443 research outputs found

    Callous-unemotional traits, low cortisol reactivity and physical aggression in children: findings from the Wirral Child Health and Development Study

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    Callous-unemotional (CU) traits are thought to confer risk for aggression via reduced amygdala responsivity to distress cues in others. Low cortisol reactivity is thought to confer risk for aggression via reduced arousal and this effect may be confined to boys. We tested the hypothesis that the association between childhood CU traits and aggression would be greatest in the absence of the inhibitory effects of cortisol reactivity, and that this effect would be sex dependent. Participants were 283 members of a stratified subsample within an epidemiological longitudinal cohort (WCHADS). Cortisol reactivity to a social stressor was assessed at 5 years. CU traits were reported by mothers at 5 years, and physical aggression by mothers and teachers at age 7. Results showed that CU traits were associated with elevated aggression at 7 years controlling for earlier aggression. There was no main effect of cortisol reactivity on regression. The association between CU traits and aggression was moderated by cortisol reactivity (p = .011) with a strong association between CU traits and aggression in the presence of low reactivity, and a small and non-significant association in the presence of high reactivity. This association was further moderated by child sex (p = .041) with the joint effect of high CU traits and low cortisol reactivity seen only in boys (p = .016). We report first evidence that a combined deficit in inhibitory processes associated with CU traits and low cortisol reactivity increases risk for childhood aggression, in a sex-dependent manner

    Autonomous weapon systems and international humanitarian law: a reply to the critics

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    In November 2012, Human Rights Watch, in collaboration with the International Human Rights Clinic at Harvard Law School, released Losing Humanity: The Case against Killer Robots.[2] Human Rights Watch is among the most sophisticated of human rights organizations working in the field of international humanitarian law. Its reports are deservedly influential and have often helped shape application of the law during armed conflict. Although this author and the organization have occasionally crossed swords,[3] we generally find common ground on key issues. This time, we have not. “Robots” is a colloquial rendering for autonomous weapon systems. Human Rights Watch’s position on them is forceful and unambiguous: “[F]ully autonomous weapons would not only be unable to meet legal standards but would also undermine essential non-safeguards for civilians.”[4] Therefore, they “should be banned and . . . governments should urgently pursue that end.”[5] In fact, if the systems cannot meet the legal standards cited by Human Rights Watch, then they are already unlawful as such under customary international law irrespective of any policy or treaty law ban on them.[6] Unfortunately, Losing Humanity obfuscates the on-going legal debate over autonomous weapon systems. A principal flaw in the analysis is a blurring of the distinction between international humanitarian law’s prohibitions on weapons per se and those on the unlawful use of otherwise lawful weapons.[7] Only the former render a weapon illegal as such. To illustrate, a rifle is lawful, but may be used unlawfully, as in shooting a civilian. By contrast, under customary international law, biological weapons are unlawful per se; this is so even if they are used against lawful targets, such as the enemy’s armed forces. The practice of inappropriately conflating these two different strands of international humanitarian law has plagued debates over other weapon systems, most notably unmanned combat aerial systems such as the armed Predator. In addition, some of the report’s legal analysis fails to take account of likely developments in autonomous weapon systems technology or is based on unfounded assumptions as to the nature of the systems. Simply put, much of Losing Humanity is either counter-factual or counter-normative. This Article is designed to infuse granularity and precision into the legal debates surrounding such weapon systems and their use in the future “battlespace.” It suggests that whereas some conceivable autonomous weapon systems might be prohibited as a matter of law, the use of others will be unlawful only when employed in a manner that runs contrary to international humanitarian law’s prescriptive norms. This Article concludes that Losing Humanity’s recommendation to ban the systems is insupportable as a matter of law, policy, and operational good sense. Human Rights Watch’s analysis sells international humanitarian law short by failing to appreciate how the law tackles the very issues about which the organization expresses concern. Perhaps the most glaring weakness in the recommendation is the extent to which it is premature. No such weapons have even left the drawing board. To ban autonomous weapon systems altogether based on speculation as to their future form is to forfeit any potential uses of them that might minimize harm to civilians and civilian objects when compared to other systems in military arsenals

    Keep Rollin' - Whole-Body Motion Control and Planning for Wheeled Quadrupedal Robots

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    We show dynamic locomotion strategies for wheeled quadrupedal robots, which combine the advantages of both walking and driving. The developed optimization framework tightly integrates the additional degrees of freedom introduced by the wheels. Our approach relies on a zero-moment point based motion optimization which continuously updates reference trajectories. The reference motions are tracked by a hierarchical whole-body controller which computes optimal generalized accelerations and contact forces by solving a sequence of prioritized tasks including the nonholonomic rolling constraints. Our approach has been tested on ANYmal, a quadrupedal robot that is fully torque-controlled including the non-steerable wheels attached to its legs. We conducted experiments on flat and inclined terrains as well as over steps, whereby we show that integrating the wheels into the motion control and planning framework results in intuitive motion trajectories, which enable more robust and dynamic locomotion compared to other wheeled-legged robots. Moreover, with a speed of 4 m/s and a reduction of the cost of transport by 83 % we prove the superiority of wheeled-legged robots compared to their legged counterparts.Comment: IEEE Robotics and Automation Letter

