cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Two formation channels of UCDs in Hickson Compact Groups
Creators: name: Da Rocha, C.
name: Mieske, S.
name: Georgiev, I. Y.
name: Hilker, M.
name: Ziegler, B. L.
name: de Oliveira, C. Mendes
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: The formation of ultra-compact dwarf galaxies (UCDs) is believed to be interaction driven, and UCDs are abundant in the cores of galaxy clusters, environments that mark the end-point of galaxy evolution. Nothing is known about the properties of UCDs in compact groups of galaxies, environments where most of galaxy evolution and interaction is believed to occur and where UCDs in intermediate state of evolution may be expected. The main goal of this study is to detect and characterize, for the first time, the UCD population of compact groups. For that, 2 groups in different evolutionary stages, HCG 22 and HCG 90, were targeted with VLT/FORS2/MXU. We detect 16 and 5 objects belonging to HCG 22 and HCG 90, respectively, covering the magnitude range -10.0 > M_R > -11.5 mag. Their colours are consistent with old ages covering a broad range in metallicities. Photometric mass estimates put 4 objects in HCG 90 and 9 in HCG 22 in the mass range of UCDs (>2x10^6 M_Sun) for an assumed age of 12 Gyr. These UCDs are on average 2-3 times larger than typical Galactic GCs, covering a range of 2 >~ r_h >~ 21 pc. The UCDs in HCG 22 are more concentrated around the central galaxy than in HCG 90, at the 99% confidence level. They cover a broad range in [alpha/Fe] abundances from sub- to super-solar. The spectra of 3 UCDs show tentative evidence for intermediate age stellar populations. We calculate the specific frequency (S_N) of UCDs for both groups, finding that HCG 22 has about three times higher S_N than HCG 90. The ensemble properties of the detected UCDs supports 2 co-existing formation channels: a star cluster origin and an origin as tidally stripped dwarf nuclei. Our results imply that the UCDs detected in both groups do not, in their majority, originate from relatively recent galaxy interactions. Most of the detected UCDs have likely been brought into the group with their host galaxies.[abridged]
description: Accepted for publication at A&A, 17 pages, 9 figures + 2 additional figures
Predicting regrowth of low-grade gliomas after radiotherapy
Creators: name: Plaszczynski, Stephane
name: Grammaticos, Basile
name: Pallud, Johan
name: Campagne, Jean-Eric
name: Badoual, Mathilde
Publisher: name: arXiv
Year: 2022
Subjects: subject: Medical Physics (physics.med-ph)
subject: FOS: Physical sciences

description: Diffuse low grade gliomas are invasive and incurable brain tumours that inevitably transform into higher grade ones. A classical treatment to delay this transition is radiotherapy (RT). Following RT, the tumour gradually shrinks during a period of typically 6 months to 4 years before regrowing. To improve the patient's health-related quality of life and help clinicians build personalised follow-ups, one would benefit from predictions of the time during which the tumour is expected to decrease. The challenge is to provide a reliable estimate of this regrowth time shortly after RT (i.e. with few data), although patients react differently to the treatment. To this end, we analyse the tumour size dynamics from a batch of 20 high-quality longitudinal data, and propose a simple and robust analytical model, with just 4 parameters. From the study of their correlations, we build a statistical constraint that helps determine the regrowth time even for patients for which we have only a few measurements of the tumour size. We validate the procedure on the data and predict the regrowth time at the moment of the first MRI after RT, with precision of, typically, 6 months. Using virtual patients, we study whether some forecast is still possible just three months after RT. We obtain some reliable estimates of the regrowth time in 75\% of the cases, in particular for all "fast-responders". The remaining 25\% represent cases where the actual regrowth time is large and can be safely estimated with another measurement a year later. These results show the feasibility of making personalised predictions of the tumour regrowth time shortly after RT.
The devil’s northern triangle : Howard Adams and Métis multidimensional relationships with and within colonialism
Creators: name: Voth, Daniel Jacob-Paul
Publisher: name: University of British Columbia
Year: 2015

description: This dissertation deploys the life’s work of Métis scholar and activist Howard Adams to show that his binaristic positioning of Métis people within the colonial world is first productive for elucidating and analyzing the devastation wrought on his people by the processes of colonization, and second an incomplete analysis of Métis political relationships with and within colonialism. Adams’ thought contains an uncomfortable positioning whereby the Métis are framed as colonized subjects while also being the products of the racist and destructive processes of colonialism. Adams does not interrogate this uncomfortable positioning in his work. Instead, he reinforces Métis people as exclusively colonized subjects. This dissertation posits that being the products of colonialism while also being colonized subjects opens a space to examine the range of relationships Métis people have with their kin in other Indigenous nations. I argue that looking at inter-Indigenous politics through this complex positioning shows how Métis interact and resist the ideology and processes of colonialism that seek to terminate and dispossess them from their territories, while also illuminating the way Métis political actors engage in zero-sum—and in some cases, colonial—relationships with other Indigenous peoples. I examine this through the critical juncture formed during the Red River Resistance in 1869-70: in the process of resisting the advancement of the Settler state, Métis political actors attempted to set up a sphere of power at Red River to the exclusion of most other Indigenous peoples. I then examine the reproduction of the legacy of zero-sum relationships in the formation and breakup of the Indian and Métis Conference (forerunner to the Manitoba Métis Federation), followed by the attempt by Métis and other Indigenous peoples to strategically deploy the law. The examination of these strategic deployments is informed by the interaction between Métis and Treaty 1 peoples at the Manitoba Court of Appeal hearing of MMF v. Canada. I conclude that embracing the discomfort in Adams’ positioning helps inform Métis political engagements with other Indigenous peoples. The benefit of this positioning is that it contributes to building informed inter-Indigenous decolonizing movements.
