cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Dataset balancing can hurt model performance
Creators: name: Moore, R. Channing
name: Ellis, Daniel P. W.
name: Fonseca, Eduardo
name: Hershey, Shawn
name: Jansen, Aren
name: Plakal, Manoj
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (cs.LG)
subject: Sound (cs.SD)
subject: Audio and Speech Processing (eess.AS)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Machine learning from training data with a skewed distribution of examples per class can lead to models that favor performance on common classes at the expense of performance on rare ones. AudioSet has a very wide range of priors over its 527 sound event classes. Classification performance on AudioSet is usually evaluated by a simple average over per-class metrics, meaning that performance on rare classes is equal in importance to the performance on common ones. Several recent papers have used dataset balancing techniques to improve performance on AudioSet. We find, however, that while balancing improves performance on the public AudioSet evaluation data it simultaneously hurts performance on an unpublished evaluation set collected under the same conditions. By varying the degree of balancing, we show that its benefits are fragile and depend on the evaluation set. We also do not find evidence indicating that balancing improves rare class performance relative to common classes. We therefore caution against blind application of balancing, as well as against paying too much attention to small improvements on a public evaluation set.
description: 5 pages, 3 figures, ICASSP 2023
Long range order in the dipolar XY antiferromagnet Er$_2$Sn$_2$O$_7$
Creators: name: Petit, S.
name: Lhotel, E.
name: Damay, F.
name: Boutrouille, P.
name: Forget, A.
name: Colson, D.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Er$_2$Sn$_2$O$_7$ remains a puzzling case among the extensively studied frustrated compounds of the rare-earth pyrochlore family. Indeed, while a first order transition towards a long-range antiferromagnetic state with the so-called Palmer-Chalker structure is theoretically predicted, it has not been observed yet, leaving the issue, as to whether it is a spin-liquid candidate, open. We report on neutron scattering and magnetization measurements which evidence a second order transition towards this Palmer-Chalker ordered state around 108 mK. Extreme care was taken to ensure a proper thermalization of the sample, which has proved to be crucial to successfully observe the magnetic Bragg peaks. At the transition, a gap opens in the excitations, superimposed on a strong quasielastic signal. The exchange parameters, refined from a spin wave analysis in applied magnetic field, confirm that Er$_2$Sn$_2$O$_7$ is a realization of the dipolar XY pyrochlore antiferromagnet. The proximity of competing phases and the strong XY anisotropy of the Er$^{3+}$ magnetic moment might be at the origin of enhanced fluctuations, leading to the unexpected nature of the transition, the low ordering temperature, and the observed multi-scale dynamics.
description: 7 pages, 6 figures
Derivation of the Generalized Time-independent Schrodinger Equation. The New Stochastic Quantum Mechanics: Think and calculate
Creators: name: Batanov-Gaukhman, Mikhail
Publisher: name: arXiv
Year: 2017
Subjects: subject: General Physics (physics.gen-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In this article, the following results are obtained: the process of a randomly wandering particle having a size and a continuous trajectory of motion is considered; (b) based on the study of this probabilistic process, a derivation of the Schrodinger equation is proposed; the Planck constant h is expressed in terms of the characteristics of the stationary stochastic process under consideration; the probability distribution density of the n-order derivative for a n-times differentiable stationary stochastic process is determined; it is shown that the obtained generalized Schrodinger equation is applicable not only to describe the possible states of microcosm objects, but also for discrete states of a number of macrocosm stochastic systems
description: PDF file: 59 pages, 7 figures
Existence of a cylinder foliated by periodic orbits in the generalized Chazy differential equation
Creators: name: Llibre, Jaume
name: Novaes, Douglas D.
name: Valls, Claudia
Publisher: name: arXiv
Year: 2023
Subjects: subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics
subject: 34C23, 34C25, 34C45, 34A36

description: The generalized Chazy differential equation corresponds to the following two-parameter family of differential equations \begin{equation*}\label{gcdeq} \dddot x+|x|^q \ddot x+\dfrac{k |x|^q}{x}\dot x^2=0, \end{equation*} which has its regularity varying with $q$ , a positive integer. Indeed, for $q=1$ it is discontinuous on the straight line $x=0$, whereas for $q$ a positive even integer it is polynomial, and for $q>1$ a positive odd integer it is continuous but not differentiable on the straight line $x=0$. In 1999, the existence of periodic solutions in the generalized Chazy differential equation was numerically observed for $q=2$ and $k=3$. In this paper, we prove analytically the existence of such periodic solutions. Our strategy allows to establish sufficient conditions ensuring that the generalized Chazy differential equation, for $k=q+1$ and any positive integer $q$ , has actually an invariant topological cylinder foliated by periodic solutions in the $(x,\dot x,\ddot x)$-space. In order to set forth the bases of our approach, we start by considering $q=1,2,3$, which are representatives of the different classes of regularity. For an arbitrary positive integer $q$, an algorithm is provided for checking the sufficient conditions for the existence of such an invariant cylinder, which we conjecture that always exists. The algorithm was successfully applied up to $q=100$.
