2,116 research outputs found
Teleportation of a quantum state of a spatial mode with a single massive particle
Mode entanglement exists naturally between regions of space in ultra-cold
atomic gases. It has, however, been debated whether this type of entanglement
is useful for quantum protocols. This is due to a particle number
superselection rule that restricts the operations that can be performed on the
modes. In this paper, we show how to exploit the mode entanglement of just a
single particle for the teleportation of an unknown quantum state of a spatial
mode. We detail how to overcome the superselection rule to create any initial
quantum state and how to perform Bell state analysis on two of the modes. We
show that two of the four Bell states can always be reliably distinguished,
while the other two have to be grouped together due to an unsatisfied phase
matching condition. The teleportation of an unknown state of a quantum mode
thus only succeeds half of the time.Comment: 12 pages, 1 figure, this paper was presented at TQC 2010 and extends
the work of Phys. Rev. Lett. 103, 200502 (2009
Dissipation enhanced vibrational sensing in an olfactory molecular switch
Motivated by a proposed olfactory mechanism based on a
vibrationally-activated molecular switch, we study electron transport within a
donor-acceptor pair that is coupled to a vibrational mode and embedded in a
surrounding environment. We derive a polaron master equation with which we
study the dynamics of both the electronic and vibrational degrees of freedom
beyond previously employed semiclassical (Marcus-Jortner) rate analyses. We
show: (i) that in the absence of explicit dissipation of the vibrational mode,
the semiclassical approach is generally unable to capture the dynamics
predicted by our master equation due to both its assumption of one-way
(exponential) electron transfer from donor to acceptor and its neglect of the
spectral details of the environment; (ii) that by additionally allowing strong
dissipation to act on the odorant vibrational mode we can recover exponential
electron transfer, though typically at a rate that differs from that given by
the Marcus-Jortner expression; (iii) that the ability of the molecular switch
to discriminate between the presence and absence of the odorant, and its
sensitivity to the odorant vibrational frequency, are enhanced significantly in
this strong dissipation regime, when compared to the case without mode
dissipation; and (iv) that details of the environment absent from previous
Marcus-Jortner analyses can also dramatically alter the sensitivity of the
molecular switch, in particular allowing its frequency resolution to be
improved. Our results thus demonstrate the constructive role dissipation can
play in facilitating sensitive and selective operation in molecular switch
devices, as well as the inadequacy of semiclassical rate equations in analysing
such behaviour over a wide range of parameters.Comment: 12 pages, 6 figures, close to published version, comments welcom
Raman spectroscopy analysis of Paleolithic industry from Guadalteba terrace river, Campillos (Guadalteba county, Southern of Iberian Peninsula)
ArtĂculo sobre la aplicaciĂłn de la espectroscopĂa ramĂĄn a los materiales de la terraza fluvial del RĂo Guadalteba, en Campillos
The sound of violets: the ethnographic potency of poetry?
This paper takes the form of a dialogue between the two authors, and is in two halves, the first half discursive and propositional, and the second half exemplifying the rhetorical, epistemological and metaphysical affordances of poetry in critically scrutinising the rhetoric, epistemology and metaphysics of educational management discourse.
Phipps and Saunders explore, through ideas and poems, how poetry can interrupt and/or illuminate dominant values in education and in educational research methods, such as:
âą alternatives to the military metaphors â targets, strategies and the like â that dominate the soundscape of education;
âą the kinds and qualities of the cognitive and feeling spaces that might be opened up by the shifting of methodological boundaries;
âą the considerable work done in ethnography on the use of the poetic: anthropologists have long used poetry as a medium for expressing their sense of empathic connection to their field and their subjects, particularly in considering the creativity and meaning-making that characterise all human societies in different ways;
âą the particular rhetorical affordances of poetry, as a discipline, as a practice, as an art, as patterned breath; its capacity to shift phonemic, and therewith methodological, authority; its offering of redress to linear and reductive attempts at scripting social life, as always already given and without alternative
Serum free light chains are reduced in endurance trained older adults: Evidence that exercise training may reduce basal inflammation in older adults
Traditionally, free light chains (FLCs) are used as key serum biomarkers in the diagnosis and monitoring of plasma cell malignancies, but polyclonal FLCs can also be used as an accurate real-time indicator of immune-activation and inflammation. The primary aim of the present study was to assess the effects of exercise training status on serum FLCs in older adults, and secondly, to examine if training status moderated serum FLC responses to acute exercise. Kappa and lambda serum FLC levels were measured in 45 healthy older adults (aged â„ 60 years) who were either sedentary, physically active or endurance trained. FLCs were measured at baseline and in response to an acute bout of submaximal exercise. The endurance trained group had significantly lower levels of kappa and lambda serum FLCs compared with physically active or sedentary elderly adults; these effects were independent of age, BMI and renal function. There was no significant difference in whole immunoglobulins between groups. Exercise training status had no effect on serum FLC responses to acute exercise, which were marginal. In conclusion, endurance training was associated with lower FLC levels compared with less physically active individuals. These findings suggest that long-term endurance training may be beneficial in reducing basal inflammation in older adults as well as elevated FLCs present in inflammatory and autoimmune conditions, often associated with ageing. FLCs may serve as a useful biomarker for monitoring the efficacy of exercise intervention studies in healthy and clinical populations
