5,534 research outputs found
Discovery potential for Higgs bosons beyond the SM
The discovery potential of the CMS detector for the MSSM neutral and charged
Higgs bosons at the LHC is presented based on studies with full detector
simulation and event reconstruction of the principal discovery channels.Comment: Prepared for International Europhysics Conference on High Energy
Physics (EPS-HEP2007), Manchester, England, 19-25 Jul 200
Coreference detection of low quality objects
The problem of record linkage is a widely studied problem that aims to identify coreferent (i.e. duplicate) data in a structured data source. As indicated by Winkler, a solution to the record linkage problem is only possible if the error rate is sufficiently low. In other words, in order to succesfully deduplicate a database, the objects in the database must be of sufficient quality. However, this assumption is not always feasible. In this paper, it is investigated how merging of low quality objects into one high quality object can improve the process of record linkage. This general idea is illustrated in the context of strings comparison, where strings of low quality (i.e. with a high typographical error rate) are merged into a string of high quality by using an n-dimensional Levenshtein distance matrix and compute the optimal alignment between the dirty strings. Results are presented and possible refinements are proposed
Summary of the CMS Discovery Potential for the MSSM SUSY Higgses
This work summarises the present understanding of the expected MSSM SUSY
Higgs reach for CMS. Many of the studies presented here result from detailed
detector simulations incorporating final CMS detector design and response. With
30 fb-1 the h -> gamma,gamma and h -> bb channels allow to cover most of the
MSSM parameter space. For the massive A,H,H+ MSSM Higgs states the channels A,H
-> tau,tau and H+ -> tau,nu turn out to be the most profitable ones in terms of
mass reach and parameter space coverage. Consequently CMS has made a big effort
to trigger efficiently on taus. Provided neutralinos and sleptons are not too
heavy, there is an interesting complementarity in the reaches for A,H ->
tau,tau and A,H -> chi,chi.Comment: 19 pages, 27 figure
Measurement of the H/A -> tau tau cross section and possible constraints on tan beta
The achievable precision of the cross section times branching ratio
measurement from the event rates is estimated for the MSSM H/A -> tau tau decay
in the associated production process gg -> b bbar H/A at large tan beta in CMS.
This work demonstrates that the above production and decay process exhibit a
large sensitivity to tan beta and thus add as a significant observable to a
global fit of the SUSY parameters. To illustrate this potential an example is
given concerning the achievable tan beta determination accuracy that could be
reached from the event rates and for a given set of SUSY parameters and
uncertainties
Internalization of a polysialic acid-binding Escherichia coli bacteriophage into eukaryotic neuroblastoma cells
Eukaryotic organisms are continuously exposed to bacteriophages, which are efficient gene transfer agents in bacteria. However, bacteriophages are considered not to pass the eukaryotic cell membrane and enter nonphagocytic cells. Here we report the binding and penetration of Escherichia coli PK1A2 bacteriophage into live eukaryotic neuroblastoma cells in vitro. The phage interacts with cell surface polysialic acid, which shares structural similarity with the bacterial phage receptor. Using fluorescence and electron microscopy, we show that phages are internalized via the endolysosomal route and persist inside the human cells up to one day without affecting cell viability. Phage capsid integrity is lost in lysosomes, and the phage DNA is eventually degraded. We did not detect the entry of phage DNA into the nucleus; however, we speculate that this might occur as a rare event, and propose that this potential mechanism could explain prokaryote-eukaryote gene flow.Peer reviewe
Lymphatic endothelium stimulates melanoma metastasis and invasion via MMP14-dependent Notch3 and b1-integrin activation
Lymphatic invasion and lymph node metastasis correlate with poor clinical outcome in melanoma. However, the mechanisms of lymphatic dissemination in distant metastasis remain incompletely understood. We show here that exposure of expansively growing human WM852 melanoma cells, but not singly invasive Bowes cells, to lymphatic endothelial cells (LEC) in 3D co-culture facilitates melanoma distant organ metastasis in mice. To dissect the underlying molecular mechanisms, we established LEC co-cultures with different melanoma cells originating from primary tumors or metastases. Notably, the expansively growing metastatic melanoma cells adopted an invasively sprouting phenotype in 3D matrix that was dependent on MMP14, Notch3 and β1-integrin. Unexpectedly, MMP14 was necessary for LEC-induced Notch3 induction and coincident β1-integrin activation. Moreover, MMP14 and Notch3 were required for LEC-mediated metastasis of zebrafish xenografts. This study uncovers a unique mechanism whereby LEC contact promotes melanoma metastasis by inducing a reversible switch from 3D growth to invasively sprouting cell phenotype
