cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Stable marked point processes
Creators: name: McElroy, Tucker
name: Politis, Dimitris N.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Statistics Theory (math.ST)
subject: FOS: Mathematics
subject: 62M10, 62M30, 62M40 (Primary)

description: In many contexts such as queuing theory, spatial statistics, geostatistics and meteorology, data are observed at irregular spatial positions. One model of this situation involves considering the observation points as generated by a Poisson process. Under this assumption, we study the limit behavior of the partial sums of the marked point process $\{(t_i,X(t_i))\}$, where X(t) is a stationary random field and the points t_i are generated from an independent Poisson random measure $\mathbb{N}$ on $\mathbb{R}^d$. We define the sample mean and sample variance statistics and determine their joint asymptotic behavior in a heavy-tailed setting, thus extending some finite variance results of Karr [Adv. in Appl. Probab. 18 (1986) 406--422]. New results on subsampling in the context of a marked point process are also presented, with the application of forming a confidence interval for the unknown mean under an unknown degree of heavy tails.
description: Published at http://dx.doi.org/10.1214/009053606000001163 in the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org)
Magnetic Interactions Between Radical Pairs in Chiral Graphene Nanoribbons
Creators: name: Wang, Tao
name: Sanz, Sofia
name: Castro-Esteban, Jesús
name: Lawrence, James
name: Berdonces-Layunta, Alejandro
name: Mohammed, Mohammed S. G.
name: Vilas-Varela, Manuel
name: Corso, Martina
name: Peña, Diego
name: Frederiksen, Thomas
name: de Oteyza, Dimas G.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Magnetic graphene nanoribbons (GNRs) have become promising candidates for future applications, including quantum technologies. Here, we characterize magnetic states hosted by chiral graphene nanoribbons (chGNRs). The substitution of a hydrogen atom at the chGNR edge by a ketone group effectively adds one p_z electron to the π-electron network, thus producing an unpaired π radical. A closely related scenario occurs for regular ketone-functionalized chGNRs in which one oxygen atom is missing. Two such radical states can interact via exchange coupling and we study those interactions as a function of their relative position, which includes a remarkable dependence on the chirality, as well as on the nature of the surrounding GNR, i.e., with or without ketone functionalization. In addition, we determine the parameters whereby this type of systems with oxygen heteroatoms can be adequately described within the widely used mean-field Hubbard model. Altogether, we provide new insights to both theoretically model and devise GNR-based nanostructures with tunable magnetic properties.
Modeling non-linear dielectric susceptibilities of supercooled molecular liquids
Creators: name: Speck, Thomas
Publisher: name: arXiv
Year: 2021
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: Advances in high-precision dielectric spectroscopy has enabled access to non-linear susceptibilities of polar molecular liquids. The observed non-monotonic behavior has been claimed to provide strong support for theories of dynamic arrest based on thermodynamic amorphous order. Here we approach this question from the perspective of dynamic facilitation, an alternative view focusing on emergent kinetic constraints underlying the dynamic arrest of a liquid approaching its glass transition. We derive explicit expressions for the frequency-dependent higher-order dielectric susceptibilities exhibiting a non-monotonic shape, the height of which increases as temperature is lowered. We demonstrate excellent agreement with the experimental data for glycerol, challenging the idea that non-linear response functions reveal correlated relaxation in supercooled liquids.
Observation of $B^{\pm} \to ψ(2S) π^{\pm}$ and search for direct CP-violation
Creators: name: Bhardwaj, V.
name: Kumar, R.
name: Singh, J. B.
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We report the first observation of $B^{\pm}\toψ(2S)π^{\pm}$, a Cabibbo- and color-suppressed decay. This analysis is based on $657\times10^{6}$ $B\overline B$ events collected at the $Υ(4S)$ resonance with the Belle detector at the KEKB energy-asymmetric $e^+e^-$ collider. The measured branching fraction is ($2.44 \pm 0.22 \pm 0.20$)$\times 10^{-5}$ and the charge asymmetry is $\mathcal{A}=0.022 \pm 0.085 \pm 0.016$. The ratio of the branching fractions $\mathcal {B}(B^{\pm} \to ψ(2S) π^{\pm})$$/ \mathcal {B}(B^{\pm} \to ψ(2S) K^{\pm})$ $ = (3.99 \pm 0.36\pm 0.17)%$ is also determined.
description: 6 pages, 3 figures, submitted to PRD(RC)
An Analysis Of Entire Space Multi-Task Models For Post-Click Conversion Prediction
Creators: name: O'Brien, Conor
name: Liu, Kin Sum
name: Neufeld, James
name: Barreto, Rafael
name: Hunt, Jonathan J
Publisher: name: arXiv
Year: 2021
Subjects: subject: Information Retrieval (cs.IR)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Industrial recommender systems are frequently tasked with approximating probabilities for multiple, often closely related, user actions. For example, predicting if a user will click on an advertisement and if they will then purchase the advertised product. The conceptual similarity between these tasks has promoted the use of multi-task learning: a class of algorithms that aim to bring positive inductive transfer from related tasks. Here, we empirically evaluate multi-task learning approaches with neural networks for an online advertising task. Specifically, we consider approximating the probability of post-click conversion events (installs) (CVR) for mobile app advertising on a large-scale advertising platform, using the related click events (CTR) as an auxiliary task. We use an ablation approach to systematically study recent approaches that incorporate both multitask learning and "entire space modeling" which train the CVR on all logged examples rather than learning a conditional likelihood of conversion given clicked. Based on these results we show that several different approaches result in similar levels of positive transfer from the data-abundant CTR task to the CVR task and offer some insight into how the multi-task design choices address the two primary problems affecting the CVR task: data sparsity and data bias. Our findings add to the growing body of evidence suggesting that standard multi-task learning is a sensible approach to modelling related events in real-world large-scale applications and suggest the specific multitask approach can be guided by ease of implementation in an existing system.
description: RecSys 21 Late Breaking Results
Collective behavior of Zr-substituted polyoxometalates in solution: Insights from molecular dynamics simulations part 1
Creators: name: Chaumont, Alain
name: Carbó, Jorge J.
name: Jiménez-Lozano, Pablo
name: Puiggalí Jou, Jordi
Publisher: name: Zenodo
Year: 2025
Subjects: subject: Molecular Dynamics Simulation
subject: Polyoxometalates
subject: Zirconium
subject: Liquid-Liquid interfaces

