cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Algebraic cycles and intersections of three quadrics
Creators: name: Laterveer, Robert
Publisher: name: arXiv
Year: 2021
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 14C15

description: Let $Y$ be a smooth complete intersection of three quadrics, and assume the dimension of $Y$ is even. We show that $Y$ has a multiplicative Chow-Künneth decomposition, in the sense of Shen-Vial. As a consequence, the Chow ring of (powers of) $Y$ displays K3-like behaviour. As a by-product of the argument, we also establish a multiplicative Chow-Künneth decomposition for double planes.
description: 19 pages, to appear in Math. Proceedings of the Cambridge Philosophical Society, comments welcome. arXiv admin note: substantial text overlap with arXiv:2105.02224, arXiv:2105.02016, arXiv:2009.11061
Immersed boundary simulations of cell-cell interactions in whole blood
Creators: name: Kassen, Andrew
name: Barrett, Aaron
name: Shankar, Varun
name: Fogelson, Aaron L.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Numerical Analysis (math.NA)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: We present a new method for the geometric reconstruction of elastic surfaces simulated by the immersed boundary method with the goal of simulating the motion and interactions of cells in whole blood. Our method uses parameter-free radial basis functions for high-order meshless parametric reconstruction of point clouds and the elastic force computations required by the immersed boundary method. This numerical framework allows us to consider the effect of endothelial geometry and red blood cell motion on the motion of platelets. We find red blood cells to be crucial for understanding the motion of platelets, to the point that the geometry of the vessel wall has a negligible effect in the presence of RBCs. We describe certain interactions that force the platelets to remain near the endothelium for extended periods, including a novel platelet motion that can be seen only in 3-dimensional simulations that we term "unicycling." We also observe red blood cell-mediated interactions between platelets and the endothelium for which the platelet has reduced speed. We suggest that these behaviors serve as mechanisms that allow platelets to better maintain vascular integrity.
description: 33 pages, 7 figures, 2 tables
Exceptional Heavy-Fermion Semimetals in Three Dimensions
Creators: name: Tao, Yu-Liang
name: Qin, Tao
name: Xu, Yong
Publisher: name: arXiv
Year: 2021
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Topological heavy-fermion systems in three dimensions are usually classified as topological insulators or semimetals. Here, we theoretically predict a different type of heavy-fermion system (dubbed exceptional heavy-fermion semimetal) by studying a three-dimensional periodic Anderson model consisting of strongly correlated localized $f$ electrons and itinerant conduction $c$ electrons in a zincblende lattice. Due to the breaking of inversion symmetry, the quasiparticle lifetimes at different sublattices are distinct, leading to the emergence of Weyl exceptional rings in the complex pole of the Green's function at finite temperatures; such rings lead to the appearance of bounded Fermi surfaces (bulk Fermi disks). As temperatures rise, two pairs of Weyl exceptional rings merge into two exceptional rings with one bounded bulk Fermi surface (bulk Fermi tube), which are experimentally measurable by angle-resolved photoemission spectroscopy. Finally, we use the dynamical mean field theory to calculate the spectral functions which illustrate the emergence of bulk Fermi tubes. Our work thus opens the door for studying exceptional heavy-fermion semimetal phases in three dimensions.
description: 13 pages, 11 figures, published version
On the origin of chirality in plasmonic meta-molecules
Creators: name: Martens, Kevin
name: Funck, Timon
name: Santiago, Eva Y.
name: Govorov, Alexander O.
name: Burger, Sven
name: Liedl, Tim
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optics (physics.optics)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Chirality is a fundamental feature in all domains of nature, ranging from particle physics over electromagnetism to chemistry and biology. Chiral objects lack a mirror plane and inversion symmetry and therefore cannot be spatially aligned with their mirrored counterpart, their enantiomer. Both natural molecules and artificial chiral nanostructures can be characterized by their light-matter interaction, which is reflected in circular dichroism (CD). Using DNA origami, we assemble model meta-molecules from multiple plasmonic nanoparticles, representing meta-atoms accurately positioned in space. This allows us to reconstruct piece by piece the impact of varying macromolecular geometries on their surrounding optical near fields. Next to the emergence of CD signatures in the instance that we architect a third dimension, we design and implement sign flipping signals through addition or removal of single particles in the artificial molecules. Our data and theoretical modelling reveal the hitherto unrecognized phenomenon of chiral plasmonic-dielectric coupling, explaining the intricate electromagnetic interactions within hybrid DNA-based plasmonic nanostructures.
description: Article and Supporting Information
Impact of efavirenz pharmacokinetics and pharmacogenomics on neuropsychological performance in older HIV-infected patients
Creators: name: Robertson, Kevin
name: Felton-Coleman, Angela
name: Sandkovsky, Uriel
name: Swindells, Susan
name: Podany, Anthony T.
name: Fletcher, Courtney V.
name: Owen, Andrew
name: Winchester, Lee C.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2017

description: Pharmacokinetics (PK) and pharmacodynamics of efavirenz and its 8-hydroxy metabolite (8-OH-efavirenz) have not been robustly evaluated in older HIV-infected persons.
