cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Multi-band behaviour of the TeV blazar PG 1553+113 in optical range on diverse timescales
Creators: name: Agarwal, A.
name: Mihov, B.
name: Andruchow, I.
name: Cellone, Sergio A.
name: Anupama, G. C.
name: Agrawal, V.
name: Zola, S.
name: Slavcheva-Mihova, L.
name: Ozdonmez, Aykut
name: Ege, Ergun
name: Raj, Ashish
name: Mammana, Luis
name: Zibecchi, L.
name: Fernández-Lajús, E.
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Context. The TeV BL Lac object PG 1553+113 is one of the primary candidates for a binary supermassive black hole system. Aims. We study the flux and spectral variability of PG 1553+113 on intra-night to long-term timescales using (i) BVRI data collected over 76 nights from January 2016 to August 2019 involving nine optical telescopes and (ii) historical VR data (including ours) obtained for the period from 2005 to 2019. Methods. We analysed the light curves using various statistical tests, fitting and cross-correlation techniques, and methods for the search for periodicity. We examined the colour-magnitude diagrams before and after the corresponding light curves were corrected for the long-term variations. Results. Our intra-night monitoring, supplemented with literature data, results in a low duty cycle of ~(10-18)%. In April 2019, we recorded a flare, which marks the brightest state of PG 1553+113 for the period from 2005 to 2019: R = 13.2 mag. This flare is found to show a clockwise spectral hysteresis loop on its VR colour-magnitude diagram and a time lag in the sense that the V-band variations lead the R-band ones. We obtain estimates of the radius, the magnetic field strength, and the electron energy that characterize the emission region related to the flare. We find a median period of (2.21 +/- 0.04) years using the historical light curves. In addition, we detect a secondary period of about 210 days using the historical light curves corrected for the long-term variations. We briefly discuss the possible origin of this period.
description: 21 pages, 22 figures, accepted for publication in A&A
The effect of the spectator charge on the charged pion spectra in peripheral ultrarelativistic heavy-ion collisions
Creators: name: Szczurek, A
name: Rybicki, A
name: Gorski, A Z
Publisher: name: arXiv
Year: 2007
Subjects: subject: Nuclear Theory (nucl-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We estimate the electromagnetic effect of the spectator charge on the momentum spectra of charged pions produced in peripheral Pb+Pb collisions at SPS energies. We find a large effect which results in strongly varying structures in the $x_F$ dependence of the $π^+/π^-$ ratio, especially at low transverse momenta where a deep valley in the above ratio is predicted at $x_F \sim$ 0.15 -- 0.20. The effect depends on initial conditions. Thus, it provides new information on the space and time evolution of the non-perturbative pion creation process.
description: a talk presented by A.Szczurek at the international conference Quark Matter 2006, Shanghai, November 2006
ERICC Working Paper _ What is counted and why in crisis-affected education systems? A comprehensive review of education data systems in Jordan
Creators: name: ERICC Consortium
Publisher: name: figshare
Year: 2024
Subjects: classificationCode: 390201
subject: Education policy

description: In the contexts of conflict and crises, timely and reliable data is critical but often very difficult to obtain for governments and other stakeholders responsible for providing education services for affected populations. In Jordan, the arrival of approximately 1.3 million Syrian refugees since 2011 has challenged the lower-middle-income country to adequately plan and provide schooling for all students, regardless of nationality. This data systems review explores what education data is available and how it is used by stakeholders in Jordan to improve access, quality, continuity and outcomes for children affected by conflict and crisis. The methodology included a desk review of relevant literature coupled with 11 stakeholder interviews. In total, 14 data systems were identified and grouped into five main categories: (i) international large-scale assessments, (ii) national large-scale assessments, (iii) education management information systems, (iv) other sample-level data, and (v) other population-level data. The predominant focus of these systems is on student-related data, followed by data pertaining to teachers and principals with limited ability to disaggregate data for students of different nationalities. Overall, results found that 29% of data systems focus on data related to access, 50% collect data on continuity, and all collect data on quality and/or educational outcomes. Seven key challenges facing Jordan’s educational data systems were identified: capacity, device shortage, old data recovery, technical, financial, planning, and working in silos. Taken together, the results highlight the lack of refugee-specific educational data publicly available. While levels of refugee access to school (i.e. enrolment data) is available, data collected and used on disaggregate levels to assess trends and provisions for vulnerable student groups is either not carried out or not shared publicly. In addition, the review highlights the need for more meaningful qualitative data on educational quality and student outcomes, and the lack of sharing and coordination of data among various education stakeholders. This is of particular concern for the education of refugee students as the data collected on their schooling is fragmented among government and NGO stakeholders. These trends reflect some of the findings of other conflict-affected contexts but also illustrate how data systems have been developed recently to increase access to and improve education, and how Jordanian officials are particularly aware, through data, of the gender-based achievement gap.