description: Files related with the AMBER MD simulations of 500ns for studying [W5O18Zr(OH)(OH2)]3- ions with TBA+ counterions in aqueous solution at 3 different anion concentrations, 0.024 M (2 W5Zr and 6 TBA), 0.068 M (6 W5Zr and 18 TBA) and 0.178 M (18 W5Zr and 54 TBA) in a cubic box of 51.83, 52,63 and 55.13 Å3, respectively. 

Uploaded files for each simulation: input for the simulation (.in ), output from the simulation (.lis), topology file describing the system (.parm7), input coordinates (t_0.rst7), final coordinates after the simulation (t_500.rst7) and the trajectory file (.nc).
Ramos Tolosa, Jorge (2022). Palestina desde las epistemologías del sur. CLACSO / Centro de Estudos Sociais.
Creators: name: Castillo-Flores, Alonso Emilio
Publisher: name: Zenodo
Year: 2023

description: Jorge Ramos Tolosa, profesor de historia de la Universitat de València ha escrito un libro muy necesario y actual, un texto comprometido con su tiempo, a su vez, un libro de rigor histórico. Ramos Tolosa no esconde su filiación y su fe decolonial. Denuncia la hipocresía occidental pro-ucraniana frente a la destrucción de Palestina. Su vida —dice— está dedicada a Palestina. En los últimos años ha publicado Existir es Resistir. Pasado y presente de Palestina-Israel (2017) (con Diego Checa), Los años clave de Palestina-Israel. Pablo de Azcárate y la ONU (1947-1952) (2019), Una historia contemporánea de Palestina-Israel (2020) y Palestina: una història essencial (2020).
Barriers to the adoption of alternative dispute resolution within the Irish construction industry: a systematic literature review
Creators: name: Ryan, Cathal
name: Spillane, John
name: Bradley, Jim
Publisher: name: University of Limerick
Year: 2025
Subjects: classificationCode: 40
subject: Engineering

description: The Construction Contracts Act 2013 introduced statutory adjudication to the Republic of Ireland's construction industry. Since the legislation became operative in 2016, uptake of adjudication has admittedly been slow. This research aims to identify the barriers that may cause the non-utilisation of newly introduced alternative dispute resolution (ADR) methods. To address this, a systematic literature review (SLR) is conducted. The search comprises of research documents containing the terms "alternative dispute resolution", "construction", and "Ireland", published between the years 2004-2024. Of the initial 77 documents, 20 are eligible for inclusion in this study. Following this, an exhaustive list of potential barriers is extracted and documented. 16 barriers are identified, including cost of ADR for clients, and third?party's capability, among others. The contribution of this research is to highlight the barriers facing newly introduced ADR methods, a finding that may garner the attention of policy makers, and subsequently enable them to begin addressing the barriers identified. Resultantly making newer methods, such as adjudication in Ireland's construction industry, more accessible and feasible to those they are intended to assist.
Concordance: In-flight Calibration of X-ray Telescopes without Absolute References
Creators: name: Marshall, Herman L.
name: Chen, Yang
name: Drake, Jeremy J.
name: Guainazzi, Matteo
name: Kashyap, Vinay L.
name: Meng, Xiao-Li
name: Plucinsky, Paul P.
name: Ratzlaff, Peter
name: van Dyk, David A.
name: Wang, Xufei
Publisher: name: arXiv
Year: 2021
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We describe a process for cross-calibrating the effective areas of X-ray telescopes that observe common targets. The targets are not assumed to be "standard candles" in the classic sense, in that we assume that the source fluxes have well-defined, but {\it a priori} unknown values. Using a technique developed by Chen et al. (2019, arXiv:1711.09429) that involves a statistical method called {\em shrinkage estimation}, we determine effective area correction factors for each instrument that brings estimated fluxes into the best agreement, consistent with prior knowledge of their effective areas. We expand the technique to allow unique priors on systematic uncertainties in effective areas for each X-ray astronomy instrument and to allow correlations between effective areas in different energy bands. We demonstrate the method with several data sets from various X-ray telescopes.
description: 37 pages, 9 figures, and 10 tables plus an appendix with 7 data tables. Accepted for publication in the Astronomical Journal
On affine usages in signal-based communication
Creators: name: Amadio, Roberto
name: Dogguy, Mehdi
Publisher: name: arXiv
Year: 2008
Subjects: subject: Logic in Computer Science (cs.LO)
subject: FOS: Computer and information sciences