Echium parviflorum Moench, Methodus
Creators: name: Peruzzi, Lorenzo
name: Galasso, Gabriele
name: Domina, Gianniantonio
name: Bartolucci, Fabrizio
name: Santangelo, Annalisa
name: Alessandrini, Alessandro
name: Astuti, Giovanni
name: D'Antraccoli, Marco
name: Roma-Marzio, Francesco
name: Ardenghi, Nicola M. G.
name: Barberis, Giuseppina
name: Conti, Fabio
name: Bernardo, Liliana
name: Peccenini, Simonetta
name: Stinca, Adriano
name: Wagensommer, Robert P.
name: Bonari, Gianmaria
name: Iamonico, Duilio
name: Iberite, Mauro
name: Viciani, Daniele
name: Guacchio, Emanuele Del
name: Galdo, Gianpietro Giusso Del
name: Lastrucci, Lorenzo
name: Villani, Mariacristina
name: Brunu, Antonello
name: Magrini, Sara
name: Pistarino, Annalaura
name: Brullo, Salvatore
name: Salmeri, Cristina
Publisher: name: Zenodo
Year: 2019
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Boraginales
Boraginaceae
Echium
Echium parviflorum

description: Echium parviflorum Moench, Methodus: 423. 1794. [4 May 1794]
 Ind. Loc.:—“in Anglia, Italia ”. EST, ITA
 Type:—Not designated.
 Compiled by:— C. Salmeri
description: Published as part of Peruzzi, Lorenzo, Galasso, Gabriele, Domina, Gianniantonio, Bartolucci, Fabrizio, Santangelo, Annalisa, Alessandrini, Alessandro, Astuti, Giovanni, D'Antraccoli, Marco, Roma-Marzio, Francesco, Ardenghi, Nicola M. G., Barberis, Giuseppina, Conti, Fabio, Bernardo, Liliana, Peccenini, Simonetta, Stinca, Adriano, Wagensommer, Robert P., Bonari, Gianmaria, Iamonico, Duilio, Iberite, Mauro, Viciani, Daniele, Guacchio, Emanuele Del, Galdo, Gianpietro Giusso Del, Lastrucci, Lorenzo, Villani, Mariacristina, Brunu, Antonello, Magrini, Sara, Pistarino, Annalaura, Brullo, Salvatore & Salmeri, Cristina, 2019, An inventory of the names of native, non-endemic vascular plants described from Italy, their loci classici and types, pp. 1-215 in Phytotaxa 410 (1) on page 63, DOI: 10.11646/phytotaxa.410.1.1, http://zenodo.org/record/13716045
Polymyxin-resistant, carbapenem-resistant Acinetobacter baumannii is eradicated by a triple combination of agents that lack individual activity
Creators: name: Nation, Roger L.
name: Thamlikitkul, Visanu
name: Shin, Beom Soo
name: Kaye, Keith S.
name: Bulitta, Jürgen B.
name: Tsuji, Brian T.
name: Forrest, Alan
name: Garonzik, Samira M.
name: Li, Jian
name: Silveira, Fernanda P.
name: Tao, Xun
name: Lenhard, Justin R.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2017

description: Objectives: The emergence of polymyxin resistance threatens to leave clinicians with few options for combatting drug-resistant Acinetobacter baumannii . The objectives of the current investigation were to define the in vitro emergence of polymyxin resistance and identify a combination regimen capable of eradicating A. baumannii with no apparent drug susceptibilities.

Methods: Two clonally related, paired, A. baumannii isolates collected from a critically ill patient who developed colistin resistance while receiving colistin methanesulfonate in a clinical population pharmacokinetic study were evaluated: an A. baumannii isolate collected before (03-149.1, polymyxin-susceptible, MIC 0.5 mg/L) and an isolate collected after (03-149.2, polymyxin-resistant, MIC 32 mg/L, carbapenem-resistant, ampicillin/sulbactam-resistant). Using the patient's unique pharmacokinetics, the patient's actual regimen received in the clinic was recreated in a hollow-fibre infection model (HFIM) to track the emergence of polymyxin resistance against 03-149.1. A subsequent HFIM challenged the pan-resistant 03-149.2 isolate against polymyxin B, meropenem and ampicillin/sulbactam alone and in two-drug and three-drug combinations.

Results: Despite achieving colistin steady-state targets of an AUC 0-24 >60 mg·h/L and C avg of >2.5 mg/L, colistin population analysis profiles confirmed the clinical development of polymyxin resistance. During the simulation of the patient's colistin regimen in the HFIM, no killing was achieved in the HFIM and amplification of polymyxin resistance was observed by 96 h. Against the polymyxin-resistant isolate, the triple combination of polymyxin B, meropenem and ampicillin/sulbactam eradicated the A. baumannii by 96 h in the HFIM, whereas monotherapies and double combinations resulted in regrowth.

Conclusions: To combat polymyxin-resistant A. baumannii , the triple combination of polymyxin B, meropenem and ampicillin/sulbactam holds great promise.
