cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Fundamental solutions for micropolar fluids
Creators: name: Shu, Jian-Jun
name: Lee, Jenn Shiun
Publisher: name: arXiv
Year: 2014
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: New fundamental solutions for micropolar fluids are derived in explicit form for two- and three-dimensional steady unbounded Stokes and Oseen flows due to a point force and a point couple, including the two-dimensional micropolar Stokeslet, the two- and three-dimensional micropolar Stokes couplet, the three-dimensional micropolar Oseenlet, and the three-dimensional micropolar Oseen couplet. These fundamental solutions do not exist in Newtonian flow due to the absence of microrotation velocity field. The flow due to these singularities is useful for understanding and studying microscale flows. As an application, the drag coefficients for a solid sphere or a circular cylinder that translates in a low-Reynolds-number micropolar flow are determined and compared with those corresponding to Newtonian flow. The drag coefficients in a micropolar fluid are greater than those in a Newtonian fluid.
Utilization of Methodology for enhanced Assessment on Best Practices at the EU level
Creators: name: Bagkatzounis, Ioannis
Publisher: name: Zenodo
Year: 2022
Subjects: perceptions
narratives
migration
best practices

description: The main objective of this policy brief is to provide an overview of the main methodological challenges in the field of best practices assessment in relation to narratives about Europe/the EU. Moreover, it provides policy recommendations as well as a structured approach which is intended to create fertile ground for actors, allowing them to conduct an enhanced Best Practices assessment at the European Union (EU) level. This policy brief also points out outcomes from the collection of measures, good practices, countermeasures, tools, and approaches utilized for assessing misleading narratives, and biased expectations towards the EU whilst examining the perspective of refugees, migrants, and asylum seekers. In conclusion, several best practices and recommendations are identified. The aforementioned practices could potentially be established as feasible and effective approach to enhance the pre-established modus operandi, addressing contemporary methodological challenges within the field of migrants’ European narratives and perceptions.
Measures and Optimization for Robustness and Vulnerability in Disconnected Networks
Creators: name: Zhu, Liwang
name: Bao, Qi
name: Zhang, Zhongzhi
Publisher: name: arXiv
Year: 2023
Subjects: subject: Social and Information Networks (cs.SI)
subject: Cryptography and Security (cs.CR)
subject: FOS: Computer and information sciences

description: The function or performance of a network is strongly dependent on its robustness, quantifying the ability of the network to continue functioning under perturbations. While a wide variety of robustness metrics have been proposed, they have their respective limitations. In this paper, we propose to use the forest index as a measure of network robustness, which overcomes the deficiencies of existing metrics. Using such a measure as an optimization criterion, we propose and study the problem of breaking down a network by attacking some key edges. We show that the objective function of the problem is monotonic but not submodular, which impose more challenging on the problem. We thus resort to greedy algorithms extended for non-submodular functions by iteratively deleting the most promising edges. We first propose a simple greedy algorithm with a proved bound for the approximation ratio and cubic-time complexity. To confront the computation challenge for large networks, we further propose an improved nearly-linear time greedy algorithm, which significantly speeds up the process for edge selection but sacrifices little accuracy. Extensive experimental results for a large set of real-world networks verify the effectiveness and efficiency of our algorithms, demonstrating that our algorithms outperform several baseline schemes.
description: 13 pages
The distribution of interstellar dust in CALIFA edge-on galaxies via oligochromatic radiative transfer fitting
Creators: name: De Geyter, Gert
name: Baes, Maarten
name: Camps, Peter
name: Fritz, Jacopo
name: De Looze, Ilse
name: Hughes, Thomas M.
name: Viaene, Sebastien
name: Gentile, Gianfranco
Publisher: name: arXiv
Year: 2014
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We investigate the amount and spatial distribution of interstellar dust in edge-on spiral galaxies, using detailed radiative transfer modeling of a homogeneous sample of 12 galaxies selected from the CALIFA survey. Our automated fitting routine, FitSKIRT, was first validated against artificial data. This is done by simultaneously reproducing the SDSS $g$-, $r$-, $i$- and $z$-band observations of a toy model in order to combine the information present in the different bands. We show that this combined, oligochromatic fitting, has clear advantages over standard monochromatic fitting especially regarding constraints on the dust properties. We model all galaxies in our sample using a three-component model, consisting of a double exponential disc to describe the stellar and dust discs and using a Sérsic profile to describe the central bulge. The full model contains 19 free parameters, and we are able to constrain all these parameters to a satisfactory level of accuracy without human intervention or strong boundary conditions. Apart from two galaxies, the entire sample can be accurately reproduced by our model. We find that the dust disc is about 75% more extended but only half as high as the stellar disc. The average face-on optical depth in the V-band is $0.76$ and the spread of $0.60$ within our sample is quite substantial, which indicates that some spiral galaxies are relatively opaque even when seen face-on.
