cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Lifting statistical structures
Creators: name: Grabowska, Katarzyna
name: Grabowski, Janusz
name: Kuś, Marek
name: Marmo, Giuseppe
Publisher: name: arXiv
Year: 2022
Subjects: subject: Differential Geometry (math.DG)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 53B12, 58H05, 22A22, 53B05

description: We consider some natural (functorial) lifts of geometric objects associated with statistical manifolds (metric tensor, dual connections, skewness tensor, etc.) to higher tangent bundles. It turns out that the lifted objects form again a statistical manifold structure, this time on the higher tangent bundles, with the only difference that the metric tensor is pseudo-Riemannian. What is more, natural lifts of potentials (called also divergence or contrast functions) turn out to be again potentials, this time for the lifted statistical structures. We propose an analogous procedure for lifting statistical structures on Lie algebroids and lifting contrast functions which are defined on Lie groupoids. In particular, we study in detail Lie groupoid structures of higher tangent bundles of Lie groupoids. Our geometric constructions of lifts are illustrated by explicit examples, including some important statistical models and potential functions on Lie groupoids.
description: 44 pages, the version to be published in Rev. Math. Phys
CHRONIC PELVIC PAIN IN ENDOMETRIOSIS
Creators: name: Kamalova, Dilafruz
name: Norkhujayeva, Charoskhon
Publisher: name: Zenodo
Year: 2024

description: At the moment, endometriosis is one of the most common and relevant gynecological pathologies. The breadth of its clinical manifestations is extremely high, but one of the main ones is the pain syndrome, which has a high heterogeneity. The unifying concept of algological patterns of endometriosis is chronic pelvic pain, which contributes to a pronounced decrease in the quality of life of patients. In this regard, it is necessary to analyze the key pathogenetic mechanisms of pelvic pain associated with with endometriosis, and on their basis to determine personalized therapeutic tactics.
Computing Krylov iterates in the time of matrix multiplication
Creators: name: Neiger, Vincent
name: Pernet, Clément
name: Villard, Gilles
Publisher: name: arXiv
Year: 2024
Subjects: subject: Symbolic Computation (cs.SC)
subject: FOS: Computer and information sciences

description: Krylov methods rely on iterated matrix-vector products $A^k u_j$ for an $n\times n$ matrix $A$ and vectors $u_1,\ldots,u_m$. The space spanned by all iterates $A^k u_j$ admits a particular basis -- the \emph{maximal Krylov basis} -- which consists of iterates of the first vector $u_1, Au_1, A^2u_1,\ldots$, until reaching linear dependency, then iterating similarly the subsequent vectors until a basis is obtained. Finding minimal polynomials and Frobenius normal forms is closely related to computing maximal Krylov bases. The fastest way to produce these bases was, until this paper, Keller-Gehrig's 1985 algorithm whose complexity bound $O(n^ω\log(n))$ comes from repeated squarings of $A$ and logarithmically many Gaussian eliminations. Here $ω>2$ is a feasible exponent for matrix multiplication over the base field. We present an algorithm computing the maximal Krylov basis in $O(n^ω\log\log(n))$ field operations when $m \in O(n)$, and even $O(n^ω)$ as soon as $m\in O(n/\log(n)^c)$ for some fixed real $c>0$. As a consequence, we show that the Frobenius normal form together with a transformation matrix can be computed deterministically in $O(n^ω(\log\log(n))^2)$, and therefore matrix exponentiation~$A^k$ can be performed in the latter complexity if $\log(k) \in O(n^{ω-1-\varepsilon})$ for some fixed $\varepsilon>0$. A key idea for these improvements is to rely on fast algorithms for $m\times m$ polynomial matrices of average degree $n/m$, involving high-order lifting and minimal kernel bases.
description: 10 pages, 5 algorithms
Cross-grating phase microscopy (CGM): In-silico experiment (insilex) algorithm, noise and accuracy
Creators: name: Marthy, Baptiste
name: Baffou, Guillaume
Publisher: name: arXiv
Year: 2022
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Cross-grating phase microscopy (CGM) is a quantitative phase microscopy technique based on the association of a 2-dimensional diffraction grating (cross-grating) and a regular camera sensor, separated by a millimetric distance. This simple association enables the high-resolution imaging of the complex electric field amplitude of a light beam (intensity and phase) from a single image acquisition. While CGM has been used for metrology applications in cell biology and nanophotonics this last decade, there has been few studies on its basics, especially for the microscopy community. In this article, we provide a numerical algorithm that enables the in silico (i.e. computer-simulated) data acquisition, to easily vary and observe the effects of all the CGM experimental parameters using computer means. In the frame on this article, we illustrate the interest of this numerical algorithm by using it to explain and quantify the effects of several important CGM parameters (grating-camera distance, pixel size, light intensity, numerical apertures, etc) on the noise, precision and trueness of CGM measurements. This work is aimed to push the limits of CGM toward advanced applications in biomicroscopy and nanophotonics.
description: 11 pages, 7 figures
Graph Convolutional Neural Networks Sensitivity under Probabilistic Error Model
Creators: name: Wang, Xinjue
name: Ollila, Esa
name: Vorobyov, Sergiy A.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Machine Learning (stat.ML)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Graph Neural Networks (GNNs), particularly Graph Convolutional Neural Networks (GCNNs), have emerged as pivotal instruments in machine learning and signal processing for processing graph-structured data. This paper proposes an analysis framework to investigate the sensitivity of GCNNs to probabilistic graph perturbations, directly impacting the graph shift operator (GSO). Our study establishes tight expected GSO error bounds, which are explicitly linked to the error model parameters, and reveals a linear relationship between GSO perturbations and the resulting output differences at each layer of GCNNs. This linearity demonstrates that a single-layer GCNN maintains stability under graph edge perturbations, provided that the GSO errors remain bounded, regardless of the perturbation scale. For multilayer GCNNs, the dependency of system's output difference on GSO perturbations is shown to be a recursion of linearity. Finally, we exemplify the framework with the Graph Isomorphism Network (GIN) and Simple Graph Convolution Network (SGCN). Experiments validate our theoretical derivations and the effectiveness of our approach.
Finite mathematics as the most general (fundamental) mathematics
Creators: name: Lev, Felix M
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: The purpose of this paper is to explain at the simplest possible level why finite mathematics based on a finite ring of characteristic $p$ is more general (fundamental) than standard mathematics. The belief of most mathematicians and physicists that standard mathematics is the most fundamental arose for historical reasons. However, simple mathematical arguments show that standard mathematics (involving the concept of infinities) is a degenerate case of finite mathematics in the formal limit $p\to\infty$: standard mathematics arises from finite mathematics in the degenerate case when operations modulo a number are discarded. Quantum theory based on a finite ring of characteristic $p$ is more general than standard quantum theory because the latter is a degenerate case of the former in the formal limit $p\to\infty$.
description: 22 pages, one figure
PCR techniques for clonality assays
Creators: name: Diaz-Cano, Salvador J.
name: Blanes, Alfredo
name: H J Wolfe
Publisher: name: figshare
Year: 2012
Subjects: Molecular Biology
Medicine
Cell Biology
Cancer

