cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Filaments, Bubbles, and Weak Shocks in the Gaseous Atmosphere of M87
Creators: name: Forman, W.
name: Churazov, E.
name: Jones, C.
name: Markevitch, M.
name: Nulsen, P.
name: Vikhlinin, A.
name: Begelman, M.
name: Bohringer, H.
name: Eilek, J.
name: Heinz, S.
name: Kraft, R.
name: Owen, F.
name: Pahre, M.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present the first results from a 500 ksec Chandra ACIS-I observation of M87. At soft energies (0.5-1.0 keV), we detect filamentary structures associated with the eastern and southwestern X-ray and radio arms. Many filaments are spatially resolved with widths of ~300 pc. This filamentary structure is particularly striking in the eastern arm where we suggest the filaments are outer edges of a series of plasma-filled, buoyant bubbles whose ages differ by ~6 x 10^6 years. These X-ray structures may be influenced by magnetic filamentation. At hard energies (3.5-7.5 keV), we detect a nearly circular ring of outer radius 2.8' (13 kpc) which provides an unambiguous signature of a weak shock, driven by an outburst from the SMBH. The density rise in the shock is ~1.3 (Mach number, M~1.2). The observed spectral hardening in the ring corresponds to a temperature rise T_shock / T_0 ~ 1.2, or M~1.2, in agreement with the Mach number derived independently from the gas density. Thus, for the first time, we detect gas temperature and density jumps associated with a classical shock in the atmosphere around a supermassive black hole. We also detect two additional surface brightness edges and pressure enhancements at radii of ~0.6' and ~1'. The ~0.6' feature may be over-pressurized thermal gas surrounding the relativistic plasma in the radio cocoon, the ``piston'', produced by the current episode of AGN activity. The over-pressurized gas is surrounded by a cool gas shell. The ~1' feature may be an additional weak shock from a secondary outburst. In an earlier episode, the ``piston'' was responsible for driving the 2.8' shock.
description: Extensively revised and expanded with 10 pages and 10 figures. Accepted for publication in the Astrophysical Journal
Management of Suboptimally Controlled Type 2 Diabetes Mellitus in General Practice
Creators: name: Murphy, Mark
Publisher: name: Royal College of Surgeons in Ireland
Year: 2021
Subjects: subject: 111717 Primary Health Care
subject: FOS: Health sciences

description: DSuboptimal control of cardiovascular risk factors and significant hyperglycaemia is a major burden for persons with type 2 diabetes mellitus (T2DM) and for healthcare systems. Failure to intensify medications for patients with poor control of T2DM, when indicated, is called clinical inertia and is one contributory factor to suboptimal control of T2DM. The aim of this thesis was to explore and develop the understanding of suboptimally controlled T2DM. I did this through studying the impact of interventions which can best support the management of suboptimally controlled T2DM and the development and assessment of the feasibility of a theory and evidence-based complex intervention to support treatment intensification in Irish General Practice.A systematic review of interventions for T2DM targeting patient with poor control of T2DM (HbA1c ≥ 59 mmol/mol), in community settings, including 42 randomised controlled trials, led to modest reductions in HbA1c compared to usual care (-3.7 mmol/mol). Few professionally targeted interventions to support the management of suboptimally controlled T2DM were present and interventions targeting patients with very poorly controlled T2DM were more effective.Clinical guidelines for T2DM have become more complex with the introduction of new therapeutic agents. Substantial geographical variation in the prescribing of newer T2DM medications was shown in this thesis, with very high levels of geographical variation of GLP-1 agonists (systematic component of variation of 11.4 in 2013 and 10.3 in 2014) and moderate variation for DPP-4 inhibitors. This prescribing variation may represent differences in the application of clinical guidelines, but also variation in professional opinion or patient preferences. The PhD thesis outlined the development of a complex intervention, using the Medical Research Council Framework, to support GP-led intensification of medications, where appropriate, for patients with poor control of T2DM. The intervention was found to be feasible and acceptable to patients and GPs, finding decision support helpful navigating increasingly complex medication algorithms. However, GPs thought that non-engagement by patients, with GP and hospital services, was a primary contributing factor determining suboptimal control of T2DM.Some intervention GPs consciously chose not to intensify medications for some patients who often did not engage with traditional healthcare services. This PhD thesis develops the concept of clinical inertia, with poor control of T2DM risk factors representing an understandable phenomenon for a certain cohort of patients, given significant co-morbidities.