description: We describe a type system for a synchronous pi-calculus formalising the notion of affine usage in signal-based communication. In particular, we identify a limited number of usages that preserve affinity and that can be composed. As a main application of the resulting system, we show that typable programs are deterministic.
The 1918 and 1957 Vancouver Island earthquakes
Creators: name: Cassidy, John Francis
Publisher: name: University of British Columbia
Year: 2010

description: The oceanic Juan de Fuca and Explorer plates are subducting beneath the continental America plate west of Vancouver Island. The Nootka fault zone, which separates these oceanic plates, experiences left-lateral shear due to the different rates of subduction for the Juan de Fuca (4 cm/yr) and the Explorer (<2 cm/yr) plates. Since 1918, six significant earthquakes (M= 5.3 - 7.2) have occurred in the region where the projection of this fault zone intersects central Vancouver Island. In this study two of the largest events are examined; the 1918 (Ms ≃ 7) and the 1957 (Ms ≃ 6) earthquakes. Prior to this research, no comprehensive studies of these events had been carried out. A total of 46 seismograms from 24 stations worldwide were obtained for the 1918 earthquake, and 138 seismograms from 46 stations were obtained for the 1957 earthquake. The preferred epicentre for the 1918 earthquake is 49.47°N, 126.24°W, with an estimated uncertainty of ±30 km. The preferred focal depth of 15 km indicates that this was a crustal earthquake. Magnitude estimates are Ms = 6.9 ± 0.3, mb, = 7.2 ± 0.4 and MI = 7.0, in agreement with previous studies. Surface wave analysis suggests this is a predominantly strike-slip earthquake occurring along either a NNW or an ENE striking fault. A seismic moment of 7.40x10²⁵ dyne-cm and a stress drop of 122 bars, indicative of an intraplate event, are estimated. The preferred epicentre for the 1957 earthquake is 49.65°N, 127.02°W with an uncertainty of ± 20 km. The estimated focal depth of 30 km suggests this event occurred in the subducting oceanic plate. Magnitude estimates are Ms = 5.9±0.2, rrif, = 6.3±0.3 and Mi = 5.7. Surface wave and P-nodal analyses indicate that this is a predominantly strike-slip earthquake; either dextral along a NNW striking fault, or sinistral along a ENE striking fault. The seismic moment is estimated to be 8.14x10²⁴ dyne-cm, and the stress drop to be 36 bars, which is indicative of an interplate event. The quality of these data does not allow for an unambiguous interpretation of these earthquakes in terms of seismotectonic models. However, the results of this study indicate that these earthquakes do not have normal or thrust mechanisms. The 1918 earthquake appears to be a crustal, intraplate event resulting indirectly from the complicated interaction of the Explorer, Juan de Fuca and America plates. The preferred epicentre, depth and stress drop for the 1957 earthquake are consistent with left-lateral motion between the Juan de Fuca and Explorer plates along the Nootka fault zone where it is being subducted beneath Vancouver Island. Uncertainties in the above parameters however, do not rule out the possibility of this being a crustal earthquake along a NW striking fault.
Enhancing thermopower and Nernst signal of high-mobility Dirac carriers by Fermi level tuning in the layered magnet EuMnBi$_2$
Creators: name: Tsuruda, Keigo
name: Nakagawa, Kento
name: Ochi, Masayuki
name: Kuroki, Kazuhiko
name: Tokunaga, Masashi
name: Murakawa, Hiroshi
name: Hanasaki, Noriaki
name: Sakai, Hideaki
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Dirac/Weyl semimetals hosting linearly-dispersing bands have received recent attention for potential thermoelectric applications, since their ultrahigh-mobility carriers could generate large thermoelectric and Nernst power factors. To optimize these efficiencies, the Fermi energy needs to be chemically controlled in a wide range, which is generally difficult in bulk materials because of disorder effects from the substituted ions. Here it is shown that the Fermi energy is tunable across the Dirac point for layered magnet EuMnBi$_2$ by partially substituting Gd$^{3+}$ for Eu$^{2+}$ in the insulating block layer, which dopes electrons into the Dirac fermion layer without degrading the mobility. Clear quantum oscillation observed even in the doped samples allows us to quantitatively estimate the Fermi energy shift and optimize the power factor (exceeding 100 $μ$W/K$^2$cm at low temperatures) in combination with the first-principles calculation. Furthermore, it is shown that Nernst signal steeply increases with decreasing carrier density beyond a simple theoretical prediction, which likely originates from the field-induced gap reduction of the Dirac band due to the exchange interaction with the Eu moments. Thus, the magnetic block layer provides high controllability for the Dirac fermions in EuMnBi$_2$, which would make this series of materials an appealing platform for novel transport phenomena.
description: 22 pages, 4 figures; Original version submitted for peer review; Supporting Information is included at the end of the file
Invariant indices of polarimetric purity. Generalized indices of purity for nxn covariance matrices
Creators: name: Jose, I. San
name: Gil, J. J.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Optics (physics.optics)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: FOS: Physical sciences