description: Clonal overgrowths represent the hallmark of neoplastic proliferations, and their demonstration has been proved useful clinically for the diagnosis of malignant lymphomas based on the detection of specific and dominant immunoglobulin and/or T-cell receptor gene rearrangements. Nonrandom genetic alterations can also be used to test clonal expansions and the clonal evolution of neoplasms, especially analyzing hypervariable deoxyribonucleic acid (DNA) regions from patients heterozygous for a given marker. These tests rely basically on the demonstration of loss of heterozygosity (LOH) resulting from either hemizygosity (nonrandom interstitial DNA deletions) or homozygosity of mutant alleles observed in neoplasms. LOH analyses identify clonal expansions of a tumor cell population, and point to monoclonal proliferation when multiple and consistent LOH are demonstrated. Based on the methylation-related inactivation of one X chromosome in female subjects, X-linked markers (e.g., androgen receptor gene) will provide clonality information using LOH analyses after DNA digestion with methylation-sensitive restriction endonucleases. Therefore, both non-X-linked and X-linked analyses give complementary information, related and not related to the malignant transformation pathway respectively. Applied appropriately, these tools can establish the clonal evolution of tumor cell populations (tumor heterogeneity), identify early relapses, distinguish recurrent tumors from other metachronic neoplasms, and differentiate field transformation from metastatic tumor growths in synchronic and histologically identical neoplasms.
Preserving system activity while controlling epidemic spreading in adaptive temporal networks
Creators: name: Mancastroppa, Marco
name: Vezzani, Alessandro
name: Colizza, Vittoria
name: Burioni, Raffaella
Publisher: name: arXiv
Year: 2024
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Social and Information Networks (cs.SI)
subject: Populations and Evolution (q-bio.PE)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences
subject: FOS: Biological sciences

description: Human behaviour strongly influences the spread of infectious diseases: understanding the interplay between epidemic dynamics and adaptive behaviours is essential to improve response strategies to epidemics, with the goal of containing the epidemic while preserving a sufficient level of operativeness in the population. Through activity-driven temporal networks, we formulate a general framework which models a wide range of adaptive behaviours and mitigation strategies, observed in real populations. We analytically derive the conditions for a widespread diffusion of epidemics in the presence of arbitrary adaptive behaviours, highlighting the crucial role of correlations between agents behaviour in the infected and in the susceptible state. We focus on the effects of sick-leave, comparing the effectiveness of different strategies in reducing the impact of the epidemic and preserving the system operativeness. We show the critical relevance of heterogeneity in individual behavior: in homogeneous networks, all sick-leave strategies are equivalent and poorly effective, while in heterogeneous networks, strategies targeting the most vulnerable nodes are able to effectively mitigate the epidemic, also avoiding a deterioration in system activity and maintaining a low level of absenteeism. Interestingly, with targeted strategies both the minimum of population activity and the maximum of absenteeism anticipate the infection peak, which is effectively flattened and delayed, so that full operativeness is almost restored when the infection peak arrives. We also provide realistic estimates of the model parameters for influenza-like illness, thereby suggesting strategies for managing epidemics and absenteeism in realistic populations.
description: 16 pages, 8 figures
Mesoscale Analysis Method for Surface Potential Temperature in Mountainous and Coastal Terrain
Creators: name: Deng, Xingxiu
name: Stull, Roland B., 1950-
Publisher: name: American Meteorological Society
Year: 2011