Lensing of Gravitational Waves as a Novel Probe of Graviton Mass
Creators: name: Chung, Ka-Wai
name: Li, Tjonnie Guang Feng
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The diffraction patterns of lensed gravitational waves encode information about their propagation speeds. If gravitons have mass, the dispersion relation and speed of gravitational waves will be affected in a frequency-dependent manner, which would leave traces in the diffraction pattern if the waves are lensed. In this paper, we study how the alternative dispersion relation induced by massive gravitons affects gravitational waves lensed by point-mass lenses, such as intermediate-mass black holes. We find that the waveform morphology of lensed dispersive gravitational waves depends on the graviton mass more sensitively than their unlensed counterpart. Together with lensing amplification, the waveform-morphology modifications due to lensing can improve the measurement accuracy of the graviton mass. A single lensed gravitational-wave signal enables us to measure the graviton mass with an accuracy comparable with the combined measurement across $\mathcal{O}(10^3)$ unlensed signals. Our method allows us to incorporate lensed gravitational-wave signals into existing graviton-mass measurements. Our method can also be generalized to other lens types, gravitational-wave sources, and detector networks, preparing ourselves for thoroughly understanding the nature of gravitational waves in the era of lensed gravitational-wave astronomy.
description: 6 pages, 4 figures; match the version published by Phys. Rev. D
Supersymmetric 3D gravity with torsion: asymptotic symmetries
Creators: name: Cvetkovic, B.
name: Blagojevic, M.
Publisher: name: arXiv
Year: 2007
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study the structure of asymptotic symmetries in N=1+1 supersymmetric extension of three-dimensional gravity with torsion. Using a natural generalization of the bosonic anti-de Sitter asymptotic conditions, we show that the asymptotic Poisson bracket algebra of the canonical generators has the form of two independent super-Virasoro algebras with different central charges.
description: LATEX, 21 pages, v2: minor corrections, improvements in the presentation; v3: slightly improved form of the asymptotic supersymmetry algebra
Transforming Big Data into AI‐ready data for nutrition and obesity research
Creators: name: Pathmasiri, Wimal
name: Cummiskey, Kevin
name: Gilbert, Jack A.
name: Gabriel, Kelley Pettee
name: Pfluger, Andrew
name: Gantz, Marie G.
name: Sumner, Susan C. J.
name: Green, Mark A.
name: Sazonov, Edward
name: Thomas, Diana M.
name: Cornelis, Marilyn C.
name: Dooley, Erin E.
name: Kleinberg, Samantha
name: Knight, Rob
name: Burdekin, Kate
Publisher: name: Wiley
Year: 2024

description: OBJECTIVE: Big Data are increasingly used in obesity and nutrition research to gain new insights and derive personalized guidance; however, this data in raw form are often not usable. Substantial preprocessing, which requires machine learning (ML), human judgment, and specialized software, is required to transform Big Data into artificial intelligence (AI)- and ML-ready data. These preprocessing steps are the most complex part of the entire modeling pipeline. Understanding the complexity of these steps by the end user is critical for reducing misunderstanding, faulty interpretation, and erroneous downstream conclusions.
METHODS: We reviewed three popular obesity/nutrition Big Data sources: microbiome, metabolomics, and accelerometry. The preprocessing pipelines, specialized software, challenges, and how decisions impact final AI- and ML-ready products were detailed.
RESULTS: Opportunities for advances to improve quality control, speed of preprocessing, and intelligent end user consumption were presented.
CONCLUSIONS: Big Data have the exciting potential for identifying new modifiable factors that impact obesity research. However, to ensure accurate interpretation of conclusions arising from Big Data, the choices involved in preparing AI- and ML-ready data need to be transparent to investigators and clinicians relying on the conclusions.
Emanations of Dark Matter: Muon Anomalous Magnetic Moment, Radiative Neutrino Mass, and Novel Leptogenesis at the TeV Scale
Creators: name: Hambye, Thomas
name: Kannike, Kristjan
name: Ma, Ernest
name: Raidal, Martti
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The evidence for dark matter signals a new class of particles at the TeV scale, which may manifest themselves indirectly through loop effects. In a simple model we show that these loop effects may be responsible for the enhanced muon anomalous magnetic moment, for the neutrino mass, as well as for leptogenesis in a novel way. This scenario can be verified at LHC experiments.
description: 12 pages, 3 figures
Nurses’ perspectives on caring for clients in a culturally diverse paediatric setting
Creators: name: Spencer, Mary Gervaise Elizabeth
Publisher: name: University of British Columbia
Year: 2009

description: The increasing cultural diversity of British Columbia is affecting the delivery of health care. Although there is extensive literature outlining the knowledge and skills required by nurses to provide culturally sensitive care, little is known about the perspective of nurses providing this care. The purpose of this study was to identify and describe the main issues for nurses who cared for culturally diverse clients and families in a paediatric inpatient setting. The second focus of this study was to describe the resources and supports nurses utilized and needed in order to provide this care. Kleinman's (1978) conceptualization of the three domains in which health is experienced and reacted to provided direction for examining the effects of conflicting explanatory models of health and illness from the nurse's perspective. A descriptive approach was used to address the following two research questions : 1) What issues do nurses identify as influencing their ability to provide culturally sensitive care in a paediatric setting? and 2) What agency-based resources facilitate or hinder the nurses' ability to provide culturally sensitive care? The investigator used a convenience sampling approach to recruit 42 respondents from a paediatric inpatient setting. A questionnaire developed and piloted by Lynam, Sauro et.al (1990) was adapted and used for this study. Content analysis was used to analyze openended responses, and descriptive statistics were calculated for the fixed-response questions. Communication was the overriding issue paediatric nurses faced. The communication barrier influenced the nurses' ability to assess clients and to provide care. When nurses were unable to provide optimal care, they experienced frustration and moral and ethical dilemmas. Nurses reported their ability to provide care was dependent upon the resources available. Difficulties were overcome when the nurse's personal philosophy valued client differences, and enabled her to negotiate with the client. Availability of interpreter services and resources to assist communication also affected the nurse's ability to provide care. Implications arising from this study for nursing education, practice and research are discussed.