The evolution of radio sources in the UKIDSS-DXS XMM-LSS field
Creators: name: McAlpine, Kim
name: Jarvis, Matt J.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We investigate the cosmic evolution of low luminosity ($L_{\rm{1.4GHz}}<10^{25}\rm{W~Hz^{-1}sr^{-1}}$) radio sources in the XMM Large Scale Structure survey field (XMM-LSS). We match low frequency selected (610~MHz) radio sources in the XMM-LSS field with near infrared $K$-band observations over the same field from the UKIRT Infrared Deep Sky Survey. We use both the mean $V/V_{\rm{max}}$ statistic and the radio luminosity function of these matched sources to quantify the evolution of the co-moving space density of the low luminosity radio sources in our sample. Our results indicate that the low luminosity sources evolve differently to their high luminosity counterparts out to a redshift of z$\sim$0.8. The derived luminosity function is consistent with an increase in the co-moving space density of low luminosity sources by a factor of $\sim$1.5 at z=0.8. We show that the use of the $K-z$ diagram for the radio source population, although coarser than a full photometric redshift analysis, produces consistent results with previous studies using $\sim >10$ band photometry. This offers a promising method for conducting similar analyses over the whole sky with future near- and mid-infrared surveys.
description: 8 pages, 5 figures, 2 tables, accepted for publication in MNRAS
Bouncing Wave Packets, Ehrenfest Theorem, and Uncertainty Relation based upon a new Concept for the Momentum of a Particle in a Box
Creators: name: Albrecht, I.
name: Herrmann, J.
name: Mariani, A.
name: Wiese, U. -J.
name: Wyss, V.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: For a particle in a box, the operator $-i\partial_x$ is not self-adjoint and thus does not qualify as the physical momentum. As a result, in general the Ehrenfest theorem is violated. Based upon a recently developed new concept for a self-adjoint momentum operator, we reconsider the theorem and find that it is now indeed satisfied for all physically admissible boundary conditions. We illustrate these results for bouncing wave packets which first spread, then shrink, and return to their original form after a certain revival time. We derive a very simple form of the general Heisenberg-Robertson-Schrödinger uncertainty relation and show that our construction also provides a physical interpretation for it.
description: 37 pages, 12 figures
Concentrations and turnover rates of reduced sulfur compounds in polar and sub-polar marine waters : field application of novel analytical and experimental techniques
Creators: name: Asher, Elizabeth Colleen
Publisher: name: University of British Columbia
Year: 2015

description: Dimethylsulfide (DMS), dimethylsulfoniopropionate (DMSP) and dimethyl sulfoxide (DMSO) are ubiquitous in surface marine environments. These reduced sulfur compounds are crucial to the physiological ecology of bacteria and phytoplankton. DMS also has a role in climate regulation, as a source of aerosols that back-scatter incoming solar radiation. This thesis aims to characterize the processes driving DMS/P/O accumulation in polar and sub-polar marine waters. Chapters two and three document DMS/P/O concentrations in surface waters of the Subarctic Northeast Pacific, using automated measurement systems. These studies employed an existing system based on membrane inlet mass spectrometry (MIMS) and a novel automated system for the sequential analysis of DMS/P/O (OSSCAR; see chapter three). DMS/P/O concentrations demonstrate significant spatial variability over a range of scales in both coastal and open ocean waters, revealing relationships with key oceanographic variables. Chapter four describes the first application of a recently developed, stable isotope tracer technique using purge and trap capillary inlet mass spectrometry (PT-CIMS) in Antarctic sea-ice. This chapter documents extremely rapid DMS/P/O turnover in sea-ice brines and demonstrates a previously unrecognized role for DMSO, as well as DMSP, as important sources of DMS in these environments. Chapters five and six use MIMS, PT-CIMS, and OSSCAR in parallel to examine DMS/P/O cycling in the Subarctic Northeast Pacific, and in coastal waters of the Western Antarctic Peninsula (WAP). Chapter five focuses on the spatial distribution of DMS accumulation and net production in the Subarctic Pacific, while chapter six follows the seasonal changes in DMS/P/O concentrations and its production in the WAP, and highlights short-scale temporal variability of DMS/P/O. Results demonstrate strong spatial gradients in DMS production and consumption terms (higher values in near-shore waters) in the Subarctic Pacific, and showed that net DMS production predicts DMS accumulation in surface waters. Over the seasonal cycle in the WAP, zooplankton grazing and DMSP cleavage dominated DMS production, and bacterially mediated DMS consumption controlled the removal of DMS in surface waters.