description: A proper set of indices characterizing the polarimetric purity of light and material media is defined from the eigenvalues of the corresponding coherency matrix. A simple and generalizable relation of these indices with the current parameters characterizing the global purity is obtained. A general definition for systems characterized by nxn positive semidefinite Hermitian matrices is introduced in terms of the corresponding eigenvalues and diagonal Gell-Mann matrices. The set of n-1 indices of purity has a nested structure and provide complete information about the statistical purity of the system.
description: 19 pages, 2 figures
Twenty-three new ultra-cool subdwarfs from the Sloan Digital Sky Survey
Creators: name: Lepine, Sebastien
name: Scholz, Ralf-Dieter
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: A search of the Sloan Digital Sky Survey spectroscopic database has turned up 23 new ultra-cool subdwarfs, low-mass metal-poor stars of spectral subtype M 7.0 or later. Spectra from these red objects all show very strong molecular bands of CaH but relatively weak bands of TiO, indicative of a cool, metal-poor atmosphere. Five of the stars are formally classified as M subdwarfs (sdM7.0-sdM8.5), 13 as more metal-poor extreme subdwarfs (esdM7.0-esdM8.0), and five as extremely metal-poor ultra subdwarfs (usdM7.0-usdM7.5). In the [H_r,r-z] reduced proper motion diagram, these subdwarfs clearly populate the locus of low-luminosity stars with halo kinematics. It is argued that the objects are all very low-mass, metal-poor stars from the Galactic halo (Population II). These new discoveries more than double the census of spectroscopically confirmed ultra-cool subdwarfs. We show that the stars stand out remarkably in the [g-r,r-i] color-color diagram; a proposed color and proper motion selection scheme is expected to be extremely efficient in identifying more of these old, very low mass stars in the vicinity of the Sun.
description: 4 pages, submitted to the Astrophysical Journal Letters, version 2 includes minor corrections
Polar Cremona Transformations and Monodromy of Polynomials
Creators: name: Ahmed, Imran
Publisher: name: arXiv
Year: 2007
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: Primary 14E05, 14J70, 32S55; Secondary 14F45, 32S30

description: Consider the gradient map associated to any non-constant homogeneous polynomial $f\in \C[x_0,...,x_n]$ of degree $d$, defined by \[ϕ_f=grad(f): D(f)\to \CP^n, (x_0:...:x_n)\to (f_0(x):...:f_n(x))\] where $D(f)=\{x\in \CP^n; f(x)\neq 0\}$ is the principal open set associated to $f$ and $f_i=\frac{\partial f}{\partial x_i}$. This map corresponds to polar Cremona transformations. In Proposition \ref{p1} we give a new lower bound for the degree $d(f)$ of $ϕ_f$ under the assumption that the projective hypersurface $V:f=0 $ has only isolated singularities. When $d(f)=1$, Theorem \ref{t4} yields very strong conditions on the singularities of $V$.
description: 8 pages
The fluxgate electric field meter : a feasibility study
Creators: name: Cover, Keith Sean
Publisher: name: University of British Columbia
Year: 2010

description: The fluxgate electric field meter is a new solid-state instrument capable of measuring slowly varying electric fields equally well in an insulating or conducting medium with high resolution. The field meter determines the strength of an electric field by measuring the potential difference between two insulated electrodes immersed in the electric field. The electrode insulation is important because it eliminates the contact potential noise between the conductive material of the electrode and a conductive medium. The capacitance of the insulated electrodes is of the order of 10pF; therefore measurement of the potential difference between the electrodes requires an electrometer with extremely low bias current and high input resistance. A novel electrometer was concieved and designed to accomplish this task. The new electrometer is a solid-state analogue of the vibrating-capacitor electrometer and is claimed to have zero bias current. MOS capacitors are substituted for the vibrating capacitor. The noise level for the crude, proof-of-concept electrometer was 220μVHz[sup -1/2] at 1Hz. This noise level is only 20 dB worse than the best commerical device I could locate. A crude, proof-of-concept electric field meter constructed with the electrometer had a high frequency cutoff of 150Hz and low frequency cutoff of 100μHz. Possible applications of the fluxgate electric field meter include measurement of atmospheric and interplanetary electric fields, measurement of static charge buildup, and geophysical surveys.
Variable Rate Swap Valuation
Creators: name: Lee, David
Publisher: name: Zenodo
Year: 2022
Subjects: Variable Rate Swap Valuation