description: A technique is developed to anisotropically spread surface observations in steep valleys. The goal is to create an improved objective analysis for the lowest, terrain-following numerical weather prediction (NWP) model level in mountainous terrain. The method is a mother–daughter (MD) approach, where the amount of information transferred from one grid point (the mother) to all neighboring grid points (the daughters) depends on elevation differences. The daughters become mothers and further share information with their neighboring grid points. This iterative method allows information to follow valleys around ridges, while reducing spread over the ridge top. The method is further refined to account for land–sea anisotropy. This approach is tested in the objective analyses of surface potential temperatures over the steep mountainous and coastal terrain of southwestern British Columbia, Canada. Analysis results are compared with other existing schemes using the Advanced Regional Prediction System Data Assimilation System (ADAS). It is found that the MD approach outperforms the other schemes over mountainous and coastal terrain. Copyright 2005 American Meteorological Society (AMS). Permission to use figures, tables, and brief excerpts from this work in scientific and educational works is hereby granted provided that the source is acknowledged. Any use of material in this work that is determined to be “fair use” under Section 107 of the U.S. Copyright Act or that satisfies the conditions specified in Section 108 of the U.S. Copyright Act (17 USC §108, as revised by P.L. 94-553) does not require the AMS’s permission. Republication, systematic reproduction, posting in electronic form, such as on a web site or in a searchable database, or other uses of this material, except as exempted by the above statement, requires written permission or a license from the AMS. Additional details are provided in the AMS Copyright Policy, available on the AMS Web site located at (http://www.ametsoc.org/) or from the AMS at 617-227-2425 or copyright@ametsoc.org.
Bridging or Breaking: Impact of Intergroup Interactions on Religious Polarization
Creators: name: Chaturvedi, Rochana
name: Chaturvedi, Sugat
name: Zheleva, Elena
Publisher: name: arXiv
Year: 2024
Subjects: subject: Social and Information Networks (cs.SI)
subject: Computation and Language (cs.CL)
subject: Physics and Society (physics.soc-ph)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: While exposure to diverse viewpoints may reduce polarization, it can also have a backfire effect and exacerbate polarization when the discussion is adversarial. Here, we examine the question whether intergroup interactions around important events affect polarization between majority and minority groups in social networks. We compile data on the religious identity of nearly 700,000 Indian Twitter users engaging in COVID-19-related discourse during 2020. We introduce a new measure for an individual's group conformity based on contextualized embeddings of tweet text, which helps us assess polarization between religious groups. We then use a meta-learning framework to examine heterogeneous treatment effects of intergroup interactions on an individual's group conformity in the light of communal, political, and socio-economic events. We find that for political and social events, intergroup interactions reduce polarization. This decline is weaker for individuals at the extreme who already exhibit high conformity to their group. In contrast, during communal events, intergroup interactions can increase group conformity. Finally, we decompose the differential effects across religious groups in terms of emotions and topics of discussion. The results show that the dynamics of religious polarization are sensitive to the context and have important implications for understanding the role of intergroup interactions.
Nonlocal $H$-convergence for topologically nontrivial domains
Creators: name: Waurick, Marcus
Publisher: name: arXiv
Year: 2022
Subjects: subject: Analysis of PDEs (math.AP)
subject: Mathematical Physics (math-ph)
subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: Primary 35B27, Secondary 35Q61, 74Q05

description: The notion of nonlocal $H$-convergence is extended to domains with nontrivial topology, that is, domains with non-vanishing harmonic Dirichlet and/or Neumann fields. If the space of harmonic Dirichlet (or Neumann) fields is infinite-dimensional, there is an abundance of choice of pairwise incomparable topologies generalising the one for topologically trivial $Ω$. It will be demonstrated that if the domain satisfies the Maxwell's compactness property the corresponding natural version of the corresponding (generalised) nonlocal $H$-convergence topology has no such ambiguity. Moreover, on multiplication operators the nonlocal $H$-topology coincides with the one induced by (local) $H$-convergence introduced by Murat and Tartar. The topology is used to obtain nonlocal homogenisation results including convergence of the associated energy for electrostatics. The derived techniques prove useful to deduce a new compactness criterion relevant for nonlinear static Maxwell problems.
description: 39 pages, no figures; v2: 46 pages; thorough revision taken all referee comments in to account
Expression of galectins-1 and -3 correlates with defective mononuclear cell apoptosis in patients with juvenile idiopathic arthritis
Creators: name: Diaz-Cano, Salvador J.
name: H J Wolfe
name: M De Miguel
name: C A Maldonado
name: G A Rabinovich
name: M Harjacek
Publisher: name: figshare
Year: 2012
Subjects: subject: Medicine
subject: Immunology
subject: FOS: Clinical medicine
subject: Cell Biology