Multi-epoch parsec-scale observations of the blazar PKS 1510-089
Creators: name: Orienti, M.
name: Venturi, T.
name: Dallacasa, D.
name: D'Ammando, F.
name: Giroletti, M.
name: Giovannini, G.
name: Vercellone, S.
name: Tavani, M.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: (Abridged) We investigate the flux density variability and changes in the parsec-scale radio structure of the flat spectrum radio quasar PKS 1510-089. This source was target of multi-epoch VLBI and Space-VLBI observations at 4.8, 8.4 and 22 GHz carried out between 1999 and 2001. The comparison of the parsec-scale structure observed at different epochs shows the presence of a non-stationary jet feature moving with a superluminal apparent velocity of 16.2c+-0.7c. Over three epochs at 8.4 GHz during this period the core flux density varies of about 50%, while the scatter in the jet flux density is within 10%. The polarization percentage of both core and jet components significantly change from 2 to 9 per cent, while the polarization angle of the core shows an abrupt change of about 90 degrees becoming roughly perpendicular to the jet direction, consistent with a change in the opacity. To complete the picture of the physical processes at work, we complemented our observations with multi-epoch VLBA data at 15 GHz from the MOJAVE programme spanning a time baseline from 1995 to 2010. Since 1995 jet components are ejected roughly once per year with the same position angle and an apparent speed between 15c and 20c, indicating that no jet precession is taking place on a timescale longer than a decade in our frame. The variability of the total intensity flux density together with variations in the polarization properties may be explained assuming either a change between the optically-thick and -thin regimes produced by a shock that varies the opacity, or a highly ordered magnetic field produced by the compression of the relativistic plasma by a shock propagating along the jet. Taking into account the high gamma-ray emission observed from this source by the AGILE and Fermi satellites we investigated the connection between the radio and gamma-ray activity during 2007-2010.
description: 12 pages, 13 figures; accepted for publication in MNRAS
Systematic analysis of single heavy baryons $Λ_{Q}$, $Σ_{Q}$ and $Ω_{Q}$
Creators: name: Yu, Guo-Liang
name: Li, Zhen-Yu
name: Wang, Zhi-Gang
name: Lu, Jie
name: Yan, Meng
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Motivated by great progresses in experiments in searching for the heavy baryons, we systematically analyze the mass spectra and root mean square radius of single heavy baryons $Λ_{Q}$, $Σ_{Q}$ and $Ω_{Q}$. The calculations of the mass spectra are carried out in the frame work of Godfrey-Isgur (GI) relativized quark model, where the baryon is regarded as a three-body system of quarks. Our results show that the mass of single heavy baryon with $λ$-mode is lower than those of the $ρ$-mode and $λ$-$ρ$ mixing mode, which indicates that the lowest state is dominated by the $λ$-mode. Basing on this research, we systematically calculate the mass spectra and the root mean square radius of the baryons with $λ$ excited mode. With these predicated mass spectra, the Regge trajectories in the ($J$,$M^{2}$) plane are constructed, and the slopes, intercepts of the Regge trajectories are obtained by linear fitting. It is found that all available experimental data are well reproduced by model predictions and fit nicely to the constructed Regge trajectories.
description: to be published in Nuclear Physics B
Projected Gradient Descent for Spectral Compressed Sensing via Symmetric Hankel Factorization
Creators: name: Li, Jinsheng
name: Cui, Wei
name: Zhang, Xu
Publisher: name: arXiv
Year: 2024
Subjects: subject: Information Retrieval (cs.IR)
subject: FOS: Computer and information sciences

description: Current spectral compressed sensing methods via Hankel matrix completion employ symmetric factorization to demonstrate the low-rank property of the Hankel matrix. However, previous non-convex gradient methods only utilize asymmetric factorization to achieve spectral compressed sensing. In this paper, we propose a novel nonconvex projected gradient descent method for spectral compressed sensing via symmetric factorization named Symmetric Hankel Projected Gradient Descent (SHGD), which updates only one matrix and avoids a balancing regularization term. SHGD reduces about half of the computation and storage costs compared to the prior gradient method based on asymmetric factorization. {Besides, the symmetric factorization employed in our work is completely novel to the prior low-rank factorization model, introducing a new factorization ambiguity under complex orthogonal transformation}. Novel distance metrics are designed for our factorization method and a linear convergence guarantee to the desired signal is established with $O(r^2\log(n))$ observations. Numerical simulations demonstrate the superior performance of the proposed SHGD method in phase transitions and computation efficiency compared to state-of-the-art methods.