Information-Driven Adaptive Sensing Based on Deep Reinforcement Learning
Creators: name: Murad, Abdulmajid
name: Kraemer, Frank Alexander
name: Bach, Kerstin
name: Taylor, Gavin
Publisher: name: arXiv
Year: 2020
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences

description: In order to make better use of deep reinforcement learning in the creation of sensing policies for resource-constrained IoT devices, we present and study a novel reward function based on the Fisher information value. This reward function enables IoT sensor devices to learn to spend available energy on measurements at otherwise unpredictable moments, while conserving energy at times when measurements would provide little new information. This is a highly general approach, which allows for a wide range of use cases without significant human design effort or hyper-parameter tuning. We illustrate the approach in a scenario of workplace noise monitoring, where results show that the learned behavior outperforms a uniform sampling strategy and comes close to a near-optimal oracle solution.
description: 8 pages, 8 figures
High energy DVCS on a photon and related meson exclusive production
Creators: name: Machado, M. V. T.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In this work we estimate the differential cross section for the high energy deeply virtual Compton scattering on a photon target within the QCD dipole-dipole scattering formalism. For the phenomenology, a saturation model for the dipole-dipole cross section for two photon scattering is considered. Its robustness is supported by good description of current accelerator data. In addition, we consider the related exclusive vector meson production processes. This analysis is focused on the light $ρ$ and $ϕ$ meson production, which produce larger cross sections. The phenomenological results are compared with the theoretical calculation using the CD BFKL approach.
description: 6 pages, 5 figures. Version to be published in Physical Review D
title: Predictive Density Combination Using a Tree-Based Synthesis Function
Creators: name: Chernis, Tony
name: Hauzenberger, Niko
name: Huber, Florian
name: Koop, Gary
name: Mitchell, James
Publisher: name: Bank of Canada
Year: 2023

description: Bayesian predictive synthesis (BPS) is a method of combining predictive distributions based on agent opinion analysis theory, which encompasses many common approaches to combining density forecasts. The key ingredient in BPS is a synthesis function. This is typically specified parametrically as a dynamic linear regression. In this paper, we develop a nonparametric treatment of the synthesis function using regression trees. We show the advantages of our tree-based approach in two macroeconomic forecasting applications. The first uses density forecasts for GDP growth from the euro area’s Survey of Professional Forecasters. The second combines density forecasts of US inflation produced by many regression models involving different predictors. Both applications demonstrate the benefits—in terms of improved forecast accuracy and interpretability—of modeling the synthesis function nonparametrically.
description: La synthèse de prévisions bayésienne est une méthode servant à combiner des distributions prédictives qui est basée sur la théorie d’analyse des avis d’agents et qui englobe de nombreuses approches courantes pour la combinaison de prévisions par densité de probabilités. L’élément clé de cette méthode consiste en une fonction de synthèse qui est  généralement définie de façon paramétrique sous forme d’une régression linéaire dynamique. Dans cette étude, nous élaborons un mode de traitement non paramétrique de la fonction de synthèse fondé sur des arbres de régression. Nous montrons les avantages que notre mode de traitement présente dans le cadre de deux exercices de prévision macroéconomique. Dans le premier exercice, nous utilisons des prévisions par densité de probabilités de la croissance du produit intérieur brut issues de l’enquête menée auprès des prévisionnistes professionnels de la zone euro. Dans le second, nous combinons des prévisions par densité de probabilités de l’inflation aux États-Unis, qui sont produites par de nombreux modèles de régression comportant différents prédicteurs. Ces deux exercices démontrent les avantages que procure la modélisation non paramétrique de la fonction de synthèse, sur le plan de l’amélioration de l’exactitude et de l’interprétabilité des prévisions.
Potential for modulation of the hydrophobic effect inside chaperonins
Creators: name: England, Jeremy L.
name: Pande, Vijay S.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Biomolecules (q-bio.BM)
subject: FOS: Biological sciences

description: Despite the spontaneity of some in vitro protein folding reactions, native folding in vivo often requires the participation of barrel-shaped multimeric complexes known as chaperonins. Although it has long been known that chaperonin substrates fold upon sequestration inside the chaperonin barrel, the precise mechanism by which confinement within this space facilitates folding remains unknown. In this study, we examine the possibility that the chaperonin mediates a favorable reorganization of the solvent for the folding reaction. We begin by discussing the effect of electrostatic charge on solvent-mediated hydrophobic forces in an aqueous environment. Based on these initial physical arguments, we construct a simple, phenomenological theory for the thermodynamics of density and hydrogen bond order fluctuations in liquid water. Within the framework of this model, we investigate the effect of confinement within a chaperonin-like cavity on the configurational free energy of water by calculating solvent free energies for cavities corresponding to the different conformational states in the ATP- driven catalytic cycle of the prokaryotic chaperonin GroEL. Our findings suggest that one function of chaperonins may be to trap unfolded proteins and subsequently expose them to a micro-environment in which the hydrophobic effect, a crucial thermodynamic driving force for folding, is enhanced.
