73,072 research outputs found
Speaker-normalized sound representations in the human auditory cortex
The acoustic dimensions that distinguish speech sounds (like the vowel differences in âbootâ and âboatâ) also differentiate speakersâ voices. Therefore, listeners must normalize across speakers without losing linguistic information. Past behavioral work suggests an important role for auditory contrast enhancement in normalization: preceding context affects listenersâ perception of subsequent speech sounds. Here, using intracranial electrocorticography in humans, we investigate whether and how such context effects arise in auditory cortex. Participants identified speech sounds that were preceded by phrases from two different speakers whose voices differed along the same acoustic dimension as target words (the lowest resonance of the vocal tract). In every participant, target vowels evoke a speaker-dependent neural response that is consistent with the listenerâs perception, and which follows from a contrast enhancement model. Auditory cortex processing thus displays a critical feature of normalization, allowing listeners to extract meaningful content from the voices of diverse speakers
An eco-solution for track & trace of goods and third party logistics
This paper presents a new economic cost-effective solution known as the Web and telephony based method for tracking and tracing of goods and small and medium sized third party logistic providers. Considering that these companies usually operate on very flat margins, a comparison is made of the available track and trace technologies like GPS, mobile phone approximated GPS and Java based cell tracking in terms of costs, operating risks, and other evaluation criteria
Improved high-temperature resistant matrix resins
A study was performed with the objective of developing matrix resins that exhibit improved thermo-oxidative stability over state-of-the-art high temperature resins for use at temperatures up to 644 K (700 F) and air pressures up to 0.7 MPa (100 psia). The work was based upon a TRW discovered family of polyimides currently licensed to and marketed by Ethyl Corporation as EYMYD(R) resins. The approach investigated to provide improved thermo-oxidative properties was to use halogenated derivatives of the diamine, 2, 2-bis (4-(4-aminophenoxy)phenyl) hexafluoropropane (4-BDAF). Polyimide neat resins and Celion(R) 12,000 composites prepared from fluorine substituted 4-BDAF demonstrated unexpectedly lower glass transition temperatures (Tg) and thermo-oxidative stabilities than the baseline 4-BDAF/PMDA polymer
Hadronic Production of S-wave and P-wave Charmed Beauty Mesons via Heavy Quark Fragmentation
At hadron colliders the dominant production mechanism of mesons
with large transverse momentum is due to parton fragmentation. We compute the
rates and transverse momentum spectra for production of S-wave and P-wave
mesons at the Tevatron via the direct fragmentation of the bottom
antiquark as well as the Altarelli-Parisi induced gluon fragmentation. Since
all the radially and orbitally excited mesons below the
flavor threshold will cascade into the pseudoscalar ground state through
electromagnetic and/or hadronic transitions, they all contribute to the
inclusive production of . The contributions of the excited S-wave and
P-wave states to the inclusive production of are 58 and 23\%,
respectively, and hence significant.Comment: Changes are made in the Discussio
Generating a Schr\"odinger-cat-like state via a coherent superposition of photonic operations
We propose an optical scheme to generate a superposition of coherent states
with enhanced size adopting an interferometric setting at the single-photon
level currently available in the laboratory. Our scheme employs a nondegenerate
optical parametric amplifier together with two beam splitters so that the
detection of single photons at the output conditionally implements the desired
superposition of second-order photonic operations. We analyze our proposed
scheme by considering realistic on-off photodetectors with nonideal efficiency
in heralding the success of conditional events. A high-quality performance of
our scheme is demonstrated in view of various criteria such as quantum
fidelity, mean output energy, and measure of quantum interference
The Decays to -wave Charmonium by Improved Bethe-Salpeter Approach
We re-calculate the exclusive semileptonic and nonleptonic decays of
meson to a -wave charmonium in terms of the improved Bethe-Salpeter (B-S)
approach, which is developed recently. Here the widths for the exclusive
semileptonic and nonleptonic decays, the form factors, and the charged lepton
spectrums for the semileptonic decays are precisely calculated. To test the
concerned approach by comparing with experimental measurements when the
experimental data are available, and to have comparisons with the other
approaches the results obtained by the approach and those by some approaches
else as well as the original B-S approach, which appeared in literature, are
comparatively presented and discussed.Comment: 33 pages, 5 figures, 3 table
Efficient Guiding of Cold Atoms though a Photonic Band Gap Fiber
We demonstrate the first guiding of cold atoms through a 88 mm long piece of
photonic band gap fiber. The guiding potential is created by a far-off
resonance dipole trap propagating inside the fiber with a hollow core of 12 mu
m. We load the fiber from a dark spot 85-Rb magneto optical trap and observe a
peak flux of more than 10^5 atoms/s at a velocity of 1.5 m/s. With an
additional reservoir optical dipole trap, a constant atomic flux of 1.5 10^4
atoms/s is sustained for more than 150\,ms. These results open up interesting
possibilities to study nonlinear light-matter interaction in a nearly
one-dimensional geometry and pave the way for guided matter wave
interferometry.Comment: 8 pages, 3 figure
Reptile scale paradigm: Evo-Devo, pattern formation and regeneration
The purpose of this perspective is to highlight the merit of the reptile integument as an experimental model. Reptiles represent the first amniotes. From stem reptiles, extant reptiles, birds and mammals have evolved. Mammal hairs and feathers evolved from Therapsid and Sauropsid reptiles, respectively. The early reptilian integument had to adapt to the challenges of terrestrial life, developing a multi-layered stratum corneum capable of barrier function and ultraviolet protection. For better mechanical protection, diverse reptilian scale types have evolved. The evolution of endothermy has driven the convergent evolution of hair and feather follicles: both form multiple localized growth units with stem cells and transient amplifying cells protected in the proximal follicle. This topological arrangement allows them to elongate, molt and regenerate without structural constraints. Another unique feature of reptile skin is the exquisite arrangement of scales and pigment patterns, making them testable models for mechanisms of pattern formation. Since they face the constant threat of damage on land, different strategies were developed to accommodate skin homeostasis and regeneration. Temporally, they can be under continuous renewal or sloughing cycles. Spatially, they can be diffuse or form discrete localized growth units (follicles). To understand how gene regulatory networks evolved to produce increasingly complex ectodermal organs, we have to study how prototypic scale-forming pathways in reptiles are modulated to produce appendage novelties. Despite the fact that there are numerous studies of reptile scales, molecular analyses have lagged behind. Here, we underscore how further development of this novel experimental model will be valuable in filling the gaps of our understanding of the Evo-Devo of amniote integuments
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