4,710 research outputs found
Relation Between Quantum Speed Limits And Metrics On U(n)
Recently, Chau [Quant. Inform. & Comp. 11, 721 (2011)] found a family of
metrics and pseudo-metrics on -dimensional unitary operators that can be
interpreted as the minimum resources (given by certain tight quantum speed
limit bounds) needed to transform one unitary operator to another. This result
is closely related to the weighted -norm on . Here we
generalize this finding by showing that every weighted -norm on
with 1\le p \le \limitingp induces a metric and a
pseudo-metric on -dimensional unitary operators with quantum
information-theoretic meanings related to certain tight quantum speed limit
bounds. Besides, we investigate how far the correspondence between the
existence of metrics and pseudo-metrics of this type and the quantum speed
limits can go.Comment: minor amendments, 6 pages, to appear in J.Phys.
Landau Transport equations in slave-boson mean-field theory of t-J model
In this paper we generalize slave-boson mean-field theory for model to
the time-dependent regime, and derive transport equations for model, both
in the normal and superconducting states. By eliminating the boson and
constraint fields exactly in the equations of motion we obtain a set of
transport equations for fermions which have the same form as Landau transport
equations for normal Fermi liquid and Fermi liquid superconductor, respectively
with all Landau parameters explicity given. Our theory can be viewed as a
refined version of U(1) Gauge theory where all lattice effects are retained and
strong correlation effects are reflected as strong Fermi-liquid interactions in
the transport equation. Some experimental consequences are discussed.Comment: 19 page
IT-Enabled Dynamic Capability Creation: A Perspective on Exploitative vs. Explorative IT Utilization
By focusing on today’s highly competitive and rapidly changing business environment, this study theorizes how organizations can create their dynamic capability from the utilization of information technology (IT) resources. The organizational exploitation and exploration perspective is adopted as the central theoretical basis of this study. A reflection on the exploitation and exploration of organizational IT management provides the possibility for theorizing multiple paths for IT-enabled dynamic capability creation. Under our theoretical development, the multiple paths involve different types of IT utilization capabilities that, in conjunction with organizational IT resources and other non-IT factors, lead to organizational dynamic capability. This study provides a theoretical basis for the role of IT in creating organizational dynamic capability. Specifically, it reveals the multiple types of interrelations between organizational IT resources and their utilization capabilities. This study serves as a basis for further empirical studies
Knowledge Management Systems Diffusion in Chinese Enterprises: A Multi-Stage Approach with the Technology-Organization-Environment Framework
Many enterprises encounter difficulties during the process of KMS diffusion and thus fail to gain benefits from KMS adoption. This study aims to explain why some enterprises succeed while others fail in KMS diffusion. Based on technology diffusion theory and technologyorganization- environment (TOE) framework, we propose an integrated model to examine the influence of factors from the technological, organizational, and environmental aspects on the three-stage KMS diffusion process, i.e., initiation- adoption/adaptation-acceptance /routinization /infusion. In particular, we incorporate social-cultural factors into our model to examine its effect on KMS diffusion, which has not been paid enough attention by prior KMS studies. For the specific research context, we choose China and examine how socialcultural factors influence KMS diffusion process in Chinese enterprises. This study benefits academics by providing a process perspective of KMS diffusion and also provides practical guidance for Chinese enterprises which are engaging in KMS implementation
Live–virtual–constructive simulation for testing and evaluation of air combat tactics, techniques, and procedures, Part 1: assessment framework
Analysis of femtosecond stimulated Raman spectroscopy of excited-state evolution in bacteriorhodopsin
Regulation of Ethanol-Related Behavior and Ethanol Metabolism by the Corazonin Neurons and Corazonin Receptor in Drosophila melanogaster
