cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Formalizing Randomized Matching Algorithms
Creators: name: Le, Dai Tri Man
name: Cook, Stephen A.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Logic in Computer Science (cs.LO)
subject: Computational Complexity (cs.CC)
subject: Logic (math.LO)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics
subject: F.2.2, F.4.1

description: Using Jeřábek 's framework for probabilistic reasoning, we formalize the correctness of two fundamental RNC^2 algorithms for bipartite perfect matching within the theory VPV for polytime reasoning. The first algorithm is for testing if a bipartite graph has a perfect matching, and is based on the Schwartz-Zippel Lemma for polynomial identity testing applied to the Edmonds polynomial of the graph. The second algorithm, due to Mulmuley, Vazirani and Vazirani, is for finding a perfect matching, where the key ingredient of this algorithm is the Isolating Lemma.
Corrections for "Occupation and local times for skew Brownian motion with applications to dispersion across an interface"
Creators: name: Appuhamillage, Thilanka
name: Bokil, Vrushali
name: Thomann, Enrique
name: Waymire, Edward
name: Wood, Brian
Publisher: name: arXiv
Year: 2010
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics

description: We are making corrections and acknowledging colleagues that pointed out mistakes in our recent paper titled "Occupation and local times for skew Brownian motion with applications to dispersion across an interface" which was published in Annals of Applied Probability (2011) 21(1) 183-214. Specifically the corrections are: 1. The restriction of $γ$ to non negative values in Theorem 1.3 is not needed. But one has probabilistic interpretation only when $γ$ is non negative. 2. State the correct formulas in Corollary 3.3 as their were computational errors in the original formulas. We thank Pierre Etoiré and Miguel Martinez for pointing out these errors.
description: Published in at http://dx.doi.org/10.1214/11-AAP775 the Annals of Applied Probability (http://www.imstat.org/aap/) by the Institute of Mathematical Statistics (http://www.imstat.org)
Mott-driven BEC-BCS crossover in a doped spin liquid candidate, kappa-(BEDT-TTF)4Hg2.89Br8
Creators: name: Suzuki, Y.
name: Wakamatsu, K.
name: Ibuka, J.
name: Oike, H.
name: Fujii, T.
name: Miyagawa, K.
name: Taniguchi, H.
name: Kanoda, K.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The pairing of interacting fermions leading to superfluidity has two limiting regimes: the Bardeen-Cooper-Schrieffer (BCS) scheme for weakly interacting degenerate fermions and the Bose-Einstein condensation (BEC) of bosonic pairs of strongly interacting fermions. While the superconductivity that emerges in most metallic systems is the BCS-like electron pairing, strongly correlated electrons with poor Fermi liquidity can condense into the unconventional BEC-like pairs. Quantum spin liquids harbor extraordinary spin correlation free from order and the superconductivity that possibly emerges by carrier doping of the spin liquids is expected to have a peculiar pairing nature. The present study experimentally explores the nature of the pairing condensate in a doped spin-liquid candidate material and under varying pressure, which changes the electron-electron Coulombic interactions across the Mott critical value in the system. The transport measurements reveal that the superconductivity at low pressures is a BEC-like condensate from a non-Fermi liquid and crosses over to a BCS-like condensate from a Fermi liquid at high pressures. The Nernst-effect measurements distinctively illustrate the two regimes of the pairing in terms of its robustness to the magnetic field. The present Mott tuning of the BEC-BCS crossover can be compared to the Feshbach tuning of the BEC-BCS crossover of fermionic cold atoms.
description: 25 pages, 10 figures
Investigating signal denoising and iterative reconstruction algorithms in photoacoustic tomography
Creators: name: Cheng, Jiayi
Publisher: name: University of British Columbia
Year: 2017

description: Photoacoustic tomography (PAT) is a promising biomedical imaging modality that achieves strong optical contrast and high ultrasound resolution. This technique is based on the photoacoustic (PA) effect which refers to illuminating the tissue by a nanosecond pulsed laser and generating acoustic waves by thermoelastic expansion. By detecting the PA waves, the initial pressure distribution that corresponds to the optical absorption map can be obtained by a reconstruction algorithm. In the linear array transducer based data acquisition system, the PA signals are contaminated with various noises. Also, the reconstruction suffers from artifacts and missing structures due to the limited detection view. We aim to reduce the effect of noise by a denoising preprocessing. The PAT system with a linear array transducer and a parallel data acquisition system (DAQ) has prominent band-shaped noise due to signal interference. The band-shaped noise is treated as a low-rank matrix, and the pure PA signal is treated as a sparse matrix, respectively. Robust principal component analysis (RPCA) algorithm is applied to extract the pure PA signal from the noise contaminated PA measurement. The RPCA approach is conducted on experiment data of different samples. The denoising results are compared with several methods and RPCA is shown to outperform the other methods. It is demonstrated that RPCA is promising in reducing the background noise in PA image reconstruction. We also aim to improve the iterative reconstruction. The variance reduced stochastic gradient descent (VR-SGD) algorithm is implemented in PAT reconstruction. A new forward projection matrix is also developed to more accurately match with the measurement data. Using different evaluation criteria, such as peak signal-to-noise ratio (PSNR), relative root-mean-square of reconstruction error (RRMSE) and line profile comparisons, the reconstructions from various iterative algorithms are compared. The advantages of VR-SGD are demonstrated on both simulation and experimental data. Our results indicate that VR-SGD in combination with the accurate projection matrix can lead to improved reconstruction in a small number of iterations. RPCA denoising and VR-SGD iterative reconstruction have been implemented in PAT. Our results show that RPCA and VR-SGD are promising approaches to improve the image reconstruction quality in PAT.
Towards derived equivalence classification of the cluster-tilted algebras of Dynkin type D
Creators: name: Bastian, Janine
name: Holm, Thorsten
name: Ladkani, Sefi
Publisher: name: arXiv
Year: 2010
Subjects: subject: Representation Theory (math.RT)
subject: FOS: Mathematics
subject: 16G10, 16E35, 18E30, 13F60, 16G60

