cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Extended Lagrangian approach for the numerical study of multidimensional dispersive waves: applications to the Serre-Green-Naghdi equations
Creators: name: Tkachenko, Sergey
name: Gavrilyuk, Sergey
name: Massoni, Jacques
Publisher: name: arXiv
Year: 2022
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics

description: In this paper we study two multidimensional nonlinear dispersive systems: the Serre-Green-Naghdi (SGN) equations describing dispersive shallow water flows, and Iordanskii-Kogarko-Wijngaarden (IKW) equations describing fluids containing small compressible gas bubbles. These models are Euler-Lagrange equations for a given Lagrangian and share common mathematical structure, namely the dependence of the pressure on material derivatives of macroscopic variables. We develop a generic dispersive model such that SGN and IKW systems become its special cases if only one specifies the appropriate Lagrangian, and then use the extended Lagragian approach proposed in Favrie and Gavrilyuk (2017) to build its hyperbolic approximation. The new approximate model is unconditionally hyperbolic for both SGN and IKW cases, and accurately describes dispersive phenomena, which allows to impose discontinuous initial data and study dispersive shock waves. We consider the 2-D hyperbolic version of SGN system as an example for numerical simulations and apply a second order implicit-explicit scheme in order to numerically integrate the system. The obtained 1-D and 2-D results are in close agreement with available exact solutions and numerical tests. \textbf{Keywords: } dispersive shallow water equations, bubbly fluids, Euler-Lagrange equations, hyperbolic conservation laws, multidimensional waves, implicit-explicit numerical methods
description: 40 pages, 13 figures, 2 tables
Anderson Acceleration For Bioinformatics-Based Machine Learning
Creators: name: Ali, Sarwan
name: Chourasia, Prakash
name: Patterson, Murray
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: Anderson acceleration (AA) is a well-known method for accelerating the convergence of iterative algorithms, with applications in various fields including deep learning and optimization. Despite its popularity in these areas, the effectiveness of AA in classical machine learning classifiers has not been thoroughly studied. Tabular data, in particular, presents a unique challenge for deep learning models, and classical machine learning models are known to perform better in these scenarios. However, the convergence analysis of these models has received limited attention. To address this gap in research, we implement a support vector machine (SVM) classifier variant that incorporates AA to speed up convergence. We evaluate the performance of our SVM with and without Anderson acceleration on several datasets from the biology domain and demonstrate that the use of AA significantly improves convergence and reduces the training loss as the number of iterations increases. Our findings provide a promising perspective on the potential of Anderson acceleration in the training of simple machine learning classifiers and underscore the importance of further research in this area. By showing the effectiveness of AA in this setting, we aim to inspire more studies that explore the applications of AA in classical machine learning.
description: Accepted in KDH-2023: Knowledge Discovery in Healthcare Data (IJCAI Workshop)
Metamorphoses of the flow past an obstacle of a resonantly-driven bistable polariton fluid
Creators: name: Hakim, Vincent
name: Pigeon, Simon
name: Aftalion, Amandine
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: Motivated by recent experiments, we theoretically analyze the flow past an obstacle of a one-dimensional "quantum fluid of light" which is resonantly driven, and exhibits bistability. The flow is found to abruptly change several times when the fluid velocity or the obstacle potential strength are increased. In contrast to the cases of usual fluids and superfluids, the transitions take place between stationary states. They involve the fluid bistability in an essential way. Remarkably, at the transitions points, the fluid in the obstacle wake lies in the unstable intermediate density state.
title: Modelling and control of suspensions as used in interferometric gravitational wave detectors
Creators: name: Palmer, David Andrew
Publisher: name: University of Glasgow
Year: 2001
Subjects: subject: Astrophysics.

description: In this thesis the bond graph modelling of multi-stage pendula is presented. The models are abstractions of the real physical pendula as used in the GEO 600 gravitational wave detector. In addition, Model Based Observers (MBO) for the control of these real physical pendula, are presented. The bond graph domain is utilised because it is an energy based methodology which facilitates the creation of unambiguous hierarchical models. This hierarchical property is fully exploited to produce a library of components which can be used to create complex multistage pendula in a modular fasshion. Included in these models are hierarchical wire models which can model forces due to linear extension, bending dynamics and transverse modes of vibration. Components have been validated against a real physical system and as such alternatively configured system models can be created with confidence. Bond graph pendulum models are incorporated in the design of Model Based Observer controllers. Model Based Observers are designed in the "physical domain" of bond graphs and as such provide an intuitive approach to controller design, and a unified approach to both system modelling and controller synthesis. As a case study, a Model Based Observer has been designed and successfully implemented on a real physical pendulum system. This controller damps the resonant motion of a real double pendulum. A more sophisticated Model Based Observer, incorporating a split feedback topology, which is designed to control the position of a multi-stage pendula has also been investigated.