    "Out of the loop": autonomous weapon systems and the law of armed conflict

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    The introduction of autonomous weapon systems into the “battlespace” will profoundly influence the nature of future warfare. This reality has begun to draw the attention of the international legal community, with increasing calls for an outright ban on the use of autonomous weapons systems in armed conflict. This Article is intended to help infuse granularity and precision into the legal debates surrounding such weapon systems and their future uses. It suggests that whereas some conceivable autonomous weapon systems might be prohibited as a matter of law, the use of others will be unlawful only when employed in a manner that runs contrary to the law of armed conflict’s prescriptive norms governing the “conduct of hostilities.” This Article concludes that an outright ban of autonomous weapon systems is insupportable as a matter of law, policy, and operational good sense. Indeed, proponents of a ban underestimate the extent to which the law of armed conflict, including its customary law aspect, will control autonomous weapon system operations. Some autonomous weapon systems that might be developed would already be unlawful per se under existing customary law, irrespective of any treaty ban. The use of certain others would be severely limited by that law. Furthermore, an outright ban is premature since no such weapons have even left the drawing board. Critics typically either fail to take account of likely developments in autonomous weapon systems technology or base their analysis on unfounded assumptions about the nature of the systems. From a national security perspective, passing on the opportunity to develop these systems before they are fully understood would be irresponsible. Perhaps even more troubling is the prospect that banning autonomous weapon systems altogether based on speculation as to their future form could forfeit their potential use in a manner that would minimize harm to civilians and civilian objects when compared to non-autonomous weapon systems

    Coaching through technology: a systematic review into efficacy and effectiveness for the ageing population

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    Background: Despite the evidence on the positive role of self-management, the adoption ofhealth coaching strategies for older people is still limited. To address these gaps, recent efforts havebeen made in the ICT sector in order to develop systems for delivering coaching and overcomingbarriers relating to scarcity of resources. The aim of this review is to examine the efficacy of personalhealth coaching systems for older adults using digital virtual agents.Methods: A systematic reviewof the literature was conducted in December 2019 analyzing manuscripts from four databases overthe last 10 years. Nine papers were included.Results: Despite the low number of studies, there wasevidence that technology-integrated interventions can deliver benefits for health over usual care.However, the review raises important questions about how to maintain benefits and permanence ofbehavior change produced by short-term interventions.Conclusion: These systems offer a potentialtool to reduce costs, minimize therapist burden and training, and expand the range of clients who canbenefit from them. It is desirable that in the future the number of studies will grow, considering otheraspects such as the role of the virtual coaches’ characteristics, social-presence, empathy, usability,and health literac

    Formulation of a new gradient descent MARG orientation algorithm: case study on robot teleoperation

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    We introduce a novel magnetic angular rate gravity (MARG) sensor fusion algorithm for inertial measurement. The new algorithm improves the popular gradient descent (ʻMadgwick’) algorithm increasing accuracy and robustness while preserving computa- tional efficiency. Analytic and experimental results demonstrate faster convergence for multiple variations of the algorithm through changing magnetic inclination. Furthermore, decoupling of magnetic field variance from roll and pitch estimation is pro- ven for enhanced robustness. The algorithm is validated in a human-machine interface (HMI) case study. The case study involves hardware implementation for wearable robot teleoperation in both Virtual Reality (VR) and in real-time on a 14 degree-of-freedom (DoF) humanoid robot. The experiment fuses inertial (movement) and mechanomyography (MMG) muscle sensing to control robot arm movement and grasp simultaneously, demon- strating algorithm efficacy and capacity to interface with other physiological sensors. To our knowledge, this is the first such formulation and the first fusion of inertial measure- ment and MMG in HMI. We believe the new algorithm holds the potential to impact a very wide range of inertial measurement applications where full orientation necessary. Physiological sensor synthesis and hardware interface further provides a foundation for robotic teleoperation systems with necessary robustness for use in the field

    A classroom deployment of a haptic system for learning cell biology

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    The use of haptic systems in the classroom for enhancing science education is an underexplored area. In the education literature, it has been reported that certain concepts in science education are difficult for students to grasp and, as a result, misconceptions can be formed in the students' knowledge. We conducted a study with 62 Year 8 (typically 12-13 years old) students who used a haptic application to study cell biology, specifically the concept of diffusion across a cell membrane. The preliminary analysis of the feedback from the students suggests opportunities for haptic applications to enhance their learning, and also highlights a number of points to consider in the design of the application, including the choice of haptic interface and the design of the virtual environment

    A simple and versatile 2-dimensional platform to study plant germination and growth under controlled humidity

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    We describe a simple, inexpensive, but remarkably versatile and controlled growth environment for the observation of plant germination and seedling root growth on a flat, horizontal surface over periods of weeks. The setup provides to each plant a controlled humidity (between 56% and 91% RH), and contact with both nutrients and atmosphere. The flat and horizontal geometry of the surface supporting the roots eliminates the gravitropic bias on their development and facilitates the imaging of the entire root system. Experiments can be setup under sterile conditions and then transferred to a non-sterile environment. The system can be assembled in 1-2 minutes, costs approximately 8.78perplant,isalmostentirelyreusable(0.43 per plant, is almost entirely reusable (0.43 per experiment in disposables), and is easily scalable to a variety of plants. We demonstrate the performance of the system by germinating, growing, and imaging Wheat (Triticum aestivum), Corn (Zea mays), and Wisconsin Fast Plants (Brassica rapa). Germination rates were close to those expected for optimal conditions
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