A novel artificial intelligence model for diagnosing Acanthamoeba keratitis through confocal microscopy
Creators: name: Yousefi, Siamak
name: Jacobs, Deborah
name: Greenfield, Jason
name: Tu, Elmer
name: Djalilian, Ali R
name: Soleimani, Mohammad
name: Habib, Nabiha B
name: Saeed, Hajirah N
name: Shareef, Omar
name: Ashraf, Mohammadali
name: Rahdar, Amir
name: Ciolino, Joseph
name: Cheraqpour, Kasra
Publisher: name: Elsevier
Year: 2024

description: PURPOSE: To develop an artificial intelligence (AI) model to diagnose Acanthamoeba keratitis (AK) based on in vivo confocal microscopy (IVCM) images extracted from the Heidelberg Retinal Tomograph 3 (HRT 3).
METHODS: This retrospective cohort study utilized HRT 3 IVCM images from patients who had received a culture-confirmed diagnosis of AK between 2013 and 2021 at Massachusetts Eye and Ear. Two cornea specialists independently labeled the images as AK or nonspecific finding (NSF) in a blind manner. Deep learning tasks were then conducted through Python and TensorFlow. Distinguishing between AK and NSF was designed as the task and completed through a devised convolutional neural network.
RESULTS: A dataset of 3312 confocal images from 17 patients with a culture-confirmed diagnosis of AK was used in this study. The inter-rater agreement for identifying the presence or absence of AK in IVCM images was 84 %, corresponding to a total of 2782 images on which both observers agreed and which were included in the model. 1242 and 1265 images of AK and NSF, respectively, were utilized in the training and validation sets, and 173 and 102 images of AK and NSF, respectively, were utilized in the evaluation set. Our model had an accuracy, sensitivity, and specificity of 76 % each, and a precision of 78 %.
CONCLUSIONS: We developed an HRT-based IVCM AI model for AK diagnosis utilizing culture-confirmed cases of AK. We achieved good accuracy in diagnosing AK and our model holds significant promise in the clinical application of AI in improving early AK diagnosis.
New Inflation vs. Chaotic Inflation, Higher Degree Potentials and the Reconstruction Program in light of WMAP3
Creators: name: Boyanovsky, D.
name: de Vega, H. J.
name: Ho, C. M.
name: Sanchez, N. G.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The CMB power spectra are studied for different families of single field new and chaotic inflation models in the effective field theory approach to inflation. We implement a systematic expansion in 1/N_e where N_e ~ 50 is the number of e-folds before the end of inflation. We study the dependence of the observables (n_s, r and dn_s/d\ln k) on the degree of the potential (2 n) and confront them to the WMAP3 and large scale structure data: this shows in general that fourth degree potentials (n=2) provide the best fit to the data; the window of consistency with the WMAP3 and LSS data narrows for growing n. New inflation models yield a good fit to the r and n_s data in a wide range of field and parameter space. Small field inflation yields r<0.16 while large field inflation yields r>0.16 (for N_e=50). All members of the new inflation family predict a small but negative running -4(n+1)10^{-4}< dn_s/d\ln k 0.16 (for N_e=50) and only a restricted subset of chaotic models are consistent with the combined WMAP3 bounds on r, n_s,dn_s/d\ln k with a narrow window in field amplitude around |ϕ_{50}| ~ 15 M_{Pl}.A measurement of r<0.16 (for N_e =50) will distinctly rule out a large class of chaotic scenarios and will favor new inflationary models. As a general consequence, new inflation emerges more favoured than chaotic inflation.
description: 19 pages, 18 figures. Minor additions. Matches version published in Phys. Rev. D
Internal structure of cuscuton Bloch brane
Creators: name: Bazeia, D.
name: Ferreira, D. A.
name: Marques, M. A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: This work deals with thick branes in bulk with a single extra dimension modeled by a two-field configuration. We first consider the inclusion of the cuscuton to also control the dynamics of one of the fields and investigate how it contributes to change the internal structure of the configuration in two distinct situations, with the standard and the asymmetric Bloch brane. The results show that the branes get a rich internal structure, with the geometry presenting a novel behavior which is also governed by the parameter that controls the strength of the cuscuton term. We also study the case where the dynamics of one of the two fields is only described by the cuscuton. All the models support analytical solutions which are stable against fluctuations in the metric, and the main results unveil significant modifications in the warp factor and energy density of the branes.