Impaired ethanol metabolism can lead to various alcohol-related health problems. Key enzymes in ethanol metabolism are alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH); however, neuroendocrine pathways that regulate the activities of these enzymes are largely unexplored. Here we identified a neuroendocrine system involving Corazonin (Crz) neuropeptide and its receptor (CrzR) as important physiological regulators of ethanol metabolism in Drosophila. Crz-cell deficient (Crz-CD) flies displayed significantly delayed recovery from ethanol-induced sedation that we refer to as hangover-like phenotype. Newly generated mutant lacking Crz Receptor (CrzR01) and CrzR-knockdown flies showed even more severe hangover-like phenotype, which is causally associated with fast accumulation of acetaldehyde in the CrzR01 mutant following ethanol exposure. Higher levels of acetaldehyde are likely due to 30% reduced ALDH activity in the mutants. Moreover, increased ADH activity was found in the CrzR01 mutant, but not in the Crz-CD flies. Quantitative RT-PCR revealed transcriptional upregulation of Adh gene in the CrzR01. Transgenic inhibition of cyclic AMP-dependent protein kinase (PKA) also results in significantly increased ADH activity and AdhmRNA levels, indicating PKA-dependent transcriptional regulation of Adh by CrzR. Furthermore, inhibition of PKA or cAMP response element binding protein (CREB) in CrzR cells leads to comparable hangover-like phenotype to the CrzR01 mutant. These findings suggest that CrzR-associated signaling pathway is critical for ethanol detoxification via Crz-dependent regulation of ALDH activity and Crz-independent transcriptional regulation of ADH. Our study provides new insights into the neuroendocrine-associated ethanol-related behavior and metabolism
Targeted Neural Dynamical Modeling
Latent dynamics models have emerged as powerful tools for modeling and
interpreting neural population activity. Recently, there has been a focus on
incorporating simultaneously measured behaviour into these models to further
disentangle sources of neural variability in their latent space. These
approaches, however, are limited in their ability to capture the underlying
neural dynamics (e.g. linear) and in their ability to relate the learned
dynamics back to the observed behaviour (e.g. no time lag). To this end, we
introduce Targeted Neural Dynamical Modeling (TNDM), a nonlinear state-space
model that jointly models the neural activity and external behavioural
variables. TNDM decomposes neural dynamics into behaviourally relevant and
behaviourally irrelevant dynamics; the relevant dynamics are used to
reconstruct the behaviour through a flexible linear decoder and both sets of
dynamics are used to reconstruct the neural activity through a linear decoder
with no time lag. We implement TNDM as a sequential variational autoencoder and
validate it on simulated recordings and recordings taken from the premotor and
motor cortex of a monkey performing a center-out reaching task. We show that
TNDM is able to learn low-dimensional latent dynamics that are highly
predictive of behaviour without sacrificing its fit to the neural data
Decidual glycodelin-A polarizes human monocytes into a decidual macrophage-like phenotype through Siglec-7
Decidual macrophages constitute 20-30% of the total leukocytes in the uterus of pregnant women, regulating the maternal immune tolerance and placenta development. Abnormal number or activities of decidual macrophages (dMs) are associated with fetal loss and pregnancy complications, such as preeclampsia. Monocytes differentiate into dMs in a decidua-specific microenvironment. Despite their important roles in pregnancy, the exact factors that regulate the differentiation into dMs remain unclear. Glycodelin-A (PAEP, hereafter referred to as GdA) is a glycoprotein that is abundantly present in the decidua, and plays an important role in fetomaternal defense and placental development. It modulates the differentiation and activity of several immune cell types residing in the decidua. In this study, we demonstrated that GdA induces the differentiation of human monocytes into dM-like phenotypes in terms of transcriptome, cell surface marker expression, secretome, and regulation of trophoblast and endothelial cell functions. We found that Sialic acid-binding Ig-like lectin 7 (Siglec-7) mediates the binding and biological actions of GdA in a sialic acid-dependent manner. We, therefore, suggest that GdA, induces the polarization of monocytes into dMs to regulate fetomatemal tolerance and placental development.Peer reviewe
Structural Characterization And Condition For Measurement Statistics Preservation Of A Unital Quantum Operation
We investigate the necessary and sufficient condition for a convex cone of
positive semidefinite operators to be fixed by a unital quantum operation
acting on finite-dimensional quantum states. By reducing this problem to
the problem of simultaneous diagonalization of the Kraus operators associated
with , we can completely characterize the kind of quantum states that are
fixed by . Our work has several applications. It gives a simple proof of
the structural characterization of a unital quantum operation that acts on
finite-dimensional quantum states --- a result not explicitly mentioned in
earlier studies. It also provides a necessary and sufficient condition for what
kind of measurement statistics is preserved by a unital quantum operation.
Finally, our result clarifies and extends the work of St{\o}rmer by giving a
proof of a reduction theorem on the unassisted and entanglement-assisted
classical capacities, coherent information, and minimal output Renyi entropy of
a unital channel acting on finite-dimensional quantum state.Comment: 9 pages in revtex 4.1, minor revision, to appear in J.Phys.
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