Benchmark study of symmetry-adapted ML-DFT models for magnetically doped topological insulators
Creators: name: Wasmer, Johannes
name: Rüssmann, Philipp
name: Assent, Ira
name: Blügel, Stefan
Publisher: name: Forschungzentrum Jülich
Year: 2022

description: DPG SKM 2023, SKM23, Dresden, RWTH Aachen University, Germany, 26 Mar 2023 - 31 Mar 2023
description: We present a benchmark study of surrogate models for impurities embedded into crystalline solids. Using the Korringa-Kohn-Rostoker Green Function method [1], we have built databases of several thousand calculations of single impurities (monomers) embedded into different elemental crystals, as well as magnetic transition metal impurity dimers embedded in the topological insulator Bi2Te3. We predict the converged monomer impurity electron potential and the isotropic exchange interaction of the impurity dimer in the classical Heisenberg model. From these surrogates, we intend to build transferable models for larger systems in the future, which will accelerate the convergence of our DFT codes. The study compares various recent E(3)-equivariant models such as ACE and MACE [2] in terms of performance and reproducible end-to-end workflows.[1] P. Rüßmann et al., npj Comput Mater 7, 13 (2021)[2] I. Batatia et al., arXiv:2206.07697 (2022)
La classification de l'aizi (Côte d'Ivoire, groupe kru, Niger-Congo)
Creators: name: VOGLER, Pierre
Publisher: name: Zenodo
Year: 2024

description: Cet article reprend une partie d'un texte consacré aux langues kru (Vogler 2020). Les documents s'inscrivent en faux contre un détachement de l'aizi hors du massif principal de l'ensemble, à cause de sa situation géographique très excentrée. La langue fait clairement partie du sous-groupe occidental grebo-tepo.
A Note on Restricted Online Ramsey Numbers of Matchings
Creators: name: Dvořák, Vojtěch
Publisher: name: arXiv
Year: 2020
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 05C57

description: The restricted online Ramsey numbers were introduced by Conlon, Fox, Grinshpun and He in 2019. In a recent paper, Briggs and Cox studied the restricted online Ramsey numbers of matchings and determined a general upper bound for them. They proved that for $n=3r-1=R_2(r K_2)$ we have $\tilde{R}_{2}(r K_2;n) \leq n-1$ and asked whether this was tight. In this short note, we provide a general lower bound for these Ramsey numbers. As a corollary, we answer this question of Briggs and Cox, and confirm that for $n=3r-1$ we have $\tilde{R}_{2}(r K_2;n) = n-1$. We also show that for $n'=4r-2=R_3(r K_2)$ we have $\tilde{R}_{3}(r K_2;n') = 5r-4$.
description: 3 pages
Gravitational Waves from Disks Around Spinning Black Holes: Simulations in Full General Relativity
Creators: name: Wessel, Erik
name: Paschalidis, Vasileios
name: Tsokaros, Antonios
name: Ruiz, Milton
name: Shapiro, Stuart L.
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We present fully general-relativistic numerical evolutions of self-gravitating tori around spinning black holes with dimensionless spin $a/M = 0.7$ parallel or anti-parallel to the disk angular momentum. The initial disks are unstable to the hydrodynamic Papaloizou-Pringle Instability which causes them to grow persistent orbiting matter clumps. The effect of black hole spin on the growth and saturation of the instability is assessed. We find that the instability behaves similarly to prior simulations with non-spinning black holes, with a shift in frequency due to spin-induced changes in disk orbital period. Copious gravitational waves are generated by these systems, and we analyze their detectability by current and future gravitational wave observatories for large range of masses. We find that systems of $10 M_\odot$ - relevant for black hole-neutron star mergers - are detectable by Cosmic Explorer out to $\sim300$ Mpc, while DECIGO (LISA) will be able to detect systems of $1000 M_\odot$ ($10^5M_\odot$) - relevant for disks forming in collapsing supermassive stars - out to cosmological redshift of $z\sim5$ ($z\sim 1$). Computing the accretion rate of these systems we find that these systems may also be promising sources of coincident electromagnetic signals.
description: 15 pages, 12 figures
Doping-Induced Electronic and Structural Phase Transition in the Bulk Weyl Semimetal Mo1-xWxTe2
Creators: name: Fedchenko, O.
name: Diekmann, F. K.
name: Russmann, P.
name: Kallmayer, M.
name: Odenbreit, L.
name: Souliou, S. M.
name: Frachet, M.
name: Winkelmann, A.
name: Merz, M.
name: Chernov, S. V.
name: Vasilyev, D.
name: Kutnyakhov, D.
name: Tkach, O.
name: Lytvynenko, Y.
name: Medjanik, K.
name: Schlueter, C.
name: Gloskovskii, A.
name: Peixoto, T. R. F.
name: Hoesch, M.
name: Tacon, M. Le
name: Mokrousov, Y.
name: Rossnage, K.
name: Schönhense, G.
name: Elmers, H. -J.
