1,890 research outputs found
On Four-Point Functions of Half-BPS Operators in General Dimensions
We study four-point correlation functions of half-BPS operators of arbitrary
weight for all dimensions d=3,4,5,6 where superconformal theories exist. Using
harmonic superspace techniques, we derive the superconformal Ward identities
for these correlators and present them in a universal form. We then solve these
identities, employing Jack polynomial expansions. We show that the general
solution is parameterized by a set of arbitrary two-variable functions, with
the exception of the case d=4, where in addition functions of a single variable
appear. We also discuss the operator product expansion using recent results on
conformal partial wave amplitudes in arbitrary dimension.Comment: The discussion of the case d=6 expanded; references added/correcte
Magnetic unmixing of first-order reversal curve diagrams using principal component analysis
We describe a quantitative magnetic unmixing method based on principal component analysis (PCA) of first-order reversal curve (FORC) diagrams.
For PCA we resample FORC distributions on grids that capture diagnostic signatures of single-domain (SD), pseudo-single-domain (PSD), and multidomain (MD) magnetite, as well as of minerals such as hematite. Individual FORC diagrams are recast as linear combinations of end-member (EM) FORC diagrams, located at user-defined positions in PCA space. The EM selection is guided by constraints derived from physical modeling and imposed by data scatter. We investigate temporal variations of two EMs in bulk North Atlantic sediment cores collected from the Rockall Trough and the Iberian Continental Margin. Sediments from each site contain a mixture of magnetosomes and granulometrically distinct detrital magnetite. We also quantify
the spatial variation of three EM components (a coarse silt-sized MD component, a fine silt-sized PSD component, and a mixed clay-sized component containing both SD magnetite and hematite) in surficial sediments along the flow path of the North Atlantic Deep Water (NADW). These samples were separated into granulometric fractions, which helped constrain EM definition. PCA-based unmixing reveals systematic variations in EM relative abundance as a function of distance along NADW flow. Finally, we apply PCA to the combined dataset of Rockall Trough and NADW sediments, which can be recast as a four-EM mixture, providing enhanced discrimination between components. Our method forms the foundation of a general solution to the problem of unmixing multi-component magnetic mixtures, a fundamental task of rock magnetic studies.The research leading to these results has received funding from the European Research Council under the European Union's Seventh Framework Programme (FP/2007-2013)/ERC grant agreement 320750.This is the author accepted manuscript. The final version is available from Wiley via http://dx.doi.org/10.1002/2015GC00590
Immunotherapy for Epstein-Barr Virus-Related Lymphomas
Latent EBV infection is associated with several malignancies, including EBV post-transplant lymphoproliferative disorders (LPD), Hodgkin and non-Hodgkin lymphomas, nasopharyngeal carcinoma and Burkitt lymphoma. The range of expression of latent EBV antigens varies in these tumors, which influences how susceptible the tumors are to immunotherapeutic approaches. Tumors expressing type III latency, such as in LPD, express the widest array of EBV antigens making them the most susceptible to immunotherapy. Treatment strategies for EBV-related tumors include restoring normal cellular immunity by adoptive immunotherapy with EBV-specific T cells and targeting the malignant B cells with monoclonal antibodies. We review the current immunotherapies and future studies aimed at targeting EBV antigen expression in these tumors
Positive energy unitary irreducible representations of D=6 conformal supersymmetry
We give a constructive classification of the positive energy (lowest weight)
unitary irreducible representations of the D=6 superconformal algebras
osp(8*/2N). Our results confirm all but one of the conjectures of Minwalla (for
N=1,2) on this classification. Our main tool is the explicit construction of
the norms of the states that has to be checked for positivity. We give also the
reduction of the exceptional UIRs.Comment: 27 pages, TeX with harvmac, amssym.def, amssym.tex; v.2: minor
