1,158 research outputs found

    Parental Distress and Child Behavior Problems: Parenting Behaviors as Mediators

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    Parents of children with developmental disabilities (DD) typically report higher levels of parental stress than parents of typically developing children. While the majority of the literature addresses child behavior problems as predictors of parental stress, research has shown that the relation is bi-directional. However, very little research has examined the effects of parental stress on child behavior problems and the possible parenting factors that may explain this relation. The current study utilized data from the Mindful Awareness for Parenting Stress (MAPS) study (N = 31; % male = 67.7, mean age = 3.5, SD = .96; 81% ethic minority), and examined positive parenting behaviors as mediators in the relation between parenting distress and child behavior. Results from a multiple mediation analysis indicated that parental distress had a significant direct effect on total child behavior problems, b = 1.11, p \u3c .05. Additionally, Quality of Mother’s Assistance was a significant mediator in the relation between parental distress and child behavior problems, ab = .482, 95% BCa 95% CI [.022, 2.33]. Neither Level of Involvement nor Mother’s Supportive Presence significantly mediated the relation between Parental Distress and Child Behavior Problems, ps \u3e .05. Findings suggest that improving the quality of the parent/child interaction may play a key role in the relation between parenting stress and child behavior problems. The current study could help to inform future parenting interventions by emphasizing the importance of targeting quality of parent assistance type parenting behaviors for improving child behavior outcomes

    Sitting in the Pilot's Seat; Optimizing Human-Systems Interfaces for Unmanned Aerial Vehicles

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    One of the pilot-machine interfaces (the forward viewing camera display) for an Unmanned Aerial Vehicle called the DROID (Dryden Remotely Operated Integrated Drone) will be analyzed for optimization. The goal is to create a visual display for the pilot that as closely resembles an out-the-window view as possible. There are currently no standard guidelines for designing pilot-machine interfaces for UAVs. Typically, UAV camera views have a narrow field, which limits the situational awareness (SA) of the pilot. Also, at this time, pilot-UAV interfaces often use displays that have a diagonal length of around 20". Using a small display may result in a distorted and disproportional view for UAV pilots. Making use of a larger display and a camera lens with a wider field of view may minimize the occurrences of pilot error associated with the inability to see "out the window" as in a manned airplane. It is predicted that the pilot will have a less distorted view of the DROID s surroundings, quicker response times and more stable vehicle control. If the experimental results validate this concept, other UAV pilot-machine interfaces will be improved with this design methodology

    Photometric and kinematic studies of open star clusters. III. NGC 4103, NGC 5281, and NGC 4755

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    We present CCD photometry and proper motion studies of the three open star clusters NGC 4103, NGC 5281, and NGC 4755 (kappa Cru). By fitting isochrones to the colour magnitude diagrams, we found that all three objects are young open star clusters with ages of at most t=45 Myr. They are located at distances from approx. 1600 pc to 2200 pc, derived from distance moduli (m-M)_0 ranging from 11 mag to 12 mag. We combined membership determinations based on proper motions and statistical field star subtraction to derive the initial mass function (IMF) of the clusters. The shape of the IMFs could be represented by power laws with exponents of Gamma=-1.46 +/- 0.22 for NGC 4103, Gamma=-1.60 +/- 0.50 for NGC 5281, and Gamma=-1.68 +/- 0.14 for NGC 4755, when - as a reference - Salpeter's (1955) value would be Gamma=-1.35. These results agree well with other IMF studies of open star clusters.Comment: 16 pages, 14 figures, accepted for publication in Astronomy & Astrophysic

    Social Determinants of Health and Their Impact on Mental Health and Substance Misuse

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    Health and wellbeing are shaped by many factors beyond healthcare and behavioral choices, including conditions that make up our social, economic, and physical environments. These factors are often referred to as social determinants of health (SDoHs). SDoHs not only affect our physical health, but they also can have an impact on a person’s mental wellbeing and substance use. These social determinants of health can be grouped into five major categories: 1. Neighborhood and built environment 2. Health and healthcare 3. Social and community context 4. Education 5. Economic stability To address SDoHs effectively, a “health in all policies” approach that integrates health considerations into policymaking across sectors is essential