description: Juvenile idiopathic arthritis (JIA) is characterized by hyperplasia of synovial cells and accumulation of mononuclear inflammatory infiltrates, which are locally maintained through a balance between cell proliferation and apoptosis. Although defective clearance of activated T cells in RA joints has been explained by alterations of the Fas-Fas ligand system, this has not been confirmed in synovial tissue of patients with JIA. We evaluated the relation between expression of galectin-1 (Gal-1) and galectin-3 (Gal-3) (beta-galactoside-binding proteins with pro- and anti-apoptotic properties, respectively) and the apoptosis and proliferation rates of infiltrative lymphocytes in synovial tissue of patients with JIA.
 Using slide cytometry and in situ end labeling we observed dysregulated apoptosis of infiltrating mononuclear cells within the synovial tissue of patients with JIA.
 Patients with pauciarticular JIA showed minimal apoptosis, high Bcl-2 expression, and high or normal proliferation rates, while patients with polyarticular disease showed the lowest apoptotic indexes, accompanied by low Bcl-2 expression and low proliferation rates. We found that Gal-1 expression is downregulated and Gal-3 expression is upregulated in synovial tissue from patients with JIA.
 In patients with polyarticular JIA, accumulation of inflammatory cells is mainly due to downregulated apoptosis, whereas in patients with pauciarticular disease the process results from increased proliferation. Defective mononuclear apoptosis in synovial inflammatory infiltrates from patients with JIA could be explained in part by decreased Gal-1 and increased Gal-3 expression.
Theory of the spectral function of Fermi polarons at finite temperature
Creators: name: Hu, Hui
name: Wang, Jia
name: Liu, Xia-Ji
Publisher: name: arXiv
Year: 2024
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We develop a general theory of Fermi polarons at nonzero temperature, including particle-hole excitations of the Fermi sea shake-up to arbitrarily high orders. The exact set of equations of the spectral function is derived by using both Chevy ansatz and diagrammatic approach, and their equivalence is clarified to hold in free space only, with an unregularized infinitesimal interaction strength. The correction to the polaron spectral function arising from two-particle-hole excitations is explicitly examined, for an exemplary case of Fermi polarons in one-dimensional optical lattices. We find quantitative improvements at low temperatures with the inclusion of two-particle-hole excitations, in both polaron energies and decay rates. Our exact theory of Fermi polarons with arbitrary orders of particle-hole excitations might be used to better understand the intriguing polaron dynamical responses in two or three dimensions, whether in free space or within lattices.
description: 6 pages, 4 figures; for the long version of the work, see arXiv:2403.09064
Germline RET 634 mutation positive MEN 2A-related C-cell hyperplasias have genetic features consistent with intraepithelial neoplasia
Creators: name: Diaz-Cano, Salvador J.
name: Blanes, Alfredo
name: H J Wolfe
name: M De Miguel
name: R Tashjian
Publisher: name: figshare
Year: 2012
Subjects: subject: Molecular Biology
subject: Medicine
subject: Genetics
subject: FOS: Biological sciences
subject: Cell Biology
subject: Cancer