description: 18 pages, 6 figures, 4 tables, Accepted for publication in MNRAS
The moduli space of vacua of N=2 class S theories
Creators: name: Xie, Dan
name: Yonekura, Kazuya
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We develop a systematic method to describe the moduli space of vacua of four dimensional $\mathcal{N}=2$ class ${\cal S}$ theories including Coulomb branch, Higgs branch and mixed branches. In particular, we determine the Higgs and mixed branch roots, and the dimensions of the Coulomb and Higgs components of mixed branches. They are derived by using generalized Hitchin's equations obtained from twisted compactification of 5d maximal Super-Yang-Mills, with local degrees of freedom at punctures given by (nilpotent) orbits. The crucial thing is the holomorphic factorization of the Seiberg-Witten curve and reduction of singularity at punctures. We illustrate our method by many examples including ${\mathcal N}=2$ SQCD, $T_N$ theory and Argyres-Douglas theories.
description: 33 pages, 4 figures
Evaluation of two thermal neutron detection units consisting of ZnS/${}^6$LiF scintillating layers with embedded WLS fibers read out with a SiPM
Creators: name: Mosset, J. -B.
name: Stoykov, A.
name: Greuter, U.
name: Hildebrandt, M.
name: Schlumpf, N.
name: Van Swygenhoven, H.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: Two single channel detection units for thermal neutron detection are investigated in a neutron beam. They consist of two ZnS/${}^6$LiF scintillating layers sandwiching an array of WLS fibers. The pattern of this units can be repeated laterally and vertically in order to build up a one dimensional position sensitive multi-channel detector with the needed sensitive surface and with the required neutron absorption probability. The originality of this work arises from the fact that the WLS fibers are read out with SiPMs instead of the traditionally used PMTs or MaPMTs. The signal processing system is based on a photon counting approach. For SiPMs with a dark count rate as high as 0.7 MHz, a trigger efficiency of 80% is achieved together with a system background rate lower than ${10}^{-3}$ Hz and a dead time of 30 $μ$s. No change of performance is observed for neutron count rates of up to 3.6 kHz.
description: Submitted to Nuclear Instruments and Methods A
Curbing Nigerian-Italian Human Trafficking for Sexual Exploitation
Creators: name: Jinkang, Alagie
Publisher: name: Zenodo
Year: 2022
Subjects: perceptions
narratives
migration
sexual exploitation

description: Italy’s illegal commercialised sex industry is estimated to be worth 90 million Euro and involves up to 9 million clients annually. The industry depends on migrants from Nigeria, Romania and Albania, many of whom are victims of human trafficking, abuse, exploitation, oppression, extreme educational and economic poverty, and non-integration in Italy. But despite legal and policy interventions, sexual exploitation of migrants is highly tolerated, goes largely unpunished and is increasingly threatening to migrant women's wellbeing throughout the peninsula, as in the case of migrant women from Nigeria. This brief focuses on the NigerianItalian HTSE for two main reasons: (a) Italy’s proximity to the central Mediterranean route serving as key irregular route for migrant smugglers and human traffickers; (b) Italy’s dysfunctional and emergencial asylum systems coupled with its insufficient, untimely and inefficient policy intervention on migrants' sexual exploitation, and; (c) perceptions and misinformation about Europe as source of economic and social opportunities and prestige, which all provide a fertile ground for mafia activities and organised crime to flourish. Therefore, coupled with PERCEPTIONS findings, this brief draws political attention to the intersections between irregular migration and asylum, mafia activities and organised crime, targeted deception and misinformation, abject poverty and traditional practices within the discourse of NigerianItalian HTSE.
Galaxy pairs in the Sloan Digital Sky Survey - IX: Merger-induced AGN activity as traced by the Wide-field Infrared Survey Explorer
Creators: name: Satyapal, Shobita
name: Ellison, Sara L.
name: McAlpine, William
name: Hickox, Ryan C.
name: Patton, David R.
name: Mendel, J. Trevor
Publisher: name: arXiv
Year: 2014
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Interactions between galaxies are predicted to cause gas inflows that can potentially trigger nuclear activity. Since the inflowing material can obscure the central regions of interacting galaxies, a potential limitation of previous optical studies is that obscured Active Galactic Nuclei (AGNs) can be missed at various stages along the merger sequence. We present the first large mid-infrared study of AGNs in mergers and galaxy pairs, in order to quantify the incidence of obscured AGNs triggered by interactions. The sample consists of galaxy pairs and post-mergers drawn from the Sloan Digital Sky Survey that are matched to detections by the Wide Field Infrared Sky Explorer (WISE). We find that the fraction of AGN in the pairs, relative to a mass-, redshift- and environment-matched control sample, increases as a function of decreasing projected separation. This enhancement is most dramatic in the post-merger sample, where we find a factor of 10-20 excess in the AGN fraction compared with the control. Although this trend is in qualitative agreement with results based on optical AGN selection, the mid-infrared selected AGN excess increases much more dramatically in the post-mergers than is seen for optical AGN. Our results suggest that energetically dominant optically obscured AGNs become more prevalent in the most advanced mergers, consistent with theoretical predictions.