An Integral Projection-based Semantic Autoencoder for Zero-Shot Learning
Creators: name: Heyden, William
name: Ullah, Habib
name: Siddiqui, M. Salman
name: Machot, Fadi Al
Publisher: name: arXiv
Year: 2023
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Zero-shot Learning (ZSL) classification categorizes or predicts classes (labels) that are not included in the training set (unseen classes). Recent works proposed different semantic autoencoder (SAE) models where the encoder embeds a visual feature vector space into the semantic space and the decoder reconstructs the original visual feature space. The objective is to learn the embedding by leveraging a source data distribution, which can be applied effectively to a different but related target data distribution. Such embedding-based methods are prone to domain shift problems and are vulnerable to biases. We propose an integral projection-based semantic autoencoder (IP-SAE) where an encoder projects a visual feature space concatenated with the semantic space into a latent representation space. We force the decoder to reconstruct the visual-semantic data space. Due to this constraint, the visual-semantic projection function preserves the discriminatory data included inside the original visual feature space. The enriched projection forces a more precise reconstitution of the visual feature space invariant to the domain manifold. Consequently, the learned projection function is less domain-specific and alleviates the domain shift problem. Our proposed IP-SAE model consolidates a symmetric transformation function for embedding and projection, and thus, it provides transparency for interpreting generative applications in ZSL. Therefore, in addition to outperforming state-of-the-art methods considering four benchmark datasets, our analytical approach allows us to investigate distinct characteristics of generative-based methods in the unique context of zero-shot inference.
Sharp eigenvalue estimates on degenerating surfaces
Creators: name: Große, Nadine
name: Rupflin, Melanie
Publisher: name: arXiv
Year: 2017
Subjects: subject: Differential Geometry (math.DG)
subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics

description: We consider the first non-zero eigenvalue $λ_1$ of the Laplacian on hyperbolic surfaces for which one disconnecting collar degenerates and prove that $8π\nabla\log(λ_1)$ essentially agrees with the dual of the differential of the degenerating Fenchel-Nielsen length coordinate. As a consequence, we can improve previous results of Schoen, Wolpert, Yau and Burger to obtain estimates with optimal error rates and obtain new information on the leading order terms of the polyhomogeneous expansion of $λ_1$ of Albin, Rochon and Sher.
description: Major changes to prove sharpness of the result now also for genus 2 surfaces and to split the original paper into two parts for easier publication, with this paper containing the results on eigenvalues, while the used results on holomorphic quadratic differentials are now proven in a separate paper
Odd viscosity in two-dimensional incompressible fluids
Creators: name: Ganeshan, Sriram
name: Abanov, Alexander G.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: In this work, we present observable consequences of parity-violating odd viscosity term in incompressible 2+1D hydrodynamics. For boundary conditions depending on the velocity field (flow) alone we show that: (i) The fluid flow quantified by the velocity field is independent of odd viscosity, (ii) The force acting on a closed contour is independent of odd viscosity, and (iii) The odd viscosity part of torque on a closed contour is proportional to the rate of change of area enclosed by the contour with the proportionality constant being twice the odd viscosity. The last statement allows us to define a measurement protocol of {\it odd viscostance} in analogy to Hall resistance measurements. We also consider {\it no-stress} boundary conditions which explicitly depend on odd viscosity. A classic hydrodynamics problem with no-stress boundary conditions is that of a bubble in a planar Stokes flow. We solve this problem exactly for shear and hyperbolic flows and show that the steady-state shape of the bubble in the shear flow depends explicitly on the value of odd viscosity.
description: 8 pages, 2 figures, Published version
Giant Spin Lifetime Anisotropy in Graphene Induced by Proximity Effects
Creators: name: Cummings, Aron W.
name: García, Jose H.
name: Fabian, Jaroslav
name: Roche, Stephan
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We report on fundamental aspects of spin dynamics in graphene interfaced with transition metal dichalcogenides (TMDCs). By using realistic models derived from first principles we compute the spin lifetime anisotropy, defined as the ratio of lifetimes for spins pointing out of the graphene plane to those pointing in the plane. In the presence of strong intervalley scattering the anisotropy can reach unprecedented values of tens to hundreds, while it reduces to 1/2 for weak disorder. This behavior is mediated by spin-valley locking, which is strong in TMDCs and is imprinted onto graphene. Such giant spin transport anisotropy, driven by proximity effects, provides an exciting paradigm for designing novel spin device functionalities.
