8,453 research outputs found
Geometric discord and Measurement-induced nonlocality for well known bound entangled states
We employ geometric discord and measurement induced nonlocality to quantify
non classical correlations of some well-known bipartite bound entangled states,
namely the two families of Horodecki's (, and
dimensional) bound entangled states and that of Bennett etal's in
dimension. In most of the cases our results are analytic and both
the measures attain relatively small value. The amount of quantumness in the
bound entangled state of Benatti etal and the state
having the same matrix representation (in computational basis) is same.
Coincidently, the Werner and isotropic states also exhibit the
same property, when seen as dimensional states.Comment: V2: Title changed, one more state added; 11 pages (single column), 2
figures, accepted in Quantum Information Processin
Reduction of seafood processing wastewater using technologies enhanced by swim–bed technology
The increasing growth of the seafood processing industries considerably requires more industrial process activities and water consumption. It is estimated that approximately 10–40 m3 of wastewater is generated from those industries for processing one-tonne of raw materials. Due to limitations and regulations in natural resources utilization, a suitable and systematic wastewater treatment plant is very important to meet rigorous discharge standards. As a result of food waste biodegradability, the biological treatment and some extent of swim-bed technology, including a novel acryl-fibre (biofilm) material might be used effectively to meet the effluent discharge criteria. This chapter aims to develop understanding on current problems and production of the seafood wastewater regarding treatment efficiency and methods of treatment
Quantifying trading behavior in financial markets using Google Trends
Crises in financial markets affect humans worldwide. Detailed market data on trading decisions reflect some of the complex human behavior that has led to these crises. We suggest that massive new data sources resulting from human interaction with the Internet may offer a new perspective on the behavior of market participants in periods of large market movements. By analyzing changes in Google query volumes for search terms related to finance, we find patterns that may be interpreted as “early warning signs” of stock market moves. Our results illustrate the potential that combining extensive behavioral data sets offers for a better understanding of collective human behavior
Cellular, molecular and functional characterisation of YAC transgenic mouse models of Friedreich Ataxia
Copyright © 2014 Anjomani Virmouni et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.This article has been made available through the Brunel Open Access Publishing Fund.Background - Friedreich ataxia (FRDA) is an autosomal recessive neurodegenerative disorder, caused by a GAA repeat expansion mutation within intron 1 of the FXN gene. We have previously established and performed preliminary characterisation of several human FXN yeast artificial chromosome (YAC) transgenic FRDA mouse models containing GAA repeat expansions, Y47R (9 GAA repeats), YG8R (90 and 190 GAA repeats) and YG22R (190 GAA repeats).
Methodology/Principal Findings - We now report extended cellular, molecular and functional characterisation of these FXN YAC transgenic mouse models. FXN transgene copy number analysis of the FRDA mice demonstrated that the YG22R and Y47R lines each have a single copy of the FXN transgene while the YG8R line has two copies. Single integration sites of all transgenes were confirmed by fluorescence in situ hybridisation (FISH) analysis of metaphase and interphase chromosomes. We identified significant functional deficits, together with a degree of glucose intolerance and insulin hypersensitivity, in YG8R and YG22R FRDA mice compared to Y47R and wild-type control mice. We also confirmed increased somatic GAA repeat instability in the cerebellum and brain of YG22R and YG8R mice, together with significantly reduced levels of FXN mRNA and protein in the brain and liver of YG8R and YG22R compared to Y47R.
Conclusions/Significance - Together these studies provide a detailed characterisation of our GAA repeat expansion-based YAC transgenic FRDA mouse models that will help investigations of FRDA disease mechanisms and therapy.European Union, Ataxia UK and FARA
Microwave amplification with nanomechanical resonators
Sensitive measurement of electrical signals is at the heart of modern science
and technology. According to quantum mechanics, any detector or amplifier is
required to add a certain amount of noise to the signal, equaling at best the
energy of quantum fluctuations. The quantum limit of added noise has nearly
been reached with superconducting devices which take advantage of
nonlinearities in Josephson junctions. Here, we introduce a new paradigm of
amplification of microwave signals with the help of a mechanical oscillator. By
relying on the radiation pressure force on a nanomechanical resonator, we
provide an experimental demonstration and an analytical description of how the
injection of microwaves induces coherent stimulated emission and signal
amplification. This scheme, based on two linear oscillators, has the advantage
of being conceptually and practically simpler than the Josephson junction
devices, and, at the same time, has a high potential to reach quantum limited
operation. With a measured signal amplification of 25 decibels and the addition
of 20 quanta of noise, we anticipate near quantum-limited mechanical microwave
amplification is feasible in various applications involving integrated
electrical circuits.Comment: Main text + supplementary information. 14 pages, 3 figures (main
text), 18 pages, 6 figures (supplementary information
The connection between superconducting phase correlations and spin excitations in YBaCuO: A magnetic field study
One of the most striking universal properties of the
high-transition-temperature (high-) superconductors is that they are all
derived from the hole-doping of their insulating antiferromagnetic (AF) parent
compounds. From the outset, the intimate relationship between magnetism and
superconductivity in these copper-oxides has intrigued researchers. Evidence
for this link comes from neutron scattering experiments that show the
unambiguous presence of short-range AF correlations (excitations) in cuprate
superconductors. Even so, the role of such excitations in the pairing mechanism
and superconductivity is still a subject of controversy. For
YBaCuO, where controls the hole-doping level, the most
prominent feature in the magnetic excitations spectra is the ``resonance''.
