cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Visceral adipose tissue but not subcutaneous adipose tissue is associated with urine and serum metabolites
Creators: name: Leitzmann, Michael F.
name: Schlecht, Inga
name: Gronwald, Wolfram
name: Behrens, Gundula
name: Baumeister, Sebastian E.
name: Hertel, Johannes
name: Hochrein, Jochen
name: Zacharias, Helena U.
name: Fischer, Beate
name: Oefner, Peter J.
Publisher: name: Universität Regensburg
Year: 2017
Subjects: subject: 610 Medizin

description: Obesity is a complex multifactorial phenotype that influences several metabolic pathways. Yet, few studies have examined the relations of different body fat compartments to urinary and serum metabolites. Anthropometric phenotypes (visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), the ratio between VAT and SAT (VSR), body mass index (BMI), waist circumference (WC)) and urinary and serum metabolite concentrations measured by nuclear magnetic resonance spectroscopy were measured in a population-based sample of 228 healthy adults. Multivariable linear and logistic regression models, corrected for multiple testing using the false discovery rate, were used to associate anthropometric phenotypes with metabolites. We adjusted for potential confounding variables: age, sex, smoking, physical activity, menopausal status, estimated glomerular filtration rate (eGFR), urinary glucose, and fasting status. In a fully adjusted logistic regression model dichotomized for the absence or presence of quantifiable metabolite amounts, VAT, BMI and WC were inversely related to urinary choline (ß = -0.18, p = 2.73*10−3), glycolic acid (ß = -0.20, 0.02), and guanidinoacetic acid (ß = -0.12, p = 0.04), and positively related to ethanolamine (ß = 0.18, p = 0.02) and dimethylamine (ß = 0.32, p = 0.02). BMI and WC were additionally inversely related to urinary glutamine and lactic acid. Moreover, WC was inversely associated with the detection of serine. VAT, but none of the other anthropometric parameters, was related to serum essential amino acids, such as valine, isoleucine, and phenylalanine among men. Compared to other adiposity measures, VAT demonstrated the strongest and most significant relations to urinary and serum metabolites. The distinct relations of VAT, SAT, VSR, BMI, and WC to metabolites emphasize the importance of accurately differentiating between body fat compartments when evaluating the potential role of metabolic regulation in the development of obesity-related diseases, such as insulin resistance, type 2 diabetes, and cardiovascular disease.
Photocatalytic formation of carbon–sulfur bonds
Creators: name: Wimmer, Alexander
name: König, Burkhard
Publisher: name: Universität Regensburg
Year: 2018
Subjects: subject: disulfides; photocatalysis; sulfones; sulfoxides; thiols; visible light
subject: 540 Chemie

description: This review summarizes recent developments in photocatalyzed carbon–sulfur bond formation. General concepts, synthetic strategies and the substrate scope of reactions yielding thiols, disulfides, sulfoxides, sulfones and other organosulfur compounds are discussed together with the proposed mechanistic pathways.
Finitely Suslinian models for planar compacta with applications to Julia sets
Creators: name: Blokh, Alexander
name: Curry, Clinton
name: Oversteegen, Lex
Publisher: name: arXiv
Year: 2010
Subjects: subject: General Topology (math.GN)
subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics
subject: 54F15 (Primary) 37B45, 37F10, 37F20 (Secondary)

description: A compactum $X\subset \C$ is unshielded if it coincides with the boundary of the unbounded component of $\C\sm X$. Call a compactum $X$ finitely Suslinian if every collection of pairwise disjoint subcontinua of $X$ whose diameters are bounded away from zero is finite. We show that any unshielded planar compactum $X$ admits a topologically unique monotone map $m_X:X \to X_{FS}$ onto a finitely Suslinian quotient such that any monotone map of $X$ onto a finitely Suslinian quotient factors through $m_X$. We call the pair $(X_{FS},m_X)$ (or, more loosely, $X_{FS}$) the finest finitely Suslinian model of $X$. If $f:\C\to \C$ is a branched covering map and $X \subset \C$ is a fully invariant compactum, then the appropriate extension $M_X$ of $m_X$ monotonically semiconjugates $f$ to a branched covering map $g:\C\to \C$ which serves as a model for $f$. If $f$ is a polynomial and $J_f$ is its Julia set, we show that $m_X$ (or $M_X$) can be defined on each component $Z$ of $J_f$ individually as the finest monotone map of $Z$ onto a locally connected continuum.
description: 16 pages, 3 figures; accepted for publication in Proceedings of the American Mathematical Society
Why a magnetized quantum wire can act as an active laser medium
Creators: name: Kushwaha, Manvir S
Publisher: name: arXiv
Year: 2010
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The fundamental issues associated with the magnetoplasmon excitations are investigated in a quantum wire characterized by a confining harmonic potential and subjected to a perpendicular magnetic field. We embark on the charge-density excitations in a two-subband model within the framework of Bohm-Pines' random-phase approximation. Essentially, the focus of our study is the intersubband (magnetoroton) collective excitation which changes the sign of its group velocity twice before merging with the respective single-particle continuum. The computation of the gain coefficient suggests an interesting and important application: the electronic device based on such magnetoroton modes can act as an {\it active} laser medium.
Gate-tunable large magnetoresistance in an all-semiconductor spin valve device
Creators: name: Oltscher, Martin
name: Eberle, Franz
name: Kuczmik, Thomas
name: Bayer, Andreas
name: Schuh, Dieter
name: Bougeard, Dominique
name: Ciorga, Mariusz
name: Weiss, Dieter
Publisher: name: Universität Regensburg
Year: 2017
Subjects: subject: 530 Physik

