902 research outputs found
Vaccine nationalism counterintuitively erodes public trust in leaders
Global access to resources like vaccines is key for containing the spread of infectious diseases. However, wealthy countries often pursue nationalistic policies, stockpiling doses rather than redistributing them globally. One possible motivation behind vaccine nationalism is a belief among policymakers that citizens will mistrust leaders who prioritize global needs over domestic protection. In seven experiments (total N = 4,215 adults), we demonstrate that such concerns are misplaced: Nationally representative samples across multiple countries with large vaccine surpluses (Australia, Canada, United Kingdom, and United States) trusted redistributive leaders more than nationalistic leaders—even the more nationalistic participants. This preference generalized across different diseases and manifested in both self-reported and behavioral measures of trust. Professional civil servants, however, had the opposite intuition and predicted higher trust in nationalistic leaders, and a nonexpert sample also failed to predict higher trust in redistributive leaders. We discuss how policymakers’ inaccurate intuitions might originate from overestimating others’ self-interest
The Radius of Metric Subregularity
There is a basic paradigm, called here the radius of well-posedness, which
quantifies the "distance" from a given well-posed problem to the set of
ill-posed problems of the same kind. In variational analysis, well-posedness is
often understood as a regularity property, which is usually employed to measure
the effect of perturbations and approximations of a problem on its solutions.
In this paper we focus on evaluating the radius of the property of metric
subregularity which, in contrast to its siblings, metric regularity, strong
regularity and strong subregularity, exhibits a more complicated behavior under
various perturbations. We consider three kinds of perturbations: by Lipschitz
continuous functions, by semismooth functions, and by smooth functions,
obtaining different expressions/bounds for the radius of subregularity, which
involve generalized derivatives of set-valued mappings. We also obtain
different expressions when using either Frobenius or Euclidean norm to measure
the radius. As an application, we evaluate the radius of subregularity of a
general constraint system. Examples illustrate the theoretical findings.Comment: 20 page
Radial orbit instability: review and perspectives
This paper presents elements about the radial orbit instability, which occurs
in spherical self-gravitating systems with a strong anisotropy in the radial
velocity direction. It contains an overview on the history of radial orbit
instability. We also present the symplectic method we use to explore stability
of equilibrium states, directly related to the dissipation induced instability
mechanism well known in theoretical mechanics and plasma physics.Comment: 10 pages, submitted to Transport Theory and Statistical Physics,
proceedings of Vlasovia 2009 International Conference. Corrected for typos,
redaction, and references adde
Potential barrier heights at metal on oxygen-terminated diamond interfaces
International audienceElectrical properties of metal-semiconductor (M/SC) and metal/oxide/SC structures built with Zr or ZrO_2 deposited on oxygen-terminated surfaces of (001)-oriented diamond films, comprising a stack of lightly p-doped diamond on a heavily doped layer itself homoepitaxially grown on a Ib substrate, are investigated experimentally and compared to different models. In Schottky barrier diodes, the interfacial oxide layer evidenced by high resolution transmission electron microscopy and electron energy losses spectroscopy before and after annealing, and barrier height inhomogeneities accounts for the measured electrical characteristics until flat bands are reached, in accordance with a model which generalizes that of R.T. Tung [Phys. Rev. B 45, 13509 (1992)] and permits to extract physically meaningful parameters of the three kinds of interface: (a) unannealed ones; (b) annealed at 350°C; (c) annealed at 450°C, with characteristic barrier heights of 2.2-2.5 V in case (a) while as low as 0.96 V in case (c). Possible models of potential barriers for several metals deposited on well defined oxygen-terminated diamond surfaces are discussed and compared to experimental data. It is concluded that interface dipoles of several kinds present at these compound interfaces and their chemical evolution due to annealing are the suitable ingredients able to account for the Mott-Schottky behavior when the effect of the metal work function is ignored, and to justify the reverted slope observed regarding metal work function, in contrast to the trend always reported for all other metal-semiconductor interfaces.Les propriétés électriques et structurales d'interfaces métal/diamant et métal/oxyde/diamant où le métal est le Zirconium et le semi-conducteur comporte un empilement de couches faiblement et fortement dopées au bore sur substrat Ib, sont étudiées expérimentalement et comparées à différents modèles. Dans le barrière de Schottky, une inter-couche d'oxyde d'environ 2 couches atomiques, mise en évidence par diverses techniques de microscopie électronique à transmission, est présente et ajoutée à la présence d'inhomogénéités de barrière de potentiel, est corrélée aux propriétés électriques simulées par un modèle qui généralise celui de R. T. Tung [Phys. Rev. B 45, 13509 (1992)] . Les paramètres physiquement caractéristiques des interfaces (a) non recuites, (b) recuite à 350°C et (c) recuite à 450°C peuvent ainsi être extraits, en particulier des hauteurs de barrière de 2.2-2.5 V dans le cas (a) et aussi basses que 0.96 V dans le cas (c). Les modèles possibles de fixation du niveau de Fermi aux interfaces métal/diamant sont examinés et confrontés aux données récemment publiées pour différents métaux sur la surface oxygénée du diamant. On conclue que les quantités physiques judicieuses sont l'affinité électronique du diamant, fonction de son état de surface, pour justifier l'allure générale conforme au modèle de Mott-Schottky et la force du dipole d'interface, dépendante des liaisons chimiques à l'interface, pour expliquer la pente de la variation de la barrière en fonction du travail de sortie du métal, qui est inversée par rapport à tous les autres semi-conducteurs
Validating atlas-based lesion disconnectomics in multiple sclerosis: A retrospective multi-centric study.