description: C-cell hyperplasias are normally multifocal in multiple endocrine neoplasia type 2A. We compared clonality, microsatellite pattern of tumor suppressor genes, and cellular kinetics of C-cell hyperplasia foci in each thyroid lobe. We selected 11 females from multiple endocrine neoplasia type 2A kindred treated with thyroidectomy due to hypercalcitoninemia. C-cell hyperplasia foci were microdissected for DNA extraction to analyze the methylation pattern of androgen receptor alleles and microsatellite regions (TP53, RB1, WT1, and NF1). Consecutive sections were selected for MIB-1, pRB1, p53, Mdm-2, and p21WAF1 immunostaining, DNA content analysis, and in situ end labeling. Appropriate tissue controls were run. Only two patients had medullary thyroid carcinoma foci. Nine informative C-cell hyperplasia patients showed germline point mutation in RET, eight of them with the same androgen receptor allele preferentially methylated in both lobes. C-cell hyperplasia foci showed heterogeneous DNA deletions revealed by loss of heterozygosity of TP53 (12 of 20), RB1 (6 of 14), and WT1 (4 of 20) and hypodiploid G0/G1 cells (14 of 20), low cellular turnover (MIB-1 index 4.5%, in situ end labeling index 0.03%), and significantly high nuclear area to DNA index ratio. MEN 2A (germline point mutation in RET codon 634) C-cell hyperplasias are monoclonal and genetically heterogeneous and show down-regulated apoptosis, findings consistent with an intraepithelial neoplasia. Concordant X-chromosome inactivation and interstitial gene deletions suggest clone expansions of precursors occurring at a point in embryonic development before divergence of each thyroid lobe and may represent a paradigm for other germline mutations.
Modelling of planar germanium hole qubits in electric and magnetic fields
Creators: name: Wang, Chien-An
name: Ekmel, Ercan
name: Gyure, Mark
name: Scappucci, Giordano
name: Veldhorst, Menno
name: Rimbach-Russ, Maximilian
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Hole-based spin qubits in strained planar germanium quantum wells have received considerable attention due to their favourable properties and remarkable experimental progress. The sizeable spin-orbit interaction in this structure allows for efficient qubit operations with electric fields. However, it also couples the qubit to electrical noise. In this work, we perform simulations of a heterostructure hosting these hole spin qubits. We solve the effective mass equations for a realistic heterostructure, provide a set of analytical basis wave functions, and compute the effective g-factor of the heavy-hole ground-state. Our investigations reveal a strong impact of highly excited light-hole states located outside the quantum well on the g-factor. We find that sweet spots, points of operations that are least susceptible to charge noise, for out-of-plane magnetic fields are shifted to impractically large electric fields. However, for magnetic fields close to in-plane alignment, partial sweet spots at low electric fields are recovered. Furthermore, sweet spots with respect to multiple fluctuating charge traps can be found under certain circumstances for different magnetic field alignments. This work will be helpful in understanding and improving coherence of germanium hole spin qubits.
description: 11 pages, 6 Figures
Equivariant, Safe and Sensitive -- Graph Networks for New Physics
Creators: name: Bhardwaj, Akanksha
name: Englert, Christoph
name: Naskar, Wrishik
name: Ngairangbam, Vishal S.
name: Spannowsky, Michael
Publisher: name: arXiv
Year: 2024
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: This study introduces a novel Graph Neural Network (GNN) architecture that leverages infrared and collinear (IRC) safety and equivariance to enhance the analysis of collider data for Beyond the Standard Model (BSM) discoveries. By integrating equivariance in the rapidity-azimuth plane with IRC-safe principles, our model significantly reduces computational overhead while ensuring theoretical consistency in identifying BSM scenarios amidst Quantum Chromodynamics backgrounds. The proposed GNN architecture demonstrates superior performance in tagging semi-visible jets, highlighting its potential as a robust tool for advancing BSM search strategies at high-energy colliders.
description: Restructured discussions in section 2.1 for better clarity. Matches published version
Constraining spherically symmetric metrics by the gap between photon rings
Creators: name: Aratore, Fabio
name: Tsupko, Oleg Yu.
name: Perlick, Volker
Publisher: name: arXiv
Year: 2024
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Gravitational lensing of luminous matter that surrounds a black hole or some other sufficiently compact object produces an infinite sequence of images. Besides the direct (or primary) image, it comprises demagnified and deformed replicas of the original known as photon rings which are progressively nearing the boundary of the socalled shadow. In the present paper, we present analytical approximation formulas for higher-order photon rings for an asymptotically flat, static, spherically symmetric spacetime that admits a photon sphere. We consider a geometrically thin disk of light sources in the equatorial plane and an observer at arbitrary inclination far away from the center. Fixing the emission radius and leveraging the strong deflection limit, which provides an analytical logarithmic approximation for the deflection angle, we find the deformed shape of higher-order photon rings in the form of a polar equation on the observer's screen. It has been suggested by other authors to use the relative size of photon rings for characterizing the underlying spacetime. In particular, the relative separation between two neighboring photon rings, which we call "gap parameter", was considered. We analytically calculate the gap parameter of higher-order photon rings for metrics of the considered class that may depend on multiple parameters. The advantage of using this quantity is in the fact that, to within the assumed approximations, it is independent of the mass of the central object (or of some other characteristic parameter if the mass is zero) and of the distance of the observer. Measurements of the gap parameter, which may become possible in the near future, will restrict the spacetime models that are in agreement with the observations. Even without knowing the inner and outer radii of the shining disk, it will conclusively rule out some metrics. Some examples are provided.
description: 15 pages, 5 figures, 1 table
Contact geometric mechanics: the Tulczyjew triples
Creators: name: Grabowska, Katarzyna
name: Grabowski, Janusz
Publisher: name: arXiv
Year: 2022
Subjects: subject: Symplectic Geometry (math.SG)
subject: Mathematical Physics (math-ph)
subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 37J39, 70Hxx, 70S05, 53D35, 53D10, 53D35, 70G45

description: We propose a generalization of the classical Tulczyjew triple as a geometric tool in Hamiltonian and Lagrangian formalisms which serves for contact manifolds. The rôle of the canonical symplectic structures on cotangent bundles in Tulczyjew's case is played by the canonical contact structures on the bundles $J^1L$ of first jets of sections of line bundles $L\to M$. Contact Hamiltonians and contact Lagrangians are understood as sections of certain line bundles, and they determine (generally implicit) dynamics on the contact phase space $J^1L$. We also study a contact analog of the Legendre map and the Legendre transformation of generating objects in both contact formalisms. Several explicit examples are offered.
description: 35 pages, minor changes, a few references added, to appear in Advances in Theoretical and Mathematical Physics
Probing symmetric teleparallel gravity in the early universe
Creators: name: De, Avik
name: Saha, Dalia
name: Subramaniam, Ganesh
name: Sanyal, Abhik Kumar
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: General theory of relativity can be equivalently formulated on a flat space-time associating a torsion-free affine connection of non-vanishing non-metricity scalar $Q$. In this paper, we present an extension of this, viz., the $f(Q)$ theory of gravity, and explore the early evolution of the universe in the background of anisotropic Bianchi-I model. The $f(Q)$ theory in the current setting through its geometric modification is quite successful in explaining the late time accelerated expansion. Here we note that it accommodates latest released constraints on the inflationary parameters by Planck's collaboration group with excellent precession, but fails to produce a viable decelerated expansion in the radiation dominated era.
Spin-up and the effects of a submarine canyon: Applications to upwelling in Astoria Canyon
Creators: name: Mirshak, Ramzi
name: Allen, Susan E.
Publisher: name: American Geophysical Union
Year: 2011