description: A large spin-dependent and electric field-tunable magnetoresistance of a two-dimensional electron system is a key ingredient for the realization of many novel concepts for spin-based electronic devices. The low magnetoresistance observed during the last few decades in devices with lateral semiconducting transport channels between ferromagnetic source and drain contacts has been the main obstacle for realizing spin field effect transistor proposals. Here, we show both a large two-terminal magnetoresistance in a lateral spin valve device with a two-dimensional channel, with up to 80% resistance change, and tunability of the magnetoresistance by an electric gate. The enhanced magnetoresistance is due to finite electric field effects at the contact interface, which boost spin-to-charge conversion. The gating scheme that we use is based on switching between uni- and bidirectional spin diffusion, without resorting to spin–orbit coupling. Therefore, it can also be employed in materials with low spin–orbit coupling.
Market Mechanisms and Funding Dynamics in Equity Crowdfunding
Creators: name: Hornuf, Lars
name: Schwienbacher, Armin
Publisher: name: Universität Regensburg
Year: 2017
Subjects: subject: Equity crowdfunding, Crowdinvesting, Startups, Securities issuance, Investment dynamics, Entrepreneurial finance
subject: 330 Wirtschaft

description: Equity crowdfunding is a new form of entrepreneurial finance, in which investors do not receive perks or engage in pre-purchase of the product, but rather participate in the future cash flows of a firm. In this paper, we analyze what determines individual investment decisions in this new financial market. One important factor that may influence the behavior of investors is the way the portal allocates securities. We use unique data from four German equity crowdfunding portals to examine how the allocation mechanism affects funding dynamics. In contrast with the crowdfunding campaigns on Kickstarter, on which the typical pattern of project support is U shaped, we find that equity crowdfunding dynamics are L shaped under a first-come, first-served mechanism and U shaped under a second-price auction. The evidence also shows that investors base their decisions on information provided by the entrepreneur in the form of updates as well as by the investment behavior and comments of other crowd investors.
Minimalistic Unsupervised Learning with the Sparse Manifold Transform
Creators: name: Chen, Yubei
name: Yun, Zeyu
name: Ma, Yi
name: Olshausen, Bruno
name: LeCun, Yann
Publisher: name: arXiv
Year: 2022
Subjects: subject: Machine Learning (cs.LG)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences

description: We describe a minimalistic and interpretable method for unsupervised learning, without resorting to data augmentation, hyperparameter tuning, or other engineering designs, that achieves performance close to the SOTA SSL methods. Our approach leverages the sparse manifold transform, which unifies sparse coding, manifold learning, and slow feature analysis. With a one-layer deterministic sparse manifold transform, one can achieve 99.3% KNN top-1 accuracy on MNIST, 81.1% KNN top-1 accuracy on CIFAR-10 and 53.2% on CIFAR-100. With a simple gray-scale augmentation, the model gets 83.2% KNN top-1 accuracy on CIFAR-10 and 57% on CIFAR-100. These results significantly close the gap between simplistic "white-box" methods and the SOTA methods. Additionally, we provide visualization to explain how an unsupervised representation transform is formed. The proposed method is closely connected to latent-embedding self-supervised methods and can be treated as the simplest form of VICReg. Though there remains a small performance gap between our simple constructive model and SOTA methods, the evidence points to this as a promising direction for achieving a principled and white-box approach to unsupervised learning.
description: This paper is published at ICLR 2023
Novel structures and unusual reactivity powered by tautomerism and electron delocalization in salicylimines
Creators: name: Moosavi Mehr, Seyed Hessam
Publisher: name: University of British Columbia
Year: 2018