A combined XAS and XRD Study of the High-Pressure Behaviour of GaAsO4 Berlinite
Combined X-ray absorption spectroscopy (XAS) and X-ray diffraction (XRD)
experiments have been carried out on GaAsO4 (berlinite structure) at high
pressure and room temperature. XAS measurements indicate four-fold to six-fold
coordination changes for both cations. The two local coordination
transformations occur at different rates but appear to be coupled. A reversible
transition to a high pressure crystalline form occurs around 8 GPa. At a
pressure of about 12 GPa, the system mainly consists of octahedral gallium
atoms and a mixture of arsenic in four-fold and six-fold coordinations. A
second transition to a highly disordered material with both cations in six-fold
coordination occurs at higher pressures and is irreversible.Comment: 8 pages, 5 figures, LaTeX2
The CARMA study â children on early suppressive therapy: total HIV-1 DNA quantitation 12 years post ART initiation
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Free energy and configurational entropy of liquid silica: fragile-to-strong crossover and polyamorphism
Recent molecular dynamics (MD) simulations of liquid silica, using the
``BKS'' model [Van Beest, Kramer and van Santen, Phys. Rev. Lett. {\bf 64},
1955 (1990)], have demonstrated that the liquid undergoes a dynamical crossover
from super-Arrhenius, or ``fragile'' behavior, to Arrhenius, or ``strong''
behavior, as temperature is decreased. From extensive MD simulations, we
show that this fragile-to-strong crossover (FSC) can be connected to changes in
the properties of the potential energy landscape, or surface (PES), of the
liquid. To achieve this, we use thermodynamic integration to evaluate the
absolute free energy of the liquid over a wide range of density and . We use
this free energy data, along with the concept of ``inherent structures'' of the
PES, to evaluate the absolute configurational entropy of the liquid. We
find that the temperature dependence of the diffusion coefficient and of
are consistent with the prediction of Adam and Gibbs, including in the region
where we observe the FSC to occur. We find that the FSC is related to a change
in the properties of the PES explored by the liquid, specifically an inflection
in the dependence of the average inherent structure energy. In addition, we
find that the high behavior of suggests that the liquid entropy might
approach zero at finite , behavior associated with the so-called Kauzmann
paradox. However, we find that the change in the PES that underlies the FSC is
associated with a change in the dependence of that elucidates how the
Kauzmann paradox is avoided in this system. Finally, we also explore the
relation of the observed PES changes to the recently discussed possibility that
BKS silica exhibits a liquid-liquid phase transition, a behavior that has been
proposed to underlie the observed polyamorphism of amorphous solid silica.Comment: 14 pages, 18 figure
Protocol for the development and validation procedure of the managing the link and strengthening transition from child to adult mental health care (MILESTONE) suite of measures
Background:
Mental health disorders in the child and adolescent population are a pressing public health concern. Despite the high prevalence of psychopathology in this vulnerable population, the transition from Child and Adolescent Mental Health Services (CAMHS) to Adult Mental Health Services (AMHS) has many obstacles such as deficiencies in planning, organisational readiness and policy gaps. All these factors contribute to an inadequate and suboptimal transition process. A suite of measures is required that would allow young people to be assessed in a structured and standardised way to determine the on-going need for care and to improve communication across clinicians at CAMHS and AMHS. This will have the potential to reduce the overall health economic burden and could also improve the quality of life for patients travelling across the transition boundary. The MILESTONE (Managing the Link and Strengthening Transition from Child to Adult Mental Health Care) project aims to address the significant socioeconomic and societal challenge related to the transition process. This protocol paper describes the development of two MILESTONE transition-related measures: The Transition Readiness and Appropriateness Measure (TRAM), designed to be a decision-making aide for clinicians, and the Transition Related Outcome Measure (TROM), for examining the outcome of transition.
Methods:
The TRAM and TROM have been developed and were validated following the US FDA Guidance for Patient-reported Outcome Measures which follows an incremental stepwise framework. The study gathers information from service users, parents, families and mental health care professionals who have experience working with young people undergoing the transition process from eight European countries.
Discussion:
There is an urgent need for comprehensive measures that can assess transition across the CAMHS/AMHS boundary. This study protocol describes the process of development of two new transition measures: the TRAM and TROM. The TRAM has the potential to nurture better transitions as the findings can be summarised and provided to clinicians as a clinician-decision making support tool for identifying cases who need to transition and the TROM can be used to examine the outcomes of the transition process.
Trial registration:
MILESTONE study registration: ISRCTN83240263 Registered 23-July-2015 - ClinicalTrials.gov NCT03013595 Registered 6 January 2017
Anomalous spectral weight in photoemission spectra of the hole doped Haldane chain Y2-xSrxBaNiO5
In this paper, we present photoemission experiments on the hole doped Haldane
chain compound . By using the photon energy dependence of
the photoemission cross section, we identified the symmetry of the first
ionisation states (d type). Hole doping in this system leads to a significant
increase in the spectral weight at the top of the valence band without any
change in the vicinity of the Fermi energy. This behavior, not observed in
other charge transfer oxides at low doping level, could result from the
inhomogeneous character of the doped system and from a Ni 3d-O 2p hybridization
enhancement due to the shortening of the relevant Ni-O distance in the
localized hole-doped regions.Comment: 5 pages, 4 figure
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