Publisher: name: Forschungzentrum Jülich
Year: 2023
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: arXiv (2023). doi:10.48550/ARXIV.2310.10593
description: A comprehensive study of the electronic and structural phase transition from 1T` to Td in the bulk Weyl semimetal Mo1-xWxTe2 at different doping concentrations has been carried out using time-of-flight momentum microscopy (including circular and linear dichroism), X-ray photoelectron spectroscopy (XPS), X-ray photoelectron diffraction (XPD), X-ray diffraction (XRD), angle-resolved Raman spectroscopy, transport measurements, density functional theory (DFT) and Kikuchi pattern calculations. High-resolution angle-resolved photoemission spectroscopy (ARPES) at 20 K reveals surface electronic states, which are indicative of topological Fermi arcs. Their dispersion agrees with the position of Weyl points predicted by DFT calculations based on the experimental crystal structure of our samples determined by XRD. Raman spectroscopy confirms the inversion symmetry breaking for the Td -phase, which is a necessary condition for the emergence of topological states. Transport measurements show that increasing the doping concentration from 2 to 9% leads to an increase in the temperature of the phase transition from 1T` to Td from 230 K to 270 K. Magnetoresistance and longitudinal elastoresistance show significantly increased values in the Td -phase due to stimulated inter-pocket electron backscattering. The results demonstrate the close relationship between electronic properties and elastic deformations in MoTe2.
description: Published by arXiv
Wake transition and aerodynamics of a dragonfly-inspired airfoil
Creators: name: Chiarini, Alessandro
name: Nastro, Gabriele
Publisher: name: arXiv
Year: 2025
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: We investigate the dynamics and the stability of the incompressible flow past a corrugated dragonfly-inspired airfoil in the two-dimensional (2D) $α-Re$ parameter space, where $α$ is the angle of attack and $Re$ is the Reynolds number. The angle of attack is varied between $-5^\circ \le α\le 10^\circ$, and $Re$ (based on the free-stream velocity and the airfoil chord) is increased up to $Re=6000$. The study relies on linear stability analyses and three-dimensional (3D) nonlinear direct numerical simulations. For all $α$ the primary instability consists of a Hopf bifurcation towards a periodic regime. The linear stability analysis reveals that two distinct modes drive the flow bifurcation for positive and negative $α$, being characterised by a different frequency and a distinct triggering mechanism. The critical $Re$ decreases as $|α|$ increases, and scales as a power law for large positive/negative $α$. At intermediate $Re$, different limit cycles arise depending on $α$, each one characterised by a distinctive vortex interaction, leading thus to secondary instabilities of different nature. For intermediate positive/negative $α$ vortices are shed from both the top/bottom leading- and trailing-edge shear layers, and the two phenomena are frequency locked. By means of Floquet stability analysis, we show that the secondary instability consists of a 2D subharmonic bifurcation for large negative $α$, of a 2D Neimark--Sacker bifurcation for small negative $α$, of a 3D pitchfork bifurcation for small positive $α$, and of a 3D subharmonic bifurcation for large positive $α$. The aerodynamic performance of the dragonfly-inspired airfoil is discussed in relation to the different flow regimes emerging in the $α-Re$ space of parameters.
Are there Radio-quiet Solar Flares?
Creators: name: Benz, Arnold O.
name: Brajsa, Roman
name: Magdalenic, Jasmina
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Some 15% of solar flares having a soft X-ray flux above GOES class C5 are reported to lack coherent radio emission in the 100 - 4000 MHz range (type I - V and decimetric emissions). A detailed study of 29 such events reveals that 22 (76%) of them occurred at a radial distance of more than 800'' from the disk center, indicating that radio waves from the limb may be completely absorbed in some flares. The remaining seven events have statistically significant trends to be weak in GOES class and to have a softer non-thermal X-ray spectrum. All of the non-limb flares that were radio-quiet > 100 MHz were accompanied by metric type III emission below 100 MHz. Out of 201 hard X-ray flares, there was no flare except near the limb (R>800'') without coherent radio emission in the entire meter and decimeter range. We suggest that flares above GOES class C5 generally emit coherent radio waves when observed radially above the source.
description: Solar Physics, in press
Reversible saddle-node separatrix-loop bifurcation
Creators: name: Burylko, Oleksandr
name: Wolfrum, Matthias
name: Yanchuk, Serhiy
Publisher: name: Weierstrass Institute
Year: 2024
Subjects: subject: Homoclinic bifurcations
subject: time-reversibility
subject: 34C14
subject: 34C23
subject: 34C37

description: We describe the unfolding of a special variant of the codimension-two Saddle-Node Separatrix-Loop (SNSL) bifurcation that occurs in systems with time-reversibility. While the classical SNSL bifurcation can be characterized as the collision of a saddle-node equilibrium with a limit cycle, the reversible variant (R-SNSL) is characterised by as the collision of a saddle-node equilibrium with a boundary separating a dissipative and a conservative region in phase space. Moreover, we present several reversible versions of the SNIC (Saddle-Node on Invariant Circle) bifurcation and discuss the role of an additional reversible saddle equilibrium in all these scenarios. As an example, we provide a detailed bifurcation scenario for a reversible system of two coupled phase rotators (a system on a 2D torus) involving a R-SNSL bifurcation.
