3,466 research outputs found

    Beluga, Delphinapterus leucas, Group Sizes in Cook Inlet, Alaska, Based on Observer Counts and Aerial Video

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    Belugas, Delphinapterus leucas, groups were videotaped concurrent to observer counts during annual NMFS aerial surveys of Cook Inlet, Alaska, from 1994 to 2000. The videotapes provided permanent records of whale groups that could be examined and compared to group size estimates ade by aerial observers.Examination of the video recordings resulted in 275 counts of 79 whale groups. The McLaren formula was used to account for whales missed while they were underwater (average correction factor 2.03; SD=0.64). A correction for whales missed due to video resolution was developed by using a second, paired video camera that magnified images relative to the standard video. This analysis showed that some whales were missed either because their image size fell below the resolution of hte standard video recording or because two whales surfaced so close to each other that their images appeared to be one large whale. The correction method that resulted depended on knowing the average whale image size in the videotapes. Image sizes were measured for 2,775 whales from 275 different passes over whale groups. Corrected group sizes were calcualted as the product of the original count from video, the correction factor for whales missed underwater, and the correction factor for whales missed due to video resolution (averaged 1.17; SD=0.06). A regression formula was developed to estimate group sizes from aerial observer counts; independent variables were the aerial counts and an interaction term relative to encounter rate (whales per second during the counting of a group), which were regressed against the respective group sizes as calculated from the videotapes. Significant effects of encounter rate, either positive or negative, were found for several observers. This formula was used to estimate group size when video was not available. The estimated group sizes were used in the annual abundance estimates

    Anxiety Guide: A Guide for Parents

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    Anxiety characteristics in individuals with Williams syndrome

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    BACKGROUND: Williams syndrome anxiety research predominantly focuses on disorder prevalence and symptomatology, categorised using standardised mental health classifications. However, the use of these assessments may not fully capture the phenotypic features of anxiety in Williams syndrome. In this study, we examined characteristics of anxiety using a formulation framework. METHOD: A semi-structured interview was conducted with thirteen parents of individuals with Williams syndrome (median age: 19, age range: 12-45, 8 females). RESULTS: Various anxiety triggers were reported, including anxiety triggered by phobias, uncertainty and negative emotions in others. The range of described behaviours was diverse with both avoidant and active coping strategies for anxiety management reported. CONCLUSIONS: Many of the characteristics described were consistent with findings in the intellectual disability and typically developing literature, although novel information was identified. The study demonstrates the utility of a formulation framework to explore anxiety characteristics in atypical populations and has outlined new avenues for research

    Evaluation of aircraft microwave data for locating zones for well stimulation and enhanced gas recovery

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    Imaging radar was evaluated as an adjunct to conventional petroleum exploration techniques, especially linear mapping. Linear features were mapped from several remote sensor data sources including stereo photography, enhanced LANDSAT imagery, SLAR radar imagery, enhanced SAR radar imagery, and SAR radar/LANDSAT combinations. Linear feature maps were compared with surface joint data, subsurface and geophysical data, and gas production in the Arkansas part of the Arkoma basin. The best LANDSAT enhanced product for linear detection was found to be a winter scene, band 7, uniform distribution stretch. Of the individual SAR data products, the VH (cross polarized) SAR radar mosaic provides for detection of most linears; however, none of the SAR enhancements is significantly better than the others. Radar/LANDSAT merges may provide better linear detection than a single sensor mapping mode, but because of operator variability, the results are inconclusive. Radar/LANDSAT combinations appear promising as an optimum linear mapping technique, if the advantages and disadvantages of each remote sensor are considered

    Winds of Planet Hosting Stars

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    The field of exoplanetary science is one of the most rapidly growing areas of astrophysical research. As more planets are discovered around other stars, new techniques have been developed that have allowed astronomers to begin to characterise them. Two of the most important factors in understanding the evolution of these planets, and potentially determining whether they are habitable, are the behaviour of the winds of the host star and the way in which they interact with the planet. The purpose of this project is to reconstruct the magnetic fields of planet hosting stars from spectropolarimetric observations, and to use these magnetic field maps to inform simulations of the stellar winds in those systems using the Block Adaptive Tree Solar-wind Roe Upwind Scheme (BATS-R-US) code. The BATS-R-US code was originally written to investigate the behaviour of the Solar wind, and so has been altered to be used in the context of other stellar systems. These simulations will give information about the velocity, pressure and density of the wind outward from the host star. They will also allow us to determine what influence the winds will have on the space weather environment of the planet. This paper presents the preliminary results of these simulations for the star Ï„\tau Bo\"otis, using a newly reconstructed magnetic field map based on previously published observations. These simulations show interesting structures in the wind velocity around the star, consistent with the complex topology of its magnetic field.Comment: 8 pages, 2 figures, accepted for publication in the peer-reviewed proceedings of the 14th Australian Space Research Conference, held at the University of South Australia, 29th September - 1st October 201

