163 research outputs found
The Scope of the IBGP Routing Anomaly Problem
Correctness problems in the iBGP routing, the de-facto standard to spread global routing information in Autonomous Systems, are a well-known issue. Configurations may route cost-suboptimal, inconsistent, or even behave non-convergent and -deterministic. However, even if a lot of studies have shown many exemplary problematic configurations, the exact scope of the problem is largely unknown: Up to now, it is not clear which problems may appear under which iBGP architectures. The exact scope of the iBGP correctness problem is of high theoretical and practical interest. Knowledge on the resistance of specific architecture schemes against certain anomaly classes and the reasons may help to improve other iBGP schemes. Knowledge on the specific problems of the different schemes helps to identify the right scheme for an AS and develop workarounds
Light Stop Searches at the LHC in Events with two b-Jets and Missing Energy
We propose a new method to discover light top squarks (stops) in the
co-annihilation region at the Large Hadron Collider (LHC). The bino-like
neutralino is the lightest supersymmetric particle (LSP) and the lighter stop
is the next-to-LSP. Such scenarios can be consistent with electroweak
baryogenesis and also with dark matter constraints. We consider the production
of two stops in association with two b-quarks, including pure QCD as well as
mixed electroweak-QCD contributions. The stops decay into a charm quark and the
LSP. For a higgsino-like light chargino the electroweak contributions can
exceed the pure QCD prediction. We show the size of the electroweak
contributions as a function of the stop mass and present the LHC discovery
reach in the stop-neutralino mass plane.Comment: 12 pages, 10 figure
Scalability of iBGP Path Diversity Concepts
Abstract. Improving the path diversity seems to be the next fundamental step in the iBGP evolution. Focusing the advantages an improvement of the path diversity implies, network protocol designers have disregarded the most critical drawback so far: The effect on the scalability of the iBGP routing, a fundamental requirement for production usage. This aspect is examined by the analyses discussed in our paper. In this paper, we provide the theoretical groundwork for scalability analyses of four highly relevant path diversity schemes. Based on this groundwork, we exemplarily predict the information load the schemes induce in a system of a large ISP. Generalizing the system-specific results, we give an outlook on the load that can be expected in comparable ASs. We found that for two schemes currently in the standardization process, scalability problems in large ASs as they are operated by ISPs seem likely
Hadronic production of bottom-squark pairs with electroweak contributions
We present the complete computation of the tree-level and the next-to-leading
order electroweak contributions to bottom-squark pair production at the LHC.
The computation is performed within the minimal supersymmetric extension of the
Standard Model. We discuss the numerical impact of these contributions in
several supersymmetric scenarios.Comment: 33 pages, v2: preprint numbers correcte
Hadronic production of squark-squark pairs: The electroweak contributions
We compute the electroweak (EW) contributions to squark--squark pair
production processes at the LHC within the framework of the Minimal
Supersymmetric Standard Model (MSSM). Both tree-level EW contributions, of
O(alpha_s alpha + alpha^2), and next-to-leading order (NLO) EW corrections, of
O(alpha_s^2 alpha), are calculated. Depending on the flavor and chirality of
the produced quarks, many interferences between EW-mediated and QCD-mediated
diagrams give non-zero contributions at tree-level and NLO. We discuss the
computational techniques and present an extensive numerical analysis for
inclusive squark--squark production as well as for subsets and single
processes. While the tree-level EW contributions to the integrated cross
sections can reach the 20% level, the NLO EW corrections typically lower the LO
prediction by a few percent.Comment: 36 pages, 18 figure
Threshold resummation for gaugino pair production at hadron colliders
We present a complete analysis of threshold resummation effects on direct
light and heavy gaugino pair production at the Tevatron and the LHC. Based on a
new perturbative calculation at next-to-leading order of SUSY-QCD, which
includes also squark mixing effects, we resum soft gluon radiation in the