Formation of Long Single Quantum Dots in High Quality InSb Nanowires Grown by Molecular Beam Epitaxy
Creators: name: Fan, Dingxun
name: Li, Sen
name: Kang, N.
name: Caroff, Philippe
name: Wang, L. B.
name: Huang, Y. Q.
name: Deng, M. T.
name: Yu, C. L.
name: Xu, H. Q.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We report on realization and transport spectroscopy study of single quantum dots (QDs) made from InSb nanowires grown by molecular beam epitaxy (MBE). The nanowires employed are 50-80 nm in diameter and the QDs are defined in the nanowires between the source and drain contacts on a Si/SiO$_2$ substrate. We show that highly tunable QD devices can be realized with the MBE-grown InSb nanowires and the gate-to-dot capacitance extracted in the many-electron regimes is scaled linearly with the longitudinal dot size, demonstrating that the devices are of single InSb nanowire QDs even with a longitudinal size of ~700 nm. In the few-electron regime, the quantum levels in the QDs are resolved and the Landé g-factors extracted for the quantum levels from the magnetotransport measurements are found to be strongly level-dependent and fluctuated in a range of 18-48. A spin-orbit coupling strength is extracted from the magnetic field evolutions of a ground state and its neighboring excited state in an InSb nanowire QD and is on the order of ~300 $μ$eV. Our results establish that the MBE-grown InSb nanowires are of high crystal quality and are promising for the use in constructing novel quantum devices, such as entangled spin qubits, one-dimensional Wigner crystals and topological quantum computing devices.
description: 19 pages, 5 figures
Replica-symmetry breaking for directed polymers
Creators: name: Hartmann, Alexander K.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: Directed polymers on 1+1 dimensional lattices coupled to a heat bath at temperature $T$ are studied numerically for three ensembles of the site disorder. In particular correlations of the disorder as well as fractal patterning are considered. Configurations are directly sampled in perfect thermal equilibrium for very large system sizes with up to $N=L^2= 32768 \times 32768 \approx 10^{9}$ sites. The phase-space structure is studied via the distribution of overlaps and hierarchical clustering of configurations. One ensemble shows a simple behavior like a ferromagnet. The other two ensembles exhibit indications for complex behavior reminiscent of multiple replica-symmetry breaking. Also results for the ultrametricity of the phase space and the phase transition behavior of $P(q)$ when varying the temperature $T$ are studied. In total, the present model ensembles offer convenient numerical accesses to comprehensively studying complex behavior.
description: 5 pages, 6 figures
Dynamic Graph Echo State Networks
Creators: name: Tortorella, Domenico
name: Micheli, Alessio
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: Social and Information Networks (cs.SI)
subject: FOS: Computer and information sciences

description: Dynamic temporal graphs represent evolving relations between entities, e.g. interactions between social network users or infection spreading. We propose an extension of graph echo state networks for the efficient processing of dynamic temporal graphs, with a sufficient condition for their echo state property, and an experimental analysis of reservoir layout impact. Compared to temporal graph kernels that need to hold the entire history of vertex interactions, our model provides a vector encoding for the dynamic graph that is updated at each time-step without requiring training. Experiments show accuracy comparable to approximate temporal graph kernels on twelve dissemination process classification tasks.
description: Accepted for oral presentation at ESANN 2021
Global existence and decay of the inhomogeneous Muskat problem with Lipschitz initial data
Creators: name: Alonso-Orán, Diego
name: Granero-Belinchón, Rafael
Publisher: name: arXiv
Year: 2021
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: In this work we study the inhomogeneous Muskat problem, \emph{i.e.} the evolution of an internal wave between two different fluids in a porous medium with discontinuous permeability. In particular, under precise conditions on the initial datum and the physical quantities of the problem, our results ensure the decay of the solutions towards the equilibrium state in the Lipschitz norm. In addition, we establish the global existence and decay of Lipschitz solutions.
Discriminative Dictionary Learning based on Statistical Methods
Creators: name: Madhuri, G.
name: Negi, Atul
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Sparse Representation (SR) of signals or data has a well founded theory with rigorous mathematical error bounds and proofs. SR of a signal is given by superposition of very few columns of a matrix called Dictionary, implicitly reducing dimensionality. Training dictionaries such that they represent each class of signals with minimal loss is called Dictionary Learning (DL). Dictionary learning methods like Method of Optimal Directions (MOD) and K-SVD have been successfully used in reconstruction based applications in image processing like image "denoising", "inpainting" and others. Other dictionary learning algorithms such as Discriminative K-SVD and Label Consistent K-SVD are supervised learning methods based on K-SVD. In our experience, one of the drawbacks of current methods is that the classification performance is not impressive on datasets like Telugu OCR datasets, with large number of classes and high dimensionality. There is scope for improvement in this direction and many researchers have used statistical methods to design dictionaries for classification. This chapter presents a review of statistical techniques and their application to learning discriminative dictionaries. The objective of the methods described here is to improve classification using sparse representation. In this chapter a hybrid approach is described, where sparse coefficients of input data are generated. We use a simple three layer Multi Layer Perceptron with back-propagation training as a classifier with those sparse codes as input. The results are quite comparable with other computation intensive methods. Keywords: Statistical modeling, Dictionary Learning, Discriminative Dictionary, Sparse representation, Gaussian prior, Cauchy prior, Entropy, Hidden Markov model, Hybrid Dictionary Learning
Photoproduction of $K^+Λ(1405) \rightarrow K^+π^0Σ^0$ extending to forward angles and low momentum transfer
Creators: name: Scheluchin, G.
