1,056 research outputs found

    Past and Present Distribution of the Red-Cockaded Woodpecker Picoides borealis and its Habitat in the Ouachita Mountains, Arkansas

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    Within the past 15 years, at least 41 and probably more active cavity tree clusters (or colonies) of Red cockaded Woodpeckers (Picoides borealis) have existed in remnant, mature shortleaf pine (Pinus echinata) woodlands in the Ouachita Mountains of Arkansas. These clusters were located on both private timberlands and in the Ouachita National Forest. Fewer than half of this number were still active in early 1991, and none remained on private timberlands. The species is presently restricted to the xeric, western margins of the Ouachitas in Scott and Polk counties within the confines of the Ouachita National Forest where it receives protection of the Endangered Species Act. The decline of P. borealis in the Ouachitas resulted from intense logging of old growth pine forests during the timber boom period, ca. 1910-1950, and from the suppression of natural fires, which subsequently allowed hardwoods to invade former pine woodlands

    Spacelab 3 flight experiment No. 3AFT23: Autogenic-feedback training as a preventive method for space adaptation syndrome

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    Space adaptation syndrome is a motion sickness-like disorder which affects up to 50 percent of all people exposed to microgravity in space. This experiment tested a physiological conditioning procedure (Autogenic-Feedback Training, AFT) as an alternative to pharmacological management. Four astronauts participated as subjects in this experiment. Crewmembers A and B served as treatment subjects. Both received preflight training for control of heart rate, respiration rate, peripheral blood volume, and skin conductance. Crewmembers C and D served as controls (i.e., did not receive training). Crewmember A showed reliable control of his own physiological responses, and a significant increase in motion sickness tolerance after training. Crewmember B, however, demonstrated much less control and only a moderate increase in motion sickness tolerance was observed after training. The inflight symptom reports and physiological data recordings revealed that Crewmember A did not experience any severe symptom episodes during the mission, while Crewmember B reported one severe symptom episode. Both control group subjects, C and D (who took antimotion sickness medication), reported multiple symptom episodes on mission day 0. Both inflight data and crew reports indicate that AFT may be an effective countermeasure. Additional data must be obtained inflight (a total of eight treatment and eight control subjects) before final evaluation of this treatment can be made

    Autogenic-feedback training: A preventive method for space adaptation syndrome

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    The progress made to date on the reduction of data for Spacelab 3 Shuttle experiment, No. 3AFT23 is reported. Four astronauts participated as subjects in this experiment. Crewmen A and B served as treatment subjects (i.e., received preflight training for control of their own motion sickness symptoms) and Crewmen C and D served as control (i.e., did not receive training). A preliminary evaluation of Autogenic Feedback Training (AFT) was made from visual inspections of graphs that were generated from the preflight and inflight and inflight physiological data which included: (1) Baseline rotating chair tests for all crewmen; (2) Posttraining rotating chair tests of treatment groups subjects; (3) Preflight data from Joint Integrated Simulations for all crewmen; and (4) Flight data for all crewmen during mission days 0 through 4, and mission day 6 for treatment subjects only. A summary of the findings suggested by these data is outlined

    Guidelines for Computing Longitudinal Dynamic Stability Characteristics of a Subsonic Transport

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    A systematic study is presented to guide the selection of a numerical solution strategy for URANS computation of a subsonic transport configuration undergoing simulated forced oscillation about its pitch axis. Forced oscillation is central to the prevalent wind tunnel methodology for quantifying aircraft dynamic stability derivatives from force and moment coefficients, which is the ultimate goal for the computational simulations. Extensive computations are performed that lead in key insights of the critical numerical parameters affecting solution convergence. A preliminary linear harmonic analysis is included to demonstrate the potential of extracting dynamic stability derivatives from computational solutions

    Burying Beetle (Coleoptera: Silphidae, Nicrophorus) Surveys on Poteau Ranger District, Ouachita National Forest

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    Surveys for American burying beetles {Nicrophorus americanus Oliver) were conducted in west-central Arkansas on Poteau Ranger District of the Ouachita National Forest in1992 and 1993. A total of 2450 Nicrophorus specimens were captured in1098 trap nights. The most frequently captured specimens were N. orbicollis, N. tomentosus, and N. pustulatus. One specimen of N. americanus was also captures. Other species of beetles were also trapped and identified in this survey. Habitats sampled were primarily well-drained uplands with proposed or recent harvests of shortleaf pine (Pinus echinata). It appears that these habitats may not harbor extensive populations of N. americanus onPoteau RD
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