description: 8 pages, 7 figures accepted to MNRAS (with minor revisions)
Regularized linearization for quantum nonlinear optical cavities: Application to Degenerate Optical Parametric Oscillators
Creators: name: Navarrete-Benlloch, Carlos
name: Roldán, Eugenio
name: Chang, Yue
name: Shi, Tao
Publisher: name: arXiv
Year: 2014
Subjects: subject: Quantum Physics (quant-ph)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Nonlinear optical cavities are crucial both in classical and quantum optics; in particular, nowadays optical parametric oscillators are one of the most versatile and tunable sources of coherent light, as well as the sources of the highest quality quantum-correlated light in the continuous variable regime. Being nonlinear systems, they can be driven through critical points in which a solution ceases to exist in favour of a new one, and it is close to these points where quantum correlations are the strongest. The simplest description of such systems consists in writing the quantum fields as the classical part plus some quantum fluctuations, linearizing then the dynamical equations with respect to the latter; however, such an approach breaks down close to critical points, where it provides unphysical predictions such as infinite photon numbers. On the other hand, techniques going beyond the simple linear description become too complicated especially regarding the evaluation of two-time correlators, which are of major importance to compute observables outside the cavity. In this article we provide a regularized linear description of nonlinear cavities, that is, a linearization procedure yielding physical results, taking the degenerate optical parametric oscillator as the guiding example. The method, which we call self-consistent linearization, is shown to be equivalent to a general Gaussian ansatz for the state of the system, and we compare its predictions with those obtained with available exact (or quasi-exact) methods.
description: Comments and suggestions are welcome
The effect of the quasar H1821+643 on the surrounding intracluster medium: revealing the underlying cooling flow
Creators: name: Walker, S. A.
name: Fabian, A. C.
name: Russell, H. R.
name: Sanders, J. S.
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We present a detailed study of the thermodynamic properties of the intracluster medium of the only low redshift galaxy cluster to contain a highly luminous quasar, H1821+643. The cluster is a highly massive, strong cool core cluster. We find that the ICM entropy around the quasar is significantly lower than that of other similarly massive strong cool core clusters within the central 80 kpc, and that the entropy lies significantly below the extrapolated baseline entropy profile from hierarchical structure formation. By comparing the scaled temperature profile with those of other strong cool core clusters of similar total mass, we see that the entropy deficiency is due to the central temperature being significantly lower. This suggests that the presence of the quasar in the core of H1821+643 has had a dramatic cooling effect on the intracluster medium around it. We find that, if the quasar was brighter in the past, Compton cooling by radiation from the quasar may have caused the low entropy and temperature levels in the ICM around the quasar. Curiously, the gradients of the steep central temperature and entropy decline are in reasonable agreement with the profiles expected for a constant pressure cooling flow. It is possible that the system has been locked into a Compton cooled feedback cycle which prevents energy release from the black hole heating the gas sufficiently to switch it off, leading to the formation of a huge (~3x10^10 solar mass) supermassive black hole.
description: 8 pages, 10 figures. Accepted for publication in MNRAS
The entropic pressure of lattice knots
Creators: name: van Rensburg, EJ Janse
Publisher: name: arXiv
Year: 2014
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences
subject: 82B41, 82B05

description: The entropic pressure in the vicinity of a cubic lattice knot is examined as a model of the entropic pressure near a knotted ring polymer in a good solvent. A model for the scaling of the pressure is developed and this is tested numerically by sampling lattice knots using a Monte Carlo algorithm. Good agreement is found between scaling predictions and numerical experiments.