name: Jude, T. C.
name: Alef, S.
name: Bauer, P.
name: Bayadilov, D.
name: Beck, R.
name: Braghieri, A.
name: Cole, P. L.
name: Di Salvo, R.
name: Elsner, D.
name: Fantini, A.
name: Freyermuth, O.
name: Fromberger, F.
name: Ghio, F.
name: Gridnev, A.
name: Hammann, D.
name: Hannappel, J.
name: Kohl, K.
name: Kozlenko, N.
name: Lapik, A.
name: Sandri, P. Levi
name: Lisin, V.
name: Mandaglio, G.
name: Messi, R.
name: Moricciani, D.
name: Mushkarenkov, A.
name: Nedorezov, V.
name: Novinsky, D.
name: Pedroni, P.
name: Polonski, A.
name: Reitz, B. -E.
name: Romaniuk, M.
name: Schmieden, H.
name: Sumachev, V.
name: Tarakanov, V.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: $K^+Λ(1405)$ photoproduction has been studied at the BGOOD experiment via the all neutral decay, $Λ(1405)\rightarrowΣ^0π^0$. The unique BGOOD experimental setup allows both the cross section and $Λ(1405)$ invariant mass distribution (line shape) to be measured over a broad $K^+$ polar angle range, extending to extreme forward $K^+$ angles unattainable at previous experiments. Evidence is provided for the role of a triangle singularity driven by the $N^*(2030)$ resonance, which appears to contribute significantly to $K^+Λ(1405)$ photoproduction. This is observed in both the angular distributions and the integrated cross section which was determined with unprecedented energy resolution. The measured line shape is also in agreement with the previous results of CLAS and ANKE, and is consistent with two poles derived in $χ$PT based models.
A Nodal Immersed Finite Element-Finite Difference Method
Creators: name: Wells, David
name: Vadala-Roth, Ben
name: Lee, Jae H.
name: Griffith, Boyce E.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics
subject: 74F10, (Primary) 74S05, 76M20 (Secondary)

description: The immersed finite element-finite difference (IFED) method is a computational approach to modeling interactions between a fluid and an immersed structure. This method uses a finite element (FE) method to approximate the stresses and forces on a structural mesh and a finite difference (FD) method to approximate the momentum of the entire fluid-structure system on a Cartesian grid. The fundamental approach used by this method follows the immersed boundary framework for modeling fluid-structure interaction (FSI), in which a force spreading operator prolongs structural forces to a Cartesian grid, and a velocity interpolation operator restricts a velocity field defined on that grid back onto the structural mesh. Force spreading and velocity interpolation both require projecting data onto the finite element space. Consequently, evaluating either coupling operator requires solving a matrix equation at every time step. Mass lumping, in which the projection matrices are replaced by diagonal approximations, has the potential to accelerate this method considerably. Constructing the coupling operators also requires determining the locations on the structure mesh where the forces and velocities are sampled. Here we show that sampling the forces and velocities at the nodes of the structural mesh is equivalent to using lumped mass matrices in the coupling operators. A key theoretical result of our analysis is that if both of these approaches are used together, the IFED method permits the use of lumped mass matrices derived from nodal quadrature rules for any standard interpolatory element. This is different from standard FE methods, which require specialized treatments to accommodate mass lumping with higher-order shape functions. Our theoretical results are confirmed by numerical benchmarks, including standard solid mechanics tests and examination of a dynamic model of a bioprosthetic heart valve.