description: 5 pages
Towards the discovery of new physics with lepton-universality ratios of $b\to s\ell\ell$ decays
Creators: name: Geng, Li-Sheng
name: Grinstein, Benjamín
name: Jäger, Sebastian
name: Camalich, Jorge Martin
name: Ren, Xiu-Lei
name: Shi, Rui-Xiang
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: Tests of lepton-universality as rate ratios in $b\to s \ell\ell$ transitions can be predicted very accurately in the Standard Model. The deficits with respect to expectations reported by the LHCb experiment in muon-to-electron ratios of the $B\to K^{(*)}\ell\ell$ decay rates thus point to genuine manifestations of lepton non-universal new physics. In this paper, we analyse these measurements in the context of effective field theory. First, we discuss the interplay of the different operators in $R_K$ and $R_{K^*}$ and provide predictions for $R_{K^*}$ in the Standard Model and in new-physics scenarios that can explain $R_K$. We also provide approximate numerical formulas for these observables in bins of interest as functions of the relevant Wilson coefficients. Secondly, we perform frequentist fits to $R_{K}$ and $R_{K^*}$. The SM disagrees with these measurements at $3.7σ$ significance. We find excellent fits in scenarios with combinations of $\mathcal O_{9(10)}^\ell=\bar sγ^μb_L~\ellγ_μ(γ_5) \ell$ operators, with pulls relative to the Standard Model in the region of $4σ$. An important conclusion of our analysis is that a lepton-specific contribution to $\mathcal O_{10}$ is essential to understand the data. Under the hypothesis that new-physics couples selectively to the muons, we also present fits to other $b\to sμμ$ data with a conservative error assessment, and comment on more general scenarios. Finally, we discuss new lepton universality ratios that, if new physics is the origin of the observed discrepancy, should contribute to the statistically significant discovery of new physics in the near future.
description: Matches published version
Surface superconductor-insulator transition induced by an electric field
Creators: name: Yin, Liyu
name: Bai, Yunfei
name: Zhang, Ming
name: Shanenko, A. A.
name: Chen, Yajiang
Publisher: name: arXiv
Year: 2023
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: It is well-known that the electric field can induce phase transitions between superconducting, metallic and insulating states in thin-film materials due to its control of the charge carrier density. Since a similar effect on the charge carriers can also be expected for surfaces of bulk samples, here we investigate the transformation of the surface states in a superconductor under an applied screened electric field. Our study is performed by numerically solving the self-consistent Bogoliubov-de Gennes equations for the one-dimensional attractive Hubbard model. It is found that the surface insulating regime occurs at sufficiently large (but still experimentally accessible) electric fields. Our calculations yield the phase diagram of the surface superconducting, metallic, and insulating states for a wide range of temperatures and applied fields. Our results are in qualitative agreement with the phase diagram obtained by the transport measurements for (Li, Fe)OHFeSe thin flakes [Sci. Bull. 64, 653 (2019); ACS Nano 14, 7513 (2020)].
description: 9 pages, 7 figures
New concise upper bounds on quantum violation of general multipartite Bell inequalities
Creators: name: Loubenets, Elena R.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: Last years, bounds on the maximal quantum violation of general Bell inequalities were intensively discussed in the literature via different mathematical tools. In the present paper, we analyze quantum violation of general Bell inequalities via the LqHV (local quasi hidden variable) modelling framework, correctly reproducing the probabilistic description of every quantum correlation scenario. The LqHV mathematical framework allows us to derive for all d and N a new upper bound (2d-1)^{N-1} on the maximal violation by an N-qudit state of all general Bell inequalities, also, new upper bounds on the maximal violation by an N-qudit state of general Bell inequalities for S settings per site. These new upper bounds essentially improve all the known precise upper bounds on quantum violation of general multipartite Bell inequalities. For some S, d and N, the new upper bounds are attainable.
description: 10 pages. arXiv admin note: text overlap with arXiv:1611.06723
Convective Instability Driven by Diffusiophoresis of Colloids in Binary Liquid Mixtures
Creators: name: Anzivino, Carmine
name: Xhani, Klejdis
name: Carpineti, Marina
name: Verrastro, Stefano
name: Zaccone, Alessio
name: Vailati, Alberto
Publisher: name: arXiv
Year: 2024
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Pattern Formation and Solitons (nlin.PS)
subject: Chemical Physics (physics.chem-ph)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: In a binary fluid mixture, the concentration gradient of a heavier molecular solute leads to a diffusive flux of solvent and solute to achieve thermodynamic equilibrium. If the solute concentration decreases with height, the system is always in a condition of stable mechanical equilibrium against gravity. We show experimentally that this mechanical equilibrium becomes unstable in case colloidal particles are dispersed uniformly within the mixture, and that the resulting colloidal suspension undergoes a transient convective instability with the onset of convection patterns. By means of a numerical analysis, we clarify the microscopic mechanism from which the observed destabilisation process originates. The solute concentration gradient drives an upward diffusiophoretic migration of colloids, in turn causing the development of a mechanically unstable layer within the sample, where the density of the suspension increases with height. Convective motions arise to minimize this localized rise in gravitational potential energy.
Circuit configurations which can/cannot show super-radiant phase transitions
Creators: name: Bamba, Motoaki
name: Imoto, Nobuyuki
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Several superconducting circuit configurations are examined on the existence of super-radiant phase transitions (SRPTs) in thermal equilibrium. For some configurations consisting of artificial atoms, whose circuit diagrams are however not specified, and an LC resonator or a transmission line, we confirm the absence of SRPTs in the thermal equilibrium following the similar analysis as the no-go theorem for atomic systems. We also show some other configurations where the absence of SRPTs cannot be confirmed.
description: 12 pages, 6 figures
Role of nuclear deformation and orientation about symmetry axis of target nucleus on heavy-ion fusion dynamics
Creators: name: Rana, Shilpa
name: Bhuyan, M.
name: Kumar, Raj
name: Carlson, B. V.