The translational potential of MR-based connectivity modelling is limited by the need for advanced diffusion imaging, which is not part of clinical protocols for many diseases. In addition, where diffusion data is available, brain connectivity analyses rely on tractography algorithms which imply two major limitations. First, tracking algorithms are known to be sensitive to the presence of white matter lesions and therefore leading to interpretation pitfalls and poor inter-subject comparability in clinical applications such as multiple sclerosis. Second, tractography quality is highly dependent on the acquisition parameters of diffusion sequences, leading to a trade-off between acquisition time and tractography precision. Here, we propose an atlas-based approach to study the interplay between structural disconnectivity and lesions without requiring individual diffusion imaging. In a multi-centric setting involving three distinct multiple sclerosis datasets (containing both 1.5 T and 3 T data), we compare our atlas-based structural disconnectome computation pipeline to disconnectomes extracted from individual tractography and explore its clinical utility for reducing the gap between radiological findings and clinical symptoms in multiple sclerosis. Results using topological graph properties showed that overall, our atlas-based disconnectomes were suitable approximations of individual disconnectomes from diffusion imaging. Small-worldness was found to decrease for larger total lesion volumes thereby suggesting a loss of efficiency in brain connectivity of MS patients. Finally, the global efficiency of the created brain graph, combined with total lesion volume, allowed to stratify patients into subgroups with different clinical scores in all three cohorts
Target structure independent elastic scattering at low momentum transfers
Analyzing powers and cross sections for the elastic scattering of polarized
7Li by targets of 6Li, 7Li and 12C are shown to depend only on the properties
of the projectile for momentum transfers of less than 1.0 fm-1. The result of a
detailed analysis of the experimental data within the framework of the coupled
channels model with ground state reorientation and transitions to the excited
states of the projectile and targets included in the coupling schemes are
presented. This work suggests that nuclear properties of weakly-bound nuclei
can be tested by elastic scattering experiments, independent of the target
used, if data are acquired for momentum transfers less than ~1.0 fm-1.Comment: 9 pages, 4 figures, 1 table, accepted in Phys. Lett.
Deformation of the N=Z nucleus 76Sr using beta-decay studies
A novel method of deducing the deformation of the N=Z nucleus 76Sr is
presented. It is based on the comparison of the experimental Gamow-Teller
strength distribution B(GT) from its beta decay with the results of QRPA
calculations. This method confirms previous indications of the strong prolate
deformation of this nucleus in a totally independent way. The measurement has
been carried out with a large Total Absorption gamma Spectrometer, "Lucrecia",
newly installed at CERN-ISOLDE.Comment: Accepted in Phys. Rev. Letter
The RMS Survey: 13CO observations of candidate massive YSOs in the southern hemisphere
Abridged: The Red MSX Source (RMS) survey is an ongoing multi-wavelength
observational programme designed to return a large, well-selected sample of
massive young stellar objects (MYSOs). Here we present 13CO observations made
towards 854 MYSOs candidates located in the 3rd and 4th quadrants. We detected
13CO emission towards a total of 751 of the 854 RMS sources observed (~88%). In
total 2185 emission components are detected above 3 level. Multiple
emission profiles are observed towards the majority of these sources - 455
sources (~60%) - with an average of ~4 molecular clouds along the line of
sight. These multiple emission features make it difficult to assign a kinematic
velocity to many of our sample. We have used archival CS (J=2-1) and maser
velocities to resolved the component multiplicity towards 82 sources and have
derived a criterion which is used to identify the most likely component for a
further 202 multiple component sources. Combined with the single component
detections we have obtained unambiguous kinematic velocities towards 580
sources (~80% of the detections). The 171 sources for which we have not been
able to determine the kinematic velocity will require additional line data.
Using the rotation curve of Brand and Blitz (1993) and their radial velocities
we calculate kinematic distances for all components detected.Comment: Summitted to A&A, the resolution of figure 1 has been reduced,
samples of Table 3 and Figure 11 are now included but the full version will
only be available in the online version of the journa
Household energy and water practices change post-occupancy in an Australian low-carbon development
© 2019 by the authors. This research comprises a longitudinal study of a cohort of residents moving into a low-carbon development and their pre- and post-occupancy household practices that consume energy and water. They are the early adopters of living in low-carbon households and provide valuable insight into the influence of design and technology on household practices. Household energy and water consumption levels are measured and normalised to the metropolitan average to discuss the influence of design and technology on use. Heating, cooling and showering practices consume the largest proportion of household energy and water use and so the changes to thermal comfort and personal hygiene practices are examined along with a consideration of the influence of lifestyle and family composition on cooling practices. Household water and energy use decreases due to technology and design influences post-occupancy. However, the personal practice history of residents influences water and energy consumption. Changes to the meaning element of personal hygiene practices show how these are interlocked and unlikely to change in their duration when there are other demanding practices to be undertaken
Optimized loading of an optical dipole trap for the production of Chromium BECs
We report on a strategy to maximize the number of chromium atoms transferred
from a magneto-optical trap into an optical trap through accumulation in
metastable states via strong optical pumping. We analyse how the number of
atoms in a chromium Bose Einstein condensate can be raised by a proper handling
of the metastable state populations. Four laser diodes have been implemented to
address the four levels that are populated during the MOT phase. The individual
importance of each state is specified. To stabilize two of our laser diode, we
have developed a simple ultrastable passive reference cavity whose long term
stability is better than 1 MHz
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