description: 8 pages, 3 figures. New version to appear in EPJC
Nonzero U_{e3}, CP violation and leptogenesis in a see-saw type softly broken A_4 symmetric model
Creators: name: Adhikary, Biswajit
name: Ghosal, Ambar
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We have shown that non-zero U_{e3} is generated in a see-saw type softly broken A_4 symmetric model through a single parameter perturbation in m_D in a single element. We have explored all possible 9 cases to study the neutrino mixing angles considering the best fitted values of Δm_{\odot}^2 and Δm_{atm}^2 with all parameters real. We have extended our analysis for the complex case and demonstrated large low energy CP violation (J_{CP}\simeq 10^{-2}) and m_{ee} in addition to mixing and mass pattern. We have also investigated leptogenesis and for a reasonable choice of model parameters compatible with low energy data, WMAP value of baryon asymmetry 6\times 10^{-10} is obtained for right handed neutrino mass scale M_0\simeq 10^{13} GeV. We have obtained a relation among the phases responsible for leptogenesis and have shown that these phases also have correlations with low energy CP violating phases.
description: 35 pages, 16 figures, discussion and reference added, version to appear in Phys. Rev. D
STAGER checklist: Standardized testing and assessment guidelines for evaluating generative artificial intelligence reliability
Creators: name: Qi, Chang
name: Mao, Weipu
name: Cheng, Quan
name: Kahlert, Ulf D.
name: Whitaker, Iain S.
name: Jeon, Che Ok
name: Gu, Shuqin
name: Chen, Jinghong
name: Liu, Zaoqu
name: Sun, Xu
name: Chen, Xin
name: Shi, Wenjie
name: Ngo, Trunghieu
name: Cabannes, Loïc
name: Wu, Haiyang
name: Lin, Anqi
name: Yuan, Shuofeng
name: Ali, Stephen
name: Huang, Haojie
name: Tang, Bufu
name: Luo, Peng
name: Ren, Gerald Sng Gui
name: Jia, Baolei
name: Zeng, Dongqiang
name: Lu, Xiaofan
name: Jiang, Aimin
name: Guo, Shipeng
name: Wang, Shixiang
name: He, Yongbin
name: Miao, Kai
name: Mou, Weiming
name: Cheungpasitporn, Wisit
name: Pu, Zhongji
name: Zhu, Lingxuan
name: Zhou, Jianguo
Publisher: name: Wiley
Year: 2024

description: Generative artificial intelligence (AI) holds immense potential for medical applications, but the lack of a comprehensive evaluation framework and methodological deficiencies in existing studies hinder its effective implementation. Standardized assessment guidelines are crucial for ensuring reliable and consistent evaluation of generative AI in healthcare. Our objective is to develop robust, standardized guidelines tailored for evaluating generative AI performance in medical contexts. Through a rigorous literature review utilizing the Web of Sciences, Cochrane Library, PubMed, and Google Scholar, we focused on research testing generative AI capabilities in medicine. Our multidisciplinary team of experts conducted discussion sessions to develop a comprehensive 32‐item checklist. This checklist encompasses critical evaluation aspects of generative AI in medical applications, addressing key dimensions such as question collection, querying methodologies, and assessment techniques. The checklist and its broader assessment framework provide a holistic evaluation of AI systems, delineating a clear pathway from question gathering to result assessment. It guides researchers through potential challenges and pitfalls, enhancing research quality and reporting and aiding the evolution of generative AI in medicine and life sciences. Our framework furnishes a standardized, systematic approach for testing generative AI's applicability in medicine. For a concise checklist, please refer to Table S or visit GenAIMed.org . 
Highlights    This work formulates the standardized testing and assessment guidelines for evaluating generative artificial intelligence (AI) reliability (STAGER) checklist, a 32‐item framework offering standardized assessment guidelines tailored for evaluating generative AI systems in medical and life science contexts.   It consists of key aspects, including question collection, querying approaches, and assessment techniques.   It enhances research quality and facilitates advances in this emerging field.
QED calculation of the 2p3/2-2p1/2 transition energy in five-electron ion of argon
Creators: name: Artemyev, A. N.
name: Shabaev, V. M.
name: Tupitsyn, I. I.
name: Plunien, G.
name: Yerokhin, V. A.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: We perform ab initio QED calculation of the (1s)^2(2s)^22p_{3/2} - (1s)^2(2s)^22p_{1/2} transition energy in the five-electron ion of argon. The calculation is carried out by perturbation theory starting with an effective screening potential approximation. Four different types of the screening potentials are considered. The rigorous QED calculations of the two lowest-order QED and electron-correlation effects are combined with approximate evaluations of the third- and higher-order electron-correlation contributions. The theoretical value for the wavelength obtained amounts to 441.261(70) (nm, air) and perfectly agrees with the experimental one, 441.2559(1) (nm, air).
description: 10 pages, 3 figures, 1 table
The impact of correlated noise on SuperWASP detection rates for transiting extra-solar planets
Creators: name: Smith, A. M. S.
name: Cameron, A. Collier
name: Christian, D. J.
name: Clarkson, W. I.
name: Enoch, B.
name: Evans, A.
name: Haswell, C. A.
name: Hellier, C.
name: Horne, K.
name: Irwin, J.
name: Kane, S. R.
name: Lister, T. A.
name: Norton, A. J.
name: Parley, N.
name: Pollacco, D. L.
name: Ryans, R.
name: Skillen, I.
name: Street, R. A.