description: accepted in IEEE Transactions on Signal Processing
Locally Structure-Preserving div-curl operators for high order Discontinuous Galerkin schemes
Creators: name: Boscheri, Walter
name: Dimarco, Giacomo
name: Pareschi, Lorenzo
Publisher: name: arXiv
Year: 2022
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics

description: We propose a novel Structure-Preserving Discontinuous Galerkin (SPDG) operator that recovers at the discrete level the algebraic property related to the divergence of the curl of a vector field, which is typically referred to as div-curl problem. A staggered Cartesian grid is adopted in 3D, where the vector field is naturally defined at the corners of the control volume, while its curl is evaluated as a cell-centered quantity. Firstly, the curl operator is rewritten as the divergence of a tensor, hence allowing compatible finite difference schemes to be devised and to be proven to mimic the algebraic div-curl property. Successively, a high order DG divergence operator is built upon integration by parts, so that the structure-preserving finite difference div-curl operator is exactly retrieved for first order discretizations. We further demonstrate that the novel SPDG schemes are capable of obtaining a zero div-curl identity with machine precision from second up to sixth order accuracy. In a second part, we show the applicability of these SPDG methods by solving the incompressible Navier-Stokes equations written in vortex-stream formulation. This hyperbolic system deals with divergence-free involutions related to the velocity and vorticity field as well as to the stream function, thus it provides an ideal setting for the validation of the novel schemes. A compatible discretization of the numerical viscosity is also proposed in order to maintain the structure-preserving property of the div-curl DG operators even in the presence of artificial or physical dissipative terms. Finally, to overcome the time step restriction dictated by the viscous sub-system, Implicit-Explicit (IMEX) Runge-Kutta time stepping techniques are tailored to handle the SPDG framework.
Dust size distributions in coagulation/fragmentation equilibrium: Numerical solutions and analytical fits
Creators: name: Birnstiel, T.
name: Ormel, C. W.
name: Dullemond, C. P.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Context. Grains in circumstellar disks are believed to grow by mutual collisions and subsequent sticking due to surface forces. Results of many fields of research involving circumstellar disks, such as radiative transfer calculations, disk chemistry, magneto-hydrodynamic simulations largely depend on the unknown grain size distribution. Aims. As detailed calculations of grain growth and fragmentation are both numerically challenging and computationally expensive, we aim to find simple recipes and analytical solutions for the grain size distribution in circumstellar disks for a scenario in which grain growth is limited by fragmentation and radial drift can be neglected. Methods. We generalize previous analytical work on self-similar steady-state grain distributions. Numerical simulations are carried out to identify under which conditions the grain size distributions can be understood in terms of a combination of power-law distributions. A physically motivated fitting formula for grain size distributions is derived using our analytical predictions and numerical simulations. Results. We find good agreement between analytical results and numerical solutions of the Smoluchowski equation for simple shapes of the kernel function. The results for more complicated and realistic cases can be fitted with a physically motivated "black box" recipe presented in this paper. Our results show that the shape of the dust distribution is mostly dominated by the gas surface density (not the dust-to-gas ratio), the turbulence strength and the temperature and does not obey an MRN type distribution.
description: 16 pages, 9 figures, accepted for publication in A&A
A robust and conservative dynamical low-rank algorithm
Creators: name: Einkemmer, Lukas
name: Ostermann, Alexander
name: Scalone, Carmen
Publisher: name: arXiv
Year: 2022
Subjects: subject: Numerical Analysis (math.NA)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: Dynamical low-rank approximation, as has been demonstrated recently, can be extremely efficient in solving kinetic equations. However, a major deficiency is that they do not preserve the structure of the underlying physical problem. For example, the classic dynamical low-rank methods violate mass, momentum, and energy conservation. In [L. Einkemmer, I. Joseph, J. Comput. Phys. 443:110495, 2021] a conservative dynamical low-rank approach has been proposed. However, directly integrating the resulting equations of motion, similar to the classic dynamical low-rank approach, results in an ill-posed scheme. In this work we propose a robust, i.e. well-posed, integrator for the conservative dynamical low-rank approach that conserves mass and momentum (up to machine precision) and significantly improves energy conservation. We also report improved qualitative results for some problems and show how the approach can be combined with a rank adaptive scheme.
Genuine non-Gaussian entanglement of light and quantum coherence for an atom from noisy multiphoton spin-boson interactions
Creators: name: Laha, Pradip
name: Yasir, P. A. Ameen
name: van Loock, Peter
Publisher: name: arXiv
Year: 2024
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Harnessing entanglement and quantum coherence plays a central role in advancing quantum technologies. In quantum optical light-atom platforms, these two fundamental resources are often associated with a Jaynes-Cummings model description describing the coherent exchange of a photon between an optical resonator mode and a two-level spin. In a generic nonlinear spin-boson system, more photons and more modes will take part in the interactions. Here we consider such a generalization -- the two-mode multiphoton Jaynes-Cummings (MPJC) model. We demonstrate how entanglement and quantum coherence can be optimally generated and subsequently manipulated in experimentally accessible parameter regimes. A detailed comparative analysis of this model reveals that nonlinearities within the MPJC interactions produce genuinely non-Gaussian entanglement, devoid of Gaussian contributions, from noisy resources. More specifically, strong coherent sources may be replaced by weaker, incoherent ones, significantly reducing the resource overhead, though at the expense of reduced efficiency. At the same time, increasing the multiphoton order of the MPJC interactions expedites the entanglement generation process, thus rendering the whole generation scheme again more efficient and robust. We further explore the use of additional dispersive spin-boson interactions and Kerr nonlinearities in order to create spin coherence solely from incoherent sources and to enhance the quantum correlations, respectively. As for the latter, somewhat unexpectedly, there is not necessarily an increase in quantum correlations due to the augmented nonlinearity. Towards possible applications of the MPJC model, we show how, with appropriately chosen experimental parameters, we can engineer arbitrary NOON states as well as the tripartite W state.