description: A family of tris(salicylaldimine) (TSAN) analogues was prepared by condensation of 2,4,6-triformylphloroglucinol (TFP) and various nitrogen-containing bases. Characterization of these compounds by ¹H NMR spectroscopy and single-crystal X-ray diffraction (SCXRD) revealed that some of them adopt the previously unknown enol-imine tautomeric form. Experimental data and ab initio modelling were used to establish which factors govern the keto-enamine/enol-imine tautomeric equilibrium, culminating in a simple structural model of TSAN behaviour. According to this model, π electron-withdrawing X groups in the NH₂X starting material stabilize the keto-enamine tautomeric form, whereas σ electron withdrawing X, e.g. electronegative heteroatoms, lead to the enol-imine form. The same tautomeric equilibrium has also been leveraged in a family of hydroxysalicylaldehyde Schiff bases to bring about facile exchange of specific aromatic CH hydrogen atoms when these compounds are dissolved in CD₃OD or D₂O under ambient conditions. The mechanism of this surprising isotopic exchange reaction has been investigated experimentally using ¹H NMR kinetic experiments on these Schiff bases and a number of control compounds as well as ab initio modelling. Both sources point to the involvement of the minor keto-enamine tautomeric form of the salicylimines, which facilitates electrophilic aromatic substitution of hydrogen with deuterium by stabilizing the sp³-hybridized Wheland intermediate formed in the course of the reaction. The impact of the keto-enamine tautomeric form on the electronic structure of TSANs has been studied in isolation by preparing a TSAN permanently “locked” in keto-enamine connectivity. This was achieved by replacing the labile proton present in regular TSANs with a non-labile methyl group. The resulting compound assumes the expected keto-enamine structure; however, a large degree of strain is introduced since coplanarity of the peripheral enamine arms with the central ring, required for electronic coupling between the two, results in steric repulsion between the methyl groups and the carbonyl oxygen atoms. The central ring of the product is consequently highly contorted. The unsatisfactory preparation of many of the salicylaldehyde precursors to the SANs above has been improved through a mild and efficient procedure using formamidine acetate and acetic anhydride. This method allows one to install up to three formyl group on various phenolic substrates without the harsh conditions encountered with common formylation techniques such as the Vilsmeier–Haack reaction.
Genetic susceptibility to increased bacterial translocation influences the response to biological therapy in patients with Crohn's disease
Creators: name: Gutiérrez, A.
name: Scharl, M.
name: Sempere, L.
name: Holler, Ernst
name: Zapater, P.
name: Almenta, I.
name: González-Navajas, J. M.
name: Such, J.
name: Wiest, Reiner
Publisher: name: Universität Regensburg
Year: 2014
Subjects: subject: 610 Medizin

description: Objective: The aetiology of Crohn's disease (CD) has been related to nucleotide-binding oligomerisation domain containing 2 (NOD2) and ATG16L1 gene variants. The observation of bacterial DNA translocation in patients with CD led us to hypothesise that this process may be facilitated in patients with NOD2/ATG16L1-variant genotypes, affecting the efficacy of anti-tumour necrosis factor (TNF) therapies. Design: 179 patients with Crohn's disease were included. CD-related NOD2 and ATG16L1 variants were genotyped. Phagocytic and bactericidal activities were evaluated in blood neutrophils. Bacterial DNA, TNFα, IFNγ, IL-12p40, free serum infliximab/adalimumab levels and antidrug antibodies were measured. Results: Bacterial DNA was found in 44% of patients with active disease versus 23% of patients with remitting disease (p=0.01). A NOD2-variant or ATG16L1-variant genotype was associated with bacterial DNA presence (OR 4.8; 95% CI 1.1 to 13.2; p=0.001; and OR 2.4; 95% CI 1.4 to 4.7; p=0.01, respectively). This OR was 12.6 (95% CI 4.2 to 37.8; p=0.001) for patients with a double-variant genotype. Bacterial DNA was associated with disease activity (OR 2.6; 95% CI 1.3 to 5.4; p=0.005). Single and double-gene variants were not associated with disease activity (p=0.19). Patients with a NOD2-variant genotype showed decreased phagocytic and bactericidal activities in blood neutrophils, increased TNFα levels in response to bacterial DNA and decreased trough levels of free anti-TNFα. The proportion of patients on an intensified biological therapy was significantly higher in the NOD2-variant groups. Conclusions: Our results characterise a subgroup of patients with CD who may require a more aggressive therapy to reduce the extent of inflammation and the risk of relapse.
Small Coupling Expansion for Multiple Sequence Alignment
Creators: name: Budzynski, Louise
name: Pagnani, Andrea
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantitative Methods (q-bio.QM)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Biological Physics (physics.bio-ph)
subject: Biomolecules (q-bio.BM)
subject: FOS: Biological sciences
subject: FOS: Physical sciences

description: The alignment of biological sequences such as DNA, RNA, and proteins, is one of the basic tools that allow to detect evolutionary patterns, as well as functional/structural characterizations between homologous sequences in different organisms. Typically, state-of-the-art bioinformatics tools are based on profile models that assume the statistical independence of the different sites of the sequences. Over the last years, it has become increasingly clear that homologous sequences show complex patterns of long-range correlations over the primary sequence as a consequence of the natural evolution process that selects genetic variants under the constraint of preserving the functional/structural determinants of the sequence. Here, we present a new alignment algorithm based on message passing techniques that overcomes the limitations of profile models. Our method is based on a new perturbative small-coupling expansion of the free energy of the model that assumes a linear chain approximation as the $0^\mathrm{th}$-order of the expansion. We test the potentiality of the algorithm against standard competing strategies on several biological sequences.
description: 22 pages, 10 figures
Constraining the $g'_1$ coupling in the minimal $B-L$ Model
Creators: name: Basso, Lorenzo
name: Moretti, Stefano
name: Pruna, Giovanni Marco
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We have combined the perturbative unitarity and the renormalisation group equations arguments in order to find a dynamical way to constrain the $g'_1$ coupling of the minimal $B-L$ extension of the Standard Model. We have analysed the role of the $g'_1$ coupling evolution in the perturbative stability of the two-to-two body scattering amplitudes of the vector boson and scalar sectors of the model and we have shown that the perturbative unitarity imposes an upper bound on the $B-L$ gauge coupling. We have made a comparison between this criterion and the triviality arguments, showing that our procedure substantially refines the triviality bounds.
description: 9 pages, 1 figure, 1 table; corrected typos, corrected formulae, changed figure, added text, results are unchanged
Anti-inflammatory effects of cell-based therapy with tyrosine hydroxylase-positive catecholaminergic cells in experimental arthritis
Creators: name: Jenei-Lanzl, Zsuzsa
name: Capellino, Silvia
name: Kees, Frieder
name: Fleck, Martin
name: Lowin, Torsten
name: Straub, Rainer H.
Publisher: name: Universität Regensburg
Year: 2015
Subjects: subject: 610 Medizin