Proteomic analysis of the small extracellular vesicles and soluble secretory proteins from cachexia inducing and non-inducing cancer cells
Creators: name: Chitti, Sai Vara Prasad
name: Kang, Taeyoung
name: Fonseka, Pamali
name: Marzan, Akbar Lulu
name: Stewart, Sarah
name: Shahi, Sanjay
name: Bramich, Kyle
name: Ang, CS
name: Pathan, Mohashin
name: Gummadi, Sriram
name: Mathivanan, Suresh
Publisher: name: La Trobe
Year: 2023
Subjects: classificationCode: 310109
subject: Proteomics and intermolecular interactions (excl. medical proteomics)

description: Cancer cachexia is a wasting syndrome characterised by the loss of fat and/or muscle mass in advanced cancer patients. It has been well-established that cancer cells themselves can induce cachexia via the release of several pro-cachectic and pro-inflammatory factors. However, it is unclear how this process is regulated and the key cachexins that are involved. In this study, we validated C26 and EL4 as cachexic and non-cachexic cell models, respectively. Treatment of adipocytes and myotubes with C26 conditioned medium induced lipolysis and atrophy, respectively. We profiled soluble secreted proteins (secretome) as well as small extracellular vesicles (sEVs) released from cachexia-inducing (C26) and non-inducing (EL4) cancer cells by label-free quantitative proteomics. A total of 1268 and 1022 proteins were identified in the secretome of C26 and EL4, respectively. Furthermore, proteomic analysis of sEVs derived from C26 and EL4 cancer cells revealed a distinct difference in the protein cargo. Functional enrichment analysis using FunRich highlighted the enrichment of proteins that are implicated in biological processes such as muscle atrophy, lipolysis, and inflammation in both the secretome and sEVs derived from C26 cancer cells. Overall, our characterisation of the proteomic profiles of the secretory factors and sEVs from cachexia-inducing and non-inducing cancer cells provides insights into tumour factors that promote weight loss by mediating protein and lipid loss in various organs and tissues. Further investigation of these proteins may assist in highlighting potential therapeutic targets and biomarkers of cancer cachexia.
The nature of voids: II. Tracing underdensities with biased galaxies
Creators: name: Nadathur, Seshadri
name: Hotchkiss, Shaun
Publisher: name: arXiv
Year: 2015
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We study how the properties of cosmic voids depend on those of the tracer galaxy populations in which they are identified. We use a suite of halo occupation distribution (HOD) mocks in a simulation, identify voids in these populations using the ZOBOV void finder and measure their abundances, sizes, tracer densities, and dark matter content. To separate the effects of bias from those of sampling density, we do the same for voids traced by randomly down-sampled subsets of the simulation dark matter particles. At the same sampling density, galaxy bias reduces the total number of voids by ~50% and can dramatically change their size distribution. The matter content of voids in biased and unbiased tracers also differs. Deducing void properties from simulation therefore requires the use of realistic galaxy mocks. We discuss how the void observables can be related to their matter content. In particular we consider the compensation of the total mass deficit in voids and find that the distinction between over- and under-compensated voids is not a function of void size alone, as has previously been suggested. However, we find a simple linear relationship between the average density of tracers in the void and the total mass compensation on much larger scales. The existence of this linear relationship holds independent of the bias and sampling density of the tracers. This provides a universal tool to classify void environments and will be important for the use of voids in observational cosmology.
description: 13 pages, 10 figures. MNRAS accepted. Main change in this version is addition of new figure (fig. 6), and shorter abstract. Figures 2, 5 and 7 contain the main results
Spectral multiplexing of telecom emitters with stable transition frequency
Creators: name: Ulanowski, Alexander
name: Merkel, Benjamin
name: Reiserer, Andreas
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: In a quantum network, coherent emitters can be entangled over large distances using photonic channels. In solid-state devices, the required efficient light-emitter interface can be implemented by confining the light in nanophotonic structures. However, fluctuating charges and magnetic moments at the nearby interface then lead to spectral instability of the emitters. Here we avoid this limitation when enhancing the photon emission up to 70(12)-fold using a Fabry-Perot resonator with an embedded 19 micrometer thin crystalline membrane, in which we observe around 100 individual erbium emitters. In long-term measurements, they exhibit an exceptional spectral stability of < 0.2 MHz that is limited by the coupling to surrounding nuclear spins. We further implement spectrally multiplexed coherent control and find an optical coherence time of 0.11(1) ms, approaching the lifetime limit of 0.3 ms for the strongest-coupled emitters. Our results constitute an important step towards frequency-multiplexed quantum-network nodes operating directly at a telecommunication wavelength.
PRISM: A Hierarchical Intrusion Detection Architecture for Large-Scale Cyber Networks
Creators: name: Javed, Yahya
name: Khayat, Mosab A.
name: Elghariani, Ali A.
name: Ghafoor, Arif
Publisher: name: arXiv
Year: 2021
Subjects: subject: Cryptography and Security (cs.CR)
subject: FOS: Computer and information sciences

description: The increase in scale of cyber networks and the rise in sophistication of cyber-attacks have introduced several challenges in intrusion detection. The primary challenge is the requirement to detect complex multi-stage attacks in realtime by processing the immense amount of traffic produced by present-day networks. In this paper we present PRISM, a hierarchical intrusion detection architecture that uses a novel attacker behavior model-based sampling technique to minimize the realtime traffic processing overhead. PRISM has a unique multi-layered architecture that monitors network traffic distributedly to provide efficiency in processing and modularity in design. PRISM employs a Hidden Markov Model-based prediction mechanism to identify multi-stage attacks and ascertain the attack progression for a proactive response. Furthermore, PRISM introduces a stream management procedure that rectifies the issue of alert reordering when collected from distributed alert reporting systems. To evaluate the performance of PRISM, multiple metrics have been proposed, and various experiments have been conducted on a multi-stage attack dataset. The results exhibit up to 7.5x improvement in processing overhead as compared to a standard centralized IDS without the loss of prediction accuracy while demonstrating the ability to predict different attack stages promptly.