Publisher: name: arXiv
Year: 2024
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Nuclear shape and orientation degrees of freedom are incorporated into the calculation of the double-folding nuclear potential within the relativistic mean-field (RMF) formalism. The quadrupole deformations ($β_2$), nuclear densities and the effective nucleon-nucleon (NN) interaction potential are obtained using the RMF approach for the Hybrid, NL3$^*$ and NL3 parameterizations. The calculated quadrupole deformations are included in the target densities through the nuclear radius. The deformation and orientation-dependent microscopic nuclear potentials are further employed to obtain fusion barrier characteristics and cross-sections for 12 even-even heavy-ion reactions with doubly magic spherical $^{16}$O and $^{48}$Ca as projectiles along with deformed targets from different mass regions. The results obtained for the relativistic R3Y NN potential are compared with those of the Reid version of the non-relativistic M3Y NN potential as well as with the available experimental data. A decrease in the barrier height and increase in the cross-section is observed upon the inclusion of target quadrupole deformations in the nuclear density distributions at the target orientation angles, $θ_2\le58^\circ$ for the R3Y NN potential and at $θ_2\le60^\circ$ for the M3Y NN potential. On comparing the $θ_2$-integrated cross-section calculated using M3Y and R3Y NN potentials with spherical and deformed densities, one observes that the deformed densities and the relativistic R3Y NN potential obtained for the Hybrid parameter set provide better agreement with the available experimental data for all the considered reactions. Moreover, the modifications in the characteristics of the fusion barrier and hence in the cross-section with the inclusion of nuclear shape degrees of freedom and orientations are found to become more prominent in reactions forming heavier compound nuclei.
FastText Embedding for Yoruba
Creators: name: Adelani, David Ifeoluwa
Publisher: name: Zenodo
Year: 2022
Subjects: Word embeddings, FastText

description: FastText Embedding for Yoruba, as part of the PhD thesis of David Ifeoluwa Adelani. The embedding was trained for the Massive vs. Curated Embeddings for Low-Resourced Languages: the Case of Yorùbá and Twi paper
Theory of spatially non-symmetric kinetic equilibria for collisionless plasmas
Creators: name: Cremaschini, Claudio
name: Tessarotto, Massimo
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Mathematical Physics (math-ph)
subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: The problem posed by the possible existence/non-existence of spatially non-symmetric kinetic equilibria has remained unsolved in plasma theory. For collisionless magnetized plasmas this involves the construction of stationary solutions of the Vlasov-Maxwell equations. In this paper the issue is addressed for non-relativistic plasmas both in astrophysical and laboratory contexts. The treatment is based on a Lagrangian variational description of single-particle dynamics. Starting point is a non-perturbative formulation of gyrokinetic theory, which allows one to construct "a posteriori" with prescribed order of accuracy an asymptotic representation for the magnetic moment. In terms of the relevant particle adiabatic invariants generalized bi-Maxwellian equilibria are proved to exist. These are shown to recover, under suitable assumptions, a Chapman-Enskog form which permits an analytical treatment of the corresponding fluid moments. In particular, the constrained posed by the Poisson and the Ampere equations are analyzed, both for quasi-neutral and non-neutral plasmas. The conditions of existence of the corresponding non-symmetric kinetic equilibria are investigated. As a notable feature, both astrophysical and laboratory plasmas are shown to exhibit, under suitable conditions, a kinetic dynamo, whereby the equilibrium magnetic field can be self-generated by the equilibrium plasma currents.
description: 15 pages
Chemical prospection and antioxidant activity of Humiria balsamifera (Aubl.) A. St. Hil. AND Hymenaea courbaril L.
Creators: name: de Matos, Jhuliana Monteiro
name: Costa, Andressa Rose Castro
name: Justino, Marciel Nascimento
name: Camara, Marcos Bispo Pinheiro
name: Vasconcelos, Osmar Luis Silva
name: Marques, J. C.
name: Brandão, Clenilma Marques
name: de Carvalho Marques, Georgiana Eurides
Publisher: name: Taylor & Francis
Year: 2023
Subjects: subject: Biochemistry
subject: Environmental Sciences not elsewhere classified
subject: Chemical Sciences not elsewhere classified
subject: Ecology
subject: FOS: Biological sciences
subject: Biological Sciences not elsewhere classified
subject: Inorganic Chemistry
subject: FOS: Chemical sciences
subject: Science Policy
subject: Plant Biology

description: The objective of this study was to conduct chemical analyses of bioactive compounds found in the bark and leaves of Humiria balsamifera (Aubl.) A. St. Hil. and Hymenaea courbaril L. Chemical screening was performed to detect the presence of secondary metabolites. Quantification of the concentrations of phenolic compounds, anthocyanins, flavonoids, and antioxidants was performed by ultraviolet spectrophotometry through recommended methodologies. Extracts of the leaves of Humiria balsamifera (Aubl.) A. St. Hil. were found to have high concentrations of flobabénic tannins. Tannins, flavonoids, flavonols, flavonones, flavanonols, xanthones, steroids, and saponins were also found in bark extracts of the same species. The plant species Humiria balsamifera (Aubl.) A. St. Hil. and Hymenaea courbaril L. showed potential for antioxidant activity and for use in the pharmacological and food industries.