Massive particle pair production and oscillation in Friedman Universe: dark energy and matter interaction
Creators: name: Xue, She-Sheng
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The classical Friedman equations of time-varying Hubble function $H$, dark-energy and matter densities couple to quantised field equations for massive modes $M\gg H$. Numerically solving these equations, we show the particle-antiparticle pairs production and oscillation in microscopic time scale ${\mathcal O}(M^{-1})$. A massive pair plasma state is formed in macroscopic time scale ${\mathcal O}(H^{-1})$. Its density and pressure introduce the interaction of matter and dark energy densities in the Friedman equations. Focusing on epochs after reheating, we show that the negative dark energy tracks down the radiation energy in the radiation epoch. Such tracking dynamics ends, and dark energy becomes positive in the matter epoch. The matter converts to dark energy, and their present values are comparable, explaining the cosmic coincidence. As a result, a class of effective interacting dark energy models is advocated to confront cosmological observations.
description: 20 pages and 3 Figures. arXiv admin note: substantial text overlap with arXiv:2112.09661
Genome-Wide Assessment of Efficiency and Specificity in CRISPR/Cas9 Mediated Multiple Site Targeting in Arabidopsis
Creators: name: Haak, David C.
name: Teixeira, Paulo J. P. L.
name: Nishimura, Marc T.
name: James, Sean R.
name: Peterson, Brenda A.
name: Dangl, Jeffery L.
name: Nimchuk, Zachary L.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2016

description: Simultaneous multiplex mutation of large gene families using Cas9 has the potential to revolutionize agriculture and plant sciences. The targeting of multiple genomic sites at once raises concerns about the efficiency and specificity in targeting. The model Arabidopsis thaliana is widely used in basic plant research. Previous work has suggested that the Cas9 off-target rate in Arabidopsis is undetectable. Here we use deep sequencing on pooled plants simultaneously targeting 14 distinct genomic loci to demonstrate that multiplex targeting in Arabidopsis is highly specific to on-target sites with no detectable off-target events. In addition, chromosomal translocations are extremely rare. The high specificity of Cas9 in Arabidopsis makes this a reliable method for clean mutant generation with no need to enhance specificity or adopt alternate Cas9 variants.
Compact Representation for Specific Heat of Interacting Fermion Systems in Terms of Fully Renormalized Matsubara Green Function
Creators: name: Miyake, Kazumasa
name: Tsuruta, Atsushi
Publisher: name: arXiv
Year: 2015
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: On the basis of the Luttinger-Ward formalism for the thermodynamic potential, the specific heat of single-component interacting fermion systems with fixed chemical potential is compactly expressed in terms of the fully renormalized Matsubara Green function.
description: 10 pages, 1 figure, published in JPSJ online on August 18
Discovering data using the ODISSEI Portal
Creators: name: Maineri, Angelica
name: Braukmann, Ricarda
Publisher: name: Zenodo
Year: 2022
Subjects: Data portal
Metadata interface
ODISSEI

description: In this session, we will show the first version of the ODISSEI Portal to the Open Science community to gather feedback on the interface and search functionality, in order to enhance the user experience. After a short introduction to ODISSEI and the ODISSEI Portal, participants will be given time to explore the Portal and search for datasets themselves. The remainder of the session is devoted to discuss the participants’ impressions and suggestions for future improvements of the interface and Portal functionalities.
Character-level White-Box Adversarial Attacks against Transformers via Attachable Subwords Substitution
Creators: name: Liu, Aiwei
name: Yu, Honghai
name: Hu, Xuming
name: Li, Shu'ang
name: Lin, Li
name: Ma, Fukun
name: Yang, Yawen
name: Wen, Lijie
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computation and Language (cs.CL)
subject: FOS: Computer and information sciences
subject: I.2.7
subject: 68T50

description: We propose the first character-level white-box adversarial attack method against transformer models. The intuition of our method comes from the observation that words are split into subtokens before being fed into the transformer models and the substitution between two close subtokens has a similar effect to the character modification. Our method mainly contains three steps. First, a gradient-based method is adopted to find the most vulnerable words in the sentence. Then we split the selected words into subtokens to replace the origin tokenization result from the transformer tokenizer. Finally, we utilize an adversarial loss to guide the substitution of attachable subtokens in which the Gumbel-softmax trick is introduced to ensure gradient propagation. Meanwhile, we introduce the visual and length constraint in the optimization process to achieve minimum character modifications. Extensive experiments on both sentence-level and token-level tasks demonstrate that our method could outperform the previous attack methods in terms of success rate and edit distance. Furthermore, human evaluation verifies our adversarial examples could preserve their origin labels.
description: 13 pages, 3 figures. EMNLP 2022
Four-fermion deformations of the massless Schwinger model and confinement
Creators: name: Cherman, Aleksey
name: Jacobson, Theodore
name: Shifman, Mikhail
name: Unsal, Mithat
name: Vainshtein, Arkady
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We consider the massless charge-$N$ Schwinger model and its deformation with two four-fermion operators. Without the deformations, this model exhibits chiral symmetry breaking without confinement. It is usually asserted that the massless Schwinger model is always deconfined and a string tension emerges only when a mass for the fermion field is turned on. We show that in the presence of these four-fermion operators, the massless theory can in fact confine. One of the four-fermion deformations is chirally neutral, and is a marginal deformation. The other operator can be relevant or irrelevant, and respects a $\mathbb{Z}_2$ subgroup of chiral symmetry for even $N$, hence forbidding a mass term. When it is relevant, even the exactly massless theory exhibits both confinement and spontaneous chiral symmetry breaking. The construction is analogous to QCD(adj) in 2d. While the theory without four-fermion deformations is deconfined, the theory with these deformations is generically in a confining phase. We study the model on $\mathbb{R}^2$ using bosonization, and also analyze the mechanism of confinement on $\mathbb{R}\times S^1$, where we find that confinement is driven by fractional instantons.