description: We provide a far reaching derived equivalence classification of the cluster-tilted algebras of Dynkin type D and suggest standard forms for the derived equivalence classes. We believe that the classification is complete, but some subtle questions remain open. We introduce another notion of equivalence called good mutation equivalence which is slightly stronger than derived equivalence but is algorithmically more tractable, and give a complete classification together with standard forms.
description: 42 pages; v2: Minor revision. Title and abstract changed, slight changes to the introduction and in the presentation of main results in Section 2
Brain tumour segmentation with incomplete imaging data
Creators: name: Ruffle, James K
name: Mohinta, Samia
name: Gray, Robert J
name: Hyare, Harpreet
name: Nachev, Parashkev
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Artificial Intelligence (cs.AI)
subject: Tissues and Organs (q-bio.TO)
subject: FOS: Computer and information sciences
subject: FOS: Biological sciences

description: The complex heterogeneity of brain tumours is increasingly recognized to demand data of magnitudes and richness only fully-inclusive, large-scale collections drawn from routine clinical care could plausibly offer. This is a task contemporary machine learning could facilitate, especially in neuroimaging, but its ability to deal with incomplete data common in real world clinical practice remains unknown. Here we apply state-of-the-art methods to large scale, multi-site MRI data to quantify the comparative fidelity of automated tumour segmentation models replicating the various levels of sequence availability observed in the clinical reality. We compare deep learning (nnU-Net-derived) segmentation models with all possible combinations of T1, contrast-enhanced T1, T2, and FLAIR sequences, trained and validated with five-fold cross-validation on the 2021 BraTS-RSNA glioma population of 1251 patients, with further testing on a real-world 50 patient sample diverse in not only MRI scanner and field strength, but a random selection of pre- and post-operative imaging also. Models trained on incomplete imaging data segmented lesions well, often equivalently to those trained on complete data, exhibiting Dice coefficients of 0.907 (single sequence) to 0.945 (full datasets) for whole tumours, and 0.701 (single sequence) to 0.891 (full datasets) for component tissue types. Incomplete data segmentation models could accurately detect enhancing tumour in the absence of contrast imaging, quantifying its volume with an R2 between 0.95-0.97, and were invariant to lesion morphometry. Deep learning segmentation models characterize tumours well when missing data and can even detect enhancing tissue without the use of contrast. This suggests translation to clinical practice, where incomplete data is common, may be easier than hitherto believed, and may be of value in reducing dependence on contrast use.
description: 26 pages, 8 figures, 4 supplementary tables
Studying phylogeny by producing phylogenetic trees of primates using morphological and molecular characteristics.
Creators: name: Kennedy, Chas.
Publisher: name: QUBES Educational Resources
Year: 2022

description: An assignment constructing phylogenetic trees using shared, derived morphological traits and molecular differences among 18 primate species and two outlier species has been developed. Skull and body images and a table of morphological characteristics were used to fill in a pre-fabricated tree. Molecular differences of the cytochrome b gene obtained from the NCBI website was used to generate a tree using the Phylogeny.fr website for the same 20 species. Several followup questions were provided upon completion of the assignment.
CYLD controls c-MYC expression through the JNK-dependent signaling pathway in hepatocellular carcinoma
Creators: name: Pannem, Rajeswara Rao
name: Dorn, Christoph
name: Ahlqvist, Kristofer
name: Bosserhoff, Anja K.
name: Hellerbrand, Claus
name: Massoumi, Ramin
Publisher: name: Universität Regensburg
Year: 2014
Subjects: subject: apoptosis, signal transduction, cell proliferation, hepatic tumor, carcinoma, hepatocellular, cell line, down-regulation, hepatocyte, ki-67 antigen, phosphotransferases, mice, neoplasms, signal pathway, c-myc genes, signal transduction pathways, protein overexpression, tissue microarray, ubiquitination
subject: 615 Pharmazie