Search for Heavy Neutral MSSM Higgs Bosons with CMS: Reach and Higgs-Mass Precision
The search for MSSM Higgs bosons will be an important goal at the LHC. We
analyze the search reach of the CMS experiment for the heavy neutral MSSM Higgs
bosons with an integrated luminosity of 30 or 60 fb^-1. This is done by
combining the latest results for the CMS experimental sensitivities based on
full simulation studies with state-of-the-art theoretical predictions of MSSM
Higgs-boson properties. The results are interpreted in MSSM benchmark scenarios
in terms of the parameters tan_beta and the Higgs-boson mass scale, M_A. We
study the dependence of the 5 sigma discovery contours in the M_A-tan_beta
plane on variations of the other supersymmetric parameters. The largest effects
arise from a change in the higgsino mass parameter mu, which enters both via
higher-order radiative corrections and via the kinematics of Higgs decays into
supersymmetric particles. While the variation of can shift the
prospective discovery reach (and correspondingly the ``LHC wedge'' region) by
about Delta tan_beta = 10, we find that the discovery reach is rather stable
with respect to the impact of other supersymmetric parameters. Within the
discovery region we analyze the accuracy with which the masses of the heavy
neutral Higgs bosons can be determined. We find that an accuracy of 1-4% should
be achievable, which could make it possible in favourable regions of the MSSM
parameter space to experimentally resolve the signals of the two heavy MSSM
Higgs bosons at the LHC.Comment: 24 pages, 8 figure
SOXS: a wide band spectrograph to follow up transients
SOXS (Son Of X-Shooter) will be a spectrograph for the ESO NTT telescope
capable to cover the optical and NIR bands, based on the heritage of the
X-Shooter at the ESO-VLT. SOXS will be built and run by an international
consortium, carrying out rapid and longer term Target of Opportunity requests
on a variety of astronomical objects. SOXS will observe all kind of transient
and variable sources from different surveys. These will be a mixture of fast
alerts (e.g. gamma-ray bursts, gravitational waves, neutrino events), mid-term
alerts (e.g. supernovae, X-ray transients), fixed time events (e.g. close-by
passage of minor bodies). While the focus is on transients and variables, still
there is a wide range of other astrophysical targets and science topics that
will benefit from SOXS. The design foresees a spectrograph with a
Resolution-Slit product ~ 4500, capable of simultaneously observing over the
entire band the complete spectral range from the U- to the H-band. The limiting
magnitude of R~20 (1 hr at S/N~10) is suited to study transients identified
from on-going imaging surveys. Light imaging capabilities in the optical band
(grizy) are also envisaged to allow for multi-band photometry of the faintest
transients. This paper outlines the status of the project, now in Final Design
Phase.Comment: 12 pages, 14 figures, to be published in SPIE Proceedings 1070
The phylogenetically-related pattern recognition receptors EFR and XA21 recruit similar immune signaling components in monocots and dicots
During plant immunity, surface-localized pattern recognition receptors (PRRs) recognize pathogen-associated molecular patterns (PAMPs). The transfer of PRRs between plant species is a promising strategy for engineering broad-spectrum disease resistance. Thus, there is a great interest in understanding the mechanisms of PRR-mediated resistance across different plant species. Two well-characterized plant PRRs are the leucine-rich repeat receptor kinases (LRR-RKs) EFR and XA21 from Arabidopsis thaliana (Arabidopsis) and rice, respectively. Interestingly, despite being evolutionary distant, EFR and XA21 are phylogenetically closely related and are both members of the sub-family XII of LRR-RKs that contains numerous potential PRRs. Here, we compared the ability of these related PRRs to engage immune signaling across the monocots-dicots taxonomic divide. Using chimera between Arabidopsis EFR and rice XA21, we show that the kinase domain of the rice XA21 is functional in triggering elf18-induced signaling and quantitative immunity to the bacteria Pseudomonas syringae pv. tomato (Pto) DC3000 and Agrobacterium tumefaciens in Arabidopsis. Furthermore, the EFR:XA21 chimera associates dynamically in a ligand-dependent manner with known components of the EFR complex. Conversely, EFR associates with Arabidopsis orthologues of rice XA21-interacting proteins, which appear to be involved in EFR-mediated signaling and immunity in Arabidopsis. Our work indicates the overall functional conservation of immune components acting downstream of distinct LRR-RK-type PRRs between monocots and dicots
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