2,331 research outputs found
Synchrotron radiation by slowly rotating fermions
No full textThis article is published as Buzzegoli, Matteo, Jonathan D. Kroth, Kirill Tuchin, and Nandagopal Vijayakumar. "Synchrotron radiation by slowly rotating fermions." Physical Review D 107, no. 5 (2023): L051901.
DOI: 10.1103/PhysRevD.107.L051901.
Attribution 4.0 International (CC BY 4.0).
Copyright 2023 The Authors.
Posted with permission
Sokolov--Ternov effect in rotating systems
No full textWe study electromagnetic radiation by electrically charged fermions embedded in a rotating medium in an external magnetic field. We compute the dependence of the radiation intensity on the angular velocity Ω of the rotating medium for fermion polarizations along and opposite the magnetic field direction in intense subcritical fields. The polarization dependence of the photon radiation results in the Sokolov-Ternov effect - the radiative polarization of fermions. We study the dependence of the degree of polarziation on Ω. We found that rotation significantly changes the degree of polarization. We show that the rotating quark-gluon plasma acquires a finite magnetic moment that exhibits complex dependence on Ω.This is a preprint from Kroth, Jonathan D., and Kirill Tuchin. "Sokolov--Ternov effect in rotating systems." arXiv preprint arXiv:2409.20569 (2024). doi: https://doi.org/10.48550/arXiv.2409.20569
Photon radiation by relatively slowly rotating fermions in magnetic field
No full textWe study the electromagnetic radiation by a fermion carrying an electric charge q embedded in a medium rotating with constant angular velocity Ω parallel or anti-parallel to an external constant magnetic field B. We assume that the rotation is "relatively slow"; namely, that the angular velocity Ω is much smaller than the inverse magnetic length qB−−−√. In practice, such angular velocity can be extremely high. The fermion motion is a superposition of two circular motions: one due to its rigid rotation caused by forces exerted by the medium, another due to the external magnetic field. We derive an exact analytical expression for the spectral rate and the total intensity of this type of synchrotron radiation. Our numerical calculations indicate very high sensitivity of the radiation to the angular velocity of rotation. We show that the radiation intensity is strongly enhanced if qB and Ω point in the same direction and is suppressed otherwise.This is a pre-print of the article Buzzegoli, Matteo, Jonathan D. Kroth, Kirill Tuchin, and Nandagopal Vijayakumar. "Photon radiation by relatively slowly rotating fermions in magnetic field." arXiv preprint arXiv:2306.03863 (2023).
DOI: 10.48550/arXiv.2306.03863.
Copyright 2023 The Authors.
Attribution 4.0 International (CC BY 4.0).
Posted with permission
Citizen participation in news
No full textThe process of producing news has changed significantly due to the advent of the Web, which has enabled the increasing involvement of citizens in news production. This trend has been given many names, including participatory journalism, produsage, and crowd-sourced journalism, but these terms are ambiguous and have been applied inconsistently, making comparison of news systems difficult. In particular, it is problematic to distinguish the levels of citizen involvement, and therefore the extent to which news production has genuinely been opened up. In this paper we perform an analysis of 32 online news systems, comparing them in terms of how much power they give to citizens at each stage of the news production process. Our analysis reveals a diverse landscape of news systems and shows that they defy simplistic categorisation, but it also provides the means to compare different approaches in a systematic and meaningful way. We combine this with four case studies of individual stories to explore the ways that news stories can move and evolve across this landscape. Our conclusions are that online news systems are complex and interdependent, and that most do not involve citizens to the extent that the terms used to describe them imply
Tar sandstone investigation in southwestern Uinta Basin
No full textreportDuring the month of July 1972, the author assisted by Jonathan Mann studied the oil impregnated sandstone (hereafter OISS) deposits in the Lower Unit of the Parachute Creek Member of the Green River Formation on the southwestern edge of the Uinta Basin, along the Roan Cliffs and within the Roan Plateau. Careful mapping was conducted to determine the extent of the Sunnyside OISS deposit and to relate it to other deposits in the general vicinity. In addition to this mapping, which was restricted to the Flat Canyon and Sunnyside 15 min. quadrangles, (correlation investigations? ) were carried out in Nine Mile Canyon, Argyle Canyon, Indian Canyon, and at the headwaters of Avintaquin Canyon near Reservation Ridge (see USGS 7 1/2 min. quadrangles Gray Head Peak, 1969, and Flat Ridge, Utah, 1969). These areas, in this report, are further subdivided into smaller regions (often ridges or canyons) for further expansion of the results of the investigation. A number of the canyons could only be studied by hiking them through, others because of the size of the area studied and time requirements were studied by numerous stops from a four-wheel-drive truck. A field method to categorize the estimated richness of the OISS was used in the mapping: A numeral from I-V was assigned to a deposit, I being void of tar and progressing with each number until very rich OISS would be classed as V
An answer to a paper, [electronic resource] : Called A Memorial Of the Poor Inhabitants, Tradesmen and Labourers of the Kingdom of Ireland. By the Author of the Short View of the State of Ireland.