description: A parameterization for the on-shelf mass flux induced by upwelling through a shelf break submarine canyon is estimated by laboratory spin-up experiments. We determine the effects of a submarine canyon on flow evolution implicitly by measuring the topographic drag force in the context of a heuristic model. Trials were performed across a range of values for the shelf break velocity, Coriolis frequency, and buoyancy frequency. Assuming the drag force within the canyon is balanced locally by rotation, we propose a parameterization for upwelling through a canyon provided that the Coriolis frequency, buoyancy frequency, shelf break velocity, and canyon dimensions at the shelf break depth are known. We use our results to compare wind-forced and canyon-forced upwelling over Astoria Canyon off the coast of Washington State. The analysis suggests that canyon-forced upwelling through Astoria Canyon is of equal importance to wind-forced upwelling directly above it on seasonal scales. An edited version of this paper was published by AGU. Copyright 2005 American Geophysical Union.
Inferring Dynamic Networks from Marginals with Iterative Proportional Fitting
Creators: name: Chang, Serina
name: Koehler, Frederic
name: Qu, Zhaonan
name: Leskovec, Jure
name: Ugander, Johan
Publisher: name: arXiv
Year: 2024
Subjects: subject: Machine Learning (stat.ML)
subject: Machine Learning (cs.LG)
subject: Social and Information Networks (cs.SI)
subject: Optimization and Control (math.OC)
subject: Statistics Theory (math.ST)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: A common network inference problem, arising from real-world data constraints, is how to infer a dynamic network from its time-aggregated adjacency matrix and time-varying marginals (i.e., row and column sums). Prior approaches to this problem have repurposed the classic iterative proportional fitting (IPF) procedure, also known as Sinkhorn's algorithm, with promising empirical results. However, the statistical foundation for using IPF has not been well understood: under what settings does IPF provide principled estimation of a dynamic network from its marginals, and how well does it estimate the network? In this work, we establish such a setting, by identifying a generative network model whose maximum likelihood estimates are recovered by IPF. Our model both reveals implicit assumptions on the use of IPF in such settings and enables new analyses, such as structure-dependent error bounds on IPF's parameter estimates. When IPF fails to converge on sparse network data, we introduce a principled algorithm that guarantees IPF converges under minimal changes to the network structure. Finally, we conduct experiments with synthetic and real-world data, which demonstrate the practical value of our theoretical and algorithmic contributions.
description: Conference version available from https://proceedings.mlr.press/v235/chang24b.html
Are PCR artifacts in microdissected samples preventable?
Creators: name: Diaz-Cano, Salvador J.
Publisher: name: figshare
Year: 2012
Subjects: subject: Molecular Biology
subject: Medicine
subject: Genetics
subject: FOS: Biological sciences
subject: Cancer

description: In many instances, molecular results are determined by technical conditions and need validation. Loss of heterozygosity (LOH) and microsatellite instability (MSI) analyses share these limitations too, but only a few articles directly study the technical aspects of molecular tests. Additional bands must be carefully distinguished from polymerase chain reaction (PCR) artifacts and different options must be inves- tigated and systematically excluded: Target DNA modifications induced by fixation and processing in paraffin-embedded tissues. The repetitive sequence would result in a higher incidence of primer misannealing and hairpin formation. The amplification conditions can also determine the specificity of the reaction. The high incidence of PCR artifacts using microdissected samples is related to the small concentration of target DNA, fixation-induced changes of DNA, and conditions in the am- plification of repetitive sequence (especially for those CG-rich sequences) favoring misannealing and hairpin formation. Ap- propriate modifications to avoid the previously mentioned conditions will significantly improve the reproducibility of LOH and MSI test in microdissected samples.
Een halve eeuw onderzoek naar onderwijsachterstanden
Creators: name: Driessen, Geert
Publisher: name: Didactief Online
Year: 2022
Subjects: onderwijsachterstanden
onderzoek

description: Geert Driessen doet al 40 jaar onderzoek naar onderwijsachterstanden. Zijn voorstel voor de toekomst: handhaaf het totale budget, maar beperk het aantal onderzoeken, en verhoog de kwaliteit daarvan. Misschien nemen politici, ambtenaren en bewindslieden het dan meer serieus – ook wanneer de uitkomsten een inconvenient truth zouden inhouden. Het is bovendien aan de ‘vierde macht’, de ambtenaren, om breder en verder te kijken dan hun bewindslieden. Zij zijn de hoeders van goed onderwijs. Het wordt tijd dat zij die taak ook wat meer waarmaken?
Contribution of the microvessel network to the clonal and kinetic profiles of adrenal cortical proliferative lesions
Creators: name: Diaz-Cano, Salvador J.
name: Blanes, Alfredo
name: H J Wolfe
name: M De Miguel
name: H Galera
Publisher: name: figshare
Year: 2012
Subjects: subject: Molecular Biology
subject: Medicine
subject: Genetics
subject: FOS: Biological sciences
subject: Cell Biology
subject: Cancer