Binary black hole merger dynamics and waveforms
Creators: name: Baker, John G.
name: Centrella, Joan
name: Choi, Dae-Il
name: Koppitz, Michael
name: van Meter, James
Publisher: name: arXiv
Year: 2006
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We study dynamics and radiation generation in the last few orbits and merger of a binary black hole system, applying recently developed techniques for simulations of moving black holes. Our analysis of the gravitational radiation waveforms and dynamical black hole trajectories produces a consistent picture for a set of simulations with black holes beginning on circular-orbit trajectories at a variety of initial separations. We find profound agreement at the level of one percent among the simulations for the last orbit, merger and ringdown. We are confident that this part of our waveform result accurately represents the predictions from Einstein's General Relativity for the final burst of gravitational radiation resulting from the merger of an astrophysical system of equal-mass non-spinning black holes. The simulations result in a final black hole with spin parameter a/m=0.69. We also find good agreement at a level of roughly 10 percent for the radiation generated in the preceding few orbits.
description: 11 pages, 11 figures, submitted to PRD, update citations, minor changes
Modeling the spread of COVID-19 pandemic in Morocco
Creators: name: Zine, Houssine
name: Lotfi, El Mehdi
name: Mahrouf, Marouane
name: Boukhouima, Adnane
name: Aqachmar, Yassine
name: Hattaf, Khalid
name: Torres, Delfim F. M.
name: Yousfi, Noura
Publisher: name: arXiv
Year: 2020
Subjects: subject: Populations and Evolution (q-bio.PE)
subject: FOS: Biological sciences

description: Nowadays, coronavirus disease 2019 (COVID-19) poses a great threat to public health and economy worldwide. Unfortunately, there is yet no effective drug for this disease. For this, several countries have adopted multiple preventive interventions to avoid the spread of COVID-19. Here, we propose a delayed mathematical model to predict the epidemiological trend of COVID-19 in Morocco. Parameter estimation and sensitivity analysis of the proposed model are rigorously studied. Moreover, numerical simulations are presented in order to test the effectiveness of the preventive measures and strategies that were imposed by the Moroccan authorities and also help policy makers and public health administration to develop such strategies.
description: This is a preprint of a paper whose final and definite form is published in 'Analysis of Infectious Disease Problems (Covid-19) and Their Global Impact', Springer Nature Singapore Pte Ltd. First submitted 18/April/2020; revised 22/Sept/2020; accepted 08/Oct/2020
Efects of COVID‑19 on Irish general practice activity from 2019 to 2021: a retrospective analysis of 500,000 consultations using electronic medical record data
Creators: name: O'Callaghan, Michael E
name: Glynn, Liam
Publisher: name: University of Limerick
Year: 2024
Subjects: classificationCode: 42
subject: Health sciences
subject: FOS: Health sciences

description: Background General practice (GP) is crucial to primary care delivery in the Republic of Ireland and is almost fully com?puterised. General practice teams were the frst point of contact for much COVID-19-related care and there were concerns routine healthcare activities could be disrupted due to COVID-19 and related restrictions.Aims The study aimed to assess efects of the pandemic on GP activity through analysis of electronic medical record data from general practice clinics in the Irish Midwest.Methods A retrospective, descriptive study of electronic medical record data relating to patient record updates, appointments and medications prescribed across 10 GP clinics over the period 2019–2021 inclusive.Results Data relating to 1.18 million record transactions for 32 k patients were analysed. Over 500 k appointments were examined, and demographic trends presented. Overall appointment and prescribing activity increased over the study period, while a dip was observed immediately after the pandemic’s arrival in March 2020. Delivery of non-childhood immunisations increased sixfold as a result of COVID-19, childhood immunisation activity was maintained, while cervical smears decreased in 2020 as the screening programme was halted. A quarter of consultations in 2020 and 2021 were teleconsultations, and these were more commonplace for younger patients. Conclusions General practice responded robustly to the pandemic by taking on additional activities while maintaining routine services where possible. The shift to teleconsulting was a signifcant change in workfow. Analysing routinely col?lected electronic medical record data can provide valuable insights for service planning, and access to these insights would be benefcial for future pandemic responses
Dragonblood is Still Leaking: Practical Cache-based Side-Channel in the Wild
Creators: name: Braga, Daniel De Almeida
name: Fouque, Pierre-Alain
name: Sabt, Mohamed
Publisher: name: arXiv
Year: 2020
Subjects: subject: Cryptography and Security (cs.CR)
subject: FOS: Computer and information sciences

description: Recently, the Dragonblood attacks have attracted new interests on the security of WPA-3 implementation and in particular on the Dragonfly code deployed on many open-source libraries. One attack concerns the protection of users passwords during authentication. In the Password Authentication Key Exchange (PAKE) protocol called Dragonfly, the secret, namely the password, is mapped to an elliptic curve point. This operation is sensitive, as it involves the secret password, and therefore its resistance against side-channel attacks is of utmost importance. Following the initial disclosure of Dragonblood, we notice that this particular attack has been partially patched by only a few implementations. In this work, we show that the patches implemented after the disclosure of Dragonblood are insufficient. We took advantage of state-of-the-art techniques to extend the original attack, demonstrating that we are able to recover the password with only a third of the measurements needed in Dragonblood attack. We mainly apply our attack on two open-source projects: iwd (iNet Wireless Daemon) and FreeRADIUS, in order underline the practicability of our attack. Indeed, the iwd package, written by Intel, is already deployed in the Arch Linux distribution, which is well-known among security experts, and aims to offer an alternative to wpa\_supplicant. As for FreeRADIUS, it is widely deployed and well-maintained upstream open-source project. We publish a full Proof of Concept of our attack, and actively participated in the process of patching the vulnerable code. Here, in a backward compatibility perspective, we advise the use of a branch-free implementation as a mitigation technique, as what was used in hostapd, due to its quite simplicity and its negligible incurred overhead.