description: 38 pages, 5 figures; v2: minor improvements
Carroll covariant scalar fields in two dimensions
Creators: name: Bagchi, Arjun
name: Banerjee, Aritra
name: Dutta, Sudipta
name: Kolekar, Kedar S.
name: Sharma, Punit
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Conformal Carroll symmetry generically arises on null manifolds and is important for holography of asymptotically flat spacetimes, generic black hole horizons and tensionless strings. In this paper, we focus on two dimensional (2d) null manifolds and hence on the 2d Conformal Carroll or equivalently the 3d Bondi-Metzner-Sachs (BMS) algebra. Using Carroll covariance, we write the most general free massless Carroll scalar field theory and discover three inequivalent actions. Of these, two viz. the time-like and space-like actions, have made their appearance in literature before. We uncover a third that we call the mixed-derivative theory. As expected, all three theories enjoy off-shell BMS invariance. Interestingly, we find that the on-shell symmetry of mixed derivative theory is a single Virasoro algebra instead of the full BMS. We discuss potential applications to tensionless strings and flat holography.
description: v1: 49 pages, 1 figure; v2: 51 pages, 1 figure, added more discussion on Carroll geometry in section 2, added related discussions on Carroll geometry and Carroll symmetries at few other places, typos corrected, matches version to be published
On constraining Cosmology and the Halo Mass Function with Weak Gravitational Lensing
Creators: name: Gu, Shiming
name: Dor, Marc-Antoine
name: van Waerbeke, Ludovic
name: Asgari, Marika
name: Mead, Alexander
name: Tröster, Tilman
name: Yan, Ziang
Publisher: name: arXiv
Year: 2023
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: The discrepancy between the weak lensing (WL) and the {\it Planck} measurements of $S_8$ has been a subject of several studies. These studies tend to show that a suppression of the amplitude of the mass power spectrum $P(k)$ at high $k$ could resolve it. The WL signal at small-scale is sensitive to various effects, such as baryonic effects and intrinsic alignment. The accuracy of $P(k)$ depends on the modelling precision of these effects. A common approach for calculating $P(k)$ relies on a halo model. Amongst the various components necessary for the construction of $P(k)$, the halo mass function (HMF) is an important one. Traditionally, the HMF has been assumed to follow a fixed model. Recent literature shows that baryonic physics, amongst several other factors, could affect the HMF. In this study, we investigate the impact of allowing the HMF to vary. This provides a way of testing the validity of the halo model-HMF calibration using data. We find that the {\it Planck} cosmology is not compatible with the vanilla HMF for both the DES-y3 and the KiDS-1000 data. When the cosmology and the HMF parameters are allowed to vary, the {\it Planck} cosmology is no longer in tension. The modified HMF predicts a matter power spectrum with a $\sim 25\%$ power loss at $k\sim 1~{\rm h/Mpc}$, in agreement with the recent studies. We show that Stage IV surveys will be able to measure the HMF parameters with a few percent accuracy.
description: 16 pages (including appendixes), 10 figures, 3 tables, main results in Figs. 5&6
Acipenser albertensis
Creators: name: Lambe L., M.
Publisher: name: Zenodo
Year: 1902
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Actinopterygii
Acipenseriformes
Acipenseridae
Acipenser
Acipenser albertensis

description: Acipenser albertensis Sp. nov. Plate XXI, fig. 9. The strongly keeled and highly ornamented shield shown on plate XXI, apparently represents an ancient sturgeon, for which the above name is proposed. The ornamentation consists of rounded, coalescent ridges and nodes in high relief, and quite smooth, not very unlike the sculptured surface of the shell of some species of turtles. This genus has not hitherto been known from rocks lower than the Tertiary. Belly Eiver series, Eed Deer river, District of Alberta, 1901.
description: Published as part of Lambe L. M., 1902, New genera and species from the Belly River Series (mid-Cretaceous), pp. 25-81 in Geological Survey of Canada Contributions to Canadian Palaeontology 3 on page 29, DOI: 10.5281/zenodo.3233762
Fundamental solutions of an extended hydrodynamic model in two dimensions: Derivation, theory, and applications
Creators: name: Himanshi
name: Rana, Anirudh Singh
name: Gupta, Vinay Kumar
Publisher: name: arXiv
Year: 2023
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: The inability of the Navier-Stokes-Fourier equations to capture rarefaction effects motivates us to adopt the extended hydrodynamic equations. In the present work, a hydrodynamic model, which consists of the conservation laws closed with the recently propounded coupled constitutive relations (CCR), is utilized. This model is referred to as the CCR model and is adequate for describing moderately rarefied gas flows. A numerical framework based on the method of fundamental solutions is developed to solve the CCR model for rarefied gas flow problems in quasi two dimensions. To this end, the fundamental solutions of the linearized CCR model are derived in two dimensions. The significance of deriving the two-dimensional fundamental solutions is that they cannot be deduced from their three-dimensional counterparts that do exist in literature. As applications, the developed numerical framework based on the derived fundamental solutions is used to simulate (i) a rarefied gas flow between two coaxial cylinders with evaporating walls and (ii) a temperature-driven rarefied gas flow between two non-coaxial cylinders. The results for both problems have been validated against those obtained with the other classical approaches. Through this, it is shown that the method of fundamental solutions is an efficient tool for addressing quasi two-dimensional multiphase microscale gas flow problems at a low computational cost. Moreover, the findings also show that the CCR model solved with the method of fundamental solutions is able to describe rarefaction effects, like transpiration flows and thermal stress, generally well.