description: Monoclonal adrenocortical lesions have been characterized by an inverse correlation between proliferation and apoptosis, and polyclonal lesions show a direct correlation. Their relationship with the vascular pattern remains unknown in adrenocortical nodular hyperplasias (ACNHs), adenomas (ACAs), and carcinomas (ACCs). We studied 20 ACNHs, 25 ACAs, and 10 ACCs (World Health Organization classification criteria) from 55 women. The analysis included X-chromosome inactivation assay (on microdissected samples), slide and flow cytometry, and in situ end labeling. Endothelial cells were stained with anti-CD31, and the blood vessel area and density were quantified by image analysis in the same areas. Appropriate tissue controls were run in every case. Regression analyses between kinetic and vascular features were performed in both polyclonal and monoclonal lesions. Polyclonal patterns were observed in 14 of 18 informative ACNHs and 3 of 22 informative ACAs, and monoclonal patterns were seen in 4 of 18 ACNHs, 19 of 22 ACAs, and 9 of 9 ACCs. A progressive increase in microvessel area was observed in the ACNH-ACA-ACC transition but was statistically significant between benign and malignant lesions only (191.36 +/- 168.32 v 958.07 +/- 1279.86 microm(2); P < .0001). In addition, case stratification by clonal pattern showed significant differences between polyclonal and monoclonal benign lesions; 6% of polyclonal and 57% of monoclonal lesions had microvessel area >186 microm(2) (P = .0000008). Monoclonal lesions showed parallel trends (but with opposite signs) for microvessel area and density in comparison with proliferation and apoptosis, whereas polyclonal lesions showed inverse trends. In conclusion, the kinetic advantage of monoclonal adrenal cortical lesions (increased proliferation, decreased apoptosis) is maintained by parallel increases in microvessel area and density.
Higher-group global symmetry and the bosonic M5 brane
Creators: name: Armas, Jay
name: Batzios, Giorgos
name: Jain, Akash
Publisher: name: arXiv
Year: 2024
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Higher-group symmetries are combinations of higher-form symmetries which appear in various field theories. In this paper, we explain how higher-group symmetries arise in 10d and 11d supergravities when the latter are coupled to brane sources. Motivated by this observation, we study field theories at zero and finite temperature invariant under a class of continuous Abelian higher-group symmetries. We restrict the analysis to the low-energy regime where the dynamical field content exclusively consists of Goldstone fields arising from the spontaneous breaking of higher-group and spacetime symmetries. Invariant quantities are constructed and the phases of matter are classified according to the pattern of spontaneous symmetry breaking. With respect to supergravity, we highlight how such Goldstone effective theories provide a symmetry-based interpretation for the theories living on D/M-branes. As an explicit example we construct a 6-group invariant action for the bosonic M5 brane, consistent with the self-duality of the 3-form field strength on the brane. While the self-duality condition in the bosonic case needs to be imposed externally as a constraint at zero temperature, we find an equilibrium effective action for the bosonic M5 brane at finite temperature that inherently implements self-duality.
description: 36 pages. v2: minor text improvements
Accelerating Transfer Learning with Near-Data Computation on Cloud Object Stores
Creators: name: Petrescu, Diana
name: Guirguis, Arsany
name: Quoc, Do Le
name: Picorel, Javier
name: Guerraoui, Rachid
name: Dinu, Florin
Publisher: name: arXiv
Year: 2022
Subjects: subject: Machine Learning (cs.LG)
subject: Databases (cs.DB)
subject: FOS: Computer and information sciences

description: Storage disaggregation underlies today's cloud and is naturally complemented by pushing down some computation to storage, thus mitigating the potential network bottleneck between the storage and compute tiers. We show how ML training benefits from storage pushdowns by focusing on transfer learning (TL), the widespread technique that democratizes ML by reusing existing knowledge on related tasks. We propose HAPI, a new TL processing system centered around two complementary techniques that address challenges introduced by disaggregation. First, applications must carefully balance execution across tiers for performance. HAPI judiciously splits the TL computation during the feature extraction phase yielding pushdowns that not only improve network time but also improve total TL training time by overlapping the execution of consecutive training iterations across tiers. Second, operators want resource efficiency from the storage-side computational resources. HAPI employs storage-side batch size adaptation allowing increased storage-side pushdown concurrency without affecting training accuracy. HAPI yields up to 2.5x training speed-up while choosing in 86.8% of cases the best performing split point or one that is at most 5% off from the best.
description: To appear in the proceedings of SoCC '24
Environmental Scan : Seniors and Veterans Falls Prevention Initiatives in British Columbia : Executive Summary
Creators: name: Scott, Vicky
name: Gallagher, Elaine
name: Smith, Dorry
name: Votova, Kristine
name: Brussoni, Mariana
Publisher: name: The University of British Columbia
Year: 2022