description: Variable rate swap is a special type of interest rate swap in which one leg of the swap corresponds to fixed rate payments while the other involves fixed rate payments for an initial period of time and a floating rate for the rest. The floating rate on that portion is defined as a minimum of two index rates.
description: https://osf.io/j3p7q/wiki/home/
Title Normalization & Quality Control: Making Excel Work for You and Not the Other Way Around
Creators: name: Burt, Claralyn
Publisher: name: Digital Repository at the University of Maryland
Year: 2019
Subjects: Microsoft Excel, Functions, Formulas, Title normalization, Quality Control

description: Every year, the Continuing Resources & Database Management Division systematically renews the journal and serial subscriptions for the Library.There are many moving parts resulting in a multi-step, multi-month workflow. This past 2018 renewal season, I streamlined the process in two innovative ways: title normalization and using the IF function in Excel as a quality control step. I began by cleaning the data to normalize the titles. After completing a rigorous vLookUp function, I added a quality control step with an IF function to ensure that the matches were accurate. Because I took the time to standardize and normalize my data at the beginning of this process, I could create a better, more inclusive formula. Ultimately, I did not have to manually check hundreds of titles because I engineered Excel to do it for me. This saved time and money in meeting the needs of the users and researchers here at McKeldin Library.
description: Every year, the Continuing Resources & Database Management Division systematically renews the journal and serial subscriptions for the Library.There are many moving parts resulting in a multi-step, multi-month workflow. This past 2018 renewal season, I streamlined the process in two innovative ways: title normalization and using the IF function in Excel as a quality control step. I began by cleaning the data to normalize the titles. After completing a rigorous vLookUp function, I added a quality control step with an IF function to ensure that the matches were accurate. Because I took the time to standardize and normalize my data at the beginning of this process, I could create a better, more inclusive formula. Ultimately, I did not have to manually check hundreds of titles because I engineered Excel to do it for me. This saved time and money in meeting the needs of the users and researchers here at McKeldin Library.
Equilibrium Low Temperature Heat Capacity of the Spin Density Wave compound (TMTTF)2 Br: effect of a Magnetic Field
Creators: name: Sahling, S.
name: Lasjaunias, J. C.
name: Mélin, R.
name: Monceau, P.
name: Reményi, G.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We have investigated the effect of the magnetic field (B) on the very low-temperature equilibrium heat capacity ceq of the quasi-1 D organic compound (TMTTF)2Br, characterized by a commensurate Spin Density Wave (SDW) ground state. Below 1K, ceq is dominated by a Schottky-like contribution, very sensitive to the experimental time scale, a property that we have previously measured in numerous DW compounds. Under applied field (in the range 0.2- 7 T), the equilibrium dynamics, and hence ceq extracted from the time constant, increases enormously. For B = 2-3 T, ceq varies like B2, in agreement with a magnetic Zeeman coupling. Another specific property, common to other Charge/Spin density wave (DW) compounds, is the occurrence of metastable branches in ceq, induced at very low temperature by the field exceeding a critical value. These effects are discussed within a generalization to SDWs in a magnetic field of the available Larkin-Ovchinnikov local model of strong pinning. A limitation of the model when compared to experiments is pointed out.
description: 10 pages, 11 figures
Symmetry interaction and many-body correlations
Creators: name: Papa, M.
name: Giuliani, G.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: It is shown how many-body correlations involving the symmetry potential naturally arise in the molecular dynamics CoMD-II model. The effect of these correlations on the collision dynamics at the Fermi energies is discussed. Small level of correlations for systems of moderate asymmetry are able to produce large effects also in simple observables like the charge distributions. The comparison with predictions based on Equation Of State static calculations is also discussed.
description: 11 pages, 3 figures
On application of stochastic differential equations for simulation of nonlinear wave-particle resonant interactions
Creators: name: Lukin, A. S.
name: Artemyev, A. V.
name: Petrukovich, A. A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: Long-term simulations of energetic electron fluxes in many space plasma systems require accounting for two groups of processes with well separated time-scales: microphysics of electron resonant scattering by electromagnetic waves and electron adiabatic heating/transport by mesoscale plasma flows. Examples of such systems are Earth's radiation belts and Earth's bow shock, where ion-scale plasma injections and cross-shock electric fields determine the general electron energization, whereas electron scattering by waves relax anisotropy of electron distributions and produces small populations of high-energy electrons. The applicability of stochastic differential equations is a promising approach for including effects of resonant wave-particle interaction into codes of electron tracing in global models. This study is devoted to test of such equations for systems with nondiffusive wave-particle interactions, i.e. systems with nonlinear effects of phase trapping and bunching. We consider electron resonances with intense electrostatic whistler-mode waves often observed in the Earth's radiation belts. We demonstrate that nonlinear resonant effects can be described by stochastic differential equations with the non-Gaussian probability distribution of random variations of electron energies.
Effects of non-WKB Alfven waves on a multicomponent solar wind with differential ion flow
Creators: name: Li, Bo
name: Li, Xing
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present multicomponent solar wind models self-consistently incorporating the contribution from dissipationless, monochromatic, finite-wavelength (non-WKB), hydromagnetic, toroidal Alfvén waves, which are coupled to the flow only through the ponderomotive forces. We find that the non-WKB effects are significant, for the fast and slow solar wind solutions alike. Compared with their non-WKB counterparts the WKB ones are more effective in accelerating the solar wind inside the Alfvén point, producing significantly enhanced ion fluxes and considerably reduced alpha abundance in the inner corona. Only when $ω\gtrsim 3.5\times 10^{-3}$ ($1.5\times 10^{-3}$) $\rm rad s^{-1}$ can the fast (slow) wind models be adequately approximated by the WKB one. Moreover, while the Alfvén waves tend to reduce the magnitude of the proton-alpha speed difference $|U_{αp}|$ in general, different mechanisms operate in two different regimes separated by an $ω_c\sim {several}\times 10^{-5}$ $\rm rad s^{-1}$. When $ω> ω_c$, the fluctuations are wave-like and tend to accelerate both ion species, thereby losing most of their energy by doing work on ion flows; whereas when $ω< ω_c$, a quasi-static behavior results: the fluctuations may act to accelerate the slower flowing ion species but decelerate the faster moving one in a large portion of the computational domain, and only a minor fraction of the wave energy flux injected at the base is lost. The consequences of $ω_c$ on the velocity fluctuation spectra of protons and alpha particles, which are likely to be obtained by future missions like Solar Orbiter and Solar Probe, are discussed.
description: 12 pages, 5 figures, accepted for publication in ApJ
Off-center HII regions in power-law density distributions
Creators: name: Arthur, S. J.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The expansion of ionization fronts in uniform and spherically symmetric power-law density distributions is a well-studied topic. However, in many situations, such as a star formed at the edge of a molecular cloud core, an offset power-law density distribution would be more appropriate. In this paper a few of the main issues of the formation and expansion of HII regions in such media are outlined and results are presented for the particular cases where the underlying power laws are 1/r^2 and 1/r^3. A simple criterion is developed for determining whether the initial photoionized region will be unbounded, which depends on the power-law exponent and the ratio of the equivalent Stroemgren radius produced by the star in a uniform medium to the stellar offset distance. In the expansion stage, the ionized volumes will eventually become unbounded unless pressure balance with the external medium is reached before the ionization front velocity becomes supersonic with respect to the ionized gas.
description: 9 pages, 10 figures, emulate ApJ style, submitted to The Astrophysical Journal
Inference on the structure of gene regulatory networks
Creators: name: Wang, Yue
name: Wang, Zikun
Publisher: name: arXiv
Year: 2021
Subjects: subject: Molecular Networks (q-bio.MN)
subject: FOS: Biological sciences
subject: 92-08, 92-10