    Hubble Space Telescope Angular Velocity Estimation During the Robotic Servicing Mission

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    In 2004 NASA began investigation of a robotic servicing mission for the Hubble Space Telescope (HST). Such a mission would require estimates of the HST attitude and rates in order to achieve a capture by the proposed Hubble robotic vehicle (HRV). HRV was to be equipped with vision-based sensors, capable of estimating the relative attitude between HST and HRV. The inertial HST attitude is derived from the measured relative attitude and the HRV computed inertial attitude. However, the relative rate between HST and HRV cannot be measured directly. Therefore, the HST rate with respect to inertial space is not known. Two approaches are developed to estimate the HST rates. Both methods utilize the measured relative attitude and the HRV inertial attitude and rates. First, a nonlinear estimator is developed. The nonlinear approach estimates the HST rate through an estimation of the inertial angular momentum. The development includes an analysis of the estimator stability given errors in the measured attitude. Second, a linearized approach is developed. The linearized approach is a pseudo-linear Kalman filter. Simulation test results for both methods are given, including scenarios with erroneous measured attitudes. Even though the development began as an application for the HST robotic servicing mission, the methods presented are applicable to any rendezvous/capture mission involving a non-cooperative target spacecraft

    Quantum reflection of atoms from a solid surface at normal incidence

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    We observed quantum reflection of ultracold atoms from the attractive potential of a solid surface. Extremely dilute Bose-Einstein condensates of ^{23}Na, with peak density 10^{11}-10^{12}atoms/cm^3, confined in a weak gravito-magnetic trap were normally incident on a silicon surface. Reflection probabilities of up to 20 % were observed for incident velocities of 1-8 mm/s. The velocity dependence agrees qualitatively with the prediction for quantum reflection from the attractive Casimir-Polder potential. Atoms confined in a harmonic trap divided in half by a solid surface exhibited extended lifetime due to quantum reflection from the surface, implying a reflection probability above 50 %.Comment: To appear in Phys. Rev. Lett. (December 2004)5 pages, 4 figure

    Precision Pointing Control to and Accurate Target Estimation of a Non-Cooperative Vehicle

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    In 2004, NASA began investigating a robotic servicing mission for the Hubble Space Telescope (HST). Such a mission would not only require estimates of the HST attitude and rates in order to achieve capture by the proposed Hubble Robotic Vehicle (HRV), but also precision control to achieve the desired rate and maintain the orientation to successfully dock with HST. To generalize the situation, HST is the target vehicle and HRV is the chaser. This work presents a nonlinear approach for estimating the body rates of a non-cooperative target vehicle, and coupling this estimation to a control scheme. Non-cooperative in this context relates to the target vehicle no longer having the ability to maintain attitude control or transmit attitude knowledge

    Dynamics of femtosecond laser absorption of fused silica in the ablation regime

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    International audienceWe investigate the ultrafast absorption dynamics of fused silica irradiated by a single 500 fs laser pulse in the context of micromachining applications. A 60-fs-resolution pump-probe experiment that measures the reflectivity and transmissivity of the target under excitation is developed to reveal the evolution of plasma absorption. Above the ablation threshold, an overcritical plasma with highly non-equilibrium conditions is evidenced in a thin layer at the surface. The maximum electron density is reached at a delay of 0:5 ps after the peak of the pump pulse, which is a strong indication of the occurrence of electronic avalanche. The results are further analyzed to determine the actual feedback of the evolution of the optical properties of the material on the pump pulse. We introduce an important new quantity, namely, the duration of absorption of the laser by the created plasma, corresponding to the actual timespan of laser absorption by inverse Bremsstrahlung. Our results indicate an increasing contribution of plasma absorption to the total material absorption upon raising the excitation fluence above the ablation threshold. The role of transient optical properties during the energy deposition stage is characterized and our results emphasize the necessity to take it into account for better understanding and control of femtosecond laser-dielectrics interaction
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