description: 18 pages, 15 figures
Superconductivity in CeBeH$_{8}$ and CeBH$_{8}$ at moderate pressures
Creators: name: Hou, Yu
name: Li, Bin
name: Bai, Yan
name: Hao, Xiaofeng
name: Yang, Yeqian
name: Chi, Fengfeng
name: Liu, Shengli
name: Cheng, Jie
name: Shi, Zhixiang
Publisher: name: arXiv
Year: 2022
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: High-pressure structural searches of superhydrides CeBeH$_8$ and CeBH$_8$ were performed under ambient pressure up to 300 GPa. We identify $Fm\overline{3}m$-CeBeH$_8$ with a superconducting transition temperature $T_{c}$ of 56 K at 10 GPa. Two more phases with spacegroup $R\overline{3}m$ and $C2/m$, were investigated within the increasing pressures. CeBH$_8$ shows a similar phase transition process as CeBeH$_8$ but with higher transition pressures and higher $T_c$. $Fm\overline{3}m$-CeBH$_8$ is predicted to be superconducting above 120 GPa with a maximum $T_{c}$ of 118 K at 150 GPa. $R\overline{3}m$-CeBH$_8$ and $C2/m$-CeBH$_8$ are dynamically stable above 120 GPa and 100 GPa, respectively. The maximum $T_{c}$ is 123 K at 195 GPa for $R\overline{3}m$-CeBH$_8$, and 115 K at 350 GPa for $C2/m$-CeBH$_8$. Our work enriches the family of ternary hydrides and may provide a useful guideline for further search for superconducting hydrides at low and moderate pressures.
Optimization of a Line Detection Algorithm for Autonomous Vehicles on a RISC-V with Accelerator
Creators: name: Belda, María José
name: Olcoz, Katzalin
name: Castro, Fernando
name: Tirado, Francisco
Publisher: name: arXiv
Year: 2024
Subjects: subject: Hardware Architecture (cs.AR)
subject: FOS: Computer and information sciences

description: In recent years, autonomous vehicles have attracted the attention of many research groups, both in academia and business, including researchers from leading companies such as Google, Uber and Tesla. This type of vehicles are equipped with systems that are subject to very strict requirements, essentially aimed at performing safe operations -- both for potential passengers and pedestrians -- as well as carrying out the processing needed for decision making in real time. In many instances, general-purpose processors alone cannot ensure that these safety, reliability and real-time requirements are met, so it is common to implement heterogeneous systems by including accelerators. This paper explores the acceleration of a line detection application in the autonomous car environment using a heterogeneous system consisting of a general-purpose RISC-V core and a domain-specific accelerator. In particular, the application is analyzed to identify the most computationally intensive parts of the code and it is adapted accordingly for more efficient processing. Furthermore, the code is executed on the aforementioned hardware platform to verify that the execution effectively meets the existing requirements in autonomous vehicles, experiencing a 3.7x speedup with respect to running without accelerator.
High-momentum oscillating tails of strongly interacting 1D gases in a box
Creators: name: Aupetit-Diallo, Gianni
name: Musolino, Silvia
name: Albert, Mathias
name: Vignolo, Patrizia
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We study the momentum distribution of strongly interacting one-dimensional mixtures of particles at zero temperature in a box potential. We find that the magnitude of the $1/k^4$ tail of the momentum distribution is not only due to short-distance correlations, but also to the presence of the rigid walls, breaking the Tan's relation relating this quantity to the adiabatic derivative of the energy with respect to the inverse of the interaction strength. The additional contribution is a finite-size effect that includes a $k$-independent and an oscillating part. This latter, surprisingly, encodes information on long-range spin correlations.
description: 6 pages, 2 figures and supplemental materials
Observation of gravitationally induced vertical striation of polarized ultracold neutrons by spin-echo spectroscopy
Creators: name: Afach, S.
name: Ayres, N. J.
name: Ban, G.
name: Bison, G.
name: Bodek, K.
name: Chowdhuri, Z.
name: Daum, M.
name: Fertl, M.
name: Franke, B.
name: Griffith, W. C.
name: Grujić, Z. D.
name: Harris, P. G.
name: Heil, W.
name: Hélaine, V.
name: Kasprzak, M.
name: Kermaidic, Y.
name: Kirch, K.
name: Knowles, P.
name: Koch, H. -C.
name: Komposch, S.
name: Kozela, A.
name: Krempel, J.
name: Lauss, B.
name: Lefort, T.
name: Lemière, Y.
name: Mtchedlishvili, A.
name: Musgrave, M.
name: Naviliat-Cuncic, O.
name: Pendlebury, J. M.
name: Piegsa, F. M.
name: Pignol, G.
name: Plonka-Spehr, C.
name: Prashanth, P. N.
name: Quéméner, G.
name: Rawlik, M.
name: Rebreyend, D.
name: Ries, D.
name: Roccia, S.
name: Rozpedzik, D.
name: Schmidt-Wellenburg, P.
name: Severijns, N.
name: Thorne, J. A.
name: Weis, A.
name: Wursten, E.
name: Wyszynski, G.
name: Zejma, J.
name: Zenner, J.
name: Zsigmond, G.
