2,539 research outputs found
Sigma-lognormal modeling of speech
Human movement studies and analyses have been fundamental in many scientific
domains, ranging from neuroscience to education, pattern recognition to
robotics, health care to sports, and beyond. Previous speech motor models were
proposed to understand how speech movement is produced and how the resulting
speech varies when some parameters are changed. However, the inverse approach,
in which the muscular response parameters and the subject's age are derived
from real continuous speech, is not possible with such models. Instead, in the
handwriting field, the kinematic theory of rapid human movements and its
associated Sigma-lognormal model have been applied successfully to obtain the
muscular response parameters. This work presents a speech kinematics based
model that can be used to study, analyze, and reconstruct complex speech
kinematics in a simplified manner. A method based on the kinematic theory of
rapid human movements and its associated Sigma lognormal model are applied to
describe and to parameterize the asymptotic impulse response of the
neuromuscular networks involved in speech as a response to a neuromotor
command. The method used to carry out transformations from formants to a
movement observation is also presented. Experiments carried out with the
(English) VTR TIMIT database and the (German) Saarbrucken Voice Database,
including people of different ages, with and without laryngeal pathologies,
corroborate the link between the extracted parameters and aging, on the one
hand, and the proportion between the first and second formants required in
applying the kinematic theory of rapid human movements, on the other. The
results should drive innovative developments in the modeling and understanding
of speech kinematics.Comment: Published in Open Acce
Thermoelectric power of bulk black-phosphorus
The potential of bulk black-phosphorus for thermoelectric applications has
been experimentally studied. The Seebeck Coefficient (S) has been measured in
the temperature range from 300 K to 385 K, finding a value of S = +335 +- 10
uV/K at room temperature (indicating a naturally occurring p-type
conductivity). S increases with temperature, as expected for p-type
semiconductors, which can be attributed to an increase of the charge carrier
density. The electrical resistance drops up to a 40 % while heating in the
studied temperature range. As a consequence, the power factor at 385 K is 2.7
times higher than that at room temperature. This work demonstrates the
feasibility of black-phosphorus in thermoelectric applications, such as thermal
energy scavenging, which typically require devices with high performance at
temperatures above room temperature.Comment: 3 figure
Development of a novel vaccine delivery system based on Gantrez nanoparticles.
The adjuvant capacity of a novel vaccine vector “Gantrez-nanoparticles” (NP)
towards coated or encapsulated ovalbumin (OVA) was investigated. OVA nanoparticles
were prepared by a solvent displacement method previously described. The protein was
incorporated during the manufacturing process (OVA-encapsulated nanoparticles) or
after the preparation (OVA-coated nanoparticles). The mean size of the different
nanoparticle formulations was lower than 300 nm, and the OVA content ranged
approximately from 67 μg/mg nanoparticles (for OVA-coated nanoparticles) to 30
μg/mg nanoparticles (for OVA-encapsulated nanoparticles). All the OVA-NP
formulations were capable of amplifying the antibodies titres (IgG1 and IgG2a) in mice
after a single subcutaneous inoculation with respect free OVA or OVA adsorbed to
Alum. Furthermore, the elicited response was, for some formulations, predominantly
Th1 subtype. Thus, the formulation that contained mainly the antigen inside, and with a
low concentration of cross-linking agent, displayed the best potential to induce a Th1
response after 35 days post-immunisation. These results are highly suggestive for the
use of Gantrez nanoparticles as an efficient antigen delivery system, especially when a
long lasting Th1 cytokine response is required
Biomarkers predicting the controller dose of omalizumab in patients with chronic spontaneous urticaria
Background
Clinical trials showed the efficacy of 300 mg/4 weeks of omalizumab (OMA) during 6 months in patients with severe chronic spontaneous urticaria (CSU). Nevertheless, in real life, many patients require higher doses and/or longer treatment. This study assesses the real-life performance of OMA in severe CSU and identifies factors associated with the response.
Methods
CSU patients eligible for OMA were recruited prospectively. Clinical data and a blood test were collected before OMA initiation. Urticaria Activity Score 7 (UAS7) was calculated at baseline and every 3 months during OMA treatment. CSU control was defined as UAS7 <7 points. This work was partially sponsored by OMA manufacturer.