threshold region at leading and next-to-leading logarithmic accuracy, retaining
at the same time the full SUSY-QCD corrections in the finite coefficient
function. This allows us to correctly match the resummed to the perturbative
cross section. Universal subleading logarithms are resummed in full matrix
form. We find that threshold resummation slightly increases and considerably
stabilizes the invariant mass spectra and total cross sections with respect to
the next-to-leading order calculation. For future reference, we present total
cross sections and their theoretical errors in tabular form for several
commonly used SUSY benchmark points, gaugino pairs, and hadron collider
energies.Comment: 28 pages, 5 tables, 17 figure
Venetoclax enhances the efficacy of therapeutic antibodies in B-cell malignancies by augmenting tumor cell phagocytosis
Immunotherapy has evolved as a powerful tool for the treatment of B-cell malignancies, and patient outcomes have improved by combining therapeutic antibodies with conventional chemotherapy. Overexpression of antiapoptotic B-cell lymphoma 2 (Bcl-2) is associated with a poor prognosis, and increased levels have been described in patients with "double-hit" diffuse large B-cell lymphoma, a subgroup of Burkitt's lymphoma, and patients with pediatric acute lymphoblastic leukemia harboring a t(17;19) translocation. Here, we show that the addition of venetoclax (VEN), a specific Bcl-2 inhibitor, potently enhanced the efficacy of the therapeutic anti-CD20 antibody rituximab, anti-CD38 daratumumab, and anti-CD19-DE, a proprietary version of tafasitamab. This was because of an increase in antibody-dependent cellular phagocytosis by macrophages as shown in vitro and in vivo in cell lines and patient-derived xenograft models. Mechanistically, double-hit lymphoma cells subjected to VEN triggered phagocytosis in an apoptosis-independent manner. Our study identifies the combination of VEN and therapeutic antibodies as a promising novel strategy for the treatment of B-cell malignancies
Pediatric T-ALL type-1 and type-2 relapses develop along distinct pathways of clonal evolution
The mechanisms underlying T-ALL relapse remain essentially unknown. Multilevel-omics in 38 matched pairs of initial and relapsed T-ALL revealed 18 (47%) type-1 (defined by being derived from the major ancestral clone) and 20 (53%) type-2 relapses (derived from a minor ancestral clone). In both types of relapse, we observed known and novel drivers of multidrug resistance including MDR1 and MVP, NT5C2 and JAK-STAT activators. Patients with type-1 relapses were specifically characterized by IL7R upregulation. In remarkable contrast, type-2 relapses demonstrated (1) enrichment of constitutional cancer predisposition gene mutations, (2) divergent genetic and epigenetic remodeling, and (3) enrichment of somatic hypermutator phenotypes, related to BLM, BUB1B/PMS2 and TP53 mutations. T-ALLs that later progressed to type-2 relapses exhibited a complex subclonal architecture, unexpectedly, already at the time of initial diagnosis. Deconvolution analysis of ATAC-Seq profiles showed that T-ALLs later developing into type-1 relapses resembled a predominant immature thymic T-cell population, whereas T-ALLs developing into type-2 relapses resembled a mixture of normal T-cell precursors. In sum, our analyses revealed fundamentally different mechanisms driving either type-1 or type-2 T-ALL relapse and indicate that differential capacities of disease evolution are already inherent to the molecular setup of the initial leukemia
SUSY parameter determination at the LHC using cross sections and kinematic edges
We study the determination of supersymmetric parameters at the LHC from a
global fit including cross sections and edges of kinematic distributions. For
illustration, we focus on a minimal supergravity scenario and discuss how well
it can be constrained at the LHC operating at 7 and 14 TeV collision energy,
respectively. We find that the inclusion of cross sections greatly improves the
accuracy of the SUSY parameter determination, and allows to reliably extract
model parameters even in the initial phase of LHC data taking with 7 TeV
collision energy and 1/fb integrated luminosity. Moreover, cross section
information may be essential to study more general scenarios, such as those
with non-universal gaugino masses, and distinguish them from minimal,
universal, models.Comment: 22 pages, 8 figure
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