700 research outputs found
Acoustic signal typing for evaluation of voice quality in tracheoesophageal speech
Summary: Because of the aperiodicity of many tracheoesophageal voices, acoustic analysis of the tracheoesophageal voice is less straightforward than that of the normal voice. This study presents the development and testing of an acoustic signal typing system based on visual inspection of a narrow-band spectrogram that can be used by researchers for classification of voice quality in tracheoesophageal speech. In addition to this classification system, a selection of acoustic measures [median fundamental frequency, standard deviation of fundamental frequency, jitter, percentage of voiced (%Voiced), harmonics-to-noise ratio (HNR), glottal-to-noise excitation (GNE) ratio, and band energy difference (BED)] was computed to provide more insight into the acoustic components of tracheoesophageal voice quality. For clinical relevance, relationships between the acoustic signal types and an overall judgment of the voice were investigated as well. Results showed that the four acoustic signal types form a good basis for performing more acoustic analyses and give a good impression of the overall quality of the voice
Properties of Saturn Kilometric Radiation measured within its source region
On 17 October 2008, the Cassini spacecraft crossed the southern sources of
Saturn kilometric radiation (SKR), while flying along high-latitude nightside
magnetic field lines. In situ measurements allowed us to characterize for the
first time the source region of an extra-terrestrial auroral radio emission.
Using radio, magnetic field and particle observations, we show that SKR sources
are surrounded by a hot tenuous plasma, in a region of upward field-aligned
currents. Magnetic field lines supporting radio sources map a continuous,
high-latitude and spiral-shaped auroral oval observed on the dawnside,
consistent with enhanced auroral activity. Investigating the Cyclotron Maser
Instability (CMI) as a mechanism responsible for SKR generation, we find that
observed cutoff frequencies are consistent with radio waves amplified
perpendicular to the magnetic field by hot (6 to 9 keV) resonant electrons,
measured locally
Progression characteristics of the European Friedreich's Ataxia Consortium for Translational Studies (EFACTS): a 4-year cohort study
BACKGROUND: The European Friedreich's Ataxia Consortium for Translational Studies (EFACTS) investigates the natural history of Friedreich's ataxia. We aimed to assess progression characteristics and to identify patient groups with differential progression rates based on longitudinal 4-year data to inform upcoming clinical trials in Friedreich's ataxia. METHODS: EFACTS is a prospective, observational cohort study based on an ongoing and open-ended registry. Patients with genetically confirmed Friedreich's ataxia were seen annually at 11 clinical centres in seven European countries (Austria, Belgium, France, Germany, Italy, Spain, and the UK). Data from baseline to 4-year follow-up were included in the current analysis. Our primary endpoints were the Scale for the Assessment and Rating of Ataxia (SARA) and the activities of daily living (ADL). Linear mixed-effect models were used to analyse annual disease progression for the entire cohort and subgroups defined by age of onset and ambulatory abilities. Power calculations were done for potential trial designs. This study is registered with ClinicalTrials.gov, NCT02069509. FINDINGS: Between Sept 15, 2010, and Nov 20, 2018, of 914 individuals assessed for eligibility, 602 patients were included. Of these, 552 (92%) patients contributed data with at least one follow-up visit. Annual progression rate for SARA was 0·82 points (SE 0·05) in the overall cohort, and higher in patients who were ambulatory (1·12 [0·07]) than non-ambulatory (0·50 [0·07]). ADL worsened by 0·93 (SE 0·05) points per year in the entire cohort, with similar progression rates in patients who were ambulatory (0·94 [0·07]) and non-ambulatory (0·91 [0·08]). Although both SARA and ADL showed slightly greater worsening in patients with typical onset (symptom onset at ≤24 years) than those with late onset (symptom onset ≥25 years), differences in progression slopes were not significant. For a 2-year parallel-group trial, 230 (115 per group) patients would be required to detect a 50% reduction in SARA progression at 80% power: 118 (59 per group) if only individuals who are ambulatory are included. With ADL as the primary outcome, 190 (95 per group) patients with Friedreich's ataxia would be needed, and fewer patients would be required if only individuals with early-onset are included. INTERPRETATION: Our findings for stage-dependent progression rates have important implications for clinicians and researchers, as they provide reliable outcome measures to monitor disease progression, and enable tailored sample size calculation to guide upcoming clinical trial designs in Friedreich's ataxia. FUNDING: European Commission, Voyager Therapeutics, and EuroAtaxia
Parameter estimation in spatially extended systems: The Karhunen-Loeve and Galerkin multiple shooting approach
Parameter estimation for spatiotemporal dynamics for coupled map lattices and
continuous time domain systems is shown using a combination of multiple
shooting, Karhunen-Loeve decomposition and Galerkin's projection methodologies.
