5,287 research outputs found
Tilting modules and the p-canonical basis
In this paper we propose a new approach to tilting modules for reductive
algebraic groups in positive characteristic. We conjecture that translation
functors give an action of the (diagrammatic) Hecke category of the affine Weyl
group on the principal block. Our conjecture implies character formulas for the
simple and tilting modules in terms of the p-canonical basis, as well as a
description of the principal block as the anti-spherical quotient of the Hecke
category. We prove our conjecture for GL_n using the theory of 2-Kac-Moody
actions. Finally, we prove that the diagrammatic Hecke category of a general
crystallographic Coxeter group may be described in terms of parity complexes on
the flag variety of the corresponding Kac-Moody group.Comment: 145 pages. Many TikZ figures (best viewed in colour). v3: many minor
changes, detail and references for Kac-Moody flag varieties adde
A principled information valuation for communications during multi-agent coordination
Decentralised coordination in multi-agent systems is typically achieved using communication. However, in many cases, communication is expensive to utilise because there is limited bandwidth, it may be dangerous to communicate, or communication may simply be unavailable at times. In this context, we argue for a rational approach to communication --- if it has a cost, the agents should be able to calculate a value of communicating. By doing this, the agents can balance the need to communicate with the cost of doing so. In this research, we present a novel model of rational communication that uses information theory to value communications, and employ this valuation in a decision theoretic coordination mechanism. A preliminary empirical evaluation of the benefits of this approach is presented in the context of the RoboCupRescue simulator
Modular Koszul duality
We prove an analogue of Koszul duality for category of a
reductive group in positive characteristic larger than 1 plus the
number of roots of . However there are no Koszul rings, and we do not prove
an analogue of the Kazhdan--Lusztig conjectures in this context. The main
technical result is the formality of the dg-algebra of extensions of parity
sheaves on the flag variety if the characteristic of the coefficients is at
least the number of roots of plus 2.Comment: 62 pages; image displays best in pd
Pre-Interaction Identification by Dynamic Grip Classification
We present a novel authentication method to identify users as they pick up a mobile device. We use a combination of back-of-device capacitive sensing and accelerometer measurements to perform classification, and obtain increased performance compared to previous accelerometer-only approaches. Our initial results suggest that users can be reliably identified during the pick-up movement before interaction commences
Modular perverse sheaves on flag varieties I: tilting and parity sheaves
In this paper we prove that the category of parity complexes on the flag
variety of a complex connected reductive group is a "graded version" of the
category of tilting perverse sheaves on the flag variety of the dual group, for
any field of coefficients whose characteristic is good. We derive some
consequences on Soergel's modular category O, and on multiplicities and
decomposition numbers in the category of perverse sheaves.Comment: 42 pages; with a joint appendix with Geordie Williamso
The cross-contamination potential of mobile telephones
The use of mobile devices for professional, business, educational, personal and social purposes has accelerated exponentially over the last decade. Staff working in healthcare organisations, and patients and visitors using healthcare settings, understandably want to use mobile technology. Concerns have been raised about safety in terms of interference with equipment, and threats to privacy and dignity, yet less policy attention has been paid to infection risks.
Healthcare professional students were supplied with smartphones as part of a larger educational project. Devices collected from a sub-sample of students working in operating theatre contexts were sampled to estimate the cross-contamination potential of the technology. A longitudinal multiple measures design was used. Under laboratory conditions, samples were taken from surfaces using swabbing techniques followed by contact plating. The devices were subsequently cleaned with 70% isopropyl alcohol and returned to the students.
All devices demonstrated microbial contamination and over three quarters (86%) polymicrobial contamination. The technique and sites used to sample for microbial contamination influenced the levels of contamination identified. Swabbing alone was less likely to isolate polymicrobial contamination than contact plating, and some microorganisms were isolated only by contact plates and not by swabbing of the same area.
The findings from this study demonstrate further research is urgently needed to inform evidence-based infection control policy on the use of personal equipment such as mobile devices in the healthcare settings where contamination may have adverse effects on patients, staff and visitors
Bleomycin increases neutrophil adhesion to human vascular endothelial cells independently of upregulation of ICAM-1 and E-selectin
© 2016 Taylor & Francis. Aim of the Study: Bleomycin-induced lung disease is a serious complication of therapy characterized by alveolar injury, cytokine release, inflammatory cell recruitment, and eventually pulmonary fibrosis. The mechanisms underlying bleomycin-induced pulmonary fibrosis may be relevant to other progressive scarring diseases of the lungs. Pulmonary vascular endothelial cells are critically involved in immune cell extravasation at sites of injury through adhesion molecule expression and cytokine release. We sought to determine the effects of bleomycin on adhesion molecule expression and cytokine release by pulmonary vascular endothelial cells, and their functional relevance to inflammatory cell recruitment. Materials and Methods: The effects of pharmacologically relevant concentrations of bleomycin on adhesion molecule expression and cytokine release by human vascular endothelial cells in vitro were studied by flow cytometry, quantitative polymerase chain reaction, and enzyme-linked immunosorbent assay. A flow chamber model was used to assess the functional consequences on adhesion of flowing human neutrophils to endothelial cell monolayers. Results: Bleomycin increased intercellular adhesion molecule 1 (ICAM-1; CD54), vascular cell adhesion molecule (VCAM-1; CD106), and E-selectin (CD62E) expression, and increased monocyte chemoattractant protein (MCP-1) and interleukin (IL-8) release by endothelial cells. Increases in protein expression were accompanied by increased mRNA transcription. In contrast, there was no direct effect of bleomycin on the profibrotic cytokines transforming growth factor-beta (TGF-β), platelet-derived growth factor-BB (PDGF-BB), or endothelin-1. Under flow conditions, endothelial cells exposed to bleomycin supported increased neutrophil adhesion which was independent of ICAM-1 or E-selectin. Conclusion: Our findings demonstrate that bleomycin promotes endothelial-mediated inflammation and neutrophil adhesion. These mechanisms may contribute to the development of pulmonary fibrosis by supporting immune cell recruitment in the lungs
Mode-Wise Entanglement of Gaussian States
We address the decomposition of a multi-mode pure Gaussian state with respect
to a bi-partite division of the modes. For any such division the state can
always be expressed as a product state involving entangled two-mode squeezed
states and single mode local states at each side. The character of entanglement
of the state can therefore be understood modewise; that is, a given mode on one
side is entangled with only one corresponding mode of the other, and therefore
the total bi-partite entanglement is the sum of the modewise entanglement. This
decomposition is generally not applicable to all mixed Gaussian states.
However, the result can be extended to a special family of "isotropic" states,
characterized by a phase space covariance matrix with a completely degenerate
symplectic spectrum.Comment: 4 pages, RevTex4. Replaced with revised version with reference added
to a previous related paper. Minor typographical errors correcte
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