Fiber entropy and algorithmic complexity of random orbits
Creators: name: Zimmermann, Elias
Publisher: name: arXiv
Year: 2021
Subjects: subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics

description: Let $Θ$ be a finite alphabet. We consider a bundle of measure preserving transformations $(T_θ)_{θ\in Θ}$ acting on a probability space $(X,μ)$, which are chosen randomly according to an ergodic stochastic process $(Ξ,ν,σ)$ with state space $Θ$. This describes a paradigmatic case of a random dynamical system (RDS). Considering a finite partition $\mathcal{P}$ of $X$ we show that the conditional algorithmic complexity of a random orbit $x, T_{α_{0}}(x),T_{α_{1}}\circ T_{α_{0}}(x),...$ in $X$ along a sequence $α= α_{0}α_{1}α_{2}...$ in $Ξ$ equals almost surely the fiber entropy of the RDS with respect to $\mathcal{P}$, whenever the latter is ergodic. This extends a classical result of A. A. Brudno connecting algorithmic complexity and entropy in deterministic dynamical systems.
Learning with hidden variables
Creators: name: Roudi, Yasser
name: Taylor, Graham
Publisher: name: arXiv
Year: 2015
Subjects: subject: Neurons and Cognition (q-bio.NC)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Machine Learning (cs.LG)
subject: Neural and Evolutionary Computing (cs.NE)
subject: Machine Learning (stat.ML)
subject: FOS: Biological sciences
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Learning and inferring features that generate sensory input is a task continuously performed by cortex. In recent years, novel algorithms and learning rules have been proposed that allow neural network models to learn such features from natural images, written text, audio signals, etc. These networks usually involve deep architectures with many layers of hidden neurons. Here we review recent advancements in this area emphasizing, amongst other things, the processing of dynamical inputs by networks with hidden nodes and the role of single neuron models. These points and the questions they arise can provide conceptual advancements in understanding of learning in the cortex and the relationship between machine learning approaches to learning with hidden nodes and those in cortical circuits.
description: revised version accepted in Current Opinion in Neurobiology
Global Non-Linearly Stable Large-Data Solutions to the Einstein Scalar Field System
Creators: name: Kilgore, Eric
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Analysis of PDEs (math.AP)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: I study a class of global, causal geodesically complete solutions to the spherically symmetric Einstein scalar field (SSESF) system . Extending results of Luk-Oh (Quantitative Decay Rates for Dispersive Solutions to the Einstein-Scalar Field System in Spherical Symmetry, arXiv:1402.2984), Luk-Oh-Yang (Solutions to the Einstein-Scalar-Field System in Spherical Symmetry with Large Bounded Variation Norms, arXiv:1605.03893), I provide new bounds controlling higher derivatives of both the metric components of the solution and the scalar field itself for large data solutions to SSESF. Moreover, by constructing a particular set of generalized wave-coordinates, I show that, assuming sufficient regularity of the data, these solutions are globally non-linearly stable to non-spherically symmetric perturbations by recent results of Luk and Oh. In particular, I demonstrate the existence of a large collection of non-trivial examples of large data, globally nonlinearly stable, dispersive solutions to the Einstein scalar field system.
description: 59 pages
Asymptotic behaviours of q-orthogonal polynomials from a q-Riemann Hilbert Problem
Creators: name: Joshi, Nalini
name: Latimer, Tomas Lasic
Publisher: name: arXiv
Year: 2021
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: We describe a Riemann-Hilbert problem for a family of $q$-orthogonal polynomials, $\{ P_n(x) \}_{n=0}^\infty$, and use it to deduce their asymptotic behaviours in the limit as the degree, $n$, approaches infinity. We find that the $q$-orthogonal polynomials studied in this paper share certain universal behaviours in the limit $n\to\infty$. In particular, we observe that the asymptotic behaviour near the location of their smallest zeros, $x \sim q^{n/2}$, and norm, $\|P_n\|_2$, are independent of the weight function as $n\to\infty$.
description: 23 pages, 1 figure
Optimizing qubit resources for quantum chemistry simulations in second quantization on a quantum computer
Creators: name: Moll, Nikolaj
name: Fuhrer, Andreas
name: Staar, Peter
name: Tavernelli, Ivano
Publisher: name: arXiv
Year: 2015
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum chemistry simulations on a quantum computer suffer from the overhead needed for encoding the fermionic problem in a bosonic system of qubits. By exploiting the block diagonality of a fermionic Hamiltonian, we show that the number of required qubits can be reduced by a factor of two or more. There is no need to go into the basis of the Hilbert space for this reduction because all operations can be performed in the operator space. The scheme is conceived as a pre-computational step that would be performed on a classical computer prior to the actual quantum simulation. We apply this scheme to reduce the number of qubits necessary to simulate both the Hamiltonian of the two-site Fermi-Hubbard model and the hydrogen molecule. Both quantum systems can then be simulated with a two-qubit quantum computer.