Results
Eighty-nine adults (19.1% males) with severe CSU were recruited. Median duration of CSU prior to OMA initiation was 2 years, and median severity by UAS7 at baseline was 24 points (range 10–42 points). OMA controlled 94.4% of patients, but 17.9% of responders required doses >300 mg/4 weeks. A blood basophil count >20 cells/μL (OR 13.33; 95% CI 3.32–52.63; p 29 months at the end of the study (active responders, AR). AR had received OMA for a median of 45 months (30–100 months). There were no significant differences in clinical or analytical factors between RR and AR patients.
Conclusions
Low blood basophil count and the presence of hypothyroidism might serve as biomarkers for the controller dose of OMA in severe CSU patients.Funding for open Access charge: Universidad de Málaga / CBUA.
Instituto de Salud Carlos III; Novartis Pharmaceuticals Corporation; Consejería de Salud y Bienestar Social, Junta de Andalucí
Polyamine-induced modulation of genes involved in ethylene biosynthesis and signalling pathways and nitric oxide production during olive mature fruit abscission
After fruit ripening, many fruit-tree species undergo massive natural fruit abscission. Olive (Olea europaea L.) is a stone-fruit with cultivars such as Picual (PIC) and Arbequina (ARB) which differ in mature fruit abscission potential. Ethylene (ET) is associated with abscission, but its role during mature fruit abscission remains largely uncharacterized. The present study investigates the possible roles of ET and polyamine (PA) during mature fruit abscission by modulating genes involved in the ET signalling and biosynthesis pathways in the abscission zone (AZ) of both cultivars. Five ET-related genes (OeACS2, OeACO2, OeCTR1, OeERS1, and OeEIL2) were isolated in the AZ and adjacent cells (AZ–AC), and their expression in various olive organs and during mature fruit abscission, in relation to interactions between ET and PA and the expression induction of these genes, was determined. OeACS2, OeACO2, and OeEIL2 were found to be the only genes that were up-regulated in association with mature fruit abscission. Using the inhibition of ET and PA biosynthesis, it is demonstrated that OeACS2 and OeEIL2 expression are under the negative control of PA while ET induces their expression in AZ–AC. Furthermore, mature fruit abscission depressed nitric oxide (NO) production present mainly in the epidermal cells and xylem of the AZ. Also, NO production was differentially responsive to ET, PA, and different inhibitors. Taken together, the results indicate that PA-dependent ET signalling and biosynthesis pathways participate, at least partially, during mature fruit abscission, and that endogenous NO and 1-aminocyclopropane-1-carboxylic acid maintain an inverse correlation, suggesting an antagonistic action of NO and ET in abscission signalling
CAST solar axion search with 3^He buffer gas: Closing the hot dark matter gap
The CERN Axion Solar Telescope (CAST) has finished its search for solar
axions with 3^He buffer gas, covering the search range 0.64 eV < m_a <1.17 eV.
This closes the gap to the cosmological hot dark matter limit and actually
overlaps with it. From the absence of excess X-rays when the magnet was
pointing to the Sun we set a typical upper limit on the axion-photon coupling
of g_ag < 3.3 x 10^{-10} GeV^{-1} at 95% CL, with the exact value depending on
the pressure setting. Future direct solar axion searches will focus on
increasing the sensitivity to smaller values of g_a, for example by the
currently discussed next generation helioscope IAXO.Comment: 5 pages, 2 figures. Last version uploade
CAST constraints on the axion-electron coupling
In non-hadronic axion models, which have a tree-level axion-electron
interaction, the Sun produces a strong axion flux by bremsstrahlung, Compton
scattering, and axio-recombination, the "BCA processes." Based on a new
calculation of this flux, including for the first time axio-recombination, we
derive limits on the axion-electron Yukawa coupling g_ae and axion-photon
interaction strength g_ag using the CAST phase-I data (vacuum phase). For m_a <
10 meV/c2 we find g_ag x g_ae< 8.1 x 10^-23 GeV^-1 at 95% CL. We stress that a
next-generation axion helioscope such as the proposed IAXO could push this
sensitivity into a range beyond stellar energy-loss limits and test the
hypothesis that white-dwarf cooling is dominated by axion emission
2D-Tasks for Cognitive Rehabilitation
Neuropsychological Rehabilitation is a complex clinic process which tries to restore or compensate cognitive and behavioral disorders in people suffering from a central nervous system injury. Information and Communication Technologies (ICTs) in Biomedical Engineering play an essential role in this field, allowing improvement and expansion of present rehabilitation programs.
This paper presents a set of cognitive rehabilitation 2D-Tasks for patients with Acquired Brain Injury (ABI). These tasks allow a high degree of personalization and individualization in therapies, based on the opportunities offered by new technologies
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