name: Triaud, A. H. M. J.
name: West, R. G.
name: Wheatley, P. J.
name: Wilson, D. M.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present a model of the stellar populations in the fields observed by one of the SuperWASP-N cameras in the 2004 observing season. We use the Besancon Galactic model to define the range of stellar types and metallicities present, and populate these objects with transiting extra-solar planets using the metallicity relation of Fischer & Valenti (2005). We investigate the ability of SuperWASP to detect these planets in the presence of realistic levels of correlated systematic noise (`red noise'). We find that the number of planets that transit with a signal-to-noise ratio of 10 or more increases linearly with the number of nights of observations. Based on a simulation of detection rates across 20 fields observed by one camera, we predict that a total of 18.6 \pm 8.0 planets should be detectable from the SuperWASP-N 2004 data alone. The best way to limit the impact of co-variant noise and increase the number of detectable planets is to boost the signal-to-noise ratio, by increasing the number of observed transits for each candidate transiting planet. This requires the observing baseline to be increased, by spending a second observing season monitoring the same fields.
description: Omitted co-authors reinstated. 9 pages, 7 figures, accepted for publication in MNRAS
Non-Gaussian states for continuous variable quantum computation via Gaussian maps
Creators: name: Ghose, Shohini
name: Sanders, Barry C.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We investigate non-Gaussian states of light as ancillary inputs for generating nonlinear transformations required for quantum computing with continuous variables. We consider a recent proposal for preparing a cubic phase state, find the exact form of the prepared state and perform a detailed comparison to the ideal cubic phase state. We thereby identify the main challenges to preparing an ideal cubic phase state and describe the gates implemented with the non-ideal prepared state. We also find the general form of operations that can be implemented with ancilla Fock states, together with Gaussian input states, linear optics and squeezing transformations, and homodyne detection with feed forward, and discuss the feasibility of continuous variable quantum computing using ancilla Fock states.
description: 8 pages, 6 figures
Dissection of the protostellar envelope surrounding IRAS 05173-0555 in L1634
Creators: name: Beltran, M. T.
name: Wiseman, J.
name: Ho, P. T. P.
name: Estalella, R.
name: Fuller, G.
name: Wootten, A.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Context. The youngest protostars that power energetic outflows are surrounded by infalling and rotating envelopes that contain most of the mass of the system. Aims. To study the properties and kinematics of the protostellar envelope surrounding the embedded source IRAS 05173-0555 in L1634. Methods. We carried out VLA ammonia observations at 1.3 cm with the VLA in the D configuration to map the gas towards the core of L1634. Results. The NH3 emission towards IRAS 05173-0555 is resolved and shows two components clearly distinguishable morphologically: a cross-like structure, roughly elongated in the direction of the HH 240/241 outflow and associated with IRAS 05173-0555, plus an arc-like stream elongated towards the north. The properties and kinematics of the gas suggest that the origin of the cross-like morphology could be the interaction between the outflow and the envelope. A more compact and flattened structure, which could be undergoing rotation about the axis of the outflow, has been detected towards the center of the cross-like envelope. The northern stream, which has properties and velocity different from those of the cross-like envelope, is likely part of the original cloud envelope, and could be either a quiescent core that would never form stars, or be in a prestellar phase.
description: 10 pages, 9 figures, accepted for publication in A&A
Online Graph Dictionary Learning
Creators: name: Vincent-Cuaz, Cédric
name: Vayer, Titouan
name: Flamary, Rémi
name: Corneli, Marco
name: Courty, Nicolas
Publisher: name: arXiv
Year: 2021
Subjects: subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Dictionary learning is a key tool for representation learning, that explains the data as linear combination of few basic elements. Yet, this analysis is not amenable in the context of graph learning, as graphs usually belong to different metric spaces. We fill this gap by proposing a new online Graph Dictionary Learning approach, which uses the Gromov Wasserstein divergence for the data fitting term. In our work, graphs are encoded through their nodes' pairwise relations and modeled as convex combination of graph atoms, i.e. dictionary elements, estimated thanks to an online stochastic algorithm, which operates on a dataset of unregistered graphs with potentially different number of nodes. Our approach naturally extends to labeled graphs, and is completed by a novel upper bound that can be used as a fast approximation of Gromov Wasserstein in the embedding space. We provide numerical evidences showing the interest of our approach for unsupervised embedding of graph datasets and for online graph subspace estimation and tracking.