MicroRNA-4521 targets hepatoma up-regulated protein (HURP) to inhibit the malignant progression of breast cancer
Creators: name: Li, Changwen
name: Peng, Sen
name: Tang, Chuangang
Publisher: name: Taylor & Francis
Year: 2021
Subjects: subject: Biophysics
subject: Biochemistry
subject: Microbiology
subject: FOS: Biological sciences
subject: Cell Biology
subject: Genetics
subject: Molecular Biology
subject: Physiology
subject: Chemical Sciences not elsewhere classified
subject: Biological Sciences not elsewhere classified
subject: Developmental Biology
subject: Cancer
subject: Hematology

description: Breast cancer (BC) is a common malignancy among women, and microRNAs (miRNAs) play a role in its progression. Reportedly, microRNA-4521 (miR-4521) participates in regulating the progression of some carcinomas. In the present work, miR-4521 and hepatoma up-regulated protein (HURP) mRNA expressions in BC tissues and cell lines were examined by qRT-PCR. After miR-4521 was overexpressed or knocked down in BC cells, CCK-8 experiment and EdU experiment were employed to detect BC cell growth. Moreover, the Transwell assay was adopted to detect the migration and invasion. Subsequently, flow cytometry was executed to evaluate the changes in cell cycle progression. KEGG analysis was utilized to predict the signaling pathways related with the target genes of miR-524-5p. The binding relationship between miR-4521 and HURP 3ʹUTR was validated by dual-luciferase reporter gene experiment. HURP and NF-kB p65 protein expression in BC cells was detected by Western blot. It was revealed that, miR-4521 was lowly expressed in BC tissues, and its expression was associated with tumor grade, lymph node metastasis and clinical stage of the patients. Overexpression of miR-4521 suppressed the growth, migration, invasion and cell cycle progression of BC cells and restrained p65 expression; downregulation of miR-4521 in BC cells showed opposite biological effects. Additionally, HURP was a downstream target gene of miR-4521, and overexpression of HURP reversed the above effects of miR-4521 overexpression. In short, miR-4521 can inhibit BC progression by modulating the HURP/NF-κB pathway.
Structure, anticoagulant and cytotoxic activity of a sulfated polysaccharide from green seaweed Chaetomorpha linum
Creators: name: Quach, Thu Thi Minh
name: Nguyen, Nu Thi
name: Yuguchi, Yoshiaki
name: Dang, Luong Vu
name: Van Ngo, Quang
name: Thanh, Thuy Thi Thu
Publisher: name: Taylor & Francis
Year: 2023
Subjects: subject: Biochemistry
subject: Pharmacology
subject: Biotechnology
subject: Chemical Sciences not elsewhere classified
subject: Cancer
subject: Hematology
subject: Plant Biology
subject: FOS: Biological sciences

description: In this article, chemical structure and conformation in an aqueous solution of a new sulfated polysaccharide, PCL, extracted from green seaweed Chaetomorpha linum were elucidated by SEC-MALL, IR, NMR and SAXS. The results indicated that the obtained polysaccharide is a sulfated arabinogalactan with a molecular weight of 223 kDa, and is mainly composed of →3,6)-α-D-Galp4S→ and →2)-α-L-Araf→ connecting together through 1→3 glycoside linkages. It has a broken rod-like conformation in solution with Rgc estimated as 0.43 nm from SAXS measurements. The polysaccharide exhibited a notable anticoagulant activity measured by the assays of activated partial thromboplastintime, thrombintime and prothrombine time as well as a significant cytotoxic activity against hepatocellular, human breast cancer, and cervical cancer cell lines.
Exact lowest-Landau-level solutions for vortex precession in Bose-Einstein condensates
Creators: name: Biasi, Anxo
name: Bizon, Piotr
name: Craps, Ben
name: Evnin, Oleg
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: Analysis of PDEs (math.AP)
subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: The Lowest Landau Level (LLL) equation emerges as an accurate approximation for a class of dynamical regimes of Bose-Einstein Condensates (BEC) in two-dimensional isotropic harmonic traps in the limit of weak interactions. Building on recent developments in the field of spatially confined extended Hamiltonian systems, we find a fully nonlinear solution of this equation representing periodically modulated precession of a single vortex. Motions of this type have been previously seen in numerical simulations and experiments at moderately weak coupling. Our work provides the first controlled analytic prediction for trajectories of a single vortex, suggests new targets for experiments, and opens up the prospect of finding analytic multi-vortex solutions.
description: v2: minor improvements, published in PRA
Variability in morphology, phytochemicals and antioxidant activity in Bistorta amplexicaulis (D. Don) Greene populations under variable habitats and altitudes
Creators: name: Javid, Hanan
name: Qadir, Roof Ul
name: Magray, Junaid A.
name: Wani, Bilal A.
name: Nawchoo, Irshad A.