Symbolic computation of the Birkhoff normal form in the problem of stability of the triangular libration points
Creators: name: Shevchenko, I. I.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: The problem of stability of the triangular libration points in the planar circular restricted three-body problem is considered. A software package, intended for normalization of autonomous Hamiltonian systems by means of computer algebra, is designed so that normalization problems of high analytical complexity could be solved. It is used to obtain the Birkhoff normal form of the Hamiltonian in the given problem. The normalization is carried out up to the 6th order of expansion of the Hamiltonian in the coordinates and momenta. Analytical expressions for the coefficients of the normal form of the 6th order are derived. Though intermediary expressions occupy gigabytes of the computer memory, the obtained coefficients of the normal form are compact enough for presentation in typographic format. The analogue of the Deprit formula for the stability criterion is derived in the 6th order of normalization. The obtained floating-point numerical values for the normal form coefficients and the stability criterion confirm the results by Markeev (1969) and Coppola and Rand (1989), while the obtained analytical and exact numeric expressions confirm the results by Meyer and Schmidt (1986) and Schmidt (1989). The given computational problem is solved without constructing a specialized algebraic processor, i.e., the designed computer algebra package has a broad field of applicability.
description: 18 pages
The EPOCH Project: I. Periodic variable stars in the EROS-2 LMC database
Creators: name: Kim, Dae-Won
name: Protopapas, Pavlos
name: Bailer-Jones, Coryn A. L.
name: Byun, Yong-Ik
name: Chang, Seo-Won
name: Marquette, Jean-Baptiste
name: Shin, Min-Su
Publisher: name: arXiv
Year: 2014
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The EPOCH (EROS-2 periodic variable star classification using machine learning) project aims to detect periodic variable stars in the EROS-2 light curve database. In this paper, we present the first result of the classification of periodic variable stars in the EROS-2 LMC database. To classify these variables, we first built a training set by compiling known variables in the Large Magellanic Cloud area from the OGLE and MACHO surveys. We crossmatched these variables with the EROS-2 sources and extracted 22 variability features from 28 392 light curves of the corresponding EROS-2 sources. We then used the random forest method to classify the EROS-2 sources in the training set. We designed the model to separate not only $δ$ Scuti stars, RR Lyraes, Cepheids, eclipsing binaries, and long-period variables, the superclasses, but also their subclasses, such as RRab, RRc, RRd, and RRe for RR Lyraes, and similarly for the other variable types. The model trained using only the superclasses shows 99% recall and precision, while the model trained on all subclasses shows 87% recall and precision. We applied the trained model to the entire EROS-2 LMC database, which contains about 29 million sources, and found 117 234 periodic variable candidates. Out of these 117 234 periodic variables, 55 285 have not been discovered by either OGLE or MACHO variability studies. This set comprises 1 906 $δ$ Scuti stars, 6 607 RR Lyraes, 638 Cepheids, 178 Type II Cepheids, 34 562 eclipsing binaries, and 11 394 long-period variables. A catalog of these EROS-2 LMC periodic variable stars will be available online at http://stardb.yonsei.ac.kr and at the CDS website (http://vizier.u-strasbg.fr/viz-bin/VizieR).
description: 18 pages, 20 figures, suggseted language-editing by the A&A editorial office is applied
Neutron activation analysis of the 30Si content of highly enriched 28Si: proof of concept and estimation of the achievable uncertainty
Creators: name: D'Agostino, Giancarlo
name: Mana, Giovanni
name: Oddone, Massimo
name: Prata, Michele
name: Bergamaschi, Luigi
name: Giordani, Laura
Publisher: name: arXiv
Year: 2014
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: We investigated the use of neutron activation to estimate the 30Si mole fraction of the ultra-pure silicon material highly enriched in 28Si for the measurement of the Avogadro constant. Specifically, we developed a relative method based on Instrumental Neutron Activation Analysis and using a natural-Si sample as a standard. To evaluate the achievable uncertainty, we irradiated a 6 g sample of a natural-Si material and modeled experimentally the signal that would be produced by a sample of the 28Si-enriched material of similar mass and subjected to the same measurement conditions. The extrapolation of the expected uncertainty from the experimental data indicates that a measurement of the 30Si mole fraction of the 28Si-enriched material might reach a 4% relative combined standard uncertainty.
Risk Factors, Mechanisms and Therapeuthic for Right Heart Failure Associated with Pulmonary Hypertension
Creators: name: Zelt, Jason
Publisher: name: Université d'Ottawa / University of Ottawa
Year: 2020
Subjects: Right Heart Failure
Pulmonary Hypertension
Adenylate Kinase
Metabolism
Sympathetic Nervous System
Positron Emission Tomography

description: Right ventricular function (RV) is one of the most important predictors of prognosis in many cardiovascular disease states. Despite the significance of RV function to survival, there are no therapies that directly nor selectively improve RV function. As well, the basis for RV failure is poorly understood. This is particularly relevant for patients with pulmonary arterial hypertension (PAH), where RV failure in the setting of pressure overload is the leading cause of death. PAH will be introduced in the 2nd chapter of this thesis by comparing and refining contemporary mortality risk assessment strategies. I will then explore 1) RV neurohormonal function and, 2) RV energetics, two molecular pathways thought to be involved in the pathogenesis and progression of maladaptive RV failure. I employed small animal molecular imaging using positron emission tomography (PET) to non-invasively investigate these pathways. The PET imaging techniques employed in this thesis have the unique potential for translation to human studies, to further explore disease mechanisms.
