32,955 research outputs found
A short proof of Stein's universal multiplier theorem
We give a short proof of Stein's universal multiplier theorem, purely by
probabilistic methods, thus avoiding any use of harmonic analysis techniques
(complex interpolation or transference methods)
Speaker-sex discrimination for voiced and whispered vowels at short durations
Whispered vowels, produced with no vocal fold vibration, lack the periodic temporal fine structure which in voiced vowels underlies the perceptual attribute of pitch (a salient auditory cue to speaker sex). Voiced vowels possess no temporal fine structure at very short durations (below two glottal cycles). The prediction was that speaker-sex discrimination performance for whispered and voiced vowels would be similar for very short durations but, as stimulus duration increases, voiced vowel performance would improve relative to whispered vowel performance as pitch information becomes available. This pattern of results was shown for women’s but not for men’s voices. A whispered vowel needs to have a duration three times longer than a voiced vowel before listeners can reliably tell whether it’s spoken by a man or woman (∼30 ms vs. ∼10 ms). Listeners were half as sensitive to information about speaker-sex when it is carried by whispered compared with voiced vowels
The Real Costs and Financial Challenges of Library Networking: Part 1
Library networking has created a number of administrative and policy
issues. Questions of governance, budgeting, cooperation, and reporting
lines must be addressed. In some cases, these issues must be addressed
by librarians; in others, by campus administrators. In any event, the
importance of the research library must be recognized, and support
for the library's priorities must be marshalled.published or submitted for publicatio
Polyelectrolytes Adsorption: Chemical and Electrostatic Interactions
Mean-field theory is used to model polyelectrolyte adsorption and the
possibility of overcompensation of charged surfaces. For charged surfaces that
are also chemically attractive, the overcharging is large in high salt
conditions, amounting to 20-40% of the bare surface charge. However, full
charge inversion is not obtained in thermodynamical equilibrium for physical
values of the parameters. The overcharging increases with addition of salt, but
does not have a simple scaling form with the bare surface charge. Our results
indicate that more evolved explanation is needed in order to understand
polyelectrolyte multilayer built-up. For strong polymer-repulsive surfaces, we
derive simple scaling laws for the polyelectrolyte adsorption and overcharging.
We show that the overcharging scales linearly with the bare surface charge, but
its magnitude is very small in comparison to the surface charge. In contrast
with the attractive surface, here the overcharging is found to decrease
substantially with addition of salt. In the intermediate range of weak
repulsive surfaces, the behavior with addition of salt crosses over from
increasing overcharging (at low ionic strength) to decreasing one (at high
ionic strength). Our results for all types of surfaces are supported by full
numerical solutions of the mean-field equations.Comment: 17 pages, 7 figures, final version. to be published in PR
PDF/A-3u as an archival format for Accessible mathematics
Including LaTeX source of mathematical expressions, within the PDF document
of a text-book or research paper, has definite benefits regarding
`Accessibility' considerations. Here we describe three ways in which this can
be done, fully compatibly with international standards ISO 32000, ISO 19005-3,
and the forthcoming ISO 32000-2 (PDF 2.0). Two methods use embedded files, also
known as `attachments', holding information in either LaTeX or MathML formats,
but use different PDF structures to relate these attachments to regions of the
document window. One uses structure, so is applicable to a fully `Tagged PDF'
context, while the other uses /AF tagging of the relevant content. The third
method requires no tagging at all, instead including the source coding as the
/ActualText replacement of a so-called `fake space'. Information provided this
way is extracted via simple Select/Copy/Paste actions, and is available to
existing screen-reading software and assistive technologies.Comment: This is a post-print version of original in volume: S.M. Watt et al.