description: Posttranslational modification of different proteins via direct ubiquitin attachment is vital for mediating various cellular processes. Cylindromatosis (CYLD), a deubiquitination enzyme, is able to cleave the polyubiquitin chains from the substrate and to regulate different signaling pathways. Loss, or reduced expression, of CYLD is observed in different types of human cancer, such as hepatocellular carcinoma (HCC). However, the molecular mechanism by which CYLD affects cancerogenesis has to date not been unveiled. The aim of the present study was to examine how CYLD regulates cellular functions and signaling pathways during hepatocancerogenesis. We found that mice lacking CYLD were highly susceptible to chemically induced liver cancer. The mechanism behind proved to be an elevated proliferation rate of hepatocytes, owing to sustained c-Jun N-terminal kinase 1 (JNK1)-mediated signaling via ubiquitination of TNF receptor-associated factor 2 and expression of c-MYC. Overexpression of wild-type CYLD in HCC cell lines prevented cell proliferation, without affecting apoptosis, adhesion and migration. A combined immunohistochemical and tissue microarray analysis of 81 human HCC tissues revealed that CYLD expression is negatively correlated with expression of proliferation markers Ki-67 and c-MYC. To conclude, we found that downregulation of CYLD induces tumor cell proliferation, consequently contributing to the aggressive growth of HCC. Our findings suggest that CYLD holds potential to serve as a marker for HCC progression, and its link to c-MYC via JNK1 may provide the foundation for new therapeutic strategies for HCC patients.
Cylindromatosis gene CYLD regulates hepatocyte growth factor expression in hepatic stellate cells through interaction with histone deacetylase 7
Creators: name: Pannem, Rajeswara R.
name: Dorn, Christoph
name: Hellerbrand, Claus
name: Massoumi, Ramin
Publisher: name: Universität Regensburg
Year: 2014
Subjects: subject: 615 Pharmazie

description: Hepatic fibrosis is considered as a physiological wound‐healing response to liver injury. The process involves several factors, such as hepatocyte growth factor (HGF), which restrains hepatic injury and facilitates reversibility of fibrotic reaction in response to an acute insult. Chronic liver injury and sustained inflammation cause progressive fibrosis and, ultimately, organ dysfunction. The mechanisms tipping the balance from restoration to progressive liver tissue scarring are not well understood. In the present study, we identify a mechanism in which the tumor‐suppressor gene, cylindromatosis (CYLD), confers protection from hepatocellular injury and fibrosis. Mice lacking CYLD (CYLD−/−) were highly susceptible to hepatocellular damage, inflammation, and fibrosis and revealed significantly lower hepatic HGF levels, compared to wild‐type (WT) animals. Exogenous application of HGF rescued the liver injury phenotype of CYLD−/− mice. In the absence of CYLD, gene transcription of HGF in hepatic stellate cells was repressed through binding of histone deacetylase 7 (HDAC7) to the promoter of HGF. In WT cells, CYLD removed HDAC7 from the HGF promoter and induced HGF expression. Of note, this interaction occurred independently of the deubiquitinating activity of CYLD. Conclusions: Our findings highlight a novel link between CYLD and HDAC7, offering mechanistic insight into the contribution of these proteins to progression of liver disease. Thus, through regulation of HGF level, CYLD ameliorates hepatocellular damage and liver fibrogenesis.
Market Standards in Financial Contracting: The Euro’s Effect on Choice of Law in European Debt Securities
Creators: name: Engert, Andreas
name: Hornuf, Lars
Publisher: name: Universität Regensburg
Year: 2018
Subjects: subject: Financial contracting Standardization Network effects Debt securities Economic and monetary union
subject: 330 Wirtschaft

description: The introduction of the Euro ushered in a rise to dominance of English contract law in European debt securities. Corporate issuers in the Euro zone chose English law significantly more often than a control group from other European countries. The Euro effect on choice of law is particularly strong for debt securities in local markets that, arguably, were most affected by the Euro. The Euro effect is not explained by differences in the suitability of English law compared to other laws, a change in issuer composition or debt securities types, and the greater market share of British and American underwriters. We argue that increased standardization benefits (network effects) from a boost in cross-border investment provide the best account of why English law conquered the European debt securities market.
Eviction-like resonances for satellite orbits. Application to Phobos, the main satellite of Mars
Creators: name: Vaillant, Timothée
name: Correia, Alexandre C. M.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: The motion of a satellite can experience secular resonances between the precession frequencies of its orbit and the mean motion of the host planet around the star. Some of these resonances can significantly modify the eccentricity (evection resonance) and the inclination (eviction resonance) of the satellite. In this paper, we study in detail the secular resonances that can disturb the orbit of a satellite, in particular the eviction-like ones. Although the inclination is always disturbed while crossing one eviction-like resonance, capture can only occur when the semi-major axis is decreasing. This is, for instance, the case of Phobos, the largest satellite of Mars, that will cross some of these resonances in the future because its orbit is shrinking owing to tidal effects. We estimate the impact of resonance crossing in the orbit of the satellite, including the capture probabilities, as a function of several parameters, such as the eccentricity and the inclination of the satellite, and the obliquity of the planet. Finally, we use the method of the frequency map analysis to study the resonant dynamics based on stability maps, and we show that some of the secular resonances may overlap, which leads to chaotic motion for the inclination of the satellite.
description: Accepted for publication in Astronomy & Astrophysics
Projectivity of the moduli space of vector bundles on a curve
Creators: name: Alper, Jarod
name: Belmans, Pieter
name: Bragg, Daniel
name: Liang, Jason
name: Tajakka, Tuomas
Publisher: name: arXiv
Year: 2022
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics

description: We discuss the projectivity of the moduli space of semistable vector bundles on a curve of genus $g\geq 2$. This is a classical result from the 1960s, obtained using geometric invariant theory. We outline a modern approach that combines the recent machinery of good moduli spaces with determinantal line bundle techniques. The crucial step producing an ample line bundle follows an argument by Faltings with improvements by Esteves-Popa. We hope to promote this approach as a blueprint for other projectivity arguments.
description: 31 pages, expository article, accepted for publication in Stacks Project Expository Collection, to be published by Cambridge University Press, London Mathematical Society Lecture Note Series
Periodic excitations of bilinear quantum systems
Creators: name: Chambrion, Thomas
Publisher: name: arXiv
Year: 2011
Subjects: subject: Optimization and Control (math.OC)
subject: Systems and Control (eess.SY)
subject: Mathematical Physics (math-ph)
subject: Analysis of PDEs (math.AP)
subject: Quantum Physics (quant-ph)
subject: FOS: Mathematics
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Physical sciences

description: A well-known method of transferring the population of a quantum system from an eigenspace of the free Hamiltonian to another is to use a periodic control law with an angular frequency equal to the difference of the eigenvalues. For finite dimensional quantum systems, the classical theory of averaging provides a rigorous explanation of this experimentally validated result. This paper extends this finite dimensional result, known as the Rotating Wave Approximation, to infinite dimensional systems and provides explicit convergence estimates.
description: Available online http://www.sciencedirect.com/science/article/pii/S0005109812002865
Decreased protein binding of moxifloxacin in patients with sepsis?
Creators: name: Dorn, Christoph
name: Nowak, Hartmuth
name: Weidemann, Caroline
name: Martini, Stefan
name: Zeitlinger, Markus
name: Adamzik, Michael
name: Kees, Frieder K.
Publisher: name: Universität Regensburg
Year: 2017
Subjects: subject: fluoroquinolone, unbound fraction, ultrafiltration, septic shock
subject: 615 Pharmazie

description: The mean (SD) unbound fraction of moxifloxacin in plasma from patients with severe sepsis or septic shock was determined by ultrafiltration to 85.5±3.0% (range 81.9 and 91.6%) indicating a decreased protein binding of moxifloxacin in this population compared with the value of 58–60% provided in the Summary of Product Characteristics. However, previous investigations neglected the influence of pH and temperature on the protein binding of moxifloxacin. Maintaining physiological conditions (pH 7.4, 37°C) – as in the present study – the unbound fraction of moxifloxacin in plasma from healthy volunteers was 84%. In contrast, the unbound fraction of moxifloxacin was 77% at 4°C and 66–68% in unbuffered plasma or at pH 8.5 in fair agreement with previously published data. PK/PD parameters e.g. fAUC/MIC or ratios between interstitial fluid and free plasma concentrations, which were obtained assuming a protein binding rate of moxifloxacin of 40% or more, should be revised.
Third-party fecal microbiota transplantation following allo-HCT reconstitutes microbiome diversity
Creators: name: DeFilipp, Z.
name: Peled, J. U.
name: Li, S.
name: Mahabamunuge, J.
name: Dagher, Z.
name: Slingerland, A. E.
name: Del Rio, C.
name: Valles, B.
name: Kempner, M. E.
name: Smith, M.
name: Brown, J.
name: Dey, B. R.
name: El-Jawahri, A.
name: McAfee, S. L.
name: Spitzer, T. R.
name: Ballen, K. K.
name: Sung, A. D.
name: Dalton, T. E.
name: Messina, J. A.
name: Dettmer, Katja
name: Liebisch, G.
name: Oefner, Peter J.
name: Taur, Y.
name: Pamer, E. G.
name: Holler, E.
name: Mansour, M. K.
name: van den Brink, M. R. M.
name: Hohmann, E.
name: Jenq, R. R.
name: Chen, Y. B.
Publisher: name: Universität Regensburg
Year: 2018
Subjects: subject: 610 Medizin

description: We hypothesized that third-party fecal microbiota transplantation (FMT) may restore intestinal microbiome diversity after allogeneic hematopoietic cell transplantation (allo-HCT). In this open-label single-group pilot study, 18 subjects were enrolled before allo-HCT and planned to receive third-party FMT capsules. FMT capsules were administered no later than 4 weeks after neutrophil engraftment, and antibiotics were not allowed within 48 hours before FMT. Five patients did not receive FMT because of the development of early acute gastrointestinal (GI) graft-versus-host disease (GVHD) before FMT (n = 3), persistent HCT-associated GI toxicity (n = 1), or patient decision (n = 1). Thirteen patients received FMT at a median of 27 days (range, 19-45 days) after HCT. Participants were able to swallow and tolerate all FMT capsules, meeting the primary study endpoint of feasibility. FMT was tolerated well, with 1 treatment-related significant adverse event (abdominal pain). Two patients subsequently developed acute GI GVHD, with 1 patient also having concurrent bacteremia. No additional cases of bacteremia occurred. Median follow-up for survivors is 15 months (range, 13-20 months). The Kaplan-Meier estimates for 12-month overall survival and progression-free survival after FMT were 85% (95% confidence interval, 51%-96%) and 85% (95% confidence interval, 51%-96%), respectively. There was 1 nonrelapse death resulting from acute GI GVHD (12-month nonrelapse mortality, 8%; 95% confidence interval, 0%-30%). Analysis of stool composition and urine 3-indoxyl sulfate concentration indicated improvement in intestinal microbiome diversity after FMT that was associated with expansion of stool-donor taxa. These results indicate that empiric third-party FMT after allo-HCT appears to be feasible, safe, and associated with expansion of recipient microbiome diversity. This trial was registered at www.clinicaltrials.gov as #NCT02733744.
Requirements for Data Quality Metrics
Creators: name: Heinrich, Bernd
name: Klier, Mathias
name: Hristova, Diana
name: Schiller, Alexander Paul Rudolf
name: Szubartowicz, Michael
Publisher: name: Universität Regensburg
Year: 2018
Subjects: subject: Data Quality, data Quality assessment, data Quality metrics, requirement for metrics
subject: 330 Wirtschaft