No full textThe author of The short view = Jonathan Swift.An answer to 'To the R-d Dr. J-n S-t, the memorial .. ', by Sir John Browne.Teerink-Scouten,Hanson,Goldsmiths',Electronic reproduction.English Short Title Catalog,Reproduction of original from University of London's Goldsmiths' Library
Jonathan Ashley-Smith: mentor, role model, inspiration
No full textJonathan Ashley-Smith has been such a prominent player in the field of conservation that he has had an impact on many people’s careers. He has certainly been an inspiration for this author who presents a personal overview of the many ways in which Ashley-Smith helped steer my path
Morphologic and functional correlates of synaptic pathology in the cathepsin D knockout mouse model of congenital neuronal ceroid lipofuscinosis
No full textMutations in the cathepsin D (CTSD) gene cause an aggressive neurodegenerative disease (congenital neuronal ceroid lipofuscinosis) that leads to early death. Recent evidence suggests that presynaptic abnormalities play a major role in the pathogenesis of CTSD deficiencies. To identify the early events that lead to synaptic alterations, we investigated synaptic ultrastructure and function in presymptomatic CTSD knockout (Ctsd) mice. Electron microscopy revealed that there were significantly greater numbers of readily releasable synaptic vesicles present in Ctsd mice than in wild-type control mice as early as postnatal day 16. The size of this synaptic vesicle pool continued to increase with disease progression in the hippocampus and thalamus of the Ctsd mice. Electrophysiology revealed a markedly decreased frequency of miniature excitatory postsynaptic currents (mEPSCs) with no effect on paired-pulse modulation of the evoked excitatory post synaptic potentials in the hippocampus of Ctsd mice. The reduced mEPSCs frequency was observed before the appearance of epilepsy or any morphologic sign of synaptic degeneration. Taken together, these data indicate that CTSD is required for normal synaptic function and that a failure in synaptic trafficking or recycling may bean early and important pathologic mechanism in Ctsd mice; these presynaptic abnormalities may initiate synaptic degeneration in advance of subsequent neuronal loss
Interpellations : Three Essays on Kent Monkman = Trois essais sur Kent Monkman
No full textKent Monkman’s work fascinates. An artist of Cree origin he revisits North American historical events and western cultural representations, often under the guise of Miss Chief Eagle Testickle, his alter ego, the sexy and extravagant diva warrior. His aesthetics and drama have the effect of drawing out both what has been erased and concealed in the historical inscription of aboriginal culture the repressed desire and troubled fascination that have paradoxically contributed to shaping it.
In Interpellations. Three Essays on Kent Monkman the art historians Jonathan D. Katz, Richard W. Hill and Todd Porterfield offer perspectives and analyses on Monkman’s work that address history and genre painting, the queered Romantic landscape, the shifting and unfixed subject, race, sexuality, conquest and sovereignty, and modern versus discontinuous temporality.final article publishe
Did They Fall or Were They Pushed? What Happened in the Garden of Eden?
No full textProfessor Jonathan Magonet, Biblical Scholar, Author, Rabbi, President, Leo-Baeck College - Center for Jewish Education, London.https://digitalcommons.fairfield.edu/bennettcenter-posters/1227/thumbnail.jp
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