corrections and references added; v.3: minor corrections; v.4: to appear in
J. Phys.
Addressing School Related Gender Based Violence in Togo: A Scoping Study
This report presents findings from the scoping study of policy, practice and evidence on school-related
gender-based violence (SRGBV) in Togo, which took place in 2016. The study has been carried out as
a collaboration between the government of Togo, UNICEF, and a team at the UCL Institute of
Education (Jenny Parkes, Jo Heslop, Freya Johnson Ross, Rosie Westerveld and Elaine Unterhalter)
working alongside the consultant Dr Kossi Sénamé Dodzi. Its core elements consisted of: stakeholder
mapping and engagement in policy dialogue; analysis of legislation and policy; analysis of any
programming on SRGBV; and the identification and evaluation of research and data. The findings
presented here will be used to guide decision making for phase two of EGVS which will take place
during 2017, as well as longer term planning and action on SRGBV in Togo. The findings will provide
the basis for reflection and the development of the action plan for the next phase of the EGVS
initiative
Addressing School-Related Gender-Based Violence in Côte d’Ivoire, Togo, Zambia and Ethiopia: A Cross-country Report
This report synthesises findings from four scoping studies of policy, practice and evidence on school-related gender-based violence (SRGBV) in Zambia, Togo, Ethiopia and Côte d’Ivoire carried out in 2016-2017.This work forms part of End Gender Violence in Schools (EGVS), an initiative led by UNICEF, with support from Global Partnership for Education (GPE) and UNGEI, which aims to strengthen the production and use of high quality evidence in order to build effective approaches to address SRGBV. Data were collected through stakeholder interviews, workshops and analyses of research, policy and programme texts. The research design offers a valuable framework through which to evaluate and strengthen national action on SRGBV through collecting evidence on: prevalence and patterns of SRGBV; laws, policies and plans; structures and partnerships; responses in and around schools; prevention through teaching and learning; and systems for data collection.Overall, these findings point to the need for using an evidence-based, multi-dimensional approach when analysing, developing and enacting policy and practice on SRGBV. The analysis generates an Action Map on SRGBV through legislation, policy and structures; work in schools; and through partnerships and communities
Addressing School-Related Gender-Based Violence in Côte d’Ivoire: A Scoping Study
The main objective of the study was to analyse responses to gender-based violence in and around
schools in Côte d’Ivoire, in order to inform future planning of policy and practice initiatives. This
report draws on the data gathered by the research team, UNICEF CO, national consultants and
partners, and presents findings from a scoping study of policy, practice and evidence on schoolrelated
gender-based violence (SRGBV) in Côte d’Ivoire
Lutter contre les violences basées sur le genre en milieu scolaire en Côte d’Ivoire: Étude exploratoire
Les violences basées sur le genre en milieu scolaire (VBGMS) désignent les actes de violence physique, sexuelle et psychologique contre les garçons et les filles perpétrés au sein et aux abords des écoles, des communautés et des familles et fondés sur un accès inégal aux ressources et au pouvoir, ainsi que sur des normes et stéréotypes inéquitables. Bien que ce type de violences bénéficie d’une reconnaissance accrue en tant que problème majeur à l’échelle internationale, un examen rigoureux de la documentation disponible démontre l’absence de solutions concrètes dont l’efficacité serait avérée. Les liens entre les différents niveaux d’action (que ce soit au niveau des politiques internationales et nationales, des lois ou au niveau des projets et des actions mises en oeuvre au sein de l’école ou des communautés) n’ont, jusqu’ici, pas fait l’objet d’une attention à la hauteur de la problématique. L’initiative visant à mettre fin aux VBGMS est un partenariat entre l’UNICEF, l’Institute of Education de l’University College de Londres, l’Initiative des Nations Unies pour l’éducation des filles, le Partenariat mondial pour l’éducation et les partenaires de Côte d’Ivoire, d’Éthiopie, du Togo et de Zambie (2015–2017), et est financé par les subventions aux activités mondiales et régionales du Partenariat mondial pour l’éducation. L’initiative a pour objectif de mettre en évidence les faits en vue d’étayer, de renforcer et de mieux comprendre le processus de mise en oeuvre des politiques relatives aux VBGMS en Côte d’Ivoire, en Éthiopie, au Togo et en Zambie. Les conclusions de cette initiative contribueront aux débats internationaux et nationaux sur les façons de lutter contre les VBGMS. L'objectif principal de l'étude était d'analyser les réponses à la violence sexiste dans et aux abords des écoles en Côte d'Ivoire, en vue d'éclairer la planification des politiques et des initiatives pratiques à venir. Ce rapport s'appuie sur les données recueillies par l'équipe de recherche, l’UNICEF CO, des consultants nationaux et des partenaires, et expose les résultats d’une étude préliminaire sur les politiques, les pratiques et les faits relatifs aux VBGMS en Côte d’Ivoire
Operator mixing in N=4 SYM: The Konishi anomaly revisited
In the context of the superconformal N=4 SYM theory the Konishi anomaly can
be viewed as the descendant of the Konishi multiplet in the 10 of
SU(4), carrying the anomalous dimension of the multiplet. Another descendant
with the same quantum numbers, but this time without anomalous
dimension, is obtained from the protected half-BPS operator (the
stress-tensor multiplet). Both and are renormalized mixtures
of the same two bare operators, one trilinear (coming from the superpotential),
the other bilinear (the so-called "quantum Konishi anomaly"). Only the operator
is allowed to appear in the right-hand side of the Konishi anomaly
equation, the protected one does not match the conformal properties of
the left-hand side. Thus, in a superconformal renormalization scheme the
separation into "classical" and "quantum" anomaly terms is not possible, and
the question whether the Konishi anomaly is one-loop exact is out of context.
The same treatment applies to the operators of the BMN family, for which no
analogy with the traditional axial anomaly exists. We illustrate our abstract
analysis of this mixing problem by an explicit calculation of the mixing matrix
at level g^4 ("two loops") in the supersymmetric dimensional reduction scheme.Comment: 28 pp LaTeX, 3 figure
Some Systematics of the Coupling Constant Dependence of N=4 Yang-Mills
The operator, O_\tau, that generates infinitesimal changes of the coupling
constant in N=4 Yang-Mills sits in the same supermultiplet as the
superconformal currents. We show how superconformal current Ward identities
determine a class of terms in the operator product expansion of O_\tau with any
other operator. In certain cases, this leads to constraints on the coupling
dependence of correlation functions in N=4 Yang-Mills. As an application, we
demonstrate the exact non-renormalization of two and certain three-point
correlation functions of BPS operators.Comment: 56 pages, LaTeX; amended and expanded arguments, added reference
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