Publisher: name: arXiv
Year: 2015
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: We describe a spin-echo method for ultracold neutrons (UCNs) confined in a precession chamber and exposed to a $|B_0|=1~\text{μT}$ magnetic field. We have demonstrated that the analysis of UCN spin-echo resonance signals in combination with knowledge of the ambient magnetic field provides an excellent method by which to reconstruct the energy spectrum of a confined ensemble of neutrons. The method takes advantage of the relative dephasing of spins arising from a gravitationally induced striation of stored UCN of different energies, and also permits an improved determination of the vertical magnetic-field gradient with an exceptional accuracy of $1.1~\text{pT/cm}$. This novel combination of a well-known nuclear resonance method and gravitationally induced vertical striation is unique in the realm of nuclear and particle physics and should prove to be invaluable for the assessment of systematic effects in precision experiments such as searches for an electric dipole moment of the neutron or the measurement of the neutron lifetime.
description: 7 pages 5 figures, accepted by PRL, September, 08 2015
Geographic Variations in Retention in Care among HIV-Infected Adults in the United States
Creators: name: Horberg, Michael A.
name: Justice, Amy C.
name: Curriero, Frank C.
name: Rodriguez, Benigno
name: Rebeiro, Peter F.
name: Gebo, Kelly A.
name: Fiellin, David
name: Turner, Megan
name: Grasso, Chris
name: Napravnik, Sonia
name: Sterling, Timothy R.
name: Samji, Hasina
name: Buchacz, Kate
name: Bebawy, Sally
name: Moore, Richard D.
name: Brooks, John T.
name: Yehia, Baligh R.
name: Mayer, Kenneth H.
name: Willig, James
name: Saag, Michael S.
name: Haas, David
name: Althoff, Keri N.
name: Dubrow, Robert
name: Crane, Heidi M.
name: Boswell, Stephen
name: Kitahata, Mari M.
name: Abraham, Alison G.
name: Mugavero, Michael J.
name: Gange, Stephen J.
name: Eron, Joseph J.
name: Silverberg, Michael J.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2016

description: ObjectiveTo understand geographic variations in clinical retention, a central component of the HIV care continuum and key to improving individual- and population-level HIV outcomes.DesignWe evaluated retention by US region in a retrospective observational study.MethodsAdults receiving care from 2000–2010 in 12 clinical cohorts of the North American AIDS Cohort Collaboration on Research and Design (NA-ACCORD) contributed data. Individuals were assigned to Centers for Disease Control and Prevention (CDC)-defined regions by residential data (10 cohorts) and clinic location as proxy (2 cohorts). Retention was ≥2 primary HIV outpatient visits within a calendar year, >90 days apart. Trends and regional differences were analyzed using modified Poisson regression with clustering, adjusting for time in care, age, sex, race/ethnicity, and HIV risk, and stratified by baseline CD4+ count.ResultsAmong 78,993 adults with 444,212 person-years of follow-up, median time in care was 7 years (Interquartile Range: 4–9). Retention increased from 2000 to 2010: from 73% (5,000/6,875) to 85% (7,189/8,462) in the Northeast, 75% (1,778/2,356) to 87% (1,630/1,880) in the Midwest, 68% (8,451/12,417) to 80% (9,892/12,304) in the South, and 68% (5,147/7,520) to 72% (6,401/8,895) in the West. In adjusted analyses, retention improved over time in all regions (p<0.01, trend), although the average percent retained lagged in the West and South vs. the Northeast (p<0.01).ConclusionsIn our population, retention improved, though regional differences persisted even after adjusting for demographic and HIV risk factors. These data demonstrate regional differences in the US which may affect patient care, despite national care recommendations.
Spectral Theorems for Generalized Weyl Nodes with Impurities in a Magnetic Field
Creators: name: Solomon, Dan
name: Yee, Ho-Ung
Publisher: name: arXiv
Year: 2023
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: We prove a few spectral theorems for the density of states of a Weyl node with arbitrary topology. We show that the density of extended states of a Weyl node with random impurity potentials remains gapless in the presence of a magnetic field. Therefore, a magnetic field precludes Anderson localization in Weyl semi-metals, when inter-node transitions are suppressed for smooth enough potentials. We also provide a rigorous quantum mechanical proof of the chiral magnetic effect for arbitrary topology of a Weyl node.
description: Main article 6 pages, Supplemental Materials 9 pages, 1 figure, Added additional references
Unified model for cosmic rays above $10^{17}$ eV and the diffuse gamma-ray and neutrino backgrounds
Creators: name: Giacinti, G.
name: Kachelriess, M.
name: Kalashev, O.
name: Neronov, A.
name: Semikoz, D. V.