description: In this paper, we conduct theoretical analyses on inferring the structure of gene regulatory networks. Depending on the experimental method and data type, the inference problem is classified into 20 different scenarios. For each scenario, we discuss the problem that with enough data, under what assumptions, what can be inferred about the structure. For scenarios that have been covered in the literature, we provide a brief review. For scenarios that have not been covered in literature, if the structure can be inferred, we propose new mathematical inference methods and evaluate them on simulated data. Otherwise, we prove that the structure cannot be inferred.
Multiple dynamic matching and median filters applied to sonic well logs
Creators: name: Leaney, W. Scott Powell
Publisher: name: University of British Columbia
Year: 2010

description: Nonlinear signal matching is a generalization of cross correlation in that a discrete lag between signals is replaced with a variable lag function or 'matching function', m(x). Two methods are reviewed which attempt to solve for m(x), namely the dynamic programming approach and the inverse theory approach. Both methods suffer from pitfalls and require the input of prior constraints to ensure convergence to the correct solution. The goal of this work has been to develop a method that can handle simple or complex matching problems and can succeed without any prior knowledge constraints. The multiple dynamic matching method is the result. It uses a significance threshold to extract a set of ridge points from a similarity matrix and applies dynamic programming to obtain a set of matched sections. These significant matched sections or 'subpaths' are then combined into a set of complete matching functions and a 'mean local confidence' norm is evaluated to determine the best overall match. It is argued through a model of change between signals, that given that the correct matching function is known, the presence of large amplitude changes between signals can cause the correct matching function to appear suboptimal under similarity norms. Multiple dynamic matching, because it generates suboptimal solutions as well, does not overlook the correct matching function. Typically the top three interpretations as ranked by mean local confidence will contain the expert's choice for the correct matching function. The use of median filters to preprocess the data and enhance well log features for matching has been investigated. A new 'median decomposition' is discussed as well, and in the context of a scale - space point of view to filtering, it is argued that median scale space is the proper choice for blocky waveforms. Finally, the connection between multiple dynamic matching and pattern recognition is explored, and matching iteratively through scale is proposed as a means of further generalizing the multiple dynamic matching method, making efficient high resolution matching possible.
Novel antifungal talaroenamine L with unusual leptosphaeronyl moiety from marine-derived Talaromyces sp. HDN17-428 via HDACi elicitation
Creators: name: Anjum, Komal
name: Zhou, Luning
name: Hayyat, Khizar
name: Huang, Xiaofei
name: Wang, Jiaxiang
name: Zhang, Guojian
name: Zhu, Tianjiao
name: Che, Qian
name: Li, Dehai
Publisher: name: Taylor & Francis
Year: 2024
Subjects: subject: Pharmacology
subject: Environmental Sciences not elsewhere classified
subject: Chemical Sciences not elsewhere classified
subject: Ecology
subject: FOS: Biological sciences
subject: Inorganic Chemistry
subject: FOS: Chemical sciences
subject: Infectious Diseases
subject: FOS: Health sciences
subject: Virology