An improved scoring matrix for multiple sequence alignment
Creators: name: Shu, Jian-Jun
name: Yong, Kian Yan
name: Chan, Weng Kong
Publisher: name: arXiv
Year: 2014
Subjects: subject: Quantitative Methods (q-bio.QM)
subject: Genomics (q-bio.GN)
subject: FOS: Biological sciences

description: The way for performing multiple sequence alignment is based on the criterion of the maximum scored information content computed from a weight matrix, but it is possible to have two or more alignments to have the same highest score leading to ambiguities in selecting the best alignment. This paper addresses this issue by introducing the concept of joint weight matrix to eliminate the randomness in selecting the best multiple sequence alignment. Alignments with equal scores are iteratively rescored with the joint weight matrix of increasing level (nucleotide pairs, triplets and so on) until one single best alignment is eventually found. This method for resolving ambiguity in multiple sequence alignment can be easily implemented by use of the improved scoring matrix.
Mid- and Far-Infrared Variability of PV Cep
Creators: name: Lorenzetti, Dario
name: Antoniucci, Simone
name: Giannini, Teresa
name: Causi, Gianluca Li
name: Di Paola, Andrea
name: Arkharov, Arkady A.
name: Larionov, Valeri M.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present the collection of all the mid- and far-IR observations (3-170 um) of the young eruptive variable PV Cep available so far in the literature. These data allow us to confirm that flux variability is a prominent feature at mid-IR wavelength (3-25 um). Color-magnitude plots clearly indicate that the observed variability is not extinction-driven, but mainly influenced by fluctuations of the mass accretion rate. We interpret such variability as due to a hot spot created onto the stellar surface by the column of accreting matter, which heats the inner parts of the disk and determines the observed increase of the near- mid-IR luminosity. A quantitative characterization is given for both the spot itself and the additional thermal component created by it. Far-IR data (60-170 um) are consistent with the presence of a temperature stratification in a massive and quite un-evolved circumstellar disk.
description: 4 figures, accepted Astrophysics and Space Science 2014
Fano resonance control in a photonic crystal structure and its application to ultrafast switching
Creators: name: Yu, Yi
name: Heuck, Mikkel
name: Hu, Hao
name: Xue, Weiqi
name: Peucheret, Christophe
name: Chen, Yaohui
name: Oxenløwe, Leif Katsuo
name: Yvind, Kresten
name: Mørk, Jesper
Publisher: name: arXiv
Year: 2014
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Fano resonances appear in quantum mechanical as well as classical systems as a result of the interference between two paths: one involving a discrete resonance and the other a continuum. Compared to a conventional resonance, characterized by a Lorentzian spectral response, the characteristic asymmetric and sharp spectral response of a Fano resonance is suggested to enable photonic switches and sensors with superior characteristics. While experimental demonstrations of the appearance of Fano resonances have been made in both plasmonic and photonic-crystal structures, the control of these resonances is experimentally challenging, often involving the coupling of near-resonant cavities. Here, we experimentally demonstrate two simple structures that allow surprisingly robust control of the Fano spectrum. One structure relies on controlling the amplitude of one of the paths and the other uses symmetry breaking. Short-pulse dynamic measurements show that besides drastically increasing the switching contrast, the transmission dynamics itself is strongly affected by the nature of the resonance. The influence of slow-recovery tails implied by a long carrier lifetime can thus be reduced using a Fano resonance due to a hitherto unrecognized reshaping effect of the nonlinear Fano transfer function. For the first time, we present a system application of a Fano structure, demonstrating its advantages by the experimental realization of 10 Gbit/s all-optical modulation with bit-error-ratios on the order of 10$^{-7}$ for input powers less than 1 mW. These results represent a significant improvement compared to the use of a conventional Lorentzian resonance.
description: 15 pages, 5 figures
On a generalized conjecture of Hopf with symmetry
Creators: name: Amann, Manuel
name: Kennard, Lee
Publisher: name: arXiv
Year: 2014
Subjects: subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 53C20 (primary), 57N65 (Secondary)

description: A famous conjecture of Hopf is that the product of the two-dimensional sphere with itself does not admit a Riemannian metric with positive sectional curvature. More generally, one may conjecture that this holds for any nontrivial product. We provide evidence for this generalized conjecture in the presence of symmetry.