Publisher: name: arXiv
Year: 2015
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We investigate how the extragalactic proton component derived within the "escape model" can be explained by astrophysical sources. We consider as possible cosmic ray (CR) sources normal/starburst galaxies and radio-loud active galactic nuclei (AGN). We find that the contribution to the total extragalactic proton flux from normal and starburst galaxies is only subdominant and does not fit the spectral shape deduced in the escape model. In the case of radio-loud AGN, we show that the complete extragalactic proton spectrum can be explained by a single source population, BL Lac/FR I, for any of the potential acceleration sites in these sources. We calculate the diffuse neutrino and $γ$-ray fluxes produced by these CR protons interacting with gas inside their sources. For a spectral slope of CRs close to $α=2.1-2.2$ as suggested by shock acceleration, we find that these UHECR sources contribute the dominant fraction of both the isotropic $γ$-ray background and of the extragalactic part of the astrophysical neutrino signal observed by IceCube.
description: 10 pages, 9 eps figures; v2: minor additions, matches version to appear in PRD
Supercurrent-enabled Andreev reflection in a chiral quantum Hall edge state
Creators: name: Michelsen, Andreas B.
name: Recher, Patrik
name: Braunecker, Bernd
name: Schmidt, Thomas L.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: A chiral quantum Hall (QH) edge state placed in proximity to an s-wave superconductor experiences induced superconducting correlations. Recent experiments have observed the effect of proximity-coupling in QH edge states through signatures of the mediating process of Andreev reflection. We present the microscopic theory behind this effect by modeling the system with a many-body Hamiltonian, consisting of an s-wave superconductor, subject to spin-orbit coupling and a magnetic field, which is coupled by electron tunneling to a QH edge state. By integrating out the superconductor we obtain an effective pairing Hamiltonian in the QH edge state. We clarify the qualitative appearance of nonlocal superconducting correlations in a chiral edge state and analytically predict the suppression of electron-hole conversion at low energies (Pauli blocking) and negative resistance as experimental signatures of Andreev reflection in this setup. In particular, we show how two surface phenomena of the superconductor, namely Rashba spin-orbit coupling and a supercurrent due to the Meissner effect, are essential for the Andreev reflection. Our work provides a promising pathway to the realization of Majorana zero-modes and their parafermionic generalizations.
description: 16 pages, 9 figures. Published version
From snapshots to manifolds - A tale of shear flows
Creators: name: Farzamnik, Ehsan
name: Ianiro, Andrea
name: Discetti, Stefano
name: Deng, Nan
name: Oberleithner, Kilian
name: Noack, Bernd R.
name: Guerrero, Vanesa
Publisher: name: arXiv
Year: 2022
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: We propose a novel non-linear manifold learning from snapshot data and demonstrate its superiority over Proper Orthogonal Decomposition (POD) for shedding-dominated shear flows. Key enablers are isometric feature mapping, Isomap (Tenenbaum et al., 2000), as encoder and K-nearest neighbours (KNN) algorithm as decoder. The proposed technique is applied to numerical and experimental datasets including the fluidic pinball, a swirling jet, and the wake behind a couple of tandem cylinders. Analyzing the fluidic pinball, the manifold is able to describe the pitchfork bifurcation and the chaotic regime with only three feature coordinates. These coordinates are linked to vortex-shedding phases and the force coefficients. The manifold coordinates of the swirling jet are comparable to the POD mode amplitudes, yet allow for a more distinct manifold identification which is less sensitive to measurement noise. As similar observation is made for the wake of two tandem cylinders (Raiola et al., 2016). The tandem cylinders are aligned in streamwise distance which corresponds to the transition between the single bluff body and the reattachment regimes of vortex shedding. Isomap unveils these two shedding regimes while the Lissajous plots of first two POD mode amplitudes feature a single circle. The reconstruction error of the manifold model is small compared to the fluctuation level, indicating that the low embedding dimensions contains the coherent structure dynamics. The proposed Isomap-KNN manifold learner is expected to be of large importance in estimation, dynamic modeling and control for large range of configurations with dominant coherent structures.
Heterogeneity in Comparisons of Discontinuation of Tumor Necrosis Factor Antagonists in Rheumatoid Arthritis - A Meta-Analysis
Creators: name: Fisher, Anat
name: Freeman, Hugh R.
name: Stanely, Dana
name: Brookhart, M. Alan
name: Goel, Gautam
name: Dormuth, Colin R.
name: Bassett, Ken
name: Wright, James M.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2016

description: We did a systematic review of studies comparing discontinuation of tumor necrosis factor alpha (TNF) antagonists in rheumatoid arthritis (RA) patients, pooled hazard ratios and assessed clinical and methodological heterogeneity.