Surface Stability of SrNbO$_{3+δ}$ Grown by Hybrid Molecular Beam Epitaxy
Creators: name: Thapa, Suresh
name: Provence, Sydney
name: Heald, Steve M.
name: Kuroda, Marcelo A.
name: Comes, Ryan B.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: 4d transition metal oxides have emerged as promising materials for numerous applications including high mobility electronics. SrNbO$_{3}$ is one such candidate material, serving as a good donor material in interfacial oxide systems and exhibiting high electron mobility in ultrathin films. However, its synthesis is challenging due to the metastable nature of the d$^{1}$ Nb$^{4+}$ cation and the limitations in the delivery of refractory Nb. To date, films have been grown primarily by pulsed laser deposition (PLD), but development of a means to grow and stabilize the material via molecular beam epitaxy (MBE) would enable studies of interfacial phenomena and multilayer structures that may be challenging by PLD. To that end, SrNbO$_{3}$ thin films were grown using hybrid MBE for the first time using a tris(diethalamido)(tert-butylimido) niobium precursor for Nb and an elemental Sr source on GdScO$_{3}$ substrates. Varying thicknesses of insulating SrHfO$_{3}$ capping layers were deposited using a hafnium tert-butoxide precursor for Hf on top of SrNbO$_{3}$ films to preserve the metastable surface. Grown films were transferred in vacuo for X-ray photoelectron spectroscopy to quantify elemental composition, density of states at the Fermi energy, and Nb oxidation state. Ex situ studies by X-ray absorption near edge spectra illustrates the SrHfO$_{3}$ capping plays an important role in preserving the Nb 4d$^{1}$ metastable charge state in atmospheric conditions.
description: 11 pages, 5 figures; 3 pages of supplemental information
Pulsating dissipative solitons in a Mamyshev oscillator
Creators: name: Cao, Bo
name: Zhao, Kangjun
name: Gao, Chenxin
name: Xiao, Xiaosheng
name: Bao, Chengying
name: Yang, Changxi
Publisher: name: arXiv
Year: 2021
Subjects: subject: Pattern Formation and Solitons (nlin.PS)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Mode-locked fiber lasers provide a versatile playground to study dissipative soliton (DS) dynamics. The corresponding studies not only give insights into soliton dynamics in dissipative systems, but also contribute to femtosecond fiber laser design. Recently, Mamyshev oscillators (MOs), which rely upon a pair of narrow filters with offset passing frequencies, have emerged as a promising candidate for high power, ultrabroad bandwidth pulse generation. To date, only stable mode-locking states in MOs have been reported. Here, we present a comprehensive experimental and numerical investigation of pulsating DSs in an ytterbium MO. By reducing the filter separation down to 4 nm, we observe pulsation in a single pulse state as well as a soliton molecule state. In the single pulse state, the output pulse energy can vary as large as 40 times in our MO. Single-shot spectra measured by the dispersive Fourier transform (DFT) method reveal the spectral bandwidth breathing during pulsation and enables the observation of soliton explosion in a pulsation state. In addition, pulsation with a period lasting 9 round trips and even a chaotic pulsation state are also observed. Numerical simulations based on a lumped model qualitatively agree with our observation. Our results enrich DS dynamics in MOs and show the impact of filter separation on the stability of MOs.
Collage: Seamless Integration of Deep Learning Backends with Automatic Placement
Creators: name: Jeon, Byungsoo
name: Park, Sunghyun
name: Liao, Peiyuan
name: Xu, Sheng
name: Chen, Tianqi
name: Jia, Zhihao
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: The strong demand for efficient and performant deployment of Deep Learning (DL) applications prompts the rapid development of a rich DL ecosystem. To keep up with this fast advancement, it is crucial for modern DL frameworks to efficiently integrate a variety of optimized tensor algebra libraries and runtimes as their backends and generate the fastest possible executable using these backends. However, current DL frameworks require significant manual effort and expertise to integrate every new backend while failing to unleash its full potential. Given the fast-evolving nature of the DL ecosystem, this manual approach often slows down continuous innovations across different layers; it prevents hardware vendors from the fast deployment of their cutting-edge libraries, DL framework developers must repeatedly adjust their hand-coded rules to accommodate new versions of libraries, and machine learning practitioners need to wait for the integration of new technologies and often encounter unsatisfactory performance. In this paper, we propose Collage, a DL framework that offers seamless integration of DL backends. Collage provides an expressive backend registration interface that allows users to precisely specify the capability of various backends. By leveraging the specifications of available backends, Collage automatically searches for an optimized backend placement strategy for a given workload and execution environment. Our evaluation shows that Collage outperforms the best existing framework for each hardware by $1.26\times$, $1.43\times$, $1.40\times$ on average on NVIDIA's RTX 2070 GPU, V100 GPU, and Intel's Xeon 8259CL CPU, respectively. Collage has been open-sourced and deployed in Apache TVM.
description: Published in PACT 22
Enhancing the ecological validity of the Beads Task as a behavioral measure of intolerance of uncertainty
Creators: name: Blakey, Shannon M.
name: Abramowitz, Jonathan S.