    Analysis of geologic terrain models for determination of optimum SAR sensor configuration and optimum information extraction for exploration of global non-renewable resources. Pilot study: Arkansas Remote Sensing Laboratory, part 1, part 2, and part 3

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    Computer-generated radar simulations and mathematical geologic terrain models were used to establish the optimum radar sensor operating parameters for geologic research. An initial set of mathematical geologic terrain models was created for three basic landforms and families of simulated radar images were prepared from these models for numerous interacting sensor, platform, and terrain variables. The tradeoffs between the various sensor parameters and the quantity and quality of the extractable geologic data were investigated as well as the development of automated techniques of digital SAR image analysis. Initial work on a texture analysis of SEASAT SAR imagery is reported. Computer-generated radar simulations are shown for combinations of two geologic models and three SAR angles of incidence

    Computer Science Student-Centered Instructional Continuum

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    The Computer-Science Student-Centered Instructional Continuum (CS-SCIC) is a new framework to support PreK-12 instructors in their lesson design. Educators are faced with choices when building lessons; there is a tension between direct instruction, constructivism and constructionism and difficulty in providing differentiated instruction. Theoretically aligned to Vygotsky’s zone of proximal development, CS-SCIC places research-based instructional strategies on a simple learning continuum. Teachers use the continuum to discuss, review and design learning events. Used internationally, initial qualitative feedback from teachers who attended pilot CS-SIC workshops was emphatically positive. Future work includes more feedback from academia and formal research, including pre and post-professional development workshop surveys

    Doppler imaging and surface differential rotation of young open cluster stars - I. HD 307938 (R58) in IC 2602

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    In this paper we present Doppler images of a young active G dwarf (HD 307938) in the southern open cluster IC 2602. Spectroscopic data were obtained over a four-night period in 2000 January at the 3.9-m Anglo-Australian Telescope using the University College London Echelle Spectrograph. Simultaneous photometric observations (in the V and R bands) were obtained at the 1.0-m Australian National University telescope. By applying least-squares deconvolution (LSD) to the 2500+ photospheric lines in each echelle spectrum a single high signal-to-noise ratio LSD profile was produced for each phase of the spectroscopic observations. Maximum-entropy image reconstruction, incorporating both the LSD profiles and the photometric data, was used to produce maps of the surface features of the star, with the inclusion of the photometric data producing an increase (compared with the use of spectroscopic data alone) in the spot occupancy in both low- and mid-latitude regions of the star. The maps show that HD 307938 possesses a large, broken polar spot extending down to ∼60° latitude, as well as lower-latitude spots similar to other rapidly rotating G dwarfs. By incorporating a solar-like differential rotation law into the imaging process the surface differential rotation of HD 307938 was determined. This gave a surface shear of dΩ = 0.025 ± 0.015 rad d−1 (for an inclination angle of 60°). Thus the equator of HD 307938 laps the poles every ∼250 d and has a photospheric shear around half that of the Su

    The Profiles and Correlates of Psychopathology in Adolescents and Adults with Williams, Fragile X and Prader-Willi Syndromes

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    Psychopathology is prevalent in Williams (WS), fragile X (FXS) and Prader-Willi (PWS) syndromes. However, little is known about the potential correlates of psychopathology in these groups. A questionnaire study was completed by 111 caregivers of individuals with WS (n = 35); FXS (n = 50) and PWS (n = 26). Mean age was 26 years (range 12-57 years); 74 (67%) were male. Multiple regression analyses indicated that higher rates of health problems and sensory impairments predicted higher psychopathology in WS (p < .0001). In PWS, poorer adaptive ability predicted higher overall psychiatric disturbance (p = .001), generalised anxiety (p = .006) and hyperactivity (p = .003). There were no significant predictors in FXS. This study highlights dissociations in the potential risk markers of psychopathology between genetic syndromes. Implications for intervention are discussed

    DE 1 RIMS operational characteristics

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    The Retarding Ion Mass Spectrometer (RIMS) on the Dynamics Explorer 1 spacecraft observes both the thermal and superthermal (50 eV) ions of the ionosphere and inner magnetosphere. It is capable of measuring the detailed species distribution function of these ions in many cases. It was equipped with an integral electrometer to permit in-flight calibration of the detector sensitivities and variations thereof. A guide to understanding the RIMS data set is given. The reduction process from count rates to physical quantities is discussed in some detail. The procedure used to establish in-flight calibration is described, and results of a comparison with densities from plasma wave measurements are provided. Finally, a discussion is provided of various anomalies in the data set, including changes of channeltron efficiency with time, spin modulation of the axial sensor heads, apparent potential differences between the sensor heads, and failures of the radial head retarding potential sweep and of the -Z axial head aperture plane bias. Studies of the RIMS data set should be conducted only with a thorough awareness of the material presented here, or in collaboration with one of the scientists actively involved with RIMS data analysis
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