The Wiener criterion for nonlocal Dirichlet problems
Creators: name: Kim, Minhyun
name: Lee, Ki-Ahm
name: Lee, Se-Chan
Publisher: name: arXiv
Year: 2022
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 31B25, 31B15, 35R11

description: We study the boundary behavior of solutions to the Dirichlet problems for integro-differential operators with order of differentiability $s \in (0, 1)$ and summability $p>1$. We establish a nonlocal counterpart of the Wiener criterion, which characterizes a regular boundary point in terms of the nonlocal nonlinear potential theory.
description: 39 pages
Phase Field Crystal model for particles with n-fold rotational symmetry in two dimensions
Creators: name: Weigel, Robert F. B.
name: Schmiedeberg, Michael
Publisher: name: arXiv
Year: 2022
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We introduce a Phase Field Crystal (PFC) model for particles with n-fold rotational symmetry in two dimensions. Our approach is based on a free energy functional that depends on the reduced one-particle density, the strength of the orientation, and the direction of the orientation, where all these order parameters depend on the position. The functional is constructed such that for particles with axial symmetry (i. e. n = 2) the PFC model for liquid crystals as introduced by H. Löwen [J. Phys.: Condens. Matter 22, 364105 (2010)] is recovered. We discuss the stability of the functional and explore phases that occur for $1 \leq n \leq 6$. In addition to isotropic, nematic, stripe, and triangular order, we also observe cluster crystals with square, rhombic, honeycomb, and even quasicrystalline symmetry. The n-fold symmetry of the particles corresponds to the one that can be realized for colloids with symmetrically arranged patches. We explain how both, repulsive as well as attractive patches, are described in our model.
description: 20 pages, 12 figures
Lepidotus occidentalis Leidy 1860
Creators: name: Lambe L., M.
Publisher: name: Zenodo
Year: 1902
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Actinopterygii
Lepisosteiformes
Bramidae
Lepidotus
Lepidotus occidentalis

description: Plate XIX, fig. 3. Lepidotus occidentalis, Leidy, 1860. Trans. Amer. Philos. Soc. Extinct Vertebraba from the Judith River and Great Lignite formations of Nebraska, pi. 11, figs. 20-23. Numerous scales, from the " bad lands " of Eed Deer river, are apparently not distinguishable from those described by Leidy under the name Lepidotus occidentalis. The scale figured is fairly representative of those in the collections, as regards form and size. The lozenge-shaped, enamelled outer surface is smooth and shiny, with generally a few small, puncture or pit-like depressions scattered toward the centre; a few observed edge. Length of specimen figured 18-5 growth lines are generally parallel to its mm., greatest thickness 3*0 mm. Belly Eiver series, Eed Deer river, 1898 and 1901. Similar scales were collected by Dr. Gr. M. Dawson on Belly river, N.W.T. (Nos. 40 and 41), in 1881, and by Mr. T. C. Weston, at Eoss coulee, near Irvine on the line of the C.P.E., in 1884.
description: Published as part of Lambe L. M., 1902, New genera and species from the Belly River Series (mid-Cretaceous), pp. 25-81 in Geological Survey of Canada Contributions to Canadian Palaeontology 3 on page 29, DOI: 10.5281/zenodo.3233762
Fact-nets: towards a mathematical framework for relational quantum mechanics
Creators: name: Martin-Dussaud, Pierre
name: Carette, Titouan
name: Głowacki, Jan
name: Zatloukal, Vaclav
name: Zalamea, Federico
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The relational interpretation of quantum mechanics (RQM) has received a growing interest since its first formulation in 1996. Usually presented as an interpretational layer over the usual quantum mechanics formalism, it appears as a philosophical perspective without proper mathematical counterparts. This state of affairs has direct consequences on the scientific debate on RQM which still suffers from misunderstandings and imprecise statements. In an attempt to clarify those debates, the present paper proposes a radical reformulation of the mathematical framework of quantum mechanics which is relational from the start: fact-nets. The core idea is that all statements about the world, facts, are binary entities involving two systems that can be symmetrically thought of as observed and observer. We initiate a study of the fact-nets formalism and outline how it can shed new relational light on some familiar quantum features.
Singular limit for the compressible Navier--Stokes equations with the hard sphere pressure law on expanding domains
Creators: name: Kalousek, Martin
name: Necasova, Sarka
Publisher: name: arXiv
Year: 2022
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: The article is devoted to the asymptotic limit of the compressible Navier-Stokes system with a pressure obeying a hard--sphere equation of state on a domain expanding to the whole physical space $R^3$. Under the assumptions that acoustic waves generated in the case of ill-prepared data do not reach the boundary of the expanding domain in the given time interval and a certain relation between the Reynolds and Mach numbers and the radius of the expanding domain, we prove that the target system is the incompressible Euler system on $R^3$. We also provide an estimate of the rate of convergence expressed in terms of characteristic numbers and the radius of domains.