name: Jacoby, Ryan J.
name: Reuman, Lillian
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2016

description: To broaden the measurement of intolerance of uncertainty (IU) beyond self-report methods, recent research has examined the Beads Task as a behavioral measure of IU. In the present study, we enhanced this task to increase its ecological validity by maximizing decisional uncertainty and the importance of a correct response. Undergraduate participants (n=102) completed the Beads Task with instructions that they would complete the Cold Pressor Task (CPT) if they answered incorrectly. As hypothesized, baseline CPT endurance time and self-reported pain level were weakly associated with later Beads Task distress during the decision-making process. Furthermore, in vivo Beads Task distress was associated with self-report inhibitory IU, which measures avoidance and paralysis in the face of uncertainty, but not with prospective IU, perfectionism, or general psychological distress after making statistical adjustments for multiple comparisons. Comparisons to previous work using the Beads Task, clinical implications, and avenues for future research are discussed.
Cross-encoded quantum key distribution exploiting time-bin and polarization states with qubit-based synchronization
Creators: name: Scalcon, Davide
name: Agnesi, Costantino
name: Avesani, Marco
name: Calderaro, Luca
name: Foletto, Giulio
name: Stanco, Andrea
name: Vallone, Giuseppe
name: Villoresi, Paolo
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Robust implementation of quantum key distribution requires precise state generation and measurements, as well as a transmission that is resistant to channel disturbances. However, the choice of the optimal encoding scheme is not trivial and depends on external factors such as the quantum channel. In fact, stable and low-error encoders are available for polarization encoding, suitable for free-space channels, whereas time-bin encoding represent a good candidate for fiber-optic channels, as birefingence does not perturb this kind of states. Here we present a cross-encoded scheme where high accuracy quantum states are prepared through a self-compensating, calibration-free polarization modulator and transmitted using a polarization-to-time-bin converter. A hybrid receiver performs both time-of-arrival and polarization measurements to decode the quantum states and successfully leaded to a transmission over 50 km fiber spool without disturbances. Temporal synchronization between the two parties is performed with a qubit-based method that does not require additional hardware to share a clock reference. The system was tested in a 12 hour run and demonstrated good and stable performance in terms of key and quantum bit error rates. The flexibility of our approach represents an important step towards the development of hybrid networks with both fiber-optic and free-space links.
description: 7 pages, 6 figures
title: Augmenting Compiler Optimisations through Source-to-Source Injection of Runtime Information-aware Transformations
Creators: name: Siso Godia, Sergi
Publisher: name: University of Liverpool Repository
Year: 2025

description: Traditionally, high-performance scientific computing applications have relied on ahead-of-time compilation of statically typed programming languages such as C, C++, and FORTRAN to generate efficient machine code. Ahead-of-time compilers can perform complex dependency analysis to enable optimisations that take advantage of modern processor capabilities, such as vectorisation. HPC system vendors typically provide their own ahead-of-time proprietary compilers that are specifically tuned for their architectures. Alternatively, dynamic compilation can also take advantage of information available only at runtime to improve the quality of compiler analysis. However, they are typically designed to avoid costly optimisations in order to provide the low recompilation overhead needed for general-purpose computing, and are tightly implemented inside specific compiler toolchains, often making them incompatible with vendor proprietary compilers. This thesis explores the suitability of ahead-of-time code injection of dynamic optimisation runtimes that are able to leverage proprietary vendor tuned compilers with aggressive optimisations. To do this, the thesis presents a new compiler benchmarking approach that comprehensively evaluates the benefit of releasing contextual information at compile-time and introduces two source-to-source code injection frameworks for dynamic optimisations. One for C and C++ loops that provide average vectorisation speed-ups of x1.25 for the Intel compiler and x1.47 for the Nvidia compiler in the presented benchmarking suite. And another that leverages the OpenCL runtime compilation model to delay the evaluation of runtime invariants and achieves x1.15 speedup in selected kernels while also improving the portability of the target application.
Diffusion matrix associated with the diffusion processes of multiple conserved charges in a hot and dense hadronic matter
Creators: name: Das, Arpan
name: Mishra, Hiranmaya
name: Mohapatra, Ranjita K.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Nuclear Theory (nucl-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Bulk matter produced in heavy ion collisions has multiple conserved quantum numbers like baryon number, strangeness and electric charge. The diffusion process of these charges can be described by a diffusion matrix describing the interdependence of diffusion of different charges. The diffusion coefficient matrix is estimated here from the Boltzmann kinetic theory for the hadronic phase within relaxation time approximation. In the derivation for the same, we impose the Landau-Lifshitz conditions of fit. This leads to e.g. the diagonal diffusion coefficients to be manifestly positive definite. The explicit calculations are performed within the ambit of hadron resonance gas model with and without excluded volume corrections. It is seen that the off-diagonal components can be significant to affect the charge diffusion in a fluid with multiple conserved charges. The excluded volume correction effects is seen to be not significant in the estimation of the elements of the diffusion matrix.
description: 16 pages, 6 figures, Comments are very much welcome