123 research outputs found
Robust creation of entanglement between ions in spatially separate cavities
We present a protocol that allows the generation of a maximally entangled state between individual atoms held in spatially separate cavities. Assuming perfect detectors and neglecting spontaneous emission from the atoms, the resulting idealized scheme is deterministic. Under more realistic conditions, when the atom-cavity interaction departs from the strong coupling regime, and considering imperfect detectors, we show that the scheme is robust against experimental inefficiencies and yields probabilistic entanglement of very high fidelity
Digestion, rumen fermentation and circulating concentrations of insulin, growth hormone and IGF-1 in steers fed diets based on different proportions of maize silage and grass silage
Replacing grass silage with maize silage results in a fundamental change in the ratio of structural to non-structural carbohydrates with commensurate changes in rumen fermentation patterns and nutrient utilisation. This study investigated the effects of feeding four forage mixtures, namely grass silage (G); 67 g/100 g grass silage133 g/100 g maize silage (GGM); 67 g/100 g maize silage133/100 g grass silage (MMG); maize silage (M) to four ruminally and duodenally canulated Holstein Friesian steers. All diets were formulated to be isonitrogenous (22.4 g N/kg DM) using a concentrate mixture. Dietary dry matter (DM) and organic matter (OM) digestibility increased with ascending maize silage inclusion (P,0.1) whereas starch and neutral detergent fibre digestibility declined (P,0.05). Ratio of non-glucogenic to glucogenic precursors in the rumen fluid increased with maize silage inclusion (P,0.01) with a commensurate reduction in rumen pH (P,0.05). Mean circulating concentrations of insulin were greatest and similar in diets MMG and GGM, lower in diet M and lowest in diet G (P,0.01). There were no effects of diet on the mean circulating concentration of growth hormone (GH), or the frequency, amplitude and duration of GH pulses, or the
mean circulating concentrations of IGF-1. Increasing levels of DM, OM and starch intakes with the substitution of grass silage with maize silage affected overall digestion, nutrient partitioning and subsequent circulating concentrations of insulin
New Protocols and Lower Bound for Quantum Secret Sharing with Graph States
We introduce a new family of quantum secret sharing protocols with limited
quantum resources which extends the protocols proposed by Markham and Sanders
and by Broadbent, Chouha, and Tapp. Parametrized by a graph G and a subset of
its vertices A, the protocol consists in: (i) encoding the quantum secret into
the corresponding graph state by acting on the qubits in A; (ii) use a
classical encoding to ensure the existence of a threshold. These new protocols
realize ((k,n)) quantum secret sharing i.e., any set of at least k players
among n can reconstruct the quantum secret, whereas any set of less than k
players has no information about the secret. In the particular case where the
secret is encoded on all the qubits, we explore the values of k for which there
exists a graph such that the corresponding protocol realizes a ((k,n)) secret
sharing. We show that for any threshold k> n-n^{0.68} there exists a graph
allowing a ((k,n)) protocol. On the other hand, we prove that for any k<
79n/156 there is no graph G allowing a ((k,n)) protocol. As a consequence there
exists n_0 such that the protocols introduced by Markham and Sanders admit no
threshold k when the secret is encoded on all the qubits and n>n_0
Universality of Z3 parafermions via edge-mode interaction and quantum simulation of topological space evolution with Rydberg atoms
Parafermions are Zn generalizations of Majorana quasiparticles, with fractional non-Abelian statistics. They can be used to encode topological qudits and perform Clifford operations by their braiding. Here we investigate the generation of quantum gates by allowing Z3 parafermions to interact in order to achieve universality. In particular, we study the form of the nontopological gate that arises through direct short-range interaction of the parafermion edge modes in a Z3 parafermion chain. We show that such an interaction gives rise to a dynamical phase gate on the encoded ground space, generating a non-Clifford gate which can be tuned to belong to even levels of the Clifford hierarchy. We illustrate how to access highly noncontextual states using this dynamical gate. Finally, we propose an experiment that simulates the braiding and dynamical evolutions of the Z3 topological states with Rydberg atom technology