3d $\mathcal{N}=2$ theories and plumbing graphs: adding matter, gauging, and new dualities
Creators: name: Cheng, Shi
name: Sułkowski, Piotr
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Recently, a large class of 3d $\mathcal{N} = 2$ gauge theories with mixed Chern-Simons levels, corresponding to plumbing 3-manifolds, has been identified. In this paper we generalize these theories by including in their content chiral multiples, and analyze their properties. We find that the content of such theories can be encoded in graphs, which generalize plumbing graphs, and various operations in these theories can be represented in terms of transformations of such graphs. The operations in question include gauging global symmetries, integrating out gauge nodes, which for theories without chiral multiplets corresponds to Kirby moves, and ST-transformations that involve chiral multiplets. The dualities such as mirror triality and SQED-XYZ duality can be also represented in terms of graphs, and enable us to find many new dual theories by gauging global symmetries. In particular, we find that gauged SQED-XYZ duality leads to other dualities, which take the same form as operations of linking and unlinking discussed in the context of knots-quivers correspondence. We also find that the superpotential can be encoded in an interesting class of triangle graphs that satisfy certain consistency conditions, we discuss decoupling and Higgsing of chiral multiplets, as well as interpretation of various phenomena in terms of brane webs.
description: 66 pages, many figures
Locality of vortex stretching for the 3D Euler equations
Creators: name: Shimizu, Yuuki
name: Yoneda, Tsuyoshi
Publisher: name: arXiv
Year: 2022
Subjects: subject: Analysis of PDEs (math.AP)
subject: Differential Geometry (math.DG)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: We consider the 3D incompressible Euler equations under the following situation: small-scale vortex blob being stretched by a prescribed large-scale stationary flow. More precisely, we clarify what kind of large-scale stationary flows really stretch small-scale vortex blobs in alignment with the straining direction. The key idea is constructing a Lagrangian coordinate so that the Lie bracket is identically zero (c.f. the Frobenius theorem), and investigate the locality of the pressure term by using it.
Constraints on fundamental physical constants from bio-friendly viscosity and diffusion
Creators: name: Trachenko, K.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The problem of understanding fundamental physical constants was discussed in particle physics, astronomy and cosmology. Here, I show that a new insight comes from condensed matter physics and liquid physics in particular: fundamental constants have a bio-friendly window constrained by bio-friendly viscosity and diffusion setting the motion in essential life processes in and across cells. I also show that bounds on viscosity, diffusion and the fundamental velocity gradient in a biochemical machine can all be varied while keeping the fine-structure constant and the proton-to-electron mass ratio intact, with no implication for the production of heavy nuclei in stars. This leads to a conjecture of multiple tuning and an evolutionary mechanism.
Rhineastes eruciferus Cope 1876
Creators: name: Lambe L., M.
Publisher: name: Zenodo
Year: 1902
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Actinopterygii
Acipenseriformes
Acipenseridae
Rhineastes
Rhineastes eruciferus

description: Rhineastes eruciferus, Cape, (sp.) Ceratodus eruciferus. Cope. 1876. Proc. Acad. Nat. 8ci. Philadel., p. 259. A number of fragments of cranial bones are referred to this species after comparison with the type from the " Fort Union " beds of Montana. The sculpture consists of strong parallel or divergent ribs that, in places, frequently coalesce and are sometimes interrupted; when divergent, additional ribs are intercalated at intervals. Fragments of spines with parallel grooves and ridges, running in the direction of the length, are thought to belong to the same fish. These remains resemble, somewhat, the corresponding parts of some of the species of Rhineastes described by Cope from the Tertiary of the v/estern States, and are here assigned, at least provisionally, to that genus. Belly River series, E.ed Deer river, 1901.
description: Published as part of Lambe L. M., 1902, New genera and species from the Belly River Series (mid-Cretaceous), pp. 25-81 in Geological Survey of Canada Contributions to Canadian Palaeontology 3 on pages 29-30, DOI: 10.5281/zenodo.3233762
Stratospheric Modulation of the MJO through Cirrus Cloud Feedbacks
Creators: name: Lin, Jonathan
name: Emanuel, Kerry
Publisher: name: arXiv
Year: 2022
Subjects: subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: FOS: Physical sciences

description: Recent observations have indicated significant modulation of the Madden Julian Oscillation (MJO) by the phase of the stratospheric Quasi-Biennial Oscillation (QBO) during boreal winter. Composites of the MJO show that upper tropospheric ice cloud fraction and water vapor anomalies are generally collocated, and that an eastward tilt with height in cloud fraction exists. Through radiative transfer calculations, it is shown that ice clouds have a stronger tropospheric radiative forcing than do water vapor anomalies, highlighting the importance of incorporating upper tropospheric/lower stratospheric processes into simple models of the MJO. The coupled troposphere-stratosphere linear model previously developed by the authors is extended by including a mean wind in the stratosphere and a prognostic equation for cirrus clouds, which are forced dynamically and allowed to modulate tropospheric radiative cooling, similar to the effect of tropospheric water vapor in previous formulations. Under these modifications, the model still produces a slow, eastward propagating mode that resembles the MJO. The sign of zonal mean wind in the stratosphere is shown to control both the upward wave propagation and tropospheric vertical structure of the mode. Under varying stratospheric wind and interactive cirrus cloud radiation, the MJO-like mode has weaker growth rates under stratospheric westerlies than easterlies, consistent with the observed MJO-QBO relationship. These results are directly attributable to an enhanced barotropic mode under QBO easterlies. It is also shown that differential zonal advection of cirrus clouds leads to weaker growth rates under stratospheric westerlies than easterlies. Implications and limitations of the linear theory are discussed.