24,507 research outputs found

    CryptoQFL: Quantum Federated Learning on Encrypted Data

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    Recent advancements in Quantum Neural Networks (QNNs) have demonstrated theoretical and experimental performance superior to their classical counterparts in a wide range of applications. However, existing centralized QNNs cannot solve many real-world problems because collecting large amounts of training data to a common public site is time-consuming and, more importantly, violates data privacy. Federated Learning (FL) is an emerging distributed machine learning framework that allows collaborative model training on decentralized data residing on multiple devices without breaching data privacy. Some initial attempts at Quantum Federated Learning (QFL) either only focus on improving the QFL performance or rely on a trusted quantum server that fails to preserve data privacy. In this work, we propose CryptoQFL, a QFL framework that allows distributed QNN training on encrypted data. CryptoQFL is (1) secure, because it allows each edge to train a QNN with local private data, and encrypt its updates using quantum \homo~encryption before sending them to the central quantum server; (2) communication-efficient, as CryptoQFL quantize local gradient updates to ternary values, and only communicate non-zero values to the server for aggregation; and (3) computation-efficient, as CryptoQFL presents an efficient quantum aggregation circuit with significantly reduced latency compared to state-of-the-art approaches

    Adenosine A2A Receptors in Psychopharmacology: Modulators of Behavior, Mood and Cognition

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    The adenosine A2A receptor (A2AR) is in the center of a neuromodulatory network affecting a wide range of neuropsychiatric functions by interacting with and integrating several neurotransmitter systems, especially dopaminergic and glutamatergic neurotransmission. These interactions and integrations occur at multiple levels, including (1) direct receptor- receptor cross-talk at the cell membrane, (2) intracellular second messenger systems, (3) trans-synaptic actions via striatal collaterals or interneurons in the striatum, (4) and interactions at the network level of the basal ganglia. Consequently, A2ARs constitute a novel target to modulate various psychiatric conditions. In the present review we will first summarize the molecular interaction of adenosine receptors with other neurotransmitter systems and then discuss the potential applications of A2AR agonists and antagonists in physiological and pathophysiological conditions, such as psychostimulant action, drug addiction, anxiety, depression, schizophrenia and learning and memory

    Ground state phase diagram and superconductivity of the doped Hubbard model on six-leg square cylinders

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    We have studied the ground state properties of Hubbard model on long six-leg square cylinders with doped hole concentration per site 5.55%≤δ≤12.5%5.55\% \leq \delta\leq 12.5\% using density-matrix renormalization group. By keeping a large number of states for long system sizes, we find that the nature of the ground state is remarkably sensitive to the presence of next-nearest-neighbor electron hopping t′t'. In the positive t′t' side, we find a robust dd-wave superconducting (SC) phase characterized by coexisting quasi-long-range SC and charge density wave (CDW) correlations. Without t′t' the ground state forms an insulating stripe phase with long-range CDW order but short-range spin-spin and SC correlations. In stark contrast to four-leg cylinders, our results show that the lightly doped Hubbard model on six-leg cylinders remains insulating in the negative t′t' side where the SC correlations decay exponentially with short correlation lengths. In the larger negative t′t' side, the doped holes form a novel holon Wigner crystal with one doped hole per emergent unit cell and short-range spin-spin correlations.Comment: 8 pages, 6 figure

    Determination of fundamental properties of an M31 globular cluster from main-sequence photometry

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    M31 globular cluster B379 is the first extragalactic cluster, the age of which was determined by main-sequence photometry. In this method, the age of a cluster is obtained by fitting its CMD with stellar evolutionary models. However, different stellar evolutionary models use different parameters of stellar evolution, such as range of stellar masses, different opacities and equations of state, and different recipes, and so on. So, it is interesting to check whether different stellar evolutionary models can give consistent results for the same cluster. Brown et al. (2004a) constrained the age of B379 by comparing its CMD with isochrones of the 2006 VandenBerg models. Using SSP models of BC03 and its multi-photometry, Ma et al. (2007) independently determined the age of B379, which is in good agreement with the determination of Brown et al. (2004a). The BC03 models are calculated based on the Padova evolutionary tracks. It is necessary to check whether the age of B379 which, being determined based on the Padova evolutionary tracks, is in agreement with the determination of Brown et al. (2004a). So, in this paper, we re-determine its age using isochrones of the Padova stellar evolutionary models. In addition, the metal abundance, the distance modulus, and the reddening value for B379 are also determined in this paper. The results obtained in this paper are consistent with the previous determinations, which including the age obtained by Brown et al. (2004a). So, this paper confirms the consistence of the age scale of B379 between the Padova isochrones and the 2006 VandenBerg isochrones, i.e. the results' comparison between Brown et al. (2004a) and Ma et al. (2007) is meaningful. The results obtained in this paper are: the metallicity [M/H]=-0.325, the age τ=11.0±1.5\tau=11.0\pm1.5 Gyr, the reddening value E(B-V)=0.08, and the distance modulus (m−M)0=24.44±0.10(m-M)_{0}=24.44\pm0.10.Comment: Accepted for Publication in PASP, 7 pages, 1 figure and 1 tabl
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