Spinning AdS Propagators

We develop the embedding formalism to describe symmetric traceless tensors in Anti-de Sitter space. We use this formalism to construct the bulk-to-bulk propagator of massive spin J fields and check that it has the expected short distance and massless limits. We also and a split representation for the bulk-to-bulk propagator, by writing it as an integral over the boundary of the product of two bulk-to-boundary propagators. We exemplify the use of this representation with the computation of the conformal partial wave decomposition of Witten diagrams. In particular, we determine the Mellin amplitude associated to AdS graviton exchange between minimally coupled scalars of general dimension, including the regular part of the amplitude.Comment: 48 pages, 6 figure

The role of leading twist operators in the Regge and Lorentzian OPE limits

We study two kinematical limits, the Regge limit and the Lorentzian OPE limit, of the four-point function of the stress-tensor multiplet in Super Yang-Mills at weak coupling. We explain how both kinematical limits are controlled by the leading twist operators. We use the known expression of the four-point function up to three loops, to extract the pomeron residue at next-to-leading order. Using this data and the known form of pomeron spin up to next-to-leading order, we predict the behaviour of the four-point function in the Regge limit at higher loops. Specifically, we determine the leading log behaviour at any loop order and the next-to-leading log at four loops. Finally, we check the consistency of our results with conformal Regge theory. This leads us to predict the behaviour around $J=1$ of the OPE coefficient of the spin $J$ leading twist operator in the OPE of two chiral primary operators.Comment: 22+14 page

HIV-1 Vif and APOBEC3G: Multiple roads to one goal

The viral infectivity factor, Vif, of human immunodeficiency virus type 1, HIV-1, has long been shown to promote viral replication in vivo and to serve a critical function for productive infection of non-permissive cells, like peripheral blood mononuclear cells (PBMC). Vif functions to counteract an anti-retroviral cellular factor in non-permissive cells named APOBEC3G. The current mechanism proposed for protection of the virus by HIV-1 Vif is to induce APOBEC3G degradation through a ubiquitination-dependent proteasomal pathway. However, a new study published in Retrovirology by Strebel and colleagues suggests that Vif-induced APOBEC3G destruction may not be required for Vif's virus-protective effect. Strebel and co-workers show that Vif and APOBEC3G can stably co-exist, and yet viruses produced under such conditions are fully infectious. This new result highlights the notion that depletion of APOBEC3G is not the sole protective mechanism of Vif and that additional mechanisms exerted by this protein can be envisioned which counteract APOBEC3G and enhance HIV infectivity

Towards Inhibition of Vif-APOBEC3G Interaction: Which Protein to Target?

APOBEC proteins appeared in the cellular battle against HIV-1 as part of intrinsic cellular immunity. The antiretroviral activity of some of these proteins is overtaken by the action of HIV-1 Viral Infectivity Factor (Vif) protein. Since the discovery of APOBEC3G (A3G) as an antiviral factor, many advances have been made to understand its mechanism of action in the cell and how Vif acts in order to counteract its activity. The mainstream concept is that Vif overcomes the innate antiviral activity of A3G by direct protein binding and promoting its degradation via the cellular ubiquitin/proteasomal pathway. Vif may also inhibit A3G through mechanisms independent of proteasomal degradation. Binding of Vif to A3G is essential for its degradation since disruption of this interaction is predicted to stimulate intracellular antiviral immunity. In this paper we will discuss the different binding partners between both proteins as one of the major challenges for the development of new antiviral drugs

The ESARDA Working Group on Containment and Surveillance: Activities and achievements

The working group on containment and surveillance (C/S) is one of the discipline-oriented working groups of ESARDA ¿ the European Safeguards Research and Development Association. Its mission is (a) to provide the safeguards community with expert advice on C/S instruments and methods and on their performance and (b) to act as a forum for the exchange of information on such instruments and methods, including unattended and remote monitoring systems. Currently, sixteen institutions contribute to the working group as members or observers. The institutions represent safeguards authorities including the European Commission¿s Directorate General for Energy (in charge of the implementation of the EURATOM treaty) and the International Atomic Energy Agency (IAEA), instrument developers, plant operators, national authorities and research laboratories. The working group meets twice per year, in order to address and discuss topics of interest. To this end, individual working group members volunteer to prepare discussion and working papers. The goal is to publish the results of the working group¿s discussions, preferably in the ESARDA Bulletin. The working group¿s current topics include: (i) Guidelines for developing sealing systems; (ii) XCam: IAEA¿s Next Generation Surveillance System; (iii) Interface between Safeguards and Security; (iv) 3D Laser based applications in Safeguards; (v) New generation of sealing developments; (vi) Enhanced Data Authentication System; (vii) Designing and simulating tools for surveillance and remote monitoring, and (viii) Performance & assurance of C/S instrumentation. For the ESARDA web site, the working group maintains a compendium of C/S instruments and methods and contributes to drafting technical sheets on safeguards-specific topics. When appropriate, the working group holds joint meetings with other ESARDA working groups to discuss topics of common interest. Regarding the annual ESARDA course on Nuclear Safeguards and Non-Proliferation, the working group provides a lecturer and material on C/S instrumentation and methods. The paper describes the working group¿s current terms of reference, membership, working method, topics of interest, achievements, and gives an outlook on the topics to be addressed in the near future.JRC.E.9-Nuclear security (Ispra

The European Commission Cooperative Support Programme: Activities and Achievements

The IAEA bases its technical and scientific Programme on contributions from the Member State Support Programmes (MSSP). The European Commission Cooperative Support Programme (EC-SP) started in 1981 to support IAEA¿s activities in the field of nuclear safeguards. Since its beginning, the EC-SP has been operated by the European Commission¿s Joint Research Centre (JRC) and its institutes at Ispra-Italy, Geel-Belgium and Karlsruhe-Germany. The EC-SP tasks provide technology and expertise in many technical areas related to the effective implementation of safeguards verification measures including the detection of undeclared materials, activities, and facilities. The paper will detail the main activities of the EC-SP in recent years, namely (a) the specific work as part of tasks with well-defined milestones and deadlines, (b) training activities and (c) the technical consultancy support to the many IAEA meetings and expert groups.JRC.DG.G.8-Nuclear securit

Eco(il)logical Knowledge: on Different Ways of Relating with the Known

In this article, I narrate an ethnographic storyline that involves forest inhabitants, local politicians, development professionals, and scientific researchers in both representational and nonrepresentational worlds of knowing. I discuss how and why, in Angola, making forest knowledge through relations of distance to the forests is crucial for attaining institutional legitimacy over the forests. This way of acquiring authority and influence is championed by a broad epistemological tendency to address only the absent, which is then made present by accredited representers. Yet this technique disempowers local forest dwellers in their everyday territories and disallows the capacity that the ecological knowns have to reveal themselves. Knowing Angolan forests through absence and distance is not just a potent contemporary form of knowledge that qualifies as a way of ruling the forests, but is also integral to widespread (neo)colonial processes of distinction and separation: the knower and the known, the representer and the represented, the “cosmopolitan intellectual” and the “rustic bestial” Other. Finally, I discuss different forms of ecological knowledge in light of ethical stances toward knowing, relationality, and, ultimately, being.info:eu-repo/semantics/publishedVersio