name: Gulzar, Shabana
Publisher: name: Taylor & Francis
Year: 2023
Subjects: subject: Evolutionary Biology
subject: FOS: Biological sciences
subject: Environmental Sciences not elsewhere classified
subject: Chemical Sciences not elsewhere classified
subject: Ecology
subject: Biological Sciences not elsewhere classified
subject: Science Policy

description: Phytochemicals have become significantly important for scientific research since these possess incredibly remarkable health benefits, especially antioxidant potential to scavenge free radicals and combat the harmful effects of oxidative stress caused by adverse environmental factors. The efficacy and quantity of these phytochemicals relies upon numerous factors including the extraction method, solvent polarity and the habitat features in which the plant is growing. In this study we emphasized on phytochemical analysis and antioxidant activity of Bistorta amplexicaulis, an important medicinal plant species from Kashmir Himalaya. We evaluated antioxidant activity using different assays from all the selected sites to enumerate the impact of habitat. The sites were selected based on varying habitat features and altitude. Our results revealed that Ethyl acetate is the potent solvent for the extraction of phytochemicals. Below ground parts exhibited better scavenging activity than the above ground parts. Amongst the sites, we found the maximum antioxidant potential at Site I. A positive correlation was found between antioxidant activity and altitude while soil attributes (OC, OM, N, P, and K) and most of the morphological traits showed a negative correlation. Overall, our study identified the elite populations that could be utilized for mass propagation and harness the ultimate antioxidant potential of B. amplexicaulis.
Enhancing Sound Source Localization via False Negative Elimination
Creators: name: Song, Zengjie
name: Zhang, Jiangshe
name: Wang, Yuxi
name: Fan, Junsong
name: Zhang, Zhaoxiang
Publisher: name: arXiv
Year: 2024
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Sound source localization aims to localize objects emitting the sound in visual scenes. Recent works obtaining impressive results typically rely on contrastive learning. However, the common practice of randomly sampling negatives in prior arts can lead to the false negative issue, where the sounds semantically similar to visual instance are sampled as negatives and incorrectly pushed away from the visual anchor/query. As a result, this misalignment of audio and visual features could yield inferior performance. To address this issue, we propose a novel audio-visual learning framework which is instantiated with two individual learning schemes: self-supervised predictive learning (SSPL) and semantic-aware contrastive learning (SACL). SSPL explores image-audio positive pairs alone to discover semantically coherent similarities between audio and visual features, while a predictive coding module for feature alignment is introduced to facilitate the positive-only learning. In this regard SSPL acts as a negative-free method to eliminate false negatives. By contrast, SACL is designed to compact visual features and remove false negatives, providing reliable visual anchor and audio negatives for contrast. Different from SSPL, SACL releases the potential of audio-visual contrastive learning, offering an effective alternative to achieve the same goal. Comprehensive experiments demonstrate the superiority of our approach over the state-of-the-arts. Furthermore, we highlight the versatility of the learned representation by extending the approach to audio-visual event classification and object detection tasks. Code and models are available at: https://github.com/zjsong/SACL.
description: arXiv admin note: substantial text overlap with arXiv:2203.13412
Superexchange Interaction in Insulating EuZn$_{2}$P$_{2}$
Creators: name: Singh, Karan
name: Dan, Shovan
name: Ptok, A.
name: Zaleski, T. A.
name: Pavlosiuk, O.
name: Wiśniewski, P.
name: Kaczorowski, D.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We report magnetic and transport properties of single-crystalline EuZn$_{2}$P$_{2}$, which has trigonal CaAl$_2$Si$_2$-type crystal structure and orders antiferromagnetically at $\approx$23~K. Easy $ab$-plane magneto-crystalline anisotropy was confirmed from the magnetization isotherms, measured with a magnetic field applied along different crystallographic directions ($ab$-plane and $c$-axis). Positive Curie-Weiss temperature indicates dominating ferromagnetic correlations. Electrical resistivity displays insulating behavior with a band-gap of $\approx\,$0.177~eV, which decreases to $\approx\,$0.13~eV upon application of a high magnetic field. We explained the intriguing presence of magnetic interactions in an intermetallic insulator by the mechanism of extended superexchange, with phosphorus as an anion mediator, which is further supported by our analysis of the charge and spin density distributions. We constructed the effective Heisenberg model, with exchange parameters derived from the \textit{ab initio} DFT calculations, and employed it in Monte-Carlo simulations, which correctly reproduced the experimental value of Néel temperature.
Perturbations of continuum random Schrödinger operators with applications to Anderson orthogonality and the spectral shift function
Creators: name: Dietlein, Adrian
name: Gebert, Martin
name: Müller, Peter
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mathematical Physics (math-ph)
subject: Spectral Theory (math.SP)
subject: FOS: Physical sciences
subject: FOS: Mathematics
subject: Primary 81Q10, Secondary: 47B80, 82B44

description: We study effects of a bounded and compactly supported perturbation on multi-dimensional continuum random Schrödinger operators in the region of complete localisation. Our main emphasis is on Anderson orthogonality for random Schrödinger operators. Among others, we prove that Anderson orthogonality does occur for Fermi energies in the region of complete localisation with a non-zero probability. This partially confirms recent non-rigorous findings [V. Khemani et al., Nature Phys. 11, 560-565 (2015)]. The spectral shift function plays an important role in our analysis of Anderson orthogonality. We identify it with the index of the corresponding pair of spectral projections and explore the consequences thereof. All our results rely on the main technical estimate of this paper which guarantees separate exponential decay of the disorder-averaged Schatten $p$-norm of $χ_{a}(f(H) - f(H^τ)) χ_{b}$ in $a$ and $b$. Here, $H^τ$ is a perturbation of the random Schrödinger operator $H$, $χ_{a}$ is the multiplication operator corresponding to the indicator function of a unit cube centred about $a\in\mathbb{R}^{d}$, and $f$ is in a suitable class of functions of bounded variation with distributional derivative supported in the region of complete localisation for $H$.
