1,428 research outputs found
Quasinormal modes of charged magnetic black branes & chiral magnetic transport
We compute quasinormal modes (QNMs) of the metric and gauge field
perturbations about black branes electrically and magnetically charged in the
Einstein-Maxwell-Chern-Simons theory. By the gauge/gravity correspondence, this
theory is dual to a particular class of field theories with a chiral anomaly,
in a thermal charged plasma state subjected to a constant external magnetic
field, . The QNMs are dual to the poles of the two-point functions of the
energy-momentum and axial current operators, and they encode information about
the dissipation and transport of charges in the plasma. Complementary to the
gravity calculation, we work out the hydrodynamic description of the dual field
theory in the presence of a chiral anomaly, and a constant external . We
find good agreement with the weak field hydrodynamics, which can extend beyond
the weak regime into intermediate regimes. Furthermore, we provide results
that can be tested against thermodynamics and hydrodynamics in the strong
regime. We find QNMs exhibiting Landau level behavior, which become long-lived
at large if the anomaly coefficient exceeds a critical magnitude. Chiral
transport is analyzed beyond the hydrodynamic approximation for the five
(formerly) hydrodynamic modes, including a chiral magnetic wave.Comment: 29 pages + appendix, 14 figures; v2: references added, published
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Full Metadata Object profiling for flexible geoprocessing workflows
The design and running of complex geoprocessing workflows is an increasingly common geospatial modelling and analysis task. The Business Process Model and Notation (BPMN) standard, which provides a graphical representation of a workflow, allows stakeholders to discuss the scientific conceptual approach behind this modelling while also defining a machine-readable encoding in XML. Previous research has enabled the orchestration of Open Geospatial Consortium (OGC) Web Processing Services (WPS) with a BPMN workflow engine. However, the need for direct access to pre-defined data inputs and outputs results in a lack of flexibility during composition of the workflow and of efficiency during execution. This article develops metadata profiling approaches, described as two possible configurations, which enable workflow management at the meta-level through a coupling with a metadata catalogue. Specifically, a WPS profile and a BPMN profile are developed and tested using open-source components to achieve this coupling. A case study in the context of an event mapping task applied within a big data framework and based on analysis of the Global Database of Event Language and Tone (GDELT) database illustrates the two different architectures
Qu’est ce qu’un homosexuel libéré ?
Cet article cherche à relativiser l’idée que la période 1968-1970 a représenté un rupture totale dans l’histoire de l’homosexualité en France. Tout en acceptant que le style des nouveaux mouvements « gais » des années 1968 rompt avec celui de leur prédécesseur Arcadie, il propose une lecture contextualisée de la politique d’Arcadie qui remet en cause les interprétations de l’historiographie traditionnelle, suggérant même que la vision de l’homosexualité de ces nouveaux mouvements est quelquefois plus proche d’Arcadie qu’elle ne leur paraisse.This article aims to relativise the idea that the period 1968-70 represented a radical rupture in the history of homosexual politics in France. While accepting that the political style of the new ‘gay’ movements of the 1970s was different from that of their ‘homophile’ predecessor Arcadie, it offers a contextualised reading of Arcadie’s politics which challenges the Manichean interpretations of current historiography, and indeed argues that the gay radicals who thought they were breaking with Arcadie’s vision in fact shared more values with it than they realised
Don L. Anderson and the Caltech Seismo Lab
The following reminiscences and recollections, scientific and otherwise, were contributed by Don Anderson’s scientific colleagues. Incomplete though they are, they give a flavor of the extraordinary range of Don’s activities, his influence on Earth science, and the phenomenon that was the Caltech Seismological Laboratory in his time
An infectious recombinant foot-and-mouth disease virus expressing a fluorescent marker protein
Foot-and-mouth disease virus (FMDV) is one of the most extensively studied animal pathogens because it remains a major threat to livestock economies worldwide. However, the dynamics of FMDV infection are still poorly understood. The application of reverse genetics provides the opportunity to generate molecular tools to further dissect the FMDV life cycle. Here, we have used reverse genetics to determine the capsid packaging limitations for a selected insertion site in the FMDV genome. We show that exogenous RNA up to a defined length can be stably introduced into the FMDV genome, whereas larger insertions are excised by recombination events. This led us to construct a recombinant FMDV expressing the fluorescent marker protein, termed iLOV. Characterization of infectious iLOV-FMDV showed the virus has a plaque morphology and rate of growth similar to the parental virus. In addition, we show that cells infected with iLOV-FMDV are easily differentiated by flow cytometry using the inherent fluorescence of iLOV and that cells infected with iLOV-FMDV can be monitored in real-time with fluorescence microscopy. iLOV-FMDV therefore offers a unique tool to characterize FMDV infection in vitro, and its applications for in vivo studies are discussed
Comment on "A comparison of 103-105 year uplift rates on the South Alkyonides fault, central Greece: Holocene climate stability and the formation of coastal notches" by J. F. Cooper, G. P. Roberts, and C. J. Underwood
A smiling future: exploring the multidisciplinary associations with higher prevalence of tooth decay in minority children
With over 20 million Americans living in food deserts, it is no wonder why the children who living in these areas are consuming more processed foods. Processed foods and lack of proportional diet can have an adverse effect on the oral health of children and adults leading to tooth decay. Early Childhood Caries (ECC) is the most chronic disease in children and it is especially chronic within children who come from disadvantage backgrounds. The objective of this study is to explore the multiple paradigms of tooth decay that exist within the minority population of children. The mechanism behind what leads to tooth decay will be evaluated in conjunction with other factors such as: disparities within minority children, insurance coverage, and agriculture to demonstrate the high prevalence of ECC within minority children.