description: Accepted at Annual Computer Security Applications Conference (ACSAC 2020), December 7-11, 2020, Austin, USA. ACM, New York, NY, USA, 13 pages, ACM ISBN 978-1-4503-8858-0/20/12 Artifact available: https://gitlab.inria.fr/ddealmei/poc-iwd-acsac2020/-/tree/master/
How often does the Unruh-DeWitt detector click? Regularisation by a spatial profile
Creators: name: Louko, Jorma
name: Satz, Alejandro
Publisher: name: arXiv
Year: 2006
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We analyse within first-order perturbation theory the instantaneous transition rate of an accelerated Unruh-DeWitt particle detector whose coupling to a massless scalar field on four-dimensional Minkowski space is regularised by a spatial profile. For the Lorentzian profile introduced by Schlicht, the zero size limit is computed explicitly and expressed as a manifestly finite integral formula that no longer involves regulators or limits. The same transition rate is obtained for an arbitrary profile of compact support under a modified definition of spatial smearing. Consequences for the asymptotic behaviour of the transition rate are discussed. A number of stationary and nonstationary trajectories are analysed, recovering in particular the Planckian spectrum for uniform acceleration.
description: 30 pages, 1 figure. v3: Added references and minor clarifications
title: Bayesian spatial modelling of environmental and health data with applications in Brazilian Amazonia
title: linking environment and health in disadvantaged groups
titleType: Subtitle
Creators: name: Chacon Montalvan, Erick
Publisher: name: Lancaster University
Year: 2019

description: Impacts of climate change on human health are a major concern for public health. Increase in frequency and intensity of extreme hydro-climatic events (floods and droughts) is one of the main characteristics of climate change. The occurrence of these events can drastically affect the lives of the population through different pathways. For example, by affecting accessibility to sufficient, safe and nutritious food (food security), increasing levels of malnutrition or increasing disease incidence. We hypothesize that nutrition might be a relevant pathway through which extreme hydro-climatic events affect human health and that the impacts are worse for vulnerable groups where they exacerbate existing vulnerabilities. Then, to understand and evaluate the effects of extreme hydro-climatic events on human health, we developed three studies. First, we propose a model-based standardized index to identify and quantify extreme temporal events and compared it against the classical standardized precipitation index (SPI). We found that our index holds the properties of the SPI, but improves on the methodology by tackling some of its limitations. Second, we used the model-based standardized index to evaluate the effects of exposure to extreme hydro-climatic events during pregnancy on birth weight. We controlled for other social and placed-based factors that could influence birth weight and found out that floods could significantly reduce birth weight. We also detected characteristics of vulnerable groups where birthweight is expected to be lower. Finally, we proposed our denominated spatial item factor analysis to model and predict spatially structured latent factors. With our application on predicting food insecurity in a roadless city of the Brazilian Amazonia, we discover that severely food insecure areas were related to flood-prone, poor and marginalized neighbourhoods. In general, our results highlight the importance of policies to reduce the effects of extreme hydro-climatic events on vulnerable populations of the Brazilian Amazonia. Although our methods were motivated by the study of the impacts of extreme hydro-climatic events, they can be applied in more general cases.
Vortex pinning by meandering line defects in planar superconductors
Creators: name: Katifori, Eleni
name: Nelson, David R.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: To better understand vortex pinning in thin superconducting slabs, we study the interaction of a single fluctuating vortex filament with a curved line defect in (1+1) dimensions. This problem is also relevant to the interaction of scratches with wandering step edges in vicinal surfaces. The equilibrium probability density for a fluctuating line attracted to a particular fixed defect trajectory is derived analytically by mapping the problem to a straight line defect in the presence of a space and time-varying external tilt field. The consequences of both rapid and slow changes in the frozen defect trajectory, as well as finite size effects are discussed. A sudden change in the defect direction leads to a delocalization transition, accompanied by a divergence in the trapping length, near a critical angle.