The resulting advantages in estimating parameters have been studied and
discussed for chaotic and turbulent dynamics using small amounts of data from
subsystems, availability of only scalar and noisy time series data, effects of
space-time parameter variations, and in the presence of multiple time-scales.Comment: 11 pages, 5 figures, 4 Tables Corresponding Author - V. Ravi Kumar,
e-mail address: [email protected]
MicroRNAs and Developmental Robustness: A New Layer Is Revealed
MicroRNAs provide a new layer of regulation to ensure that a developmental program of programmed cell death yields a reproducible outcome in spite of perturbations to the system
Searches at HERA for Squarks in R-Parity Violating Supersymmetry
A search for squarks in R-parity violating supersymmetry is performed in e^+p
collisions at HERA at a centre of mass energy of 300 GeV, using H1 data
corresponding to an integrated luminosity of 37 pb^(-1). The direct production
of single squarks of any generation in positron-quark fusion via a Yukawa
coupling lambda' is considered, taking into account R-parity violating and
conserving decays of the squarks. No significant deviation from the Standard
Model expectation is found. The results are interpreted in terms of constraints
within the Minimal Supersymmetric Standard Model (MSSM), the constrained MSSM
and the minimal Supergravity model, and their sensitivity to the model
parameters is studied in detail. For a Yukawa coupling of electromagnetic
strength, squark masses below 260 GeV are excluded at 95% confidence level in a
large part of the parameter space. For a 100 times smaller coupling strength
masses up to 182 GeV are excluded.Comment: 32 pages, 14 figures, 3 table
Self-adjuvanting polymer-peptide conjugates as therapeutic vaccine candidates against cervical cancer
Dendrimers are structurally well-defined, synthetic polymers with sizes and physicochemical properties often resembling those of biomacromolecules (e.g. proteins). As a result they are promising candidates for peptide-based vaccine delivery platforms. Herein, we established a synthetic pathway to conjugate a human papillomavirus (HPV) E7 protein-derived peptide antigen to a star-polymer to create a macromolecular vaccine candidate to treat HPV-related cancers. These conjugates were able to reduce tumor growth and eradicate E7-expressing TC-1 tumors in mice after a single immunization, without the help of any external adjuvant
Measurements of Transverse Energy Flow in Deep-Inelastic Scattering at HERA
Measurements of transverse energy flow are presented for neutral current
deep-inelastic scattering events produced in positron-proton collisions at
HERA. The kinematic range covers squared momentum transfers Q^2 from 3.2 to
2,200 GeV^2, the Bjorken scaling variable x from 8.10^{-5} to 0.11 and the
hadronic mass W from 66 to 233 GeV. The transverse energy flow is measured in
the hadronic centre of mass frame and is studied as a function of Q^2, x, W and
pseudorapidity. A comparison is made with QCD based models. The behaviour of
the mean transverse energy in the central pseudorapidity region and an interval
corresponding to the photon fragmentation region are analysed as a function of
Q^2 and W.Comment: 26 pages, 8 figures, submitted to Eur. Phys.
Deep-Inelastic Inclusive ep Scattering at Low x and a Determination of alpha_s
A precise measurement of the inclusive deep-inelastic e^+p scattering cross
section is reported in the kinematic range 1.5<= Q^2 <=150 GeV^2 and
3*10^(-5)<= x <=0.2. The data were recorded with the H1 detector at HERA in
1996 and 1997, and correspond to an integrated luminosity of 20 pb^(-1). The
double differential cross section, from which the proton structure function
F_2(x,Q^2) and the longitudinal structure function F_L(x,Q^2) are extracted, is
measured with typically 1% statistical and 3% systematic uncertainties. The
measured partial derivative (dF_2(x,Q^2)/dln Q^2)_x is observed to rise
continuously towards small x for fixed Q^2. The cross section data are combined
with published H1 measurements at high Q^2 for a next-to-leading order DGLAP
QCD analysis.The H1 data determine the gluon momentum distribution in the range
3*10^(-4)<= x <=0.1 to within an experimental accuracy of about 3% for Q^2 =20
GeV^2. A fit of the H1 measurements and the mu p data of the BCDMS
collaboration allows the strong coupling constant alpha_s and the gluon
distribution to be simultaneously determined. A value of alpha
_s(M_Z^2)=0.1150+-0.0017 (exp) +0.0009-0.0005 (model) is obtained in NLO, with
an additional theoretical uncertainty of about +-0.005, mainly due to the
uncertainty of the renormalisation scale.Comment: 68 pages, 24 figures and 18 table
Forward pi^0 Production and Associated Transverse Energy Flow in Deep-Inelastic Scattering at HERA
Deep-inelastic positron-proton interactions at low values of Bjorken-x down
to x \approx 4.10^-5 which give rise to high transverse momentum pi^0 mesons
are studied with the H1 experiment at HERA. The inclusive cross section for
pi^0 mesons produced at small angles with respect to the proton remnant (the
forward region) is presented as a function of the transverse momentum and
energy of the pi^0 and of the four-momentum transfer Q^2 and Bjorken-x.
Measurements are also presented of the transverse energy flow in events
containing a forward pi^0 meson. Hadronic final state calculations based on QCD
models implementing different parton evolution schemes are confronted with the
data.Comment: 27 pages, 8 figures and 3 table
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