description: Objectives: Studies in rheumatoid arthritis (RA), osteoarthritis (OA) and mice with arthritis demonstrated tyrosine hydroxylase-positive (TH+) cells in arthritic synovium and parallel loss of sympathetic nerve fibres. The exact function of TH+ cells and mode of TH induction are not known. Methods: Synovial cells of RA/OA were isolated and cultured under normoxic/hypoxic conditions with/without stimulating enzyme cofactors of TH and inhibitors of TH. We studied TH expression and release of cytokines/catecholamines. In vivo function was tested by cell therapy with TH+ neuronal precursor cells (TH+ neuronal cells) in DBA/1 mice with collagen type II-induced arthritis (CIA). Results: Compared with normoxic conditions, hypoxia increased TH protein expression and catecholamine synthesis and decreased release of tumour necrosis factor (TNF) in OA/RA synovial cells. This inhibitory effect on TNF was reversed by TH inhibition with α-methyl-para-tyrosine (αMPT), which was particularly evident under hypoxic conditions. Incubation with specific TH cofactors (tetrahydrobiopterin and Fe2+) increased hypoxia-induced inhibition of TNF, which was also reversed by αMPT. To address a possible clinical role of TH+ cells, murine TH+ neuronal cells were generated from mesenchymal stem cells. TH+ neuronal cells exhibited a typical catecholaminergic phenotype. Adoptive transfer of TH+ neuronal cells markedly reduced CIA in mice, and 6-hydroxydopamine, which depletes TH+ cells, reversed this effect. Conclusions: The anti-inflammatory effect of TH+ neuronal cells on experimental arthritis has been presented for the first time. In RA/OA, TH+ synovial cells have TH-dependent anti-inflammatory capacities, which are augmented under hypoxia. Using generated TH+ neuronal cells might open new avenues for cell-based therapy.
Two-photon interference from a quantum emitter in hexagonal boron nitride
Creators: name: Fournier, Clarisse
name: Roux, Sébastien
name: Watanabe, Kenji
name: Taniguchi, Takashi
name: Buil, Stéphanie
name: Barjon, Julien
name: Hermier, Jean-Pierre
name: Delteil, Aymeric
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: Recently discovered quantum emitters in two-dimensional (2D) materials have opened new perspectives of integrated photonic devices for quantum information. Most of these applications require the emitted photons to be indistinguishable, which has remained elusive in 2D materials. Here, we investigate two-photon interference of a quantum emitter generated in hexagonal boron nitride (hBN) using an electron beam. We measure the correlations of zero-phonon-line photons in a Hong-Ou-Mandel (HOM) interferometer under non-resonant excitation. We find that the emitted photons exhibit a partial indistinguishability of $0.44 \pm 0.11$ in a 3 ns time window, which corresponds to a corrected value of $0.56 \pm 0.11$ after accounting for imperfect emitter purity. The dependence of the HOM visibility on the width of the post-selection time window allows us to estimate the dephasing time of the emitter to be $\sim 1.5$ ns, about half the limit set by spontaneous emission. A visibility above 90 % is under reach using Purcell effect with up-to-date 2D material photonics.
Far-from-equilibrium attractors with a realistic non-conformal equation of state
Creators: name: Alqahtani, Mubarak
Publisher: name: arXiv
Year: 2022
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Using anisotropic hydrodynamics, we examine the existence of early-time attractors of non-conformal systems undergoing Bjorken expansion. In the case of a constant mass, we find that the evolution of the scaled longitudinal pressure is insensitive to variations of initial conditions converging onto an early-time universal curve and eventually merging with the late-time Navier-Stokes attractor (the hydrodynamic attractor). On the other hand, the bulk and the shear viscous corrections do not show an early-time attractor behavior. These results are consistent with previous studies considering a constant mass. When a realistic equation of state is included in the dynamics with a thermal mass, we demonstrate for the first time the absence of strict late-time universal attractors. However, a semi-universal feature of the evolution at very late times remains.
description: 18 pages, 5 multipanel figures; v2: published version
Igusa's p-adic local zeta function associated to a polynomial mapping and a polynomial integration measure
Creators: name: Bories, Bart
Publisher: name: arXiv
Year: 2010
Subjects: subject: Number Theory (math.NT)
subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 11S80, 11S40