Dust in Hot Plasma of Nearby Dusty Elliptical Galaxies Observed with the Spitzer Space Telescope
Creators: name: Kaneda, H.
name: Onaka, T.
name: Kitayama, T.
name: Okada, Y.
name: Sakon, I.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We report on mid- and far-IR Spitzer observations of 7 nearby dusty elliptical galaxies by using the Multiband Imaging Photometer (MIPS) and Infrared Spectrograph (IRS). Our sample galaxies are known to contain an excessive amount of interstellar dust against sputtering destruction in hot plasma filling the interstellar space of elliptical galaxies. In order to study the origin and the properties of the excess dust in the hot plasma, we selected galaxies with a wide range of X-ray luminosities but similar optical luminos ities for our Spitzer Guest Observers (GO1) program. The 7 galaxies are detected at the MIPS 24 um, 70 um, and 160 um bands; the far- to mid-IR flux ratios of relatively X-ray-bright elliptical galaxies are lower than those of X-ray-faint galaxies. From the IRS spectra, polycyclic aromatic hydrocarbon (PAH) emission features are detected significantly from 5 of the 7 galaxies; t he emission intensities are weaker as the X-ray luminosity of the galaxy is larger. We have found a correlation between the far- to mid-IR flux ratio and the equivalent width of the PAH emission feature. We have obtained apparent spatial correspondence between mid-IR and X-ray distributions in the outer regions for the three X-ray-brightest galaxies in our sample. Possible interpretations for our observational results are discussed.
description: 25 pages, 7 figures, accepted for publication in Publications of the Astronomical Society of Japan
Observational and Theoretical Studies of 27 $δ$ Scuti Stars with Investigation of the Period-Luminosity Relation
Creators: name: Poro, Atila
name: Paki, Ehsan
name: Mazhari, Golnaz
name: Sarabi, Soroush
name: Alicavus, Filiz Kahraman
name: Farahani, Farzaneh Ahangarani
name: Guilani, Hamidreza
name: Popov, Alexander A.
name: Zubareva, Alexandra M.
name: Jalalabadi, Behjat Zarei
name: Nourmohammad, Mahshid
name: Davoudi, Fatemeh
name: Arani, Zahra Sabaghpour
name: Ghalee, Amir
Publisher: name: arXiv
Year: 2021
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The multi-color CCD photometric study of 27 Delta Scuti stars is presented. By using approximately three years of photometric observations, we obtained the times of maxima and magnitude changes during the observation time interval for each star. The ephemerides of our Delta Scuti stars were calculated based on the Markov Chain Monte Carlo (MCMC) method using the observed times of maxima and the period of the stars' oscillations. We used the Gaia EDR3 parallaxes to calculate the luminosities and also the absolute magnitudes of these Delta Scuti stars. The fundamental physical parameters of all the stars in our sample such as masses and radii were estimated. We determined the pulsation modes of the stars based on the pulsation constants. Moreover, the period-luminosity (P-L) relation of Delta Scuti stars was investigated and discussed. Then, by using a machine learning classification, new P-L relations for fundamental and overtone modes are presented.
description: 5 Figures, 6 Tables, Accepted in the PASP journal
New parametrization for differences between plasma kinetic codes
Creators: name: Salzmann, David
name: Ralchenko, Yuri
Publisher: name: arXiv
Year: 2006
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: Validation and verification of plasma kinetics codes requires the development of quantitative methods and techniques for code comparisons. We describe two parameters that can be used for characterization of differences between such codes. It is shown that these parameters, which are determined from the most general results of kinetic codes, can provide important information on the differences between the basic rate coefficients employed. Application of this method is illustrated by comparisons of some results from the 3rd NLTE Code Comparison Workshop for carbon, germanium, and gold plasmas.
description: Submitted to High Energy Density Physics, 12 pages, 2 figures
Low Timing Jitter Detector for Gigahertz Quantum Key Distribution
Creators: name: Collins, R. J.
name: Hadfield, R. H.
name: Fernandez, V.
name: Nam, S. W.
name: Buller, G. S.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: A superconducting single-photon detector based on a niobium nitride nanowire is demonstrated in an optical-fibre-based quantum key distribution test bed operating at a clock rate of 3.3 GHz and a transmission wavelength of 850 nm. The low jitter of the detector leads to significant reduction in the estimated quantum bit error rate and a resultant improvement in the secrecy efficiency compared to previous estimates made by use of silicon single-photon avalanche detectors.
description: 11 pages, including 2 figures
Dark matter from a complex scalar singlet: The role of dark CP and other discrete symmetries
Creators: name: Coito, Leonardo
name: Faubel, Carlos
name: Herrero-Garcia, Juan
name: Santamaria, Arcadi
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We study the case of a pseudo-scalar dark matter candidate which emerges from a complex scalar singlet, charged under a global U(1) symmetry, which is broken both explicitly and spontaneously. The pseudo-scalar is naturally stabilized by the presence of a remnant discrete symmetry: dark CP. We study and compare the phenomenology of several simplified models with only one explicit symmetry breaking term. We find that several regions of the parameter space are able to reproduce the observed dark matter abundance while respecting direct detection and invisible Higgs decay limits: in the resonances of the two scalars, featuring the known as forbidden or secluded dark matter, and through non-resonant Higgs-mediated annihilations. In some cases, combining different measurements would allow one to distinguish the breaking pattern of the symmetry. Moreover, this setup admits a light DM candidate at the sub-GeV scale. We also discuss the situation where more than one symmetry breaking term is present. In that case, the dark CP symmetry may be spontaneously broken, thus spoiling the stability of the dark matter candidate. Requiring that this does not happen imposes a constraint on the allowed parameter space. Finally, we consider an effective field theory approach valid in the pseudo-Nambu-Goldstone boson limit and when the U(1) breaking scale is much larger than the electroweak scale.