What goes in a child’s mouth can really determine the state of their oral healthcare, however more times than not children lack the responsibility and depend heavily upon their guardian to get their dental needs met. The development of ECC can lead to more severe problems if left untreated, and currently there is a high prevalence of untreated ECC in predominantly minority neighborhoods where families are typically low income. Low-income means they are less likely to have a primary dentist leading to more untreated ECC, however it is also important to look at the federally funded programs. The government has been able to take strides in helping provided coverage for these at-risk children. ECC is chronic and can be detrimental to a child’s healthcare. What goes in the child’s mouth is also important in that in low-income neighborhoods there are deserts full of no organic options. This can have an adverse effect on the child’s help by their famine nutritional needs.
There is a need for new policy to be implemented in order to increase the rate at which children go to the dentist as well as gain access to avoidable options. Although there were limits within this study, there are many suggested improvements and directions for future research to address.
In conclusion, although the data reported here supports the conclusion that more evidence is needed that will lead to significant policy reform to eliminate the high prevalence of ECC especially within children coming from minority backgrounds. Positive progress is being made due to the constant support from both the government and community resources as well as dental practitioners who are focused on making a difference in the oral health and overall well-being of children
Evolutionary diversification of an ancient gene family (rhs) through C-terminal displacement
<p>Abstract</p> <p>Background</p> <p><it>Rhs </it>genes are prominent features of bacterial genomes that have previously been implicated in genomic rearrangements in <it>E. coli</it>. By comparing <it>rhs </it>repertoires across the Enterobacteriaceae, this study provides a robust explanation of <it>rhs </it>diversification and evolution, and a mechanistic model of how <it>rhs </it>diversity is gained and lost.</p> <p>Results</p> <p><it>Rhs </it>genes are ubiquitous and comprise six structurally distinct lineages within the Enterobacteriaceae. There is considerable intergenomic variation in <it>rhs </it>repertoire; for instance, in <it>Salmonella enterica</it>, <it>rhs </it>are restricted to mobile elements, while in <it>Escherichia coli </it>one <it>rhs </it>lineage has diversified through transposition as older lineages have been deleted. Overall, comparative genomics reveals frequent, independent gene gains and losses, as well as occasional lateral gene transfer, in different genera. Furthermore, we demonstrate that Rhs 'core' domains and variable C-termini are evolutionarily decoupled, and propose that <it>rhs </it>diversity is driven by homologous recombination with circular intermediates. Existing C-termini are displaced by laterally acquired alternatives, creating long arrays of dissociated 'tips' that characterize the appearance of <it>rhs </it>loci.</p> <p>Conclusion</p> <p><it>Rhs </it>repertoires are highly dynamic among Enterobacterial genomes, due to repeated gene gains and losses. In contrast, the primary structures of <it>Rhs </it>genes are evolutionarily conserved, indicating that <it>rhs </it>sequence diversity is driven, not by rapid mutation, but by the relatively slow evolution of novel core/tip combinations. Hence, we predict that a large pool of dissociated <it>rhs </it>C-terminal tips exists episomally and these are potentially transmitted across taxonomic boundaries.</p
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