description: For p prime, we give an explicit formula for Igusa's local zeta function associated to a polynomial mapping f=(f_1,...,f_t): Q_p^n -> Q_p^t, with f_1,...,f_t in Z_p[x_1,...,x_n], and an integration measure on Z_p^n of the form |g(x)||dx|, with g another polynomial in Z_p[x_1,...,x_n]. We treat the special cases of a single polynomial and a monomial ideal separately. The formula is in terms of Newton polyhedra and will be valid for f and g sufficiently non-degenerated over F_p with respect to their Newton polyhedra. The formula is based on, and is a generalization of results of Denef - Hoornaert, Howald et al., and Veys - Zuniga-Galindo.
description: 20 pages, 5 figures, 2 tables
A User Interface for Sense-making of the Reasoning Process while Interacting with Robots
Creators: name: Wang, Chao
name: Deigmoeller, Joerg
Publisher: name: arXiv
Year: 2022
Subjects: subject: Human-Computer Interaction (cs.HC)
subject: FOS: Computer and information sciences

description: As knowledge graph has the potential to bridge the gap between commonsense knowledge and reasoning over actionable capabilities of mobile robotic platforms, incorporating knowledge graph into robotic system attracted increasing attention in recent years. Previously, graph visualization has been used wildly by developers to make sense of knowledge representations. However, due to lacking the link between abstract knowledge of the real-world environment and the robot's actions, transitional visualization tools are incompatible for expert-user to understand, test, supervise and modify the graph-based reasoning system with the embodiment of the robots. Therefore, we developed an interface which enables robotic experts to send commands to the robot in natural language, then interface visualizes the procedures of the robot mapping the command to the functions for querying in the commonsense knowledge database, links the result to the real world instances in a 3D map and demonstrate the execution of the robot from the first-person perspective of the robot. After 3 weeks of usage of the system by robotic experts in their daily development, some feedback was collected, which provides insight for designing such systems.
description: 5 figures
Dynamics of direct impact accretion in degenerate binary systems
Creators: name: Kramarev, Nikita
name: Yudin, Andrey
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We consider the gas dynamics in an accreting binary system of degenerate stars within the framework of the Newtonian approximation. In such a system, the accretion stream can impact the surface of a white dwarf (WD) or neutron star (NS) as a result of the very compact orbit. This causes a loss of angular momentumfrom the orbit and spin-up of the accretor. We construct approximations for the specific angular momentum of the accreting matter which goes to spin up the accretor and some other parameters of the system. It is shown that the obtained approximation of the specific momentum is qualitatively different from the widely used Keplerian formula. It should affect the boundary between scenarios of immediate tidal disruption and slow mass loss of the donor in WD-WD and NS-NS binaries, as well as the time of stable mass transfer in the stripping scenario.
description: 9 pages, 9 figs, 6 tables. Published in MNRAS
Torridincolidae
Creators: name: Bilton, David T.
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Torridincolidae

description: Torridincolidae   Delevea namibiensis Endrödy-Younga, 1997
Described from the Northern Cape and Namibia and not apparently reported since. Abundant in the Oorlogskloof River (Site 11) below Driefontein Waterfall, where it was netted from small riffles. I have also found the species abundantly in drying, isolated pools in the Groen River, beside the N7, ca. 2 km S of Garies (Northern Cape), in October 2014 and September 2016.
 Dineutus punctatus Aubé, 1838
A South African near-endemic, taken from deep pools in streams and rivers on the Bokkeveld. Sites 5 & 11.
 * Aulonogyrus abdominalis (Aubé, 1838)
A widespread southern African species. Deep, slow pools at Site 5.
 Aulonogyrus marginatus (Aubé, 1838)
Another southern African species known from South Africa, Lesotho and Botswana. Deep stream pools on sandstone at Site 12.
 * Aulonogyrus splendidulus (Aubé, 1838)
Reported previously only from the Western and Eastern Cape provinces, in streams and rivers. Mixed with the last species at Site 12.
description: Published as part of Bilton, David T., 2017, Water beetles from the Bokkeveld Plateau: a semi-arid hotspot of freshwater biodiversity in the Northern Cape of South Africa, pp. 191-214 in Zootaxa 4268 (2) on pages 207-209, DOI: 10.11646/zootaxa.4268.2.2, http://zenodo.org/record/580190
Approximate Reference Prior for Gaussian Random Fields
Creators: name: De Oliveira, Victor
name: Han, Zifei
Publisher: name: arXiv
Year: 2022
Subjects: subject: Methodology (stat.ME)
subject: FOS: Computer and information sciences

