472 research outputs found
Hush-a-bye, Ma baby
https://digitalcommons.library.umaine.edu/mmb-vp/6068/thumbnail.jp
Hush-a-bye, Ma Baby Missouri Waltz
Hush-a-bye, ma baby, slumbertime is cominâ soon;Rest yoâhead upon ma breast while Mammy hums a tune;The sandman is callinâ where shadows are fallinâ,While the soft breezes sigh as in days long gone by.âWay down in Missouri where I heard this melody,When I was a Pickaninny on ma Mammyâs knee;The darkies were hummin,â their banjos were strumminâ so sweet and low.Strum, strum, strum, strum, strum,Seems I hear those banjos playinâ once again,Hum, hum, hum, hum, hum,That same old plaintive strain.
[Instrumental interlude]
Hear that mournful melody, it just haunts you the whole day long,And you wander in dreams back to Dixie it seems,When you hear that old time song.Hush-a-bye, ma baby, go to sleep on Mammyâs knee,Journey back to Dixieland in dreams again with me;It seems yo Mammy was there once again,And the darkies were strumminâ that same old refrain.Way down in Missouri where I learned this lullaby,When the stars were blinkinâ and the moon was climbinâ high,And I hear Mammy Cloe, as in days long agoSinging hush-a-bye
Controls on the location of compressional deformation on the NW European margin
The distribution of Cenozoic compressional structures along the NW European margin has been compared with maps of the thickness of the crystalline crust derived from a compilation of seismic refraction interpretations and gravity modelling, and with the distribution of high-velocity lower crust and/or partially serpentinized upper mantle detected by seismic experiments. Only a subset of the mapped compressional structures coincide with areas susceptible to lithospheric weakening as a result of crustal hyperextension and partial serpentinization of the upper mantle. Notably, partially serpentinized upper mantle is well documented beneath the central part of the southern Rockall Basin, but compressional features are sparse in that area. Where compressional structures have formed but the upper mantle is not serpentinized, simple rheological modelling suggests an alternative weakening mechanism involving ductile lower crust and lithospheric decoupling. The presence of pre-existing weak zones (associated with the properties of the gouge and overpressure in fault zones) and local stress magnitude and orientation are important contributing factors
New, efficient and robust, fiber-based quantum key distribution schemes
We present a new fiber based quantum key distribution (QKD) scheme which can
be regarded as a modification of an idea proposed by Inoue, Waks and Yamamoto
(IWY) [1]. The scheme described here uses a single phase modulator and two
differential delay elements in series at the transmitter that form an
interferometer when combined with a third differential delay element at the
receiver. The protocol is characterized by a high efficiency, reduced exposure
to an attack by an eavesdropper, and higher sensitivity to such an attack when
compared to other QKD schemes. For example, the efficiency with which
transmitted data contribute to the private key is 3/4 compared with 1/4 for
BB84 [2]. Moreover, an eavesdropper can aquire a maximum of 1/3 of the key
which leads to an error probability in the private key of 1/3. This can be
compared to 1/2 and 1/4 for these same parameters in both BB84 and IWY. The
combination of these considerations should lead to increased range and key
distribution rate over present fiber-based QKD schemes.Comment: 4 pages, 5 figures, 1 equatio
Signal and System Approximation from General Measurements
In this paper we analyze the behavior of system approximation processes for
stable linear time-invariant (LTI) systems and signals in the Paley-Wiener
space PW_\pi^1. We consider approximation processes, where the input signal is
not directly used to generate the system output, but instead a sequence of
numbers is used that is generated from the input signal by measurement
functionals. We consider classical sampling which corresponds to a pointwise
evaluation of the signal, as well as several more general measurement
functionals. We show that a stable system approximation is not possible for
pointwise sampling, because there exist signals and systems such that the
approximation process diverges. This remains true even with oversampling.