description: 9 pages, 9 figures
Quantum Zeno effect for open quantum systems
Creators: name: Becker, Simon
name: Datta, Nilanjana
name: Salzmann, Robert
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Physics (quant-ph)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We prove the quantum Zeno effect in open quantum systems whose evolution, governed by quantum dynamical semigroups, is repeatedly and frequently interrupted by the action of a quantum operation. For the case of a quantum dynamical semigroup with a bounded generator, our analysis leads to a refinement of existing results and extends them to a larger class of quantum operations. We also prove the existence of a novel strong quantum Zeno limit for quantum operations for which a certain spectral gap assumption, which all previous results relied on, is lifted. The quantum operations are instead required to satisfy a weaker property of strong power-convergence. In addition, we establish, for the first time, the existence of a quantum Zeno limit for the case of unbounded generators. We also provide a variety of physically interesting examples of quantum operations to which our results apply.
description: 45 pages
Reweighting the Sivers function with jet data from STAR
Creators: name: Boglione, Mariaelena
name: D'Alesio, Umberto
name: Flore, Carlo
name: Gonzalez-Hernandez, Josè Osvaldo
name: Murgia, Francesco
name: Prokudin, Alexei
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: The reweighting procedure that using Bayesian statistics incorporates the information contained in a new data set, without the need of re-fitting, is applied to the quark Sivers function extracted from Semi-Inclusive Deep Inelastic Scattering (SIDIS) data. We exploit the recently published single spin asymmetry data for the inclusive jet production in polarized $pp$ collisions from the STAR Collaboration at RHIC, which cover a much wider $x$ region compared to SIDIS measurements. The reweighting method is extended to the case of asymmetric errors and the results show a remarkable improvement of the knowledge of the quark Sivers function.
description: 9 pages, 5 figures
Exact Kohn-Sham versus Hartree-Fock in momentum-space: examples of two-fermion systems
Creators: name: Ragot, Sebastien
Publisher: name: arXiv
Year: 2006
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: The question of how density functional theory (DFT) compares with Hartree-Fock (HF) for the computation of momentum-space properties is addressed in relation to systems for which (near) exact Kohn-Sham (KS) and HF one-electron matrices are known. This makes it possible to objectively compare HF and exact KS and hence to assess the potential of DFT for momentum space studies. The systems considered are the Moshinsky atom, the Hooke's atom and light two-electron ions, for which expressions for correlated density-matrices or momentum densities have been derived in closed-form. The results obtained show that it is necessary to make a distinction between true and approximate DFT.
description: 30 pages, accepted for publication in J. Chem. Phys. (2006)
Aperture compensated radon and fourier transforms
Creators: name: Sacchi, Mauricio Dino
Publisher: name: University of British Columbia
Year: 2009

description: In seismic data analysis, recorded data often are transformed to various domains to discriminate against coherent and incoherent noise. For instance, by mapping a shot record from time-space domain to frequency-wavenumber domain, coherent linear noise can be attenuated. Similarly, by mapping a common-midpoint gather from time-space to time-velocity domain (velocity stacks) multiples are separated from primaries based on moveout discrimination. In these procedures the correct identification of seismic events with similar moveout can be severely affected by the aperture of the array and the discrete sampling of the wavefield. Economic and/or logistic reasons usually dictate the cable length and spatial sampling of the seismic experiment. This thesis examines how the resolution (the ability to distinguish close events) of slant stack and parabolic stack operators deteriorates under limited aperture. An algorithm is developed to increase the resolution of the aforementioned operators. This procedure constructs an operator that collapses each seismic signal in the transform domain, thus diminishing truncation artifacts. The overall procedure is equivalent to the simulation of a longer array of receivers. Slant stacks and the parabolic stacks are linear operations used to map the seismic data into another domain, the transform domain (r — p or r — q). In this thesis an inverse problem is posed. This is accomplished by considering the data as the result of a linear operation onto the transform domain. This approach permits one to incorporate prior information into the problem which is utilized to attenuate truncation artifacts. The prior information is incorporated into the inverse problem by means of the Bayesian formalism. The observational errors and the prior information are combined through Bayes' rule using the likelihood function and a long tailed distribution, respectively. The posteriori probability is then used to induce the objective function of the problem. Finally, minimizing the objective function leads to the solution of the inverse problem. The advantage of incorporating a long tailed distribution to model the transform domain is that the solution is constrained to be sparse which is a desired feature for highly resolved models. The method is also used to design an artifacts-reduced 2-D discrete Fourier transform. A by-product of the method is a high resolution periodogram. This periodogram coincides with the periodogram that would have been computed with a longer array of receivers if the data consist of a limited superposition of linear events.
