2,023 research outputs found
A non-invasive device to measure mechanical interaction between tongue, palate and teeth during speech production
This paper describes an original experimental procedure to measure the
mechanical interaction between the tongue and teeth and palate during speech
production. It consists in using edentulous people as subjects and to insert
pressure sensors in the structure of their complete dental prosthesis. Hence,
there is no perturbation of the vocal tract cavity due to the sensors
themselves. Several duplicates are used with transducers situated at different
locations of the complete denture according to palatography's results, in order
to carefully analyze the production of specific sounds such as stop
consonants.. It is also possible to measure the contact pressure at different
locations on the palate for the same sound
PRESLA: An original device to measure the mechanical interaction between tongue and teeth or palate during speech production
An original experimental procedure is presented to measure the mechanical
interaction between tongue and teeth and palate during speech production. It
consists in using edentulous people as subjects and to insert pressure sensors
in the structure of a replication of their dental prosthesis. This is assumed
to induce no speech production perturbation for subjects who are used to speak
with their prosthesis. Data collected from 4 subjects of French demonstrate the
usability of the system
Z' studies at the LHC: an update
We reanalyse the potential of the LHC to discover new gauge bosons and
to discriminate between various theoretical models. Using a fast LHC detector
simulation, we have investigated how well the characteristics of bosons
from different models can be measured. For this analysis we have combined the
information coming from the cross section measurement, which provides also the
mass and total width, the forward-backward charge asymmetries on- and
off-peak, and the rapidity distribution, which is sensitive to its and couplings. We confirm that new bosons can be
observed in the process , up to masses of about 5 TeV
for an integrated luminosity of 100 fb. The off- and on-resonance peak
forward-backward charge asymmetries show that interesting
statistical accuracies can be obtained up to masses of the order of 2 TeV.
We then show how the different experimental observables allow for a diagnosis
of the boson and the distinction between the various considered models.Comment: 14 pages, latex, 6 figure
Tongue pressure recordings during speech using complete denture
This paper describes an original experimental procedure to measure mechanical
interactions between tongue and teeth during speech production. Using
edentulous people as subjects, pressure transducers are inserted in their
complete denture duplicate. Physiology is respected during sound and pressure
recording as with standard complete denture. Original calibration device is
also described in order to know what kind of information can be extracted from
the data. The measurements are realized in different experimental conditions in
order to remove the auditory and the orosensory feedbacks. Then the first
results of the pilot study are presente
Composition of dissolved organic matter within a lacustrine environment
Freshwater dissolved organic matter (DOM) is a complex mixture of chemical components that are central to many environmental processes, including carbon and nitrogen cycling. However, questions remain as to its chemical characteristics, sources and transformation mechanisms. Here, we employ 1- and 2-D nuclear magnetic resonance (NMR) spectroscopy to investigate the structural components of lacustrine DOM from Ireland, and how it varies within a lake system, as well as to assess potential sources. Major components found, such as carboxyl-rich alicyclic molecules (CRAM) are consistent with those recently identified in marine and freshwater DOM. Lignin-type markers and protein/peptides were identified and vary spatially. Phenylalanine was detected in lake areas influenced by agriculture, whereas it is not detectable where zebra mussels are prominent. The presence of peptidoglycan, lipoproteins, large polymeric carbo- hydrates and proteinaceous material supports the substantial contribution of material derived from microorganisms. Evidence is provided that peptidoglycan and silicate species may in part originate from soil microbes
Predictions for Higgs production at the Tevatron and the associated uncertainties
We update the theoretical predictions for the production cross sections of
the Standard Model Higgs boson at the Fermilab Tevatron collider, focusing on
the two main search channels, the gluon-gluon fusion mechanism and
the Higgs-strahlung processes with , including all
relevant higher order QCD and electroweak corrections in perturbation theory.