description: Vorinostat elicitation of the deep-sea fungus Talaromyces sp. HDN17-428 resulted in the isolation of one new compound, talaroenamine L (1) with unusual leptosphaeronyl moiety and three known compounds (2–4). Structures of 1–4 were confirmed by extensive NMR, HRESIMS and OR calculations. Antimicrobial activities of all compounds were tested in which compounds 1–4 showed substantial antifungal activities with MIC values ranged from 3.1 to 12.5 μM.
Effect of the uncertainty in the hadronic interaction models on the estimation of the sensitivity of the Cherenkov Telescope Array
Creators: name: Ohishi, Michiko
name: Arbeletche, Luan
name: de Souza, Vitor
name: Maier, Gernot
name: Bernlöhr, Konrad
name: Olaizola, Abelardo Moralejo
name: Bregeon, Johan
name: Arrabito, Luisa
name: Yoshikoshi, Takanori
Publisher: name: arXiv
Year: 2021
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Imaging Atmospheric Cherenkov Telescopes (IACTs) are ground-based indirect detectors for cosmic gamma rays with energies above tens of GeV. The major backgrounds for gamma-ray observations in IACTs are cosmic-ray charged particles. The capability to reject these backgrounds is the most important factor determining the gamma-ray sensitivity of IACT systems. Monte Carlo simulations are used to estimate the residual background rates and sensitivity of the systems during the design and construction phase. Uncertainties in the modeling of high-energy hadronic interactions of cosmic rays with nuclei in the air propagate into the estimates of residual background rates and subsequently into the estimated instrument sensitivity. We investigate the influence of the difference in the current hadronic interaction models on the estimated gamma-ray sensitivity of the Cherenkov Telescope Array using four interaction models (QGSJET-II-03, QGSJET-II-04, EPOS-LHC, and SIBYLL2.3c) implemented in the air shower simulation tool CORSIKA. Variations in background rates of up to a factor 2 with respect to QGSJET-II-03 are observed between the models, mainly due to differences in the $π^0$ production spectrum. These lead to ~30% differences in the estimated gamma-ray sensitivity in the 1 - 30 TeV region, assuming a 50-hour observation of a gamma-ray point-like source. The presented results also show that IACTs have a significant capability in the verification of hadronic interaction models.
description: 23 pages, 10 figures, accepted for publication in JPhysG
Developments in minimum entropy deconvolution
Creators: name: Nickerson, William Alexander
Publisher: name: University of British Columbia
Year: 2010