An in-depth study of the pre-polar candidate WX LMi
Creators: name: Vogel, J.
name: Schwope, A. D.
name: Gaensicke, B. T.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Optical photometry, spectroscopy and XMM-Newton ultraviolet and X-ray observations with full phase coverage are used for an in-depth study of WXLMi, a system formerly termed as a low-accretion rate polar. We find a constant low mass accretion rate, M_dot ~ 1.5e-13 M_sun/yr, a peculiar accretion geometry with one spot not being accessible via Roche-lobe overflow, a low temperature of the white dwarf, Teff < 8000 K and the secondary likely being Roche-lobe underfilling. All this lends further support to the changed view on WXLMi and related systems as detached binaries, i.e. magnetic post-common envelope binaries without significant Roche-lobe overflow in the past. The transfer rate determined here is compatible with accretion from a stellar wind. We use cyclotron spectroscopy to determine the accretion geometry and to constrain the plasma temperatures. Both, cyclotron spectroscopy and X-ray plasma diagnostics reveal low plasma temperatures below 3 keV on both accretion spots. For the low m_dot, high B plasma at the accretion spots in WXLMi, cyclotron cooling is dominating thermal plasma radiation in the optical. Optical spectroscopy and X-ray timing reveal atmospheric, chromospheric and coronal activity at the saturation level on the dM4.5 secondary star.
description: Accepted for publication in A&A
How to Stop (Worrying and Love) the Bubble: Boundary Changing Solutions
Creators: name: Jones, Gregory C.
name: Wang, John E.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We discover that a class of bubbles of nothing are embedded as time dependent scaling limits of previous spacelike-brane solutions. With the right initial conditions, a near-bubble solution can relax its expansion and open the compact circle. Thermodynamics of the new class of solutions is discussed and the relationships between brane/flux transitions, tachyon condensation and imaginary D-branes are outlined. Finally, a related class of simultaneous connected S-branes are also examined.
description: 47 pages; v2 introduction to Weyl cards added, comments added, references added, typos corrected, matches JHEP version
Recurrent Solar Energetic Particle Flux Enhancements Observed near Earth and Mars
Creators: name: Krishnaprasad, C.
name: Thampi, Smitha V.
name: Bhardwaj, Anil
name: Lee, Christina O.
name: Kumar, K. Kishore
name: Pant, Tarun K.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Geophysics (physics.geo-ph)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: August 1 to November 15, 2016 period was characterized by the presence of Corotating Interaction Regions (CIRs) and a few weak Coronal Mass Ejections (CMEs) in the heliosphere. In this study we show recurrent energetic electron and proton enhancements observed near Earth (1 AU) and Mars (1.43-1.38 AU) during this period. The observations near Earth are using data from instruments aboard ACE, SOHO, and SDO whereas those near Mars are by the SEP, SWIA, and MAG instruments aboard MAVEN. During this period, the energetic electron fluxes observed near Earth and Mars showed prominent periodic enhancements over four solar rotations, with major periodicities of ~27 days and ~13 days. Periodic radar blackout/weakening of radar signals at Mars are observed by MARSIS/MEX, associated with these solar energetic electron enhancements. During this period, a weak CME and a High Speed Stream (HSS)-related interplanetary shock could interact with the CIR and enhance energetic proton fluxes near 1.43-1.38 AU, and as a result, ~27 day periodicity in proton fluxes is significantly diminished at 1.43-1.38 AU. These events also cause unexpected impact on the Martian topside ionosphere, such as topside ionospheric depletion and compression observed by LPW and NGIMS onboard MAVEN. These observations are unique not only because of the recurring nature of electron enhancements seen at two vantage points, but also because they reveal unexpected impact of the weak CME and interplanetary shock on the Martian ionosphere, which provide new insight into the impact of CME-HSS interactions on Martian plasma environment.
Non-Maxwellian rate coefficients for electron and ion collisions in Rydberg plasmas: implications for excitation and ionization
Creators: name: Vrinceanu, Daniel
name: Onofrio, Roberto
name: Sadeghpour, Hossein R.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: Scattering phenomena between charged particles and highly excited Rydberg atoms are of critical importance in many processes in plasma physics and astrophysics. While a Maxwell-Boltzmann (MB) energy distribution for the charged particles is often assumed for calculations of collisional rate coefficients, in this contribution we relax this assumption and use two different energy distributions, a bimodal MB distribution and a $κ$-distribution. Both variants share a high-energy tails occurring with higher probability than the corresponding MB distribution. The high energy tail may significantly affect rate coefficients for various processes. We focus the analysis to specific situations by showing the dependence of the rate coefficients on the principal quantum number of hydrogen atoms in n-changing collisions with electrons in the excitation and ionization channels and in a temperature range relevant to the divertor region of a tokamak device. We finally discuss the implications for diagnostics of laboratory plasmas.
description: 14 pages, 4 figures, Journal of Plasma Physics collection on 'Laboratory and Astrophysical Plasmas: New Perspectives'
MPEC 2024-T175 : DAILY ORBIT UPDATE (2024 October 7)
Creators: name: Minor Planet Center Staff
Publisher: name: The Minor Planet Center
Year: 2024
Subjects: subject: Small Solar System bodies
valueUri: http://astrothesaurus.org/uat/1469

description: The Minor Planet Electronic Circulars contain information on unusual minor planets, routine data on comets and natural satellites, and occasional editorial announcements.  They are published on behalf of Division F of the International Astronomical Union by the Minor Planet Center, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.