description: Data quality and especially the assessment of data quality have been intensively discussed in research and practice alike. To support an economically oriented management of data quality and decision making under uncertainty, it is essential to assess the data quality level by means of well-founded metrics. However, if not adequately defined, these metrics can lead to wrong decisions and economic losses. Therefore, based on a decision-oriented framework, we present a set of five requirements for data quality metrics. These requirements are relevant for a metric that aims to support an economically oriented management of data quality and decision making under uncertainty. We further demonstrate the applicability and efficacy of these requirements by evaluating five data quality metrics for different data quality dimensions. Moreover, we discuss practical implications when applying the presented requirements.
A Lamperti-type representation of continuous-state branching processes with immigration
Creators: name: Caballero, M. Emilia
name: Garmendia, José Luis Pérez
name: Bravo, Gerónimo Uribe
Publisher: name: arXiv
Year: 2010
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics

description: Guided by the relationship between the breadth-first walk of a rooted tree and its sequence of generation sizes, we are able to include immigration in the Lamperti representation of continuous-state branching processes. We provide a representation of continuous-state branching processes with immigration by solving a random ordinary differential equation driven by a pair of independent Levy processes. Stability of the solutions is studied and gives, in particular, limit theorems (of a type previously studied by Grimvall, Kawazu and Watanabe and by Li) and a simulation scheme for continuous-state branching processes with immigration. We further apply our stability analysis to extend Pitman's limit theorem concerning Galton-Watson processes conditioned on total population size to more general offspring laws.
description: Published in at http://dx.doi.org/10.1214/12-AOP766 the Annals of Probability (http://www.imstat.org/aop/) by the Institute of Mathematical Statistics (http://www.imstat.org)
Deep Impact: Optical Spectroscopy and Photometry Obtained at MIRA
Creators: name: Walker, Russell G.
name: Weaver, Wm. Bruce
name: Shane, W. W.
name: Babcock, Arthur
Publisher: name: arXiv
Year: 2022
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present spectroscopic and high-precision photometric observations, spanning the optical UV to the far red, before, during, and after the NASA Deep Impact event of July 4, 2005. The inner 2000 km of the pre and post-impact coma was about 0.3 magnitude redder in B-R than in the outer coma. The pre-impact spectrum was a faint reflected solar spectrum dominated by molecular emissions extending > 40000 km from the nucleus. The post-impact light curve in R and I showed a rapid rise consistent with an expanding optically thick cloud during the first 18 minutes after impact. During the next 8 minutes the cloud became optically thin. Sixty minutes after impact the impact R-band flux reached a plateau at 7.5 x 10-15 erg cm-2 s-1 Å-1, the comet brightening by a factor of ~4.3 above its pre-impact value observed in a 15" aperture. The mean expansion velocity of the grains during the first 49 minutes was 229 {\pm} 49 m s-1. The spectrum became dominated by scattered sunlight during the first hour after impact. The volume scattering function (VSF) observed 32 minutes after impact shows strong reddening. At 49 minutes, however, the VSF shows an additional two-fold increase in the blue but only a 20 per-cent increase at 5500Å. Post-impact spectra and R-I photometry showed rapid reddening. The particle size distribution, dominated by 1 to 2.5 micron particles shortly after impact, changed dramatically during the first hour due to sublimation of water-ice particles of this size. On the night following impact the comet was still substantially brighter than before impact, but R-I had returned to its pre-impact value. B-R remained significantly redder. The ejecta 25 hours after impact was fan-shaped subtending ~180° roughly symmetrical about position angle 225°. The mean expansion velocity 90° from the direction to the Sun was 185° 12 m s-1.
description: 11 pages, 16 figures, 2 Appendices; original submission
Regression of high dimensional angular momentum states of light
Creators: name: Zia, Danilo
name: Checchinato, Riccardo
name: Suprano, Alessia
name: Giordani, Taira
name: Polino, Emanuele
name: Innocenti, Luca
name: Ferraro, Alessandro
name: Paternostro, Mauro
name: Spagnolo, Nicolò
name: Sciarrino, Fabio
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: Machine Learning (cs.LG)
subject: Optics (physics.optics)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: The Orbital Angular Momentum (OAM) of light is an infinite-dimensional degree of freedom of light with several applications in both classical and quantum optics. However, to fully take advantage of the potential of OAM states, reliable detection platforms to characterize generated states in experimental conditions are needed. Here, we present an approach to reconstruct input OAM states from measurements of the spatial intensity distributions they produce. To obviate issues arising from intrinsic symmetry of Laguerre-Gauss modes, we employ a pair of intensity profiles per state projecting it only on two distinct bases, showing how this allows to uniquely recover input states from the collected data. Our approach is based on a combined application of dimensionality reduction via principal component analysis, and linear regression, and thus has a low computational cost during both training and testing stages. We showcase our approach in a real photonic setup, generating up-to-four-dimensional OAM states through a quantum walk dynamics. The high performances and versatility of the demonstrated approach make it an ideal tool to characterize high dimensional states in quantum information protocols.
Observation of Hysteretic Transport Due to Dynamic Nuclear Spin Polarization in a GaAs Lateral Double Quantum Dot
Creators: name: Kobayashi, Takashi
name: Hitachi, Kenichi
name: Sasaki, Satoshi
name: Muraki, Koji
Publisher: name: arXiv
Year: 2011
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We report a new transport feature in a GaAs lateral double quantum dot that emerges only for magnetic field sweeps and shows hysteresis due to dynamic nuclear spin polarization (DNP). This DNP signal appears in the Coulomb blockade regime by virtue of the finite inter-dot tunnel coupling and originates from the crossing between ground levels of the spin triplet and singlet extensively used for nuclear spin manipulations in pulsed gate experiments. The unexpectedly large signal intensity is suggestive of unbalanced DNP between the two dots, which opens up the possibility of controlling electron and nuclear spin states via DC transport.
description: 5 pages, 4 figures
Supervised learning of random quantum circuits via scalable neural networks
Creators: name: Cantori, S.
name: Vitali, D.
name: Pilati, S.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Machine Learning (cs.LG)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Predicting the output of quantum circuits is a hard computational task that plays a pivotal role in the development of universal quantum computers. Here we investigate the supervised learning of output expectation values of random quantum circuits. Deep convolutional neural networks (CNNs) are trained to predict single-qubit and two-qubit expectation values using databases of classically simulated circuits. These circuits are represented via an appropriately designed one-hot encoding of the constituent gates. The prediction accuracy for previously unseen circuits is analyzed, also making comparisons with small-scale quantum computers available from the free IBM Quantum program. The CNNs often outperform the quantum devices, depending on the circuit depth, on the network depth, and on the training set size. Notably, our CNNs are designed to be scalable. This allows us exploiting transfer learning and performing extrapolations to circuits larger than those included in the training set. These CNNs also demonstrate remarkable resilience against noise, namely, they remain accurate even when trained on (simulated) expectation values averaged over very few measurements.
description: 17+ pages, 18 figures
Vortex pairing and mixing in stratified shear flows
Creators: name: Dong, Wenjing
Publisher: name: University of British Columbia
Year: 2017