Here we show that for underdoped YBaCuO, where and
are below the optimal values, modest magnetic fields suppress the resonance
significantly, much more so for fields approximately perpendicular rather than
parallel to the CuO planes. Our results indicate that the resonance
measures pairing and phase coherence, suggesting that magnetism plays an
important role in the superconductivity of cuprates. The persistence of a field
effect above favors mechanisms with preformed pairs in the normal state
of underdoped cuprates.Comment: 12 pages, 4 figures, Nature (in press
Eliciting a predatory response in the eastern corn snake (Pantherophis guttatus) using live and inanimate sensory stimuli: implications for managing invasive populations
North America's Eastern corn snake (Pantherophis guttatus) has been introduced to several islands throughout the Caribbean and Australasia where it poses a significant threat to native wildlife. Invasive snake control programs often involve trapping with live bait, a practice that, as well as being costly and labour intensive, raises welfare and ethical concerns. This study assessed corn snake response to live and inanimate sensory stimuli in an attempt to inform possible future trapping of the species and the development of alternative trap lures. We exposed nine individuals to sensory cues in the form of odour, visual, vibration and combined stimuli and measured the response (rate of tongue-flick [RTF]). RTF was significantly higher in odour and combined cues treatments, and there was no significant difference in RTF between live and inanimate cues during odour treatments. Our findings suggest chemical cues are of primary importance in initiating predation and that an inanimate odour stimulus, absent of simultaneous visual and vibratory cues, is a potential low-cost alternative trap lure for the control of invasive corn snake populations
Femtosecond control of electric currents at the interfaces of metallic ferromagnetic heterostructures
The idea to utilize not only the charge but also the spin of electrons in the
operation of electronic devices has led to the development of spintronics,
causing a revolution in how information is stored and processed. A novel
advancement would be to develop ultrafast spintronics using femtosecond laser
pulses. Employing terahertz (10 Hz) emission spectroscopy, we
demonstrate optical generation of spin-polarized electric currents at the
interfaces of metallic ferromagnetic heterostructures at the femtosecond
timescale. The direction of the photocurrent is controlled by the helicity of
the circularly polarized light. These results open up new opportunities for
realizing spintronics in the unprecedented terahertz regime and provide new
insights in all-optical control of magnetism.Comment: 3 figures and 2 tables in the main tex
The pseudogap: friend or foe of high Tc?
Although nineteen years have passed since the discovery of high temperature
superconductivity, there is still no consensus on its physical origin. This is
in large part because of a lack of understanding of the state of matter out of
which the superconductivity arises. In optimally and underdoped materials, this
state exhibits a pseudogap at temperatures large compared to the
superconducting transition temperature. Although discovered only three years
after the pioneering work of Bednorz and Muller, the physical origin of this
pseudogap behavior and whether it constitutes a distinct phase of matter is
still shrouded in mystery. In the summer of 2004, a band of physicists gathered
for five weeks at the Aspen Center for Physics to discuss the pseudogap. In
this perspective, we would like to summarize some of the results presented
there and discuss its importance in the context of strongly correlated electron
systems.Comment: expanded version, 20 pages, 11 figures, to be published, Advances in
Physic
Spectral statistics of the uni-modular ensemble
We investigate the spectral statistics of Hermitian matrices in which the
elements are chosen uniformly from U (1), called the uni-modular ensemble
(UME), in the limit of large matrix size. Using three complimentary methods; a
supersymmetric integration method, a combinatorial graph-theoretical analysis
and a Brownian motion approach, we are able to derive expressions for 1/N
corrections to the mean spectral moments and also analyse the fluctuations
about this mean. By addressing the same ensemble from three different point of
view, we can critically compare their relative advantages and derive some new
results.Comment: 35 pages, 3 figure
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