description: Accepted version
Retardation effect and dark state in a waveguide QED setup with rectangle cross section
Creators: name: Xue, Yang
name: Wang, Zhihai
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In this paper, we investigate the dynamics of a two-atom system which couples to a quasi-one dimensional waveguide with rectangle cross section. The waveguide supports different TM and TE modes and the former ones play as environment by on-demand choosing the dipole moment of the atoms. Such environment induces the interaction and collective dissipation of the atoms. When both of the two atoms are located in the middle of the waveguide, we observe a retardation effect, which is broken by moving one of the atom to be off-centered. To preserve the complete dissipation of the system via dark state mechanism, we propose a scheme where the connection of the atoms are perpendicular to the axis of the waveguide. We hope our study will be useful in quantum information processing based on state-to-art waveguide structure.
description: 6 Pages, 4 Figures. Comments are welcomed
Two-dimensional gauge anomalies and $p$-adic numbers
Creators: name: Camp, Imogen
name: Gripaios, Ben
name: Nguyen, Khoi Le Nguyen
Publisher: name: arXiv
Year: 2024
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We show how methods of number theory can be used to study anomalies in gauge quantum field theories in spacetime dimension two. To wit, the anomaly cancellation conditions for the abelian part of the local anomaly admit solutions if and only if they admit solutions in the reals and in the $p$-adics for every prime $p$ and we use this to build an algorithm to find all solutions.
description: 5 pp
Search for modulations of the solar Be-7 flux in the next-generation neutrino observatory LENA
Creators: name: Wurm, Michael
name: Caccianiga, Barbara
name: D'Angelo, Davide
name: Davini, Stefano
name: von Feilitzsch, Franz
name: Göger-Neff, Marianne
name: Lachenmaier, Tobias
name: Lewke, Timo
name: Lombardi, Paolo
name: Ludhova, Livia
name: Meindl, Quirin
name: Meroni, Emanuela
name: Miramonti, Lino
name: Möllenberg, Randolph
name: Oberauer, Lothar
name: Potzel, Walter
name: Ranucci, Gioacchino
name: Tippmann, Marc
name: Winter, Jürgen
Publisher: name: arXiv
Year: 2010
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: A next-generation liquid-scintillator detector will be able to perform high-statistics measurements of the solar neutrino flux. In LENA, solar Be-7 neutrinos are expected to cause 1.7x10^4 electron recoil events per day in a fiducial volume of 35 kilotons. Based on this signal, a search for periodic modulations on sub-percent level can be conducted, surpassing the sensitivity of current detectors by at least a factor of 20. The range of accessible periods reaches from several minutes, corresponding to modulations induced by helioseismic g-modes, to tens of years, allowing to study long-term changes in solar fusion rates.
description: 15 pages, 9 figures
Additional file 1 of Offspring production of haploid spermatid-like cells derived from mouse female germline stem cells with chromatin condensation
Creators: name: Hu, Xiaopeng
name: Wang, Hu
name: Tian, Geng. G.
name: Hou, Changliang
name: Xu, Bo
name: Zhao, Xinyan
name: Zhao, Yongqiang
name: Fang, Qian
name: Li, Xinyue
name: He, Lin
name: Chen, Xuejin
name: Li, Shangang
name: Wu, Ji
Publisher: name: figshare
Year: 2022
Subjects: subject: Genetics
subject: FOS: Biological sciences

description: Additional file 1: Table S1. Oligonucleotide primer sequences. Table S2. Valid Hi-C data. Figure S1. Characterization and identification of FGSCs. Figure S2. Characterization and identification of SSCs. Figure S3. FGSCs injected into Kitw/wv mouse seminiferous tubules transdifferentiate into male germ cells and express PLZF in a testicular microenvironment. Figure S4. PLZF was expressed in GFP positive cells by Immunofluorescence analysis. Figure S5. In vitro induction of meiosis in SSCs and formation of SLCs derived from SSCs. Figure S6. Comparison of in vitro transdifferentiation of FGSCs with in vitro differentiation of SSCs. Figure S7. Comparison between Hi-C seq and ChIP seq biological replicates. Figure S8. k-means clustering of H3K4me3 and H3K27me3 at all TSSs in different cell states and enriched GO terms. Figure S9. The number of A/B compartments, genes in TADs, and genes outside of TADs in different cell states based on four clusters. Figure S10. Methylation and expression analysis of imprinted genes.