description: Title changed; Shortened version of the previous one (v1); version as to appear in J. Spectr. Theory
Efficient simulation of quantum error correction under coherent error based on non-unitary free-fermionic formalism
Creators: name: Suzuki, Yasunari
name: Fujii, Keisuke
name: Koashi, Masato
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In order to realize fault-tolerant quantum computation, tight evaluation of error threshold under practical noise models is essential. While non-Clifford noise is ubiquitous in experiments, the error threshold under non-Clifford noise cannot be efficiently treated with known approaches. We construct an efficient scheme for estimating the error threshold of one-dimensional quantum repetition code under non-Clifford noise. To this end, we employ non-unitary free-fermionic formalism for efficient simulation of the one-dimensional repetition code under coherent noise. This allows us to evaluate the effect of coherence in noise on the error threshold without any approximation. The result shows that the error threshold becomes one third when noise is fully coherent. Our scheme is also applicable to the surface code undergoing a specific coherent noise model. The dependence of the error threshold on noise coherence can be explained with a leading-order analysis with respect to coherence terms in the noise map. We expect that this analysis is also valid for the surface code since it is a two-dimensional extension of the one-dimensional repetition code. Moreover, since the obtained threshold is accurate, our results can be used as a benchmark for approximation or heuristic schemes for non-Clifford noise.
description: 11 pages, 6 figures. v2: extension to the surface code is added
On n-tuplet fixed points for noncompact multivalued mappings via measure of noncompactness
Creators: name: Sekman, Derya
name: Bouzara, Nour El Houda
name: Karakaya, Vatan
Publisher: name: arXiv
Year: 2017
Subjects: subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: 47H9, 47H10, 34A60

description: In this paper, some results on the existence of n-tuplet fixed points for multi-valued contraction mappings are proved via measure of noncompactness. As an application, the existence of solutions for a system of integral inclusions is studied.
description: 13 pages
Top-pair production at the LHC through NNLO QCD and NLO EW
Creators: name: Czakon, Michal
name: Heymes, David
name: Mitov, Alexander
name: Pagani, Davide
name: Tsinikos, Ioannis
name: Zaro, Marco
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: In this work we present for the first time predictions for top-quark pair differential distributions at the LHC at NNLO QCD accuracy and including EW corrections. For the latter we include not only contributions of ${\cal O}(α_s^2 α)$, but also those of order ${\cal O}(α_s α^2)$ and ${\cal O}( α^3)$. Besides providing phenomenological predictions for all main differential distributions with stable top quarks, we also study the following issues. 1) The effect of the photon PDF on top-pair spectra: we find it to be strongly dependent on the PDF set used -- especially for the top $p_T$ distribution. 2) The difference between the additive and multiplicative approaches for combining QCD and EW corrections: with our scale choice, we find relatively small differences between the central predictions, but reduced scale dependence within the multiplicative approach. 3) The potential effect from the radiation of heavy bosons on inclusive top-pair spectra: we find it to be, typically, negligible.
description: 22 pages, 7 figures, version published in JHEP, results are attached in electronic form, results and additional material available from this website: http://www.precision.hep.phy.cam.ac.uk/results/ttbar-nnloqcd-nloew/
Green synthesis and biological evaluation of glaucanic acid and dihydrocompactin acid by endophytic fungus Penicillium polonicum from Zingiber officinale
Creators: name: Gupta, Suruchi
name: Choudhary, Malvi
name: Singh, Baljinder
name: Kushwaha, Manoj
name: Dhar, Manoj K.
name: Kaul, Sanjana
Publisher: name: Taylor & Francis
Year: 2024
Subjects: subject: Biochemistry
subject: Microbiology
subject: FOS: Biological sciences
subject: Pharmacology
subject: Biotechnology
subject: Environmental Sciences not elsewhere classified
subject: Chemical Sciences not elsewhere classified
subject: Ecology
subject: Biological Sciences not elsewhere classified

description: Fungal endophytes are valued for biosynthesizing chemically diverse metabolic cascade with interesting biological activities. In the current investigation, two compounds were isolated from Penicillium polonicum, an endophyte of Zingiber officinale. The active moieties, glaucanic acid (1) and dihydrocompactin acid (2) were isolated from the ethyl acetate extract of P. polonicum and characterized by NMR and mass spectroscopy. Further, bioactive potential of the isolated compounds was evaluated by antimicrobial, antioxidant and cytotoxicity assays. Compounds 1 and 2 displayed antifungal activity against phytopathogen Colletotrichum gloeosporioides with more than 50% reduction in its growth. Both the compounds exhibited antioxidant activity against free radicals (DPPH and ABTS) and cytotoxicity activity against cancer cell lines respectively. The compounds, glaucanic acid and dihydrocompactin acid are being reported for the first time from an endophytic fungus. This is the first report on the biological activities of Dihydrocompactin acid produced by endophytic fungal strain.