description: 33 pages, 13 figures, 5 tables, extended discussion on light dark matter, added references, conclusions unchanged; matches published version in JHEP
Proof of all-order finiteness for planar beta-deformed Yang-Mills
Creators: name: Ananth, Sudarshan
name: Kovacs, Stefano
name: Shimada, Hidehiko
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study a marginal deformation of N=4 Yang-Mills, with a real deformation parameter beta. This beta-deformed model has only N=1 supersymmetry and a U(1)xU(1) flavor symmetry. The introduction of a new superspace star-product allows us to formulate the theory in N=4 light-cone superspace, despite the fact that it has only N=1 supersymmetry. We show that this deformed theory is conformally invariant, in the planar approximation, by proving that its Green functions are ultra-violet finite to all orders in perturbation theory.
description: 27 pages, several figures; v3: minor corrections
Quasi-maximum-likelihood estimation in conditionally heteroscedastic time series: A stochastic recurrence equations approach
Creators: name: Straumann, Daniel
name: Mikosch, Thomas
Publisher: name: arXiv
Year: 2007
Subjects: subject: Statistics Theory (math.ST)
subject: FOS: Mathematics
subject: 60H25 (Primary) 62F10, 62F12, 62M05, 62M10, 91B84 (Secondary)

description: This paper studies the quasi-maximum-likelihood estimator (QMLE) in a general conditionally heteroscedastic time series model of multiplicative form $X_t=σ_tZ_t$, where the unobservable volatility $σ_t$ is a parametric function of $(X_{t-1},...,X_{t-p},σ_{t-1},... ,σ_{t-q})$ for some $p,q\ge0$, and $(Z_t)$ is standardized i.i.d. noise. We assume that these models are solutions to stochastic recurrence equations which satisfy a contraction (random Lipschitz coefficient) property. These assumptions are satisfied for the popular GARCH, asymmetric GARCH and exponential GARCH processes. Exploiting the contraction property, we give conditions for the existence and uniqueness of a strictly stationary solution $(X_t)$ to the stochastic recurrence equation and establish consistency and asymptotic normality of the QMLE. We also discuss the problem of invertibility of such time series models.
description: Published at http://dx.doi.org/10.1214/009053606000000803 in the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org)
Markov chain Monte Carlo analyses of the flux ratios of B, Be and Li with the DRAGON2 code
Creators: name: Luque, P. De La Torre
name: Mazziotta, M. N.
name: Loparco, F.
name: Gargano, F.
name: Serini, D.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Recent cosmic-ray measurements are challenging our models of propagation in the Galaxy. A good characterization of the secondary cosmic rays (B, Be, Li and sub-iron species) is crucial to constrain these models and exploit the precision of modern CR experiments. In this work, a Markov chain Monte Carlo analysis has been implemented to fit the experimental flux ratios between B, Be and Li and their flux ratios to the primary nuclei C and O. We have fitted the data using two different parametrizations for the spallation cross sections. The uncertainties in the evaluation of the spectra of these secondary cosmic rays, due to spallation cross sections, have been considered by introducing scale factors as nuisance parameters. We have also tested two different formulations for the diffusion coefficient, which differ in the origin of the high energy hardening of cosmic rays. Additionally, two different approaches are used to scale the cross sections, one based on a combined analysis of all the species ("combined" analysis) and the other reproducing the high energy spectra of the secondary-to-secondary flux ratios of Be/B, Li/B, Li/Be ("scaled" analysis). This allows us to make a better comparison between the propagation parameters inferred from the cross sections parametrizations tested in this work. This novel analysis has been successfully implemented using the numerical code DRAGON2 to reproduce the cosmic-ray nuclei data up to $Z=14$ from the AMS-02 experiment. It is found that the ratios of Li favor a harder spectral index of the diffusion coefficient, but compatible with the other ratios inside the observed $2σ$ uncertainties. In addition, it is shown that, including these scale factors, the secondary-to-primary flux ratios can be simultaneously reproduced.
description: 27 pages, 10 figures, 9 tables
Pre-recombinational energy release and narrow features in the CMB spectrum
Creators: name: Chluba, J.
name: Sunyaev, R. A.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Energy release in the early Universe (z~1800) and HeII (z>~7000), and therefore differ from those arising due to normal cosmological recombination in the undisturbed CMB blackbody radiation field. We present the results of numerical computations including 25 atomic shells for both HI and HeII, and discuss the contributions of several individual transitions in detail. As examples, we consider the case of instantaneous energy release (e.g. due to phase transitions) and exponential energy release because of long-lived decaying particles. Our computations show that due to possible pre-recombinational atomic transitions the variability of the CMB spectral distortion increases when comparing with the distortions arising in the normal recombination epoch. The existence of these narrow spectral features would open an unique way to separate y-distortions due to pre-recombinational ($1400
description: 17 pages, 12 Figures, 1 Table, submitted to A&A
Heat conduction through a trapped solid: effect of structural changes on thermal conductance
Creators: name: Chaudhuri, Debasish
name: Chaudhuri, Abhishek
name: Sengupta, Surajit
Publisher: name: arXiv
Year: 2006
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We study the conduction of heat across a narrow solid strip trapped by an external potential and in contact with its own liquid. Structural changes, consisting of addition and deletion of crystal layers in the trapped solid, are produced by altering the depth of the confining potential. Nonequilibrium molecular dynamics simulations and, wherever possible, simple analytical calculations are used to obtain the thermal resistance in the liquid, solid and interfacial regions (Kapitza or contact resistance). We show that these layering transitions are accompanied by sharp jumps in the contact thermal resistance. Dislocations, if present, are shown to increase the thermal resistance of the strip drastically.