description: An executive summary of the environmental scan of the seniors and veterans falls prevention initiatives in British Columbia report.
Carroll Hawking effect
Creators: name: Aggarwal, Ankit
name: Ecker, Florian
name: Grumiller, Daniel
name: Vassilevich, Dmitri
Publisher: name: arXiv
Year: 2024
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Carroll black holes with an associated Carroll temperature were introduced recently. So far, it is unclear if they exhibit a Hawking-like effect. To solve this, we study scalar fields on Carroll black hole backgrounds. Inspired by anomaly methods, we derive a Hawking-like energy-momentum tensor compatible with the Carroll temperature and the Stefan-Boltzmann law. Key steps in our derivation are the finiteness of energy at the Carroll extremal surface and compatibility with the Carroll Ward identities, thereby eliminating, respectively, the Carroll-analogs of the Boulware and Unruh vacua.
description: 5 pages, v2: added refs
A non-compact convex hull in generalized non-positive curvature
Creators: name: Basso, Giuliano
name: Krifka, Yannick
name: Soultanis, Elefterios
Publisher: name: arXiv
Year: 2023
Subjects: subject: Metric Geometry (math.MG)
subject: Differential Geometry (math.DG)
subject: Geometric Topology (math.GT)
subject: FOS: Mathematics
subject: 53C23 (Primary) 51F99 (Secondary)

description: In this article, we are interested in metric spaces that satisfy a weak non-positive curvature condition in the sense that they admit a conical geodesic bicombing. We show that the analog of a question of Gromov about compactness properties of convex hulls has a negative answer in this setting. Specifically, we prove that there exists a complete metric space $X$ that admits a conical bicombing $σ$ such that $X$ has a finite subset whose closed $σ$-convex hull is not compact.
description: v4: improved presentation and correction of some typos
’99 International Symposium on Microcredit and Urban Unemployment in China —1999 nian Zhongguo xiao’e daikuan yu chengzhen shiye wenti guoji yantaohui
Creators: name: Monschein, Ylva
Publisher: name: ASIEN: The German Journal on Contemporary Asia
Year: 2021

description: ASIEN: The German Journal on Contemporary Asia, Nr. 72 (1999): ASIEN (Juli)
Computational Dualism and Objective Superintelligence
Creators: name: Bennett, Michael Timothy
Publisher: name: arXiv
Year: 2023
Subjects: subject: Artificial Intelligence (cs.AI)
subject: Logic (math.LO)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: The concept of intelligent software is flawed. The behaviour of software is determined by the hardware that "interprets" it. This undermines claims regarding the behaviour of theorised, software superintelligence. Here we characterise this problem as "computational dualism", where instead of mental and physical substance, we have software and hardware. We argue that to make objective claims regarding performance we must avoid computational dualism. We propose a pancomputational alternative wherein every aspect of the environment is a relation between irreducible states. We formalise systems as behaviour (inputs and outputs), and cognition as embodied, embedded, extended and enactive. The result is cognition formalised as a part of the environment, rather than as a disembodied policy interacting with the environment through an interpreter. This allows us to make objective claims regarding intelligence, which we argue is the ability to "generalise", identify causes and adapt. We then establish objective upper bounds for intelligent behaviour. This suggests AGI will be safer, but more limited, than theorised.
description: Awarded "Best Student Paper" at the 17th Conference on Artificial General Intelligence, 2024
Purification and Partial Characterization of Extensin Peroxidase
Creators: name: Ahmed, Nazia
Publisher: name: London South Bank University
Year: 1996

description: The primary plant cell wall of higher plants is a focal point for growth regulation and disease resistance. Rapid responses to pathogen interaction are of fundamental importance because these fast reactions generate both primary components of plant resistance to pathogens and messenger systems that activate slower regulatory mechanisms mediated through gene activation and subsequent de novo protein synthesis. 
Plants activate a large array of defence responses during microbial infection. These include the elevation of activity of peroxidases and enhancement of insolubilization of a hydroxyproline-rich glycoprotein (HRGP), called extensin, in the cell wall. This occurs within minutes after exposing plant cells to a pathogen or an elicitor derived from a pathogen or non-pathogen. Extensin insolubilization (cross-linking between preexisting soluble extensin precursor molecules) is catalyzed by a peroxidase referred to as 'extensin peroxidase’, in the presence of hydrogen peroxide and monitored by an in vitro Superose-12 FPLC assay. 
Extensin and two ionic forms of 'extensin peroxidase' (Mono S EPIII and EPIV) were ionically eluted from intact water-washed tomato cells in suspension culture and purified to homogeneity. The molecular weights, amino acid composition and isoelectric points (pI) of both ionic forms of 'extensin peroxidase’ were demonstrated (Ahmed ef al., 1995). The substrate specificity of these enzymes has also been investigated. 'Extensin peroxidase’ is relatively substrate-specific (i.e. a particular enzyme will act primarily on a certain substrate) and appears to have a higher specificity towards its natural substrate extensin rather than other commercially purchased peroxidase substrates. 
A yeast (Saccharomyces cerevisiae) derived elicitor known to be pathogenic to tomatoes has been purified. Preliminary studies have demonstrated that elicitation of tomato fruit with this yeast elicitor for 30 min enhances extensin insolubilization.