CooTest: An Automated Testing Approach for V2X Communication Systems
Creators: name: Guo, An
name: Gao, Xinyu
name: Chen, Zhenyu
name: Xiao, Yuan
name: Liu, Jiakai
name: Ge, Xiuting
name: Sun, Weisong
name: Fang, Chunrong
Publisher: name: arXiv
Year: 2024
Subjects: subject: Software Engineering (cs.SE)
subject: FOS: Computer and information sciences

description: Perceiving the complex driving environment precisely is crucial to the safe operation of autonomous vehicles. With the tremendous advancement of deep learning and communication technology, Vehicle-to-Everything (V2X) collaboration has the potential to address limitations in sensing distant objects and occlusion for a single-agent perception system. However, despite spectacular progress, several communication challenges can undermine the effectiveness of multi-vehicle cooperative perception. The low interpretability of Deep Neural Networks (DNNs) and the high complexity of communication mechanisms make conventional testing techniques inapplicable for the cooperative perception of autonomous driving systems (ADS). Besides, the existing testing techniques, depending on manual data collection and labeling, become time-consuming and prohibitively expensive.
 In this paper, we design and implement CooTest, the first automated testing tool of the V2X-oriented cooperative perception module. CooTest devises the V2X-specific metamorphic relation and equips communication and weather transformation operators that can reflect the impact of the various cooperative driving factors to produce transformed scenes. Furthermore, we adopt a V2X-oriented guidance strategy for the transformed scene generation process and improve testing efficiency. We experiment CooTest with multiple cooperative perception models with different fusion schemes to evaluate its performance on different tasks. The experiment results show that CooTest can effectively detect erroneous behaviors under various V2X-oriented driving conditions. Also, the results confirm that CooTest can improve detection average precision and decrease misleading cooperation errors by retraining with the generated scenes.
An End-to-End Review of Gaze Estimation and its Interactive Applications on Handheld Mobile Devices
Creators: name: Lei, Yaxiong
name: He, Shijing
name: Khamis, Mohamed
name: Ye, Juan
Publisher: name: arXiv
Year: 2023
Subjects: subject: Human-Computer Interaction (cs.HC)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences
subject: H.5

description: In recent years we have witnessed an increasing number of interactive systems on handheld mobile devices which utilise gaze as a single or complementary interaction modality. This trend is driven by the enhanced computational power of these devices, higher resolution and capacity of their cameras, and improved gaze estimation accuracy obtained from advanced machine learning techniques, especially in deep learning. As the literature is fast progressing, there is a pressing need to review the state of the art, delineate the boundary, and identify the key research challenges and opportunities in gaze estimation and interaction. This paper aims to serve this purpose by presenting an end-to-end holistic view in this area, from gaze capturing sensors, to gaze estimation workflows, to deep learning techniques, and to gaze interactive applications.
description: 37 Pages, Paper accepted by ACM Computing Surveys
Wound healing mechanisms of Couroupita guianensis fruit pulp: An ethnomedicine used by traditional healers in India
Creators: name: Vasanthakumari, Kumaraguru
name: Sharmila, Chelladurai
name: Priya, Shree Jaya
name: Vadivel, Vellingiri
Publisher: name: Taylor & Francis
Year: 2023
Subjects: subject: Biochemistry
subject: Microbiology
subject: FOS: Biological sciences
subject: Cell Biology
subject: Pharmacology
subject: Biotechnology
subject: Environmental Sciences not elsewhere classified
subject: Chemical Sciences not elsewhere classified
subject: Ecology
subject: Developmental Biology
subject: Cancer
subject: Infectious Diseases
subject: FOS: Health sciences
subject: Plant Biology

description: In connection to search for safe and alternative plant-based drugs, the wound healing mechanisms of an Indian ethnomedicine Couroupita guianensis fruit pulp was analyzed in this project work. Gas chromatography coupled with mass spectrometer (GC-MS) analysis revealed the existence of phytochemicals such as 2-furoic acid, 2,4-heptadienal, pyrazole and 8-hydroxyquinoline in the methanol extract. Methanol extract of C. guianensis exhibited remarkable radical scavenging activity against 2, 2-diphenyl-1-picrylhydrazyl (DPPH) (89.88%), superoxide (91.51%), hydrogen peroxide (24.25%) and hydroxyl radicals (73.62%). Further, it showed remarkable anti-inflammatory (24.09-62.16%) and anti-bacterial activity (zone of inhibition, ZOI: 13.00 mm, minimum inhibitory concentration, MIC: 6.25 mg/mL and minimum bactericidal concentration, MBC: 12.51 mg/mL) and also controlled the growth rate of methicillin resistant Staphylococcus aureus (MRSA) within 30 min of treatment. The angiogenic potential of C. guianensis was proved in chick chorioallantoic membrane (CAM) model and it does not exhibit any toxicity in peripheral blood monocyte cells (PBMC) model.