230 research outputs found

    Geographies of generosity: beyond the 'moral turn'

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    This paper questions Geographers debates about 'caring at a distance' and the 'geographies of responsibility', focussing on the treatment of the theme of partiality in ethics and justice. Debates in Geography often present partial commitments as morally or politically problematic on the grounds that they prioritize self-interest, exclusionary, and geographically restricted ways of relating to others. We outline how debates about caring at a distance and the geographies of responsibility frame partiality as a problem to be overcome. We argue that Geography's engagements with moral philosophy are premised on faulty assumptions about the sorts of influences people are liable to act upon (one's that privilege causal knowledge as the primary motivating force), and also flawed assumptions about the sorts of problems that academic reasoning about normative issues is meant to address (the assumption that people are too egoistical and not altruistic enough). We use the theme of generosity as an entry point to argue that partiality and finitude might be the conditions for any ethical–political project that de-centres the motivation of practical action away from the sovereign self towards responsive and attentive relations of encounter with the needs of others. Understanding generosity as a modality of power suggests a revised programme for geographical investigations of the intersection between ethics, morality and politics: one which looks at how opportunities to address normative demands in multiple registers are organized and transformed; at the ways in which dispositions to respond and to be receptive to others are worked up; and how opportunities for acting responsively on these dispositions are organized

    Improved Performance of High Areal Density Indirect Drive Implosions at the National Ignition Facility using a Four-Shock Adiabat Shaped Drive

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    Hydrodynamic instabilities can cause capsule defects and other perturbations to grow and degrade implosion performance in ignition experiments at the National Ignition Facility (NIF). Here, we show the first experimental demonstration that a strong unsupported first shock in indirect drive implosions at the NIF reduces ablation front instability growth leading to a 3 to 10 times higher yield with fuel ρR > 1  g/cm[superscript 2]. This work shows the importance of ablation front instability growth during the National Ignition Campaign and may provide a path to improved performance at the high compression necessary for ignition

    Fusion Energy Output Greater than the Kinetic Energy of an Imploding Shell at the National Ignition Facility

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    A series of cryogenic, layered deuterium-tritium (DT) implosions have produced, for the first time, fusion energy output twice the peak kinetic energy of the imploding shell. These experiments at the National Ignition Facility utilized high density carbon ablators with a three-shock laser pulse (1.5 MJ in 7.5 ns) to irradiate low gas-filled (0.3  mg/cc of helium) bare depleted uranium hohlraums, resulting in a peak hohlraum radiative temperature ∼290  eV. The imploding shell, composed of the nonablated high density carbon and the DT cryogenic layer, is, thus, driven to velocity on the order of 380  km/s resulting in a peak kinetic energy of ∼21  kJ, which once stagnated produced a total DT neutron yield of 1.9×10¹⁶ (shot N170827) corresponding to an output fusion energy of 54 kJ. Time dependent low mode asymmetries that limited further progress of implosions have now been controlled, leading to an increased compression of the hot spot. It resulted in hot spot areal density (ρr∼0.3  g/cm²) and stagnation pressure (∼360  Gbar) never before achieved in a laboratory experiment

    The evolution of multiple active site configurations in a designed enzyme

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    Developments in computational chemistry, bioinformatics, and laboratory evolution have facilitated the de novo design and catalytic optimization of enzymes. Besides creating useful catalysts, the generation and iterative improvement of designed enzymes can provide valuable insight into the interplay between the many phenomena that have been suggested to contribute to catalysis. In this work, we follow changes in conformational sampling, electrostatic preorganization, and quantum tunneling along the evolutionary trajectory of a designed Kemp eliminase. We observe that in the Kemp Eliminase KE07, instability of the designed active site leads to the emergence of two additional active site configurations. Evolutionary conformational selection then gradually stabilizes the most efficient configuration, leading to an improved enzyme. This work exemplifies the link between conformational plasticity and evolvability and demonstrates that residues remote from the active sites of enzymes play crucial roles in controlling and shaping the active site for efficient catalysis

    The Parametric, Psychological, Neuropsychological, and Neuroanatomical Properties of Self and World Evaluation

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    Background: As an individual moves from adolescence to adulthood, they need to form a new sense of self as their environment changes from a limited to a more expansive structure. During this critical stage in development the last dramatic steps of neural development occur and numerous psychiatric conditions begin to manifest. Currently, there is no measure that aids in the quantification of how the individual is adapting to, and conceptualizing their role in, these new structures. To fill this gap we created the Self and World Evaluation Expressions Test(SWEET). Method: Sixty-five young adults (20.6 years-old), 36 with a history of drug use, completed the SWEET. A factor analysis was performed on the SWEET and the resultant factors were correlated with psychological, neuropsychological, and neuroanatomical battery that included both T1-wieghted and diffusion tensor magnetic resonance imaging scans. Results: We derived four factors: Self, Social-Emotional, Financial-Intellectual, and Spirituality. While showing limited relationships to psychological and neuropsychological measures, both white matter integrity and gray matter density showed significant relationships with SWEET factors. Conclusions: These findings suggest that while individual responses may not be indicative of psychological or cognitive processes they may relate to changes in brain structure. Several of these structures, such as the negative correlation of the affective impact of world with the dorsal anterior corpus callosum white matter integrity have been observed in psychiatri

    Thin Shell, High Velocity Inertial Confinement Fusion Implosions on the National Ignition Facility

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    Experiments have recently been conducted at the National Ignition Facility utilizing inertial confinement fusion capsule ablators that are 175 and 165  μm in thickness, 10% and 15% thinner, respectively, than the nominal thickness capsule used throughout the high foot and most of the National Ignition Campaign. These three-shock, high-adiabat, high-foot implosions have demonstrated good performance, with higher velocity and better symmetry control at lower laser powers and energies than their nominal thickness ablator counterparts. Little to no hydrodynamic mix into the DT hot spot has been observed despite the higher velocities and reduced depth for possible instability feedthrough. Early results have shown good repeatability, with up to 1/2 the neutron yield coming from α-particle self-heating

    Measuring the health-related Sustainable Development Goals in 188 countries: a baseline analysis from the Global Burden of Disease Study 2015

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    BACKGROUND: In September, 2015, the UN General Assembly established the Sustainable Development Goals (SDGs). The SDGs specify 17 universal goals, 169 targets, and 230 indicators leading up to 2030 ..
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