description: Kelvin-Helmholtz (KH) instabilities are an important source of mixing in oceans, lakes and the atmosphere. The process of vortex pairing can increase the amount of mixing. First, the effects of initial conditions on vortex pairing and mixing are studied by running Direct Numerical Simulations with a variety of initial perturbations. It is shown that when the subharmonic component of the perturbation is out of phase relative to the KH mode, vortex pairing is delayed or even eliminated. The amount of mixing in the simulations where the subharmonic mode is out of phase is approximately half of that in the simulations where the subharmonic mode is in phase. The time of pairing is also found to be sensitive to the phase of the subharmonic mode. A slight change of the phase can change time of pairing significantly when the subharmonic mode is close to being out of phase. Second, the effects of Prandtl number on KH instabilities, vortex pairing and mixing are studied. It is found that KH instabilities and vortex pairing are suppressed at higher Prandtl numbers, which tends to reduce the amount of mixing. This effect is counteracted by enhanced three-dimensional motions in higher Prandtl number flows. However, the general trend is for mixing and mixing efficiency to decrease as Prandtl number is increased.
Evidence for cooperative Na+ and Cl- binding by strongly hydrated L-​proline
Creators: name: Dmitrieva, Olga A.
name: Fedotova, Marina V.
name: Buchner, Richard
Publisher: name: Universität Regensburg
Year: 2017
Subjects: subject: proline hydration chloride sodium cooperative binding
subject: 540 Chemie

description: In Nature, L-proline (Pro) is a ubiquitous and highly effective osmolyte protecting cells against osmotic stress. To understand this effect, knowledge of the hydration of Pro and its interactions with dissolved salts is essential. We studied these properties by combining statistical mechanics and broadband dielec. spectroscopy and found that Pro remains strongly hydrated up to high amino acid concns. This is also the case upon NaCl addn. to a 0.6M Pro soln. Here, addnl. a ProÂ·NaCl aggregate is formed with a stability const. of KÂ° â‰ˆ 0.95...1.25 M-1, where Na+ and Cl- cooperatively bind to adjacent carboxylate-oxygen and ammonium-hydrogen atoms, resp.
On Generalized WKB Expansion of Monodromy Generating Function
Creators: name: Klimov, Roman
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mathematical Physics (math-ph)
subject: High Energy Physics - Theory (hep-th)
subject: Algebraic Geometry (math.AG)
subject: Symplectic Geometry (math.SG)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We study symplectic properties of the monodromy map of the Schrödinger equation on a Riemann surface with a meromorphic potential having second-order poles. At first, we discuss the conditions for the base projective connection, which induces its own set of Darboux homological coordinates, to imply the Goldman Poisson structure on the character variety. Using this result, we extend the paper [Theoret. and Math. Phys. 206 (2021), 258-295, arXiv:1910.07140], by performing generalized WKB expansion of the generating function of monodromy symplectomorphism (the Yang-Yang function) and computing its first three terms.
Craniofacial features of obese obstructive sleep apnea (OSA) patients in relation to the obesity onset
Creators: name: Al Furiji, Samah Nasser
Publisher: name: University of British Columbia
Year: 2017