(Eds.): CICM 2014, LNAI 8543, pp.184-199, 2014; available at
http://link.springer.com/search?query=LNAI+8543, along with supplementary
PDF. This version, with supplement as attachment, is enriched to validate as
PDF/A-3u modulo an error in white-space handling in the pdfTeX version used
to generate i
Survival of Listeria monocytogenes on a conveyor belt material with or without antimicrobial additives
Survival of Listeria monocytogenes on a conveyor belt material with or without antimicrobial additives, in the absence or presence of food debris from meat, fish and vegetables and at temperatures of 10, 25 and 37 °C was investigated. The pathogen survived best at 10 °C, and better at 25 °C than at 37 °C on both conveyor belt materials. The reduction in the numbers of the pathogen on belt material with antimicrobial additives in the first 6 h at 10 °C was 0.6 log unit, which was significantly higher (P <0.05) than the reduction of 0.2 log unit on belt material without additives. Reductions were significantly less (P <0.05) in the presence of food residue. At 37 °C and 20% relative humidity, large decreases in the numbers of the pathogen on both conveyor belt materials during the first 6 h were observed. Under these conditions, there was no obvious effect of the antimicrobial substances. However, at 25 °C and 10 °C and high humidity (60–75% rh), a rapid decrease in bacterial numbers on the belt material with antimicrobial substances was observed. Apparently the reduction in numbers of L. monocytogenes on belt material with antimicrobial additives was greater than on belt material without additives only when the surfaces were wet. Moreover, the presence of food debris neutralized the effect of the antimicrobials. The results suggest that the antimicrobial additives in conveyor belt material could help to reduce numbers of microorganisms on belts at low temperatures when food residues are absent and belts are not rapidly drie
Aggregation pheromone compounds of the black larder beetle Dermestes haemorrhoidalis Kuster (Coleoptera: Dermestidae)
Gas chromatography with simultaneous flame ionisation and electroantennographic detection (GCEAD) and gas chromatography with mass spectrometry analysis (GCMS) of abdominal extracts of adult male Dermestes haemorrhoidalis Kuster (Coleoptera: Dermestidae) revealed the presence of electrophysiologically and behaviourally active compounds to its conspecific males and females. Isopropyl dodecanoate (3), isopropyl (Z)-9-tetradecenoate (5), isopropyl tetradecanoate (6), isopropyl (Z)-9-hexadecenoate (7) and isopropyl hexadecanoate (8) were detected in male abdominal extracts only. Analysis of collected male headspace volatiles revealed the presence of six EAD-active compounds (3), (5), (6) and isopropyl tridecanoate (4) plus two unidentified compounds (1) and (9). Synthetic compounds (3), (4), (5), (6) and (7) showed EAD activity with antennae of both sexes in contrast to synthetic (8) which showed EAD activity with female antennae only. Male and female antennae of D. haemorrhoidalis reacted with high receptor potentials to isopropyl (Z)-9-dodecenoate (2), although this compound itself was detected in neither male nor female abdominal extracts or headspace volatiles. Petri dish bioassays indicated that male abdominal extracts and compounds (2), (3), (5) and (6) aroused and attracted conspecific male and female beetles significantly (
Exactly solvable model of superstring in Ramond-Ramond plane wave background
We describe in detail the solution of type IIB superstring theory in the
maximally supersymmetric plane-wave background with constant null Ramond-Ramond
5-form field strength. The corresponding light-cone Green-Schwarz action found
in hep-th/0112044 is quadratic in both bosonic and fermionic coordinates. We
find the spectrum of the light-cone Hamiltonian and the string representation
of the supersymmetry algebra. The superstring Hamiltonian has a
``harmonic-oscillator'' form in both the string-oscillator and the zero-mode
parts and thus has discrete spectrum in all 8 transverse directions. We analyze
the structure of the zero-mode sector of the theory, establishing the precise
correspondence between the lowest-lying ``massless'' string states and the type
IIB supergravity fluctuation modes in the plane-wave background. The zero-mode
spectrum has certain similarity to the supergravity spectrum in AdS_5 x S^5 of
which the plane-wave background is a special limit. We also compare the
plane-wave string spectrum with expected form of the light-cone gauge spectrum
of superstring in AdS_5 x S^5.Comment: 33 pages, latex. v4: minor sign corrections in (1.5) and (3.62), to
appear in PR
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