description: 10 pages
FRIGATE: Frugal Spatio-temporal Forecasting on Road Networks
Creators: name: Gupta, Mridul
name: Kodamana, Hariprasad
name: Ranu, Sayan
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: Modelling spatio-temporal processes on road networks is a task of growing importance. While significant progress has been made on developing spatio-temporal graph neural networks (Gnns), existing works are built upon three assumptions that are not practical on real-world road networks. First, they assume sensing on every node of a road network. In reality, due to budget-constraints or sensor failures, all locations (nodes) may not be equipped with sensors. Second, they assume that sensing history is available at all installed sensors. This is unrealistic as well due to sensor failures, loss of packets during communication, etc. Finally, there is an assumption of static road networks. Connectivity within networks change due to road closures, constructions of new roads, etc. In this work, we develop FRIGATE to address all these shortcomings. FRIGATE is powered by a spatio-temporal Gnn that integrates positional, topological, and temporal information into rich inductive node representations. The joint fusion of this diverse information is made feasible through a novel combination of gated Lipschitz embeddings with Lstms. We prove that the proposed Gnn architecture is provably more expressive than message-passing Gnns used in state-of-the-art algorithms. The higher expressivity of FRIGATE naturally translates to superior empirical performance conducted on real-world network-constrained traffic data. In addition, FRIGATE is robust to frugal sensor deployment, changes in road network connectivity, and temporal irregularity in sensing.
High Pressure Structural Stability, and Optical Properties of Scheelite type ZrGeO$_4$ and HfGeO$_4$ X-ray Phosphor Hosts
Creators: name: Shwetha, G.
name: Kanchana, V.
name: Babu, K. Ramesh
name: Vaitheeswaran, G.
name: Valsakumar, M. C.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: \emph{Ab-initio} calculations were performed on the scheelite type MGeO$_4$ (M = Hf, and Zr) compounds which find wide range of applications such as in x-ray imaging. We have studied the high pressure structural stability, elastic constants, electronic structure and optical properties of these compounds through density functional theory calculations. Two different density functional approaches namely plane wave pseudopotential method (PW-PP) and full potential linearized augmented plane wave method (FP-LAPW) were used for the present study. The ground state structural and vibrational properties are calculated and found to be in good agreement with experimental data. The compressibility of Zr and Hf germanates is found to be anisotropic as the a-axis is less compressible over c-axis due to the presence of Ge-O bonds along a-axis which is further confirmed from the ordering of the elastic constants that follows C$_{11}$ $>$ C$_{33}$. The electronic structure of the compounds has been calculated through recently developed Tran Blaha-modified Becke Johnson potential. The calculated electronic structure shows that the compounds are insulators with a gap of 5.39 eV for ZrGeO$_4$ and 6.25 eV for HfGeO$_4$ respectively. Optical anisotropy of these compounds are revealed from the computed optical properties such as complex dielectric function, refractive index, and absorption coefficient. In addition, it is observed that Ti doped ZrGeO$_4$ and HfGeO$_4$ turns out to be a good phosphor as the pristine compounds have the energy gap greater than the visible range upon Ti doping bandgap reduces as a result emission spectra occurs in the visible region and is well explained in the present study.
Universal Knight shift anomaly in the Periodic Anderson model
Creators: name: Jiang, Mi
name: Curro, Nicholas J.
name: Scalettar, Richard T.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We report a Determinant Quantum Monte Carlo investigation which quantifies the behavior of the susceptibility and the entropy in the framework of the periodic Anderson model (PAM), focussing on the evolution with different degree of conduction electron (c) -local moment (f) hybridization. These results capture the behavior observed in several experiments, including the universal behavior of the NMR Knight shift anomaly below the crossover temperature, $T^{\ast}$. We find that $T^{\ast}$ is a measure of the onset of c-f correlations and grows with increasing hybridization. These results suggest that the NMR Knight shift and spin-lattice relaxation rate measurements in non-Fermi liquid materials are strongly influenced by temperature-dependent hybridization processes. Our results provide a microscopic basis for the phenomenological two-fluid model of Kondo lattice behavior, and its evolution with pressure and temperature.
description: 5 pages, 4 figures
Angular momentum coefficients for meson strong decay and unquenched quark models
Creators: name: Burns, T. J.
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In most meson strong decay and unquenched (coupled-channel) quark models, the pair-creation operator is a scalar product of vectors in the spin and spatial degrees of freedom. While differing in the spatial part, most models have the same spin part, which creates a qq* pair coupled to spin triplet, with the spins of the initial quarks as spectators. This is a basic assumption of the 3P0 model, and is well-known to arise also in the flux tube model, starting from the strong coupling expansion of lattice QCD. In this article the same structure is shown to emerge in the Cornell model, in the dominant contributions of a more general microscopic decay model, and in the pseudoscalar-meson emission model. A solution is obtained for arbitrary matrix elements in these ``non-flip, triplet'' models, expressed as a weighted sum over spatial matrix elements. The coefficients in the expansion, which involve the spin degrees of freedom and the associated angular momentum algebra, are model-independent. Tables of the angular momentum coefficients are presented which can be used in future calculations, avoiding tedious Clebsch-Gordan sums. The symmetry and orthogonality properties of the coefficients are discussed, as well as their application to transitions involving hybrid mesons and states of mixed spin. New selection rules are derived, and existing ones generalised. The coefficients lead to model-independent relations among decay amplitudes and widths which can be tested in experiment and lattice QCD. They can also be used to explain how mass shifts in the unquenched quark model do not spoil successful predictions of the ordinary (quenched) quark model.
description: 45 pages, 4 figures, 16 tables
How can policymakers tackle misinformation and disinformation?