However, if more general measurement functionals are considered, a stable
approximation is possible if oversampling is used. Further, we show that
without oversampling we have divergence for a large class of practically
relevant measurement procedures.Comment: This paper will be published as part of the book "New Perspectives on
Approximation and Sampling Theory - Festschrift in honor of Paul Butzer's
85th birthday" in the Applied and Numerical Harmonic Analysis Series,
Birkhauser (Springer-Verlag). Parts of this work have been presented at the
IEEE International Conference on Acoustics, Speech, and Signal Processing
2014 (ICASSP 2014
Communication and trust in the bounded confidence model
The communication process in a situation of emergency is discussed within the
Scheff theory of shame and pride. The communication involves messages from
media and from other persons. Three strategies are considered: selfish (to
contact friends), collective (to join other people) and passive (to do
nothing). We show that the pure selfish strategy cannot be evolutionarily
stable. The main result is that the community structure is statistically
meaningful only if the interpersonal communication is weak.Comment: 6 pages, 5 figures, RevTeX, for ICCCI-201
Effect of seasonal changes in the pathways of methanogenesis on the ÎŽ13C values of pore water methane in a Michigan peatland
The ÎŽ13C value of pore water methane produced in a Michigan peatland varied by 11% during the year. This isotopic shift resulted from large seasonal changes in the pathways of methane production. On the basis of mass balance calculations, the ÎŽ13C value of methane from CO2 reduction (average =-71.4 ± 1.8%) was depleted in 13C compared to that produced from acetate (-44.4 ± 8.2%o). The dissolved methane at the site remained heavy (approximately-51%o) during most of the year. Tracer experiments using 14C-labeled CO2 indicated that during January 110 ± 25% of the methane was produced by CO2 reduction. Because of low-methane production rates during the winter, this C-depleted methane had only a slight effect on the isotopic composition of the methane pool. In early spring when peat temperatures and methane production rates increased, the ÎŽ13C value of the dissolved methane in shallow peat was influenced by the isotopically light methane and approached-61â°. Peat incubation experiments conducted at 15°C in May and June (when the peat reaches its maximum temperature) indicated that an average of 84 ± 9% of the methane production was from acetate and had an average ÎŽ13C value of-48.7 ± 5.6â°. Rising acetate concentrations during April-May (approaching 1 mmol L-1(mM)) followed by a rapid decrease in acetate concentrations during May-June reflected the shift toward methane production dominated by acetate fermentation. During this period, dissolved methane in shallow peat at the site returned to heavier values (approximately-5 l%o) similar to that produced in the incubation experiments
Classical capacity of quantum channels with general Markovian correlated noise
The classical capacity of a quantum channel with arbitrary Markovian
correlated noise is evaluated. For the general case of a channel with long-term
memory, which corresponds to a Markov chain which does not converge to
equilibrium, the capacity is expressed in terms of the communicating classes of
the Markov chain. For an irreducible and aperiodic Markov chain, the channel is
forgetful, and one retrieves the known expression for the capacity
Crystal structure, electronic, and magnetic properties of the bilayered rhodium oxide Sr3Rh2O7
The bilayered rhodium oxide Sr3Rh2O7 was synthesized by high-pressure and
high-temperature heating techniques. The single-phase polycrystalline sample of
Sr3Rh2O7 was characterized by measurements of magnetic susceptibility,
electrical resistivity, specific heat, and thermopower. The structural
characteristics were investigated by powder neutron diffraction study. The
rhodium oxide Sr3Rh2O7 [Bbcb, a = 5.4744(8) A, b = 5.4716(9) A, c = 20.875(2)
A] is isostructural to the metamagnetic metal Sr3Ru2O7, with five 4d electrons
per Rh, which is electronically equivalent to the hypothetic bilayered
ruthenium oxide, where one electron per Ru is doped into the Ru-327 unit. The
present data show the rhodium oxide Sr3Rh2O7 to be metallic with enhanced
paramagnetism, similar to Sr3Ru2O7. However, neither manifest contributions
from spin fluctuations nor any traces of a metamagnetic transition were found
within the studied range from 2 K to 390 K below 70 kOe.Comment: To be published in PR
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