description: Reference priors are theoretically attractive for the analysis of geostatistical data since they enable automatic Bayesian analysis and have desirable Bayesian and frequentist properties. But their use is hindered by computational hurdles that make their application in practice challenging. In this work, we derive a new class of default priors that approximate reference priors for the parameters of some Gaussian random fields. It is based on an approximation to the integrated likelihood of the covariance parameters derived from the spectral approximation of stationary random fields. This prior depends on the structure of the mean function and the spectral density of the model evaluated at a set of spectral points associated with an auxiliary regular grid. In addition to preserving the desirable Bayesian and frequentist properties, these approximate reference priors are more stable, and their computations are much less onerous than those of exact reference priors. Unlike exact reference priors, the marginal approximate reference prior of correlation parameter is always proper, regardless of the mean function or the smoothness of the correlation function. This property has important consequences for covariance model selection. An illustration comparing default Bayesian analyses is provided with a data set of lead pollution in Galicia, Spain.
Entanglement Renyi entropies in holographic theories
Creators: name: Headrick, Matthew
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Ryu and Takayanagi conjectured a formula for the entanglement (von Neumann) entropy of an arbitrary spatial region in an arbitrary holographic field theory. The von Neumann entropy is a special case of a more general class of entropies called Renyi entropies. Using Euclidean gravity, Fursaev computed the entanglement Renyi entropies (EREs) of an arbitrary spatial region in an arbitrary holographic field theory, and thereby derived the RT formula. We point out, however, that his EREs are incorrect, since his putative saddle points do not in fact solve the Einstein equation. We remedy this situation in the case of two-dimensional CFTs, considering regions consisting of one or two intervals. For a single interval, the EREs are known for a general CFT; we reproduce them using gravity. For two intervals, the RT formula predicts a phase transition in the entanglement entropy as a function of their separation, and that the mutual information between the intervals vanishes for separations larger than the phase transition point. By computing EREs using gravity and CFT techniques, we find evidence supporting both predictions. We also find evidence that large-$N$ symmetric-product theories have the same EREs as holographic ones.
description: 38 pages; v2: minor improvements to presentation; v3: corrections and improvements to presentation
Domain-dependent surface adhesion in twisted few-layer graphene: Platform for moiré-assisted chemistry
Creators: name: Hsieh, Valerie
name: Halbertal, Dorri
name: Finney, Nathan R.
name: Zhu, Ziyan
name: Gerber, Eli
name: Pizzochero, Michele
name: Kucukbenli, Emine
name: Schleder, Gabriel R.
name: Angeli, Mattia
name: Watanabe, Kenji
name: Taniguchi, Takashi
name: Kim, Eun-Ah
name: Kaxiras, Efthimios
name: Hone, James
name: Dean, Cory R.
name: Basov, D. N.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Twisted van der Waals multilayers are widely regarded as a rich platform to access novel electronic phases, thanks to the multiple degrees of freedom such as layer thickness and twist angle that allow control of their electronic and chemical properties. Here, we propose that the stacking domains that form naturally due to the relative twist between successive layers act as an additional "knob" for controlling the behavior of these systems, and report the emergence and engineering of stacking domain-dependent surface chemistry in twisted few-layer graphene. Using mid-infrared near-field optical microscopy and atomic force microscopy, we observe a selective adhesion of metallic nanoparticles and liquid water at the domains with rhombohedral stacking configurations of minimally twisted double bi- and tri-layer graphene. Furthermore, we demonstrate that the manipulation of nanoparticles located at certain stacking domains can locally reconfigure the moiré superlattice in their vicinity at the μm-scale. In addition, we report first-principles simulations of the energetics of adhesion of metal atoms and water molecules on the stacking domains in an attempt to elucidate the origin of the observed selective adhesion. Our findings establish a new approach to controlling moiré-assisted chemistry and nanoengineering.
description: 11 pages, 3 figures
Zeta functions and Bernstein-Sato polynomials for ideals in dimension two
Creators: name: Bories, Bart
Publisher: name: arXiv
Year: 2010
Subjects: subject: Algebraic Geometry (math.AG)
subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 14F10, 14H20, 11R42, 14E18

description: For a nonzero ideal I of C[x_1,...,x_n], with 0 in supp I, a generalization of a conjecture of Igusa - Denef - Loeser predicts that every pole of its topological zeta function is a root of its Bernstein-Sato polynomial. However, typically only a few roots are obtained this way. Following ideas of Veys, we study the following question. Is it possible to find a collection G of polynomials g in C[x_1,...,x_n], such that, for all g in G, every pole of the topological zeta function associated to I and the volume form gdx on the affine n-space, is a root of the Bernstein-Sato polynomial of I, and such that all roots are realized in this way. We obtain a negative answer to this question, providing counterexamples for monomial and principal ideals in dimension two, and give a partial positive result as well.
description: 19 pages, 8 figures
Topology Optimization of Multiscale Structures Considering Local and Global Buckling Response
Creators: name: Christensen, Christoffer Fyllgraf
name: Wang, Fengwen
name: Sigmund, Ole
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computational Engineering, Finance, and Science (cs.CE)
subject: Optimization and Control (math.OC)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics
subject: G.1.6; G.1.8; J.2