Creators: name: Furegon, Andrea
Publisher: name: Zenodo
Year: 2022
Subjects: perceptions
narratives
migration
policymakers
misinformation

description: Information behaviour of migrants or intended migrants is studied by researchers to understand the implications of information over migration choices. Also information circulating in host countries regarding migration can be the object of study of the complex migration research field. Assuming that the concepts of misinformation and disinformation are complex to define and to identify in the media landscape nowadays, this policy briefs aims to analyse the definitions and the dynamics of these two “information drifts” around the concept of migration and to investigate how policymakers can tackle misinformation and disinformation in the migration field.
Equilibrium currents in chiral systems with non-zero Chern number
Creators: name: Mishchenko, E. G.
name: Starykh, O. A.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We describe simple quantum-mechanical approach to calculating equilibrium particle current along the edge of a system with non-trivial band spectrum topology. The approach does not require any a priori knowledge of the band topology and, as a matter of fact, treats topological and non-topological contributions to the edge currents on the same footing. We illustrate its usefulness by demonstrating the existence of `topologically non-trivial' particle currents along the edges of three different physical systems: two-dimensional electron gas with spin-orbit coupling and Zeeman magnetic field, surface state of a topological insulator, and kagome antiferromagnet with Dzyaloshinskii-Moriya interaction. We describe relation of our results to the notion of orbital magnetization.
description: 8 pages, 4 figures
title: Foreign capital inflows and economic development: The experience of the Sudan 1958-1979
Creators: name: Yassin, Ibrahim Hassan
Publisher: name: University of Kent
Year: 2023

description: The thesis contributes to the empirical literature on foreign aid and economic development in developing countries by examining the experience of the Sudan over the period 1958 - 1979. After describing the size and structure of foreign inflows received by the Sudan, the concessional or grant element of contracted official loans is calculated. Then the excess cost of tying the assistance by end use and/or by source is quantified and related to the aid component of loans (or the benefit) in order to determine the value or net worth of the assistance. At the macrolevel, the analysis concentrates on the impact of capital imports to the Sudan on the rate of domestic saving, capital formation and the rate of economic growth. This is followed by an inquiry into the indebtedness of the Sudan and the repayments of current outstanding debt. An attempt is also made to compare the financing of economic development in the Sudan by means of aid and/or trade through their direct and indirect effects on the development process. The study shows that not only has the average grant element of the loans contracted by the Sudan been low but also the real worth has been negated by the high excess costs of tying. Furthermore, great proportions of the foreign resources have been used for consumption rather than investment which was biased towards infrastructure. Therefore, the contribution of the inflows to the rate of domestic saving and economic growth was negligible. Consequently, the Sudan faced a serious debt servicing problem which has so far led to one renegotiation.
The non-breeding ecology of Common Whitethroats Curruca communis in central Nigeria
Creators: name: Tapia Harris, Claudia
Publisher: name: The University of St Andrews
Year: 2022
Subjects: subject: Afro-Palearctic migrant
subject: Common Whitethroat
subject: Curruca communis
subject: Non-breeding
subject: Migration
subject: Winter ecology
subject: Residency
subject: Site persistence
subject: Habitat preference
subject: Site fidelity
subject: Survival
subject: Annual cycle
subject: QL698.9T2
subject: Birds--Ecology--Nigeria
subject: Migratory birds
subject: Birds--Migration

description: Identifying what drives or prevents long-distance migrants from responding to environmental changes requires a complete understanding of the ecology and behaviour of individuals throughout their annual cycle. The non-breeding period represents a significant part of an Afro-Palearctic migratory bird’s life; what occurs during this period influences an individual’s survival and future reproductive success. I studied factors that influence the population dynamics of Common Whitethroats Curruca communis during three non-breeding periods in Nigeria (2017–2020). First, I collected and analysed data from six geolocators deployed in 2019 to understand how non-breeding and breeding sites are connected. Second, I used data collected from >300 colour-ringed individuals and daily resightings to understand site persistence, within- and between-years site fidelity, fine-scale spatial movements, and habitat preference and availability. Lastly, I used daily resighting and long-term ringing data to calculate annual and overwinter survival rates. Results indicate that Whitethroats bred across eastern Europe, suggesting a somewhat high migratory spread defined by a north-eastern flight pattern, and a predominantly intermittent migratory strategy. All birds undertook a loop migration and stopped at a first non-breeding site in the Sahel. At core wintering grounds Whitethroats showed a great degree of individual variation regarding temporal and spatial behaviour: individuals exhibited different residency periods (from 1–165 days), a high degree of within- and between-years site fidelity, and many individuals established small home ranges with little significant variation through time, age, sex, and residency, despite habitat changing through the winter. Shrubs were identified as the preferred main vegetation type. High overwinter survival rates and a potential generalist strategy during the wintering period all strongly indicate that this period is likely a low-mortality period for Whitethroats. This study highlights the importance of conserving suitable habitats for Whitethroats over a very large area in both the breeding and non-breeding grounds, particularly the Sahel region, an important refuelling and stationary site.
