing evidence of nonlinear responses of biological systems to low radiation doses delivered at low dose-rates. This growing body of evidence is casting ever more doubt on the extrapolation of risks observed at high doses and dose-rates to estimate risks associated with typical environmental and occupational exposures. This paper compares current evidence on low dose, low dose-rate effects against objective criteria of causation. Finally, some questions for a post-LNT world are posed