Efficient scheme for one-way quantum computing in thermal cavities
We propose a practical scheme for one-way quantum computing based on
efficient generation of 2D cluster state in thermal cavities. We achieve a
controlled-phase gate that is neither sensitive to cavity decay nor to thermal
field by adding a strong classical field to the two-level atoms. We show that a
2D cluster state can be generated directly by making every two atoms collide in
an array of cavities, with numerically calculated parameters and appropriate
operation sequence that can be easily achieved in practical Cavity QED
experiments. Based on a generated cluster state in Box configuration,
we then implement Grover's search algorithm for four database elements in a
very simple way as an example of one-way quantum computing.Comment: 6 pages, 3 figure
Distillation of continuous-variable entanglement with optical means
We present an event-ready procedure that is capable of distilling Gaussian
two-mode entangled states from a supply of weakly entangled states that have
become mixed in a decoherence process. This procedure relies on passive optical
elements and photon detectors distinguishing the presence and the absence of
photons, but does not make use of photon counters. We identify fixed points of
the iteration map, and discuss in detail its convergence properties. Necessary
and sufficient criteria for the convergence to two-mode Gaussian states are
presented. On the basis of various examples we discuss the performance of the
procedure as far as the increase of the degree of entanglement and two-mode
squeezing is concerned. Finally, we consider imperfect operations and outline
the robustness of the scheme under non-unit detection efficiencies of the
detectors. This analysis implies that the proposed protocol can be implemented
with currently available technology and detector efficiencies.Comment: 14 pages, 12 figure
RNA sequencing reveals MMP2 and TGFB1 downregulation in LRRK2 G2019S Parkinson's iPSC-derived astrocytes
Non-neuronal cell types such as astrocytes can contribute to Parkinson's disease (PD) pathology. The G2019S
mutation in leucine-rich repeat kinase 2 (LRRK2) is one of the most common known causes of familial PD. To
characterize its effect on astrocytes, we developed a protocol to produce midbrain-patterned astrocytes from
human induced pluripotent stem cells (iPSCs) derived from PD LRRK2 G2019S patients and healthy controls.
RNA sequencing analysis revealed the downregulation of genes involved in the extracellular matrix in PD cases.
In particular, transforming growth factor beta 1 (TGFB1), which has been shown to inhibit microglial inflammatory
response in a rat model of PD, and matrix metallopeptidase 2 (MMP2), which has been shown to
degrade α-synuclein aggregates, were found to be down-regulated in LRRK2 G2019S astrocytes. Our findings
suggest that midbrain astrocytes carrying the LRRK2 G2019S mutation may have reduced neuroprotective capacity
and may contribute to the development of PD pathology
Producing the event ready two photon polarization EPR state with linear optics devices
We propose a scheme to produce the maximally two photon polarization
entangled state(EPR state) with single photon sources and the linear optics
devices. In particular, our scheme requires the photon detectors only to
distinguish the vacuum and non-vacuum Fock number states. A sophisticated
photon detector distinguishing one or two photon states is unnecessary.Comment: Published in Phys. Rev. A alread
Linking Distributive and Procedural Justice to Employee Engagement Through Social Exchange: A Field Study in India
Research linking justice perceptions to employee outcomes has referred to social exchange as its central theoretical premise. We tested a conceptual model linking distributive and procedural justice to employee engagement through social exchange mediators, namely, perceived organizational support and psychological contract, among 238 managers and executives from manufacturing and service sector firms in India. Findings suggest that perceived organizational support mediated the relationship between distributive justice and employee engagement, and both perceived organizational support and psychological contract mediated the relationship between procedural justice and employee engagement. Theoretical and practical implications with respect to organizational functions are discussed
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