description: Minimum entropy deconvolution (MED) is investigated in light of recent work, and reports of poor performance in the deconvolution of real reflection seismograms. The problems with MED fall into two catagories. The first contains problems related to operator design such as avoiding local extrema in the simplicity criterion, problems with bandwidth, and the selection of filter length and preprocessing parameters. The second is the determination of model validity for the data at hand. MED is based on the iterative maximization of a data simplicity criterion which exhibits multiple extrema. A geometrical interpretation of this algorithm leads to an intuitive alternative algorithm, the projection method, and to the conclusion that iteration starting filter governs which extremum is reached and hence output wavelet delay. Choice of starting filter is therefore tantamount to a wavelet phase assumption and there is no basis for choosing the standard, centred impulse, starting filter if the global extremum is desired. An optimum lag MED algorithm is proposed to achieve the global maximum. Bandlimiting, data tapering and other aspects of MED operator design are discussed. No criterion exists for assessing MED model validity. Studies with various synthetic reflectivity statistics reveal that "sparseness" and "simplicity" are poor descriptors of the minimum entropy assumption. Preliminary attempts to quantify MED applicability are made but fail and indicate that any successful measure must include both underlying reflectivity and wavelet characteristics. Examples using synthetic data show the advantages of the bandlimited optimum lag MED algorithm over a conventional starting filter method.
A unified theoretical framework for fluctuating-charge models in atom-space and in bond-space
Creators: name: Chen, Jiahao
name: Martínez, Todd J.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: Our previously introduced QTPIE (charge transfer with polarization current equilibration) model (J. Chen and T. J. Martinez, Chem. Phys. Lett. 438, 315 (2007)) is a fluctuating-charge model with correct asymptotic behavior. Unlike most other fluctuating-charge models, QTPIE is formulated in terms of charge-transfer variables and pairwise electronegativities, not atomic charge variables and electronegativities. The pairwise character of the electronegativities in QTPIE avoids spurious charge transfer when bonds are broken. However, the increased number of variables leads to considerable computational expense and a rank-deficient set of working equations, which is numerically inconvenient. Here, we show that QTPIE can be exactly reformulated in terms of atomic charge variables, leading to a considerable reduction in computational complexity. The transformation between atomic and bond variables is generally applicable to arbitrary fluctuating charge models, and uncovers an underlying topological framework that can be used to understand the relation between fluctuating-charge models and the classical theory of electrical circuits.
description: 36 pages, 7 figures; submitted to J. Chem. Phys
Hellman-Feynman operator sampling in Diffusion Monte Carlo calculations
Creators: name: Gaudoin, R.
name: Pitarke, J. M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: Diffusion Monte Carlo (DMC) calculations typically yield highly accurate results in solid-state and quantum-chemical calculations. However, operators that do not commute with the Hamiltonian are at best sampled correctly up to second order in the error of the underlying trial wavefunction, once simple corrections have been applied. This error is of the same order as that for the energy in variational calculations. Operators that suffer from these problems include potential energies and the density. This paper presents a new method, based on the Hellman-Feynman theorem, for the correct DMC sampling of all operators diagonal in real space. Our method is easy to implement in any standard DMC code.
Probability distributions of turbulent energy
Creators: name: Momeni, Mahdi
name: Müller, Wolf-Christian
Publisher: name: arXiv
Year: 2008
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: Probability density functions (PDFs) of scale-dependent energy fluctuations, $P[δE(\ell)]$, are studied in high-resolution direct numerical simulations of Navier-Stokes and incompressible magnetohydrodynamic (MHD) turbulence. MHD flows with and without a strong mean magnetic field are considered. For all three systems it is found that the PDFs of inertial range energy fluctuations exhibit self-similarity and monoscaling in agreement with recent solar-wind measurements [B. Hnat et al., Geophys. Res. Lett. 29(10), 86-1 (2002)]. Furthermore, the energy PDFs exhibit similarity over all scales of the turbulent system showing no substantial qualitative change of shape as the scale of the fluctuations varies. This is in contrast to the well-known behavior of PDFs of turbulent velocity fluctuations. In all three cases under consideration the $P[δE(\ell)]$ resemble Lévy-type gamma distributions $\sim Δ^{-1}\exp(-|δE|/Δ)|δE|^{-γ}$ The observed gamma distributions exhibit a scale-dependent width $Δ(\ell)$ and a system-dependent $γ$. The monoscaling property reflects the inertial-range scaling of the Elsässer-field fluctuations due to lacking Galilei invariance of $δE$. The appearance of Lévy distributions is made plausible by a simple model of energy transfer.
description: accepted for publication in PRE
Variable stars in the VVV globular clusters. II. NGC6441, NGC6569, NGC6626 (M28), NGC6656 (M22), 2MASS-GC02, and Terzan10
Creators: name: Alonso-García, Javier
name: Smith, Leigh C.
name: Catelan, Márcio
name: Minniti, Dante
name: Navarrete, Camila
name: Borissova, Jura
name: Carballo-Bello, Julio A.
name: Ramos, Rodrigo Contreras
name: Fernández-Trincado, José G.
name: Lopes, Carlos E. Ferreira
name: Gran, Felipe
name: Garro, Elisa R.
name: Geisler, Doug
name: Guo, Zhen
name: Hempel, Maren
name: Kerins, Eamonn
name: Lucas, Philip W.
name: Palma, Tali
name: Ramírez, Karla Peña
name: Alegría, Sebastián Ramírez
name: Saito, Roberto K.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The Galactic globular clusters (GGCs) located in the inner regions of the Milky Way suffer from high extinction that makes their observation challenging. The VVV survey provides a way to explore these GGCs in the near-infrared where extinction effects are highly diminished. We conduct a search for variable stars in several inner GGCs, taking advantage of the unique multi-epoch, wide-field, near-infrared photometry provided by the VVV survey. We are especially interested in detecting classical pulsators that will help us constrain the physical parameters of these GGCs. In this paper, the second of a series, we focus on NGC6656 (M22), NGC6626 (M28), NGC6569, and NGC6441; these four massive GGCs have known variable sources, but quite different metallicities. We also revisit 2MASS-GC02 and Terzan10, the two GGCs studied in the first paper of this series. We present an improved method and a new parameter that efficiently identify variable candidates in the GGCs. We also use the proper motions of those detected variable candidates and their positions in the sky and in the color-magnitude diagrams to assign membership to the GGCs. We identify and parametrize in the near-infrared numerous variable sources in the studied GGCs, cataloging tens of previously undetected variable stars. We recover many known classical pulsators in these clusters, including the vast majority of their fundamental mode RR Lyrae. We use these pulsators to obtain distances and extinctions toward these objects. Recalibrated period-luminosity-metallicity relations for the RR Lyrae bring the distances to these GGCs to a closer agreement with those reported by Gaia, except for NGC6441. Recovered proper motions for these GGCs also agree with those reported by Gaia, except for 2MASS-GC02, the most reddened GGC in our sample, where the VVV near-infrared measurements provide a more accurate determination of its proper motions.
description: Accepted for publication in A&A, 18 pages, 14 Figures, 9 Tables