description: Much work has been done in topology optimization of multiscale structures for maximum stiffness or minimum compliance design. Such approaches date back to the original homogenization-based work by Bendsøe and Kikuchi from 1988, which lately has been revived due to advances in manufacturing methods like additive manufacturing. Orthotropic microstructures locally oriented in principal stress directions provide for highly efficient stiffness optimal designs, whereas for the pure stiffness objective, porous isotropic microstructures are sub-optimal and hence not useful. It has, however, been postulated and exemplified that isotropic microstructures (infill) may enhance structural buckling stability but this has yet to be directly proven and optimized. In this work, we optimize buckling stability of multiscale structures with isotropic porous infill. To do this, we establish local density dependent Willam-Warnke yield surfaces based on local buckling estimates from Bloch-Floquet-based cell analysis to predict local instability of the homogenized materials. These local buckling-based stress constraints are combined with a global buckling criterion to obtain topology optimized designs that take both local and global buckling stability into account. De-homogenized structures with small and large cell sizes confirm validity of the approach and demonstrate huge structural gains as well as time savings compared to standard singlescale approaches.
description: Published in Computer Methods in Applied Mechanics and Engineering
A Discussion on Dirac Field Theory, No-Go Theorems and Renormalizability
Creators: name: Fabbri, Luca
Publisher: name: arXiv
Year: 2011
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study Dirac field equations coupled to electrodynamics with metric and torsion fields: we discuss how special spinorial solutions are incompatible with torsion; eventually these results will be used to sketch a discussion on the problem of renormalizability of point-like particles.
description: 10 pages
Multiscale space-time ansatz for correlation functions of quantum systems based on quantics tensor trains
Creators: name: Shinaoka, Hiroshi
name: Wallerberger, Markus
name: Murakami, Yuta
name: Nogaki, Kosuke
name: Sakurai, Rihito
name: Werner, Philipp
name: Kauch, Anna
Publisher: name: arXiv
Year: 2022
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Computational Physics (physics.comp-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Correlation functions of quantum systems -- central objects in quantum field theories -- are defined in high-dimensional space-time domains. Their numerical treatment thus suffers from the curse of dimensionality, which hinders the application of sophisticated many-body theories to interesting problems. Here, we propose a multi-scale space-time ansatz for correlation functions of quantum systems based on quantics tensor trains (QTT), ``qubits'' describing exponentially different length scales. The ansatz then assumes a separation of length scales by decomposing the resulting high-dimensional tensors into tensor trains (known also as matrix product states). We numerically verify the ansatz for various equilibrium and nonequilibrium systems and demonstrate compression rates of several orders of magnitude for challenging cases. Essential building blocks of diagrammatic equations, such as convolutions or Fourier transforms are formulated in the compressed form. We numerically demonstrate the stability and efficiency of the proposed methods for the Dyson and Bethe-Salpeter equations. {The QTT representation} provides a unified framework for implementing efficient computations of quantum field theories.
description: 28 pages, 27 figures
Components of Gröbner strata in the Hilbert scheme of points
Creators: name: Lederer, Mathias
Publisher: name: arXiv
Year: 2010
Subjects: subject: Algebraic Geometry (math.AG)
subject: Commutative Algebra (math.AC)
subject: FOS: Mathematics
subject: 14C05, 14N10, 13P10, 13B25

description: We fix the lexicographic order $\prec$ on the polynomial ring $S=k[x_{1},...,x_{n}]$ over a ring $k$. We define $\Hi^{\precΔ}_{S/k}$, the moduli space of reduced Gröbner bases with a given finite standard set $Δ$, and its open subscheme $\Hi^{\precΔ,\et}_{S/k}$, the moduli space of families of $#Δ$ points whose attached ideal has the standard set $Δ$. We determine the number of irreducible and connected components of the latter scheme; we show that it is equidimensional over ${\rm Spec}\,k$; and we determine its relative dimension over ${\rm Spec} k$. We show that analogous statements do not hold for the scheme $\Hi^{\precΔ}_{S/k}$. Our results prove a version of a conjecture by Bernd Sturmfels.
description: 49 pages
Metallicity distribution of the progenitor of the Giant Stellar Stream in the Andromeda Galaxy
Creators: name: Milošević, Stanislav
name: Mićić, Miroslav
name: Lewis, Geraint F.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The Giant Stellar Stream (GSS) is a prominent tidal feature in the halo of the Andromeda Galaxy (M31), representing the ongoing destruction of a satellite galaxy. In this paper, we investigate the formation of the GSS through detailed numerical simulations of the tidal disruption of a progenitor system. Assuming that the stream was created in a single merger event between M31 and a dwarf spheroidal galaxy with stellar mass of $10^{9}M_{\odot}$, we successfully reproduce the dynamical properties of the GSS. As the metallicity distribution along the stream has been well determined from the observations (PAndAS and AMIGA data sets), we use Monte Carlo simulations to reconstruct the original metallicity distribution of the dwarf progenitor. We find that a progenitor dwarf galaxy with a negative radial metallicity gradient, $Δ$FeH = -$0.3 \pm 0.2$, reproduces the observed GSS properties at a time between 2.4 and 2.9 Gyrs into the merger. We also show that the observed double peak metallicity distribution along the stream is a transitory structure caused by unique merger circumstances where two groups of streaming stars are moving in opposite directions, intersecting to produce the peaks.
description: 13 pages, 14 figures, MNRAS, accepted
Counting Unique-Sink Orientations
Creators: name: Foniok, Jan
name: Gärtner, Bernd
name: Klaus, Lorenz
name: Sprecher, Markus
Publisher: name: arXiv
Year: 2010
Subjects: subject: Combinatorics (math.CO)
subject: Discrete Mathematics (cs.DM)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences
subject: 90C33, 52B12, 05A16