A globally convergent method to accelerate large-scale optimization using on-the-fly model hyperreduction: application to shape optimization
Creators: name: Wen, Tianshu
name: Zahr, Matthew J.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Optimization and Control (math.OC)
subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics

description: We present a numerical method to efficiently solve optimization problems governed by large-scale nonlinear systems of equations, including discretized partial differential equations, using projection-based reduced-order models accelerated with hyperreduction (empirical quadrature) and embedded in a trust-region framework that guarantees global convergence. The proposed framework constructs a hyperreduced model on-the-fly during the solution of the optimization problem, which completely avoids an offline training phase. This ensures all snapshot information is collected along the optimization trajectory, which avoids wasting samples in remote regions of the parameters space that are never visited, and inherently avoids the curse of dimensionality of sampling in a high-dimensional parameter space. At each iteration of the proposed algorithm, a reduced basis and empirical quadrature weights are constructed precisely to ensure the global convergence criteria of the trust-region method are satisfied, ensuring global convergence to a local minimum of the original (unreduced) problem. Numerical experiments are performed on two fluid shape optimization problems to verify the global convergence of the method and demonstrate its computational efficiency; speedups over 18x (accounting for all computational cost, even cost that is traditionally considered "offline" such as snapshot collection and data compression) relative to standard optimization approaches that do not leverage model reduction are shown.
description: 40 pages, 14 figures, 4 tables
Fast Classical Simulation of Hamiltonian Dynamics by Simultaneous Diagonalization Using Clifford Transformation with Parallel Computation
Creators: name: Kawase, Yoshiaki
name: Fujii, Keisuke
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Simulating quantum many-body dynamics is important both for fundamental understanding of physics and practical applications for quantum information processing. Therefore, classical simulation methods have been developed so far. Specifically, the Trotter-Suzuki decomposition can analyze a highly complex quantum dynamics, if the number of qubits is sufficiently small so that main memory can store the state vector. However, simulation of quantum dynamics via Trotter-Suzuki decomposition requires huge number of steps, each of which accesses the state vector, and hence the simulation time becomes impractically long. To settle this issue, we propose a technique to accelerate simulation of quantum dynamics via simultaneous diagonalization of mutually commuting Pauli groups, which is also attracting a lot of attention to reduce the measurement overheads in quantum algorithms. We group the Hamiltonian into mutually commputing Pauli strings, and each of them are diagonalized in the computational basis via a Clifford transformation. Since diagonal operators are applied on the state vector simultaneously with minimum memory access, this method successfully use performance of highly parallel processors such as Graphics Processing Units (GPU). Compared to an implementation using one of the fastest simulators of quantum computers, the numerical experiments have shown that our method provides a few tens of times acceleration.
description: 14 + 2 pages, 7 + 1 figures
Analysis of the coronal green line profiles: evidence of excess blueshifts
Creators: name: Raju, K. P.
name: Chandrasekhar, T.
name: Ashok, N. M.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The coronal green line (Fe XIV 5303 A) profiles were obtained from Fabry-Perot interferometric observations of the solar corona during the total solar eclipse of 21 June 2001 from Lusaka, Zambia. The instrumental width is about 0.2 A and the spectral resolution is about 26000. About 300 line profiles were obtained within a radial range of 1.0-1.5 R\odot and position angle coverage of about 240\circ. The line profiles were fitted with single Gaussian and their intensity, Doppler velocity, and line width have been obtained. Also obtained are the centroids of the line profiles which give a measure of line asymmetry. The histograms of Doppler velocity show excess blueshifts while the centroids reveal a pre-dominant blue wing in the line profiles. It has been found that the centroids and the Doppler velocities are highly correlated. This points to the presence of multiple components in the line profiles with an excess of blueshifted components. We have then obtained the(Blue-Red) wing intensity which clearly reveals the second component, majority of which are blueshifted ones. This confirms that the coronal green line profiles often contain multicomponents with excess blueshifts which also depend on the solar activity. The magnitude of the Doppler velocity of the secondary component is in the range 20-40 km s-1 and they show an increase towards poles. The possible explanations of the multicomponents could be the type II spicules which were recently found to have important to the coronal heating or the nascent solar wind flow, but the cause of the blue asymmetry in the coronal lines above the limb remains unclear.
MOESM1 of Status and distribution changes of the endangered Green Peafowl (Pavo muticus) in China over the past three decades (1990sâ 2017)
Creators: name: Kong, Dejun
name: Wu, Fei
name: Shan, Pengfei
name: Gao, Jianyun
name: Yan, Dao
name: Luo, Weixiong
name: Yang, Xiaojun
Publisher: name: figshare
Year: 2018
Subjects: subject: Environmental Sciences not elsewhere classified
subject: Chemical Sciences not elsewhere classified
subject: Sociology
subject: FOS: Sociology
subject: Biological Sciences not elsewhere classified
subject: Inorganic Chemistry
subject: FOS: Chemical sciences

description: Additional file 1. Table S1: Historical and present status and distribution of endangered green peafowl in Yunnan, SW China (1990sâ 2017).