Gene Editing in Rabbits: Unique Opportunities for Translational Biomedical Research
Creators: name: Xu, J
name: Zhang, J
name: Yang, D
name: Song, J
name: Pallas, B
name: Zhang, C
name: Hu, J
name: Peng, X
name: Christensen, ND
name: Han, R
name: Chen, YE
Publisher: name: Frontiers
Year: 2021
Subjects: Cas9
biomedical research
gene editing
human diseases
rabbit models

description: The rabbit is a classic animal model for biomedical research, but the production of gene targeted transgenic rabbits had been extremely challenging until the recent advent of gene editing tools. More than fifty gene knockout or knock-in rabbit models have been reported in the past decade. Gene edited (GE) rabbit models, compared to their counterpart mouse models, may offer unique opportunities in translational biomedical research attributed primarily to their relatively large size and long lifespan. More importantly, GE rabbit models have been found to mimic several disease pathologies better than their mouse counterparts particularly in fields focused on genetically inherited diseases, cardiovascular diseases, ocular diseases, and others. In this review we present selected examples of research areas where GE rabbit models are expected to make immediate contributions to the understanding of the pathophysiology of human disease, and support the development of novel therapeutics.
The Properties of Low Redshift Intergalactic O VI Absorbers Determined from High S/N Observations of 14 QSOs with the Cosmic Origins Spectrograph
Creators: name: Savage, B. D.
name: Kim, T. -S.
name: Wakker, B. P.
name: Keeney, B.
name: Shull, J. M.
name: Stocke, J. T.
name: Green, J. C.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We report on the observed properties of the plasma revealed through high signal-to-noise (S/N) observations of 54 intervening O VI absorption systems containing 85 O VI and 133 H I components in a blind survey of 14 QSOs observed at ~18 km s-1 resolution with the Cosmic Origins Spectrograph (COS) over a redshift path of 3.52 at z < 0.5. Simple systems with one or two H I components and one O VI component comprise 50% of the systems. For a sample of 45 well-aligned absorption components where the temperature can be estimated, we find evidence for cool photoionized gas in 31 (69%) and warm gas (6 > log T > 5) in 14 (31%) of the components. The total hydrogen content of the 14 warm components can be estimated from the temperature and the measured value of log N(H I). The very large implied values of log N(H) range from 18.38 to 20.38 with a median of 19.35. The metallicity, [O/H], in the 6 warm components with log T > 5.45 ranges from -1.93 to 0.03 with a median value of -1.0 dex. Ground-based galaxy redshift studies reveal that most of the absorbers we detect sample gas in the IGM extending 200 to 600 kpc beyond the closest associated galaxy. We estimate the warm aligned O VI absorbers contain (4.1+/-1.1)% of the baryons at low z. The warm plasma traced by the aligned O VI and H I absorption contains nearly as many baryons as are found in galaxies.
description: 107 pages, 24 figures, accepted by the Astrophysical Journal Supplement
Phase Curves of the Kepler-11 Multi-Planet System
Creators: name: Gelino, Dawn M.
name: Kane, Stephen R.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: The Kepler mission has allowed the detection of numerous multi-planet exosystems where the planetary orbits are relatively compact. The first such system detected was Kepler-11 which has six known planets at the present time. These kinds of systems offer unique opportunities to study constraints on planetary albedos by taking advantage of both the precision timing and photometry provided by Kepler data to monitor possible phase variations. Here we present a case study of the Kepler-11 system in which we investigate the phase modulation of the system as the planets orbit the host star. We provide predictions of maximum phase modulation where the planets are simultaneously close to superior conjunction. We use corrected Kepler data for Q1-Q17 to determine the significance of these phase peaks. We find that data quarters where maximum phase peaks occur are better fit by a phase model than a "null hypothesis" model.
description: 9 pages, 4 figures, 2 tables, accepted for publication in ApJ