description: 9 pages, 3 figures, published version, minor changes
Identifying reactive trajectories using a moving transition state
Creators: name: Bartsch, Thomas
name: Uzer, T.
name: Moix, Jeremy M.
name: Hernandez, Rigoberto
Publisher: name: arXiv
Year: 2006
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: A time-dependent no-recrossing dividing surface is shown to lead to a new criterion for identifying reactive trajectories well before they are evolved to infinite time. Numerical dynamics simulations of a dissipative anharmonic two-dimensional system confirm the efficiency of this approach. The results are compared to the standard fixed transition state dividing surface that is well-known to suffer from recrossings and therefore requires trajectories to be evolved over a long time interval before they can reliably be classified as reactive or non-reactive. The moving dividing surface can be used to identify reactive trajectories in harmonic or moderately anharmonic systems with considerably lower numerical effort or even without any simulation at all.
Supplementary material for publication: 'Is there a need for a new journal metric? Correlations between JCR Impact Factor metrics and the Journal Citation Indicator - JCI'
Creators: name: Torres-Salinas, Daniel
name: Valderrama-Baca, Pilar
name: Arroyo-Machado, Wenceslao
Publisher: name: Zenodo
Year: 2021
Subjects: bibliometrics
correlations
JCR
Journal Impact Factor
Journal Citation Indicator

description: Supplementary material for publication: 'Is there a need for a new journal metric? Correlations between JCR Impact Factor metrics and the Journal Citation Indicator - JCI'
Non-equilibrium plasma generation via nano-second multi-mode laser pulses
Creators: name: Alberti, Andrea
name: Munafó, Alessandro
name: Nishihara, Munetake
name: Pantano, Carlos
name: Freund, Jonathan B.
name: Panesi, Marco
Publisher: name: arXiv
Year: 2021
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: A non-equilibrium model for laser-induced plasmas is used to describe how nano-second temporal mode-beating affects plasma kernel formation and growth in quiescent air. The chemically reactive Navier-Stokes equations describe the hydrodynamics, and non-equilibrium effects are modeled based on a two-temperature model. Inverse Bremsstrahlung and multiphoton ionization are self-consistently taken into account via a coupled solution of the equations governing plasma dynamics and beam propagation and attenuation (i.e., Radiative Transfer Equation). This strategy, despite the additional challenges it may bring, allows to minimize empiricism and enables for more accurate simulations since it does not require an artificial plasma seed to trigger breakdown. The benefits of this methodology are demonstrated by the good agreement between the predicted and the experimental plasma boundary evolution and absorbed energy. The same goes for the periodic plasma kernel structures which, as suggested by experiments and confirmed by the simulations discussed here, are linked to the modulating frequency.
A reappraisal of humanitarian intervention
Creators: name: Middleton, Kirsty Giselle
Publisher: name: University of British Columbia
Year: 2009

description: A new threat to international peace and security exists in the post Cold War years. The demise of the Cold War has brought chaos in its wake as ethnic and religious disputes engulf several regions of the world often resulting in humanitarian tragedies. The tumultuous developments of recent years have however, opened up new possibilities for international action and cooperation under the auspices of the United Nations. Consequently, a radical shift has taken place in the international community as recent humanitarian crises have not only compelled the United Nations to take a prominent role in world affairs but also a chance to expand the competence of the UN into areas previously regarded as being within the exclusive jurisdiction of member states. Moreover, the humanitarian crises of recent years have called for a reappraisal of the controversial doctrine of humanitarian intervention. This thesis explores the theoretical justifications to support the doctrine under the UN Charter and general international law and also offers a contemporary appraisal of the applicable norms in light of evolving conceptions of state sovereignty and non-intervention in internal affairs. The overall hypothesis is that not only is substantial change in the theoretical norms appropriate but that the operational capability of the United Nations to conduct a humanitarian intervention must also be reexamined in light of recent events. The remaining section of the thesis therefore considers how the United Nations can establish a more effective operational military capacity for future collective humanitarian interventions.
Lattice Results for the QCD Phase Transition
Creators: name: Mendes, Tereza
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We discuss recent results for the phase transition in finite-temperature QCD from numerical (Monte Carlo) simulations of the lattice-regularized theory. Emphasis is given to the case of two degenerate light-quark flavors. The order of the transition in this case, which could have cosmological implications, has not yet been established.
description: To appear in the Proceedings of the 1st Latin American Workshop on High Energy Phenomenology, Porto Alegre, Brazil, 1-3 Dec 2005.One figure, 4 pages