NLTE model atmospheres for the hottest white dwarfs: Spectral analysis of the compact component in nova V4743 Sgr
Creators: name: Rauch, T.
name: Orio, M.
name: Gonzales-Riestra, R.
name: Nelson, T.
name: Still, M.
name: Werner, K.
name: Wilms, J.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Half a year after its outburst in September 2002, nova V4743 Sgr evolved into the brightest supersoft X-ray source in the sky with a flux maximum around 30A. We calculated grids of synthetic energy distributions (SEDs) based on NLTE model atmospheres for the analysis of the hottest white dwarfs and present the result of fits to Chandra and XMM-Newton grating X-ray spectra of V4743 Sgr of outstanding quality, exhibiting prominent resonance lines of C V, C VI, N VI, N VII, and O VII in absorption. The nova reached its highest effective temperature (Teff = 740 +/- 70kK) around April 2003 and remained at that temperature at least until September 2003. We conclude that the white dwarf is massive, about 1.1 - 1.2 Msun. The nuclear-burning phase lasted for 2 to 2.5 years after the outburst, probably the average duration for a classical nova. The photosphere of V4743 Sgr was strongly carbon deficient (about times solar) and enriched in nitrogen and oxygen (> 5 times solar). Especially the very low C/N ratio indicates that the material at the white dwarf's surface underwent thermonuclear burning. Thus, this nova retained some of the accreted material and did not eject all of it in outburst. From March to September 2003, the nitrogen abundance is strongly decreasing, probably new material is already been accreted at this stage.
A Survey of DeFi Security: Challenges and Opportunities
Creators: name: Li, Wenkai
name: Bu, Jiuyang
name: Li, Xiaoqi
name: Peng, Hongli
name: Niu, Yuanzheng
name: Zhang, Yuqing
Publisher: name: arXiv
Year: 2022
Subjects: subject: Cryptography and Security (cs.CR)
subject: FOS: Computer and information sciences

description: DeFi, or Decentralized Finance, is based on a distributed ledger called blockchain technology. Using blockchain, DeFi may customize the execution of predetermined operations between parties. The DeFi system use blockchain technology to execute user transactions, such as lending and exchanging. The total value locked in DeFi decreased from \$200 billion in April 2022 to \$80 billion in July 2022, indicating that security in this area remained problematic. In this paper, we address the deficiency in DeFi security studies. To our best knowledge, our paper is the first to make a systematic analysis of DeFi security. First, we summarize the DeFi-related vulnerabilities in each blockchain layer. Additionally, application-level vulnerabilities are also analyzed. Then we classify and analyze real-world DeFi attacks based on the principles that correlate to the vulnerabilities. In addition, we collect optimization strategies from the data, network, consensus, smart contract, and application layers. And then, we describe the weaknesses and technical approaches they address. On the basis of this comprehensive analysis, we summarize several challenges and possible future directions in DeFi to offer ideas for further research.
BEC dark matter, Zeldovich approximation and generalized Burgers equation
Creators: name: Chavanis, Pierre-Henri
Publisher: name: arXiv
Year: 2011
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: If the dark matter in the universe is a self-gravitating Bose-Einstein condensate (BEC) with quartic self-interaction described by the Gross-Pitaevskii-Poisson system, the adhesion model, the Burgers equation and the cosmological Kardar-Parisi-Zhang (KPZ) equation that have been introduced heuristically to solve the problems inherent to cold dark matter (CDM) models find a natural justification and an interesting generalization.
First boundary Dirac eigenvalue and boundary capacity potential
Creators: name: Raulot, Simon
Publisher: name: arXiv
Year: 2022
Subjects: subject: Differential Geometry (math.DG)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: We derive new lower bounds for the first eigenvalue of the Dirac operator of an oriented hypersurface $Σ$ bounding a noncompact domain in a spin asymptotically flat manifold (M n , g) with nonnegative scalar curvature. These bounds involve the boundary capacity potential and, in some cases, the capacity of $Σ$ in (M n , g) yielding several new geometric inequalities. The proof of our main result relies on an estimate for the first eigenvalue of the Dirac operator of boundaries of compact Riemannian spin manifolds endowed with a singular metric which may have independent interest.
Microscopic calculation of the $β^-$ decays of $^{151}$Sm, $^{171}$Tm, and $^{210}$Pb with implications to detection of the cosmic neutrino background
Creators: name: Kostensalo, Joel
name: Kotila, Jenni-Mari
name: Suhonen, Jouni
Publisher: name: arXiv
Year: 2022
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The electron spectral shapes corresponding to the low-$Q$ $β^-$-decay transitions $^{151}$Sm$(5/2^-_{\rm g.s.})\to\,^{151}\textrm{Eu}(5/2^+_{\rm g.s.})$, $^{151}$Sm$(5/2^-_{\rm g.s.})\to\,^{151}\textrm{Eu}(7/2^+_{1})$, $^{171}$Tm$(1/2^+_{\rm g.s.})\to\,^{171}\textrm{Yb}(1/2^-_{\rm g.s.})$, $^{171}$Tm$(1/2^+_{\rm g.s.})\to\,^{171}\textrm{Yb}(3/2^-_{1})$, $^{210}\textrm{Pb}(0^+_{\rm g.s.})\to\,^{210}\textrm{Bi}(1^-_{\rm g.s.})$, and $^{210}\textrm{Pb}(0^+_{\rm g.s.})\to\,^{210}\textrm{Bi}(0^-_{1})$ have been computed using beta-decay theory with several refinements for these first-forbidden nonunique (ff-nu) $β^-$ transitions. These ff-nu $β^-$ transitions have non-trivial electron spectral shapes with transition nuclear matrix elements (NMEs) computed by using the microscopic Interacting Boson-Fermion Model (IBFM-2) for the decays of $^{151}$Sm and $^{171}$Tm, and the nuclear shell model (NSM) for the decay of $^{210}$Pb. Within the respective $Q$ windows, the computed ff-nu electron spectral shapes deviate maximally at sub-percent level from the universal allowed shape, except for the transition $^{210}\textrm{Pb}(0^+_{\rm g.s.})\to\,^{210}\textrm{Bi}(1^-_{\rm g.s.})$, where the maximal deviation is some 2.7$\%$. This confirms that the so-called $ξ$ approximation is fairly good for most of these low-$Q$ $β^-$ transitions and thus the allowed shape is a rather good first approximation. Our computed spectral shapes could be of interest for experiments aiming to measure the cosmic neutrino background (C$ν$B), like the PTOLEMY experiment. We have also derived C$ν$B cross sections for the ground-state transitions of the considered nuclei at the $β$ endpoint. Our findings indicate that more work on the atomic mismatch correction is needed in the future in order to extract reliable and precise C$ν$B cross sections for any nuclear target.
