1,270 research outputs found

    Higher displays arising from filtered de Rham-Witt complexes

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    For a smooth projective scheme XX over a ring RR on which pp is nilpotent that meets some general assumptions we prove that the crystalline cohomology is equipped with the structure of a higher display which is a relative version of Fontaine's strongly divisible lattices. Frobenius-divisibilty is induced by the Nygaard filtration on the relative de Rham-Witt complex. For a nilpotent PD-thickening S/RS/R we also consider the associated relative display and can describe it explicitly by a relative version of the Nygaard filtration on the de Rham-Witt complex associated to a lifting of XX over SS. We prove that there is a crystal of relative displays if moreover the mod pp reduction of XX has a smooth and versal deformation space.Comment: 19 page

    A log-motivic cohomology for semistable varieties and its pp-adic deformation theory

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    We construct log-motivic cohomology groups for semistable varieties and study the pp-adic deformation theory of log-motivic cohomology classes. Our main result is the deformational part of a pp-adic variational Hodge conjecture for varieties with semistable reduction: a rational log-motivic cohomology class in bidegree (2n,n)(2n,n) lifts to a continuous pro-class if and only if its Hyodo-Kato class lies in the nn-th step of the Hodge filtration. This generalises a theorem of Bloch-Esnault-Kerz which treats the good reduction case. In the case n=1n=1 the lifting criterion is the one obtained by Yamashita for the logarithmic Picard group. Along the way, we relate log-motivic cohomology to logarithmic Milnor KK-theory and the logarithmic Hyodo-Kato Hodge-Witt sheaves.Comment: 33 page

    Can mobile health training meet the challenge of ‘measuring better’?

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    Abstract: Mobile learning has seen a large uptake in use in low- and middleincome countries. This is driven by rhetorics of easy scaling, reaching the hard-to-reach and the potential for generating analytics from the applications used by learners. Healthcare training has seen a proliferation of apps aimed at improving accountability through tracking and measuring workplace learning. A view of the mobile phone as an agent of change is thus linked with a technocentric approach to measurement. Metrics, initially created as proxies for what gets done by health workers, are now shaping the practices they were intended to describe. In this paper, we show how, despite some valiant efforts, ‘measuring better’ remains difficult to achieve due to entrenched views of what measurement consists of. We analyse a mobile health (mHealth) classification framework, drawing out some implications of how it has been used in training health workers. These lead us to recommend moving away from a view of mobile learning linked tightly to accountability and numbers. We suggest a focus on an alternative future, where ‘measuring better’ is promoted as part of sociocultural views of learning and linked with a social justice conceptualisation of development

    L1599B: Cloud Envelope and C+ Emission in a Region of Moderately Enhanced Radiation Field

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    We study the effects of an asymmetric radiation field on the properties of a molecular cloud envelope. We employ observations of carbon monoxide (12CO and 13CO), atomic carbon, ionized carbon, and atomic hydrogen to analyze the chemical and physical properties of the core and envelope of L1599B, a molecular cloud forming a portion of the ring at approximately 27 pc from the star Lambda Ori. The O III star provides an asymmetric radiation field that produces a moderate enhancement of the external radiation field. Observations of the [CII] fine structure line with the GREAT instrument on SOFIA indicate a significant enhanced emission on the side of the cloud facing the star, while the [Ci], 12CO and 13CO J = 1-0 and 2-1, and 12CO J = 3-2 data from the PMO and APEX telescopes suggest a relatively typical cloud interior. The atomic, ionic, and molecular line centroid velocities track each other very closely, and indicate that the cloud may be undergoing differential radial motion. The HI data from the Arecibo GALFA survey and the SOFIA/GREAT [CII] data do not suggest any systematic motion of the halo gas, relative to the dense central portion of the cloud traced by 12CO and 13CO.Comment: 9 Figure

    Auger Resonant Raman Spectroscopy Used to Study the Angular Distributions of the Xe 4d5/2 → 6p Decay Spectrum

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    The Auger resonant Raman effect can be used as a method to eliminate natural lifetime broadening in resonant Auger spectra. We have coupled this method with high-resolution photons from the Advanced Light Source to study angular distributions and decay rates of the Xe4d5/2→6p resonant Auger lines. The angular distribution parameters β of almost all possible final ionic 5p4(3P, 1D, 1S)6p states have been determined. Our data, which remove the discrepancy between previous lower-resolution experimental results, are compared to different theoretical results

    Welchen völkerrechtlichen Status hat Gaza?

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    Gastbeitrag zum Nahostkrieg. Die Politik meidet die Frage nach dem Status des Gazastreifens. Gründe sind nicht nur Schwierigkeiten einer rechtlichen Einordnung, sondern auch die Sorge vor einer Aufwertung der Hamas

    Electron-Energy and –Angular Distributions in the Double Photoionization of Helium

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    Photoelectron spectra of helium have been measured at different angles and at various energies above the double-ionization threshold up to 120 eV to investigate the behavior of the energy and angular distributions, of shake-off electrons. Both energy and angular distributions clearly show a U-shaped profile which turns to a flat curve near threshold pointing to a uniform intensity distribution over the kinetic energy for all angles in this excitation energy regime. Our results for the angular-distribution asymmetry parameter indicate qualitative agreement with theoretical predictions but fail to provide them quantitatively

    Observation of Parity-Unfavored Transitions in the Nonresonant Photoionization of Argon

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    Single-photon ionization of an atom or molecule can be subdivided into parity-favored and -unfavored transitions, the latter characterized by electron emission, preferentially perpendicular to the electric vector. The nonresonant existence of these transitions is shown experimentally and studied over an extended energy range for a variety of satellite transitions in atomic argon. The spectra exhibit several clearly resolved satellite lines with strongly negative β values close to -1, independent of the photon energy. The results confirm the corresponding predictions of angular-momentum transfer theory

    Endocast of the Late Triassic (Carnian) dinosaur Saturnalia tupiniquim: implications for the evolution of brain tissue in Sauropodomorpha

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    The evolutionary history of dinosaurs might date back to the first stages of the Triassic (c. 250-240 Ma), but the oldest unequivocal records of the group come from Late Triassic (Carnian -c. 230 Ma) rocks of South America. Here, we present the first braincase endocast of a Carnian dinosaur, the sauropodomorph Saturnalia tupiniquim, and provide new data regarding the evolution of the floccular and parafloccular lobe of the cerebellum (FFL), which has been extensively discussed in the field of palaeoneurology. Previous studies proposed that the development of a permanent quadrupedal stance was one of the factors leading to the volume reduction of the FFL of sauropods. However, based on the new data for S. tupiniquim we identified a first moment of FFL volume reduction in non-sauropodan Sauropodomorpha, preceding the acquisition of a fully quadrupedal stance. Analysing variations in FFL volume alongside other morphological changes in the group, we suggest that this reduction is potentially related to the adoption of a more restricted herbivore diet. In this context, the FFL of sauropods might represent a vestigial trait, retained in a reduced version from the bipedal and predatory early sauropodomorphs
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