40,389 research outputs found

    The effects of after-school physical activity and adult encouragement on adolescents

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    Includes bibliographical references

    From Mounds to Monasteries: A Look at Spiro and Other Centers Through The Use of Metaphor

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    Previous study of the extensive and elaborate funerary offerings at the Spiro site have explained their presence by an exchange system with Spiro functioning as a gateway center. More recently, Schambach has argued extensively and passionately for Spiro’s role as an entrepôt redistributive center. However, this argument fails to account for much of the accumulation of funerary items present at Spiro. As an alternative, I propose that some ceremonial centers such as Spiro functioned solely as religious centers, much like the monasteries of medieval Europe with parallels in the use of architecture, economic support, relics, and the treatment of individuals at death. A model based on the metaphor of monastic life provides greater explanatory potential than that of the economically-driven entepôt

    An Aggregate of Spear Points from Atoka County, Oklahoma

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    Nine spear points were reported from a farm in northwestern Atoka County, Oklahoma. This aggregate of points appeared to bean isolate as no other prehistoric material was found in the vicinity. The following study discusses the setting and nature of the specimens, stylistic attributes of the spear points and their age, technological and functional characteristics of the pieces, and whether these items represent caching behavior

    Counterbalancing for serial order carryover effects in experimental condition orders

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    Reactions of neural, psychological, and social systems are rarely, if ever, independent of previous inputs and states. The potential for serial order carryover effects from one condition to the next in a sequence of experimental trials makes counterbalancing of condition order an essential part of experimental design. Here, a method is proposed for generating counterbalanced sequences for repeated-measures designs including those with multiple observations of each condition on one participant and self-adjacencies of conditions. Condition ordering is reframed as a graph theory problem. Experimental conditions are represented as vertices in a graph and directed edges between them represent temporal relationships between conditions. A counterbalanced trial order results from traversing an Euler circuit through such a graph in which each edge is traversed exactly once. This method can be generalized to counterbalance for higher order serial order carryover effects as well as to create intentional serial order biases. Modern graph theory provides tools for finding other types of paths through such graph representations, providing a tool for generating experimental condition sequences with useful properties

    Traditional and new principles of perceptual grouping

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    Perceptual grouping refers to the process of determining which regions and parts of the visual scene belong together as parts of higher order perceptual units such as objects or patterns. In the early 20th century, Gestalt psychologists identified a set of classic grouping principles which specified how some image features lead to grouping between elements given that all other factors were held constant. Modern vision scientists have expanded this list to cover a wide range of image features but have also expanded the importance of learning and other non-image factors. Unlike early Gestalt accounts which were based largely on visual demonstrations, modern theories are often explicitly quantitative and involve detailed models of how various image features modulate grouping. Work has also been done to understand the rules by which different grouping principles integrate to form a final percept. This chapter gives an overview of the classic principles, modern developments in understanding them, and new principles and the evidence for them. There is also discussion of some of the larger theoretical issues about grouping such as at what stage of visual processing it occurs and what types of neural mechanisms may implement grouping principles

    Book Review: Archeology in the Eastern Planning Region, Texas: A Planning Document

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    With the passage of the National Historic Preservation Act in 1966 and ensuing regulatory guidelines, a mandate for the development of The State Historic Preservation Plan was clearly established. During the late 1960s and the 1970s, because of limited funding and the absence of information on the structure of these plans, few states had formulated plans or if they had state plans, they were of an extremely general nature. In the 1980s, principally through funding initiatives on the part of the National Park Service and through the efforts of NPS preservation planners such as John Knoerl, many states began their first attempts at comprehensive preservation planning. One of the more highly acclaimed of these early planning documents was the Resource Protection Planning Process for Texas. The current eastern planning region document represents the culmination of over 10 years of preservation planning in the state of Texas
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