A mic to the margin : opening up spaces for alternate voices in schooling
Creators: name: Aura, Quynh
Publisher: name: University of British Columbia
Year: 2015

description: Alternate programs within schools are spaces born of alternate views and the recognition that mainstream schooling does not fully engage all students. Such programs harbour students who have come to be known as “marginalized,” among a plethora of other labels, such as: at-risk, disenfranchised, drop-out, handicapped, not meeting expectations, falling between the cracks, impoverished, disadvantaged, remedial, delinquent. Rather than becoming a place of deficit, the site of alternate settings can be a space of transformation where students begin to find their voice. In this study, former alternate school students engage in dialogue with their former teacher to (re)-explore their path within the alternate setting in writing and narrative within the methodological frames of critical pedagogy and narrative inquiry. Whispers from the margin appear as students enter alternate settings and begin to reflect upon their stories of pain and healing. In line with Hannah Arendt’s concept of primary natality, students within this educative alternate space are able to exercise their natality through self-reflection before entering the political world. As students confront their belatedness and natality in an old world, inquiry into their narrative shapes their interpretation of the world and their role within it. As student voices grow louder in the grip of narrative inquiry as a microphone for their story, transformation of Self leads to the responsibility of Arendt’s political natality and Paulo Freire’s praxis and obligation towards humanity. On this transformative platform, students stand at the intersections of social, political, and educative tensions and begin to hold a megaphone to a narrative that can continue to reflect the imaginings of alternate views from the margin.
Inclusive J/Psi photoproduction and polarization at HERA in the kt-factorization approach
Creators: name: Baranov, S. P.
name: Lipatov, A. V.
name: Zotov, N. P.
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We investigate the inclusive photoproduction of J/Psi mesons at HERA within the framework of the kt-factorization QCD approach. Our consideration is based on the color singlet model supplemented with the relevant off-shell matrix elements and the CCFM and KMR unintegrated gluon densities in a proton and in a photon. Both the direct and resolved photon contributions are taken into account. Our predictions are compared with the recent experimental data taken by the H1 and ZEUS collaborations. Special attention is put on the J/Psi polarization parameters lambda and nu which are sensitive to the production dynamics.
description: 21 pages, 15 figures
Inertial and gravitational mass in quantum mechanics
Creators: name: Kajari, E.
name: Harshman, N. L.
name: Rasel, E. M.
name: Stenholm, S.
name: Süßmann, G.
name: Schleich, W. P.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We show that in complete agreement with classical mechanics, the dynamics of any quantum mechanical wave packet in a linear gravitational potential involves the gravitational and the inertial mass only as their ratio. In contrast, the spatial modulation of the corresponding energy wave function is determined by the third root of the product of the two masses. Moreover, the discrete energy spectrum of a particle constrained in its motion by a linear gravitational potential and an infinitely steep wall depends on the inertial as well as the gravitational mass with different fractional powers. This feature might open a new avenue in quantum tests of the universality of free fall.
description: 17 pages, 7 figures, accepted in Applied Physics B; v2 has minor text and figure corrections
Integrable Floquet systems related to logarithmic conformal field theory
Creators: name: Yashin, Vsevolod I.
name: Kurlov, Denis V.
name: Fedorov, Aleksey K.
name: Gritsev, Vladimir
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: FOS: Physical sciences

description: We study an integrable Floquet quantum system related to lattice statistical systems in the universality class of dense polymers. These systems are described by a particular non-unitary representation of the Temperley-Lieb algebra. We find a simple Lie algebra structure for the elements of Temperley-Lieb algebra which are invariant under shift by two lattice sites, and show how the local Floquet conserved charges and the Floquet Hamiltonian are expressed in terms of this algebra. The system has a phase transition between local and non-local phases of the Floquet Hamiltonian. We provide a strong indication that in the scaling limit this non-equilibrium system is described by the logarithmic conformal field theory.
description: 22 pages, 2 figures