We then estimate the various uncertainties affecting these predictions: the
scale uncertainties which are viewed as a measure of the unknown higher order
effects, the uncertainties from the parton distribution functions and the
related errors on the strong coupling constant, as well as the uncertainties
due to the use of an effective theory approach in the determination of the
radiative corrections in the process at next-to-next-to-leading
order. We find that while the cross sections are well under control in the
Higgs--strahlung processes, the theoretical uncertainties are rather large in
the case of the gluon-gluon fusion channel, possibly shifting the central
values of the next-to-next-to-leading order cross sections by more than
. These uncertainties are thus significantly larger than the
error assumed by the CDF and D0 experiments in their recent
analysis that has excluded the Higgs mass range 162-166 GeV at the 95%
confidence level. These exclusion limits should be, therefore, reconsidered in
the light of these large theoretical uncertainties.Comment: 40 pages, 12 figures. A few typos are corrected and some updated
numbers are provide
CXCR4/CXCL12 Participate in Extravasation of Metastasizing Breast Cancer Cells within the Liver in a Rat Model
INTRODUCTION: Organ-specific composition of extracellular matrix proteins (ECM) is a determinant of metastatic host organ involvement. The chemokine CXCL12 and its receptor CXCR4 play important roles in the colonization of human breast cancer cells to their metastatic target organs. In this study, we investigated the effects of chemokine stimulation on adhesion and migration of different human breast cancer cell lines in vivo and in vitro with particular focus on the liver as a major metastatic site in breast cancer. METHODS: Time lapse microscopy, in vitro adhesion and migration assays were performed under CXCL12 stimulation. Activation of small GTPases showed chemokine receptor signalling dependence from ECM components. The initial events of hepatic colonisation of MDA-MB-231 and MDA-MB-468 cells were investigated by intravital microscopy of the liver in a rat model and under shRNA inhibition of CXCR4. RESULTS: In vitro, stimulation with CXCL12 induced increased chemotactic cell motility (p,0.05). This effect was dependent on adhesive substrates (type I collagen, fibronectin and laminin) and induced different responses in small GTPases, such as RhoA and Rac-1 activation, and changes in cell morphology. In addition, binding to various ECM components caused redistribution of chemokine receptors at tumour cell surfaces. In vivo, blocking CXCR4 decreased extravasation of highly metastatic MDA-MB-231 cells (p < 0.05), but initial cell adhesion within the liver sinusoids was not affected. In contrast, the less metastatic MDA-MB-468 cells showed reduced cell adhesion but similar migration within the hepatic microcirculation. CONCLUSION: Chemokine-induced extravasation of breast cancer cells along specific ECM components appears to be an important regulator but not a rate-limiting factor of their metastatic organ colonization.Claudia Wendel, André Hemping-Bovenkerk, Julia Krasnyanska, Sören Torge Mees, Marina Kochetkova, Sandra Stoeppeler and Jörg Haie
Electroweak Radiative Corrections to W Boson Production in Hadronic Collisions
The O(\alpha) electroweak radiative corrections to the process pp, ppbar\to W
\to\ell^\pm\nu (\ell=e,\mu) are calculated. The O(\alpha) corrections can be
decomposed into separately gauge invariant contributions to the W boson
production and decay processes. Factorizing the collinear singularity
associated with initial state photon radiation into the parton distribution
functions, we find that initial state corrections have a significantly smaller
effect than final state radiative corrections. We study in detail the effect of
electroweak radiative corrections on a number of interesting observables: the W
transverse mass distribution, the W to Z transverse mass ratio, the charge
asymmetry of leptons in W\to\ell\nu decays, as well as the W production cross
section and the W to Z cross section ratio. We also investigate how
experimental lepton identification requirements change the effect of the
electroweak corrections.Comment: 38 pages, Revtex, 13 embedded postscript figure
Energy Resolution Performance of the CMS Electromagnetic Calorimeter
The energy resolution performance of the CMS lead tungstate crystal electromagnetic calorimeter is presented. Measurements were made with an electron beam using a fully equipped supermodule of the calorimeter barrel. Results are given both for electrons incident on the centre of crystals and for electrons distributed uniformly over the calorimeter surface. The electron energy is reconstructed in matrices of 3 times 3 or 5 times 5 crystals centred on the crystal containing the maximum energy. Corrections for variations in the shower containment are applied in the case of uniform incidence. The resolution measured is consistent with the design goals
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