description: Unique-sink orientations (USOs) are an abstract class of orientations of the n-cube graph. We consider some classes of USOs that are of interest in connection with the linear complementarity problem. We summarise old and show new lower and upper bounds on the sizes of some such classes. Furthermore, we provide a characterisation of K-matrices in terms of their corresponding USOs.
description: 13 pages; v2: proof of main theorem expanded, plus various other corrections. Now 16 pages; v3: minor corrections
RTNet: Relation Transformer Network for Diabetic Retinopathy Multi-lesion Segmentation
Creators: name: Huang, Shiqi
name: Li, Jianan
name: Xiao, Yuze
name: Shen, Ning
name: Xu, Tingfa
Publisher: name: arXiv
Year: 2022
Subjects: subject: Image and Video Processing (eess.IV)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: Automatic diabetic retinopathy (DR) lesions segmentation makes great sense of assisting ophthalmologists in diagnosis. Although many researches have been conducted on this task, most prior works paid too much attention to the designs of networks instead of considering the pathological association for lesions. Through investigating the pathogenic causes of DR lesions in advance, we found that certain lesions are closed to specific vessels and present relative patterns to each other. Motivated by the observation, we propose a relation transformer block (RTB) to incorporate attention mechanisms at two main levels: a self-attention transformer exploits global dependencies among lesion features, while a cross-attention transformer allows interactions between lesion and vessel features by integrating valuable vascular information to alleviate ambiguity in lesion detection caused by complex fundus structures. In addition, to capture the small lesion patterns first, we propose a global transformer block (GTB) which preserves detailed information in deep network. By integrating the above blocks of dual-branches, our network segments the four kinds of lesions simultaneously. Comprehensive experiments on IDRiD and DDR datasets well demonstrate the superiority of our approach, which achieves competitive performance compared to state-of-the-arts.
description: IEEE Transactions on Medical Imaging
Star Formation Variability as a Probe for the Baryon Cycle within Galaxies
Creators: name: Shin, Eun-jin
name: Tacchella, Sandro
name: Kim, Ji-hoon
name: Iyer, Kartheik G.
name: Semenov, Vadim A.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We investigate the connection of the regulation of star formation and the cycling of baryons within and in and out of galaxies. We use idealized numerical simulations of Milky Way-mass galaxies, in which we systemically vary the galaxy morphology (bulge-to-total mass ratio) and stellar feedback strength (total eight setups with 80 simulations). By following individual gas parcels through the disk, spiral arms, and massive star-forming clumps, we quantify how gas moves and oscillates through the different phases of the interstellar medium (ISM) and forms stars. We show that the residence time of gas in the dense ISM phase ($τ_{\rm SF}$), the nature of spiral arms (strength, number), and the clump properties (number, mass function, and young star fraction) depend on both the galaxy morphology and stellar feedback. Based on these results, we quantify signatures of the baryon cycle within galaxies using the temporal and spatial power spectrum density (PSD) of the star formation history (SFH). Stronger stellar feedback leads to more bursty star formation while the correlation timescale of the SFH is longer, because stronger feedback dissolves the dense, star-forming ISM phase, leading to a more homogeneous ISM and a decrease in $τ_{\rm SF}$. The bulge strength has a similar effect: the deep gravitational potential in a bulge-dominant galaxy imposes a strong shear force that effectively breaks apart gas clumps in the ISM; this subsequently inhibits the fragmentation of cool gas and therefore the star formation in the disk, leading to a decrease in the spatial power on scales of $\sim$ 1 kpc. We conclude that measurements of the temporal and spatial PSD of the SFH can provide constraints on the baryon cycle and the star formation process.
description: 22 pages including 17 figures. Submitted to ApJ
Notes on the Parity Conjecture
Creators: name: Dokchitser, Tim
Publisher: name: arXiv
Year: 2010
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 11G40 (Primary) 11G05, 11G07 (Secondary)

description: This is an expository article, based on a lecture course given at CRM Barcelona in December 2009. The purpose of these notes is to prove, in a reasonably self-contained way, that finiteness of the Tate-Shafarevich group implies the parity conjecture for elliptic curves over number fields. Along the way, we review local and global root numbers of elliptic curves and their classification, and discuss some peculiar consequences of the parity conjecture.
description: minor corrections, to appear in a CRM Advanced Courses volume "Elliptic curves, Hilbert modular forms and Galois deformations"; 43 pages