description: Objectives: Obstructive Sleep Apnea prevalence is substantially higher in men and subjects with higher body mass indexed. OSA is present in 41% of individuals with a BMI>28 kg/m², and in up to 78% in morbidly obese patients. Obesity alone is not the sole cause of OSA and craniofacial morphology is also a key determinant of the predisposition to airway collapse. There is still controversial data on the craniofacial characteristics of obese OSA patients and we hypothesize that the age when individuals become obese, can affect the craniofacial features of obese OSA patients. Methods: The prospective sample consisted of 39 obese and 43 non-obese OSA adults matched for age and OSA severity from a retrospective cohort. The age of obesity onset was determined through a questionnaire and diagnosis of craniofacial and airway morphology was made from standard cephalometric radiographs. Result: Twelve early obese, 21 late obese and 29 non-obese OSA patients were deemed eligible for this study. The mean age was 45.6, 50.9 and 48.1 years for early, late and non-obese groups, respectively. Non-obese OSA, compared to obese subjects, showed a significantly more retrognathic mandible, larger maxillo-mandibular discrepancy, shorter lower facial height, deeper overbite, less upper incisors proclination and protrusion, longer soft palate, higher position of hyoid bone, narrower inferior airway space, longer airway length and less obtuse head posture. The early obesity group, compared to non-obese, showed a prognathic mandible, longer lower facial height, more proclined upper incisors, caudally positioned hyoid bone, wider inferior airway space and shorter airway length. The late obesity group, compared to non-obese group, showed a proclined and protrusive upper incisors, shallower overbite, inferiorly positioned hyoid bone, shorter airway length and obtuse cranio-cervical angle. There was no significant difference between early and late obesity groups. Conclusion: Obese OSA patients have more developed craniofacial skeletons with less bony and airway constriction than their non-obese counterparts; and early and late obesity groups showed discrepancies in their characteristics which were different from non-obese subjects, suggesting a possible impact of obesity onset on craniofacial characteristics. Further studies are still needed to determine the effect of obesity onset on craniofacial development.
Transport of multispecies ion crystals through a junction in an RF Paul trap
Creators: name: Burton, William Cody
name: Estey, Brian
name: Hoffman, Ian M.
name: Perry, Abigail R.
name: Volin, Curtis
name: Price, Gabriel
Publisher: name: arXiv
Year: 2022
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We report on the first demonstration of transport of a multispecies ion crystal through a junction in an RF Paul trap. The trap is a two-dimensional surface-electrode trap with an X junction and segmented control electrodes to which time-varying voltages are applied to control the shape and position of potential wells above the trap surface. We transport either a single $^{171}$Yb$^+$ ion or a crystal composed of a $^{138}$Ba$^+$ ion cotrapped with the $^{171}$Yb$^+$ ion to any port of the junction. We characterize the motional excitation by performing multiple round-trips through the junction and back to the initial well position without cooling. The final excitation is then measured using sideband asymmetry. For a single $^{171}$Yb$^+$ ion, transport with a $4\;\mathrm{m/s}$ average speed induces between $0.013\pm0.001$ and $0.014\pm0.001$ quanta of excitation per round trip, depending on the exit port. For a Ba-Yb crystal, transport at the same speed induces between $0.013\pm0.001$ and $0.030\pm0.002$ quanta per round trip of excitation to the axial center of mass mode. Excitation in the axial stretch mode ranges from $0.005\pm0.001$ to $0.021\pm0.001$ quanta per round trip.
description: 6 pages, 4 figures, plus 2 page supplement
Entangling photons via the double quantum Zeno effect
Creators: name: Brinke, Nicolai ten
name: Osterloh, Andreas
name: Schützhold, Ralf
Publisher: name: arXiv
Year: 2011
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We propose a scheme for entangling two photons via the quantum Zeno effect, which describes the inhibition of quantum evolution by frequent measurements and is based on the difference between summing amplitudes and probabilities. For a given error probability $P_{\rm error}$, our scheme requires that the one-photon loss rate $ξ_{1γ}$ and the two-photon absorption rate $ξ_{2γ}$ in some medium satisfy $ξ_{1γ}/ξ_{2γ}=2P_{\rm error}^2/π^2$, which is significantly improved in comparison to previous approaches. Again based on the quantum Zeno effect, as well as coherent excitations, we present a possibility to fulfill this requirement in an otherwise linear optics set-up.
description: 4 pages RevTeX, 2 figures
Phishing Attacks Detection -- A Machine Learning-Based Approach
Creators: name: Salahdine, Fatima
name: Mrabet, Zakaria El
name: Kaabouch, Naima
Publisher: name: arXiv
Year: 2022
Subjects: subject: Cryptography and Security (cs.CR)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Phishing attacks are one of the most common social engineering attacks targeting users emails to fraudulently steal confidential and sensitive information. They can be used as a part of more massive attacks launched to gain a foothold in corporate or government networks. Over the last decade, a number of anti-phishing techniques have been proposed to detect and mitigate these attacks. However, they are still inefficient and inaccurate. Thus, there is a great need for efficient and accurate detection techniques to cope with these attacks. In this paper, we proposed a phishing attack detection technique based on machine learning. We collected and analyzed more than 4000 phishing emails targeting the email service of the University of North Dakota. We modeled these attacks by selecting 10 relevant features and building a large dataset. This dataset was used to train, validate, and test the machine learning algorithms. For performance evaluation, four metrics have been used, namely probability of detection, probability of miss-detection, probability of false alarm, and accuracy. The experimental results show that better detection can be achieved using an artificial neural network.
description: 2021 IEEE 12th Annual Ubiquitous Computing, Electronics & Mobile Communication Conference (UEMCON)
Revisiting the wire medium: a resonant metalens
Creators: name: Lemoult, Fabrice
name: Lerosey, Geoffroy
name: Fink, Mathias
Publisher: name: arXiv
Year: 2010
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: This article is the first one in a series of two dealing with the concept of "resonant metalens" we recently introduced [Phys. Rev. Lett. 104, 203901 (2010)]. Here, we focus on the physics of a medium with finite dimensions consisting on a square lattice of parallel conducting wires arranged on a sub-wavelength scale. This medium supports electromagnetic fields that vary much faster than the operating wavelength. We show that such modes are dispersive due to the finiteness of the medium. Their dispersion relation is established in a simple way, a link with designer plasmons is made, and the canalization phenomenon is reinterpreted at the light of our model. We explain how to take advantage of this dispersion in order to code sub-wavelength wave fields in time. Finally, we show that the resonant nature of the medium ensures an efficient coupling of these modes with free space propagating waves and, thanks to the Purcell effect, with a source placed in the near field of the medium.
Infinitely transitive actions on real affine suspensions
Creators: name: Kuyumzhiyan, Karine
name: Mangolte, Frédéric
Publisher: name: arXiv
Year: 2010
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics

description: A group G acts infinitely transitively on a set Y if for every positive integer m, its action is m-transitive on Y. Given a real affine algebraic variety Y of dimension greater than or equal to two, we show that, under a mild restriction, if the special automorphism group of Y (the group generated by one-parameter unipotent subgroups) is infinitely transitive on each connected component of the smooth locus of Y, then for any real affine suspension X over Y, the special automorphism group of X is infinitely transitive on each connected component of the smooth locus of X. This generalizes a recent result by Arzhantsev, Kuyumzhiyan and Zaidenberg over the field of real numbers.
RV-exoplanet eccentricities: Good, Beta, and Best
Creators: name: Stevenson, A. T.
name: Haswell, C. A.
name: Faria, J. P.
name: Barnes, J. R.
name: Barstow, J. K.
name: Dickinson, H.
name: Standing, M. R.
Publisher: name: arXiv
Year: 2025
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: We examine the eccentricity distribution(s) of radial velocity detected exoplanets. Previously, the eccentricity distribution was found to be described well by a Beta distribution with shape parameters $a=0.867, b=3.03$. Increasing the sample size by a factor of 2.25, we find that the CDF regression method now prefers a mixture model of Rayleigh + Exponential distributions over the Beta distribution, with an increase in Bayesian evidence of $Δ\ln{Z}\sim 77$ ($12.6\,σ$). Using PDF regression, the eccentricity distribution is best described by a Gamma distribution, with a Rayleigh + Exponential mixture a close second. The mixture model parameters, $α= 0.68\pm0.05, λ=3.32\pm0.25, σ=0.11\pm0.01$, are consistent between methods. We corroborate findings that exoplanet eccentricities are drawn from independent parent distributions when splitting the sample by period, mass, and multiplicity. Systems with a known outer massive companion provide no positive evidence for an eccentricity distribution distinct from those without. We quantitatively show M-dwarf hosted planets share a common eccentricity distribution with those orbiting FGK-type stars. We release our python code, eccentriciPy, which allows bespoke tailoring of the input archive to create more relevant priors for particular problems in RV planet discovery and characterisation. We re-characterised example planets using either traditional Beta, or updated priors, finding differences for recovery of low-amplitude multi-signal systems. We explore the effects of a variety of prior choices. The accurate determination of small but non-zero eccentricity values has wide-ranging implications for modelling the structure and evolution of planets and their atmospheres due to the energy dissipated by tidal flexing.
description: 28 pages, 22 figures, 13 tables. Accepted for publication in MNRAS
A closed formula for the asymptotic expansion of the Bergman kernel
Creators: name: Xu, Hao
Publisher: name: arXiv
Year: 2011
Subjects: subject: Differential Geometry (math.DG)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: We prove a graph theoretic closed formula for coefficients in the Tian-Yau-Zelditch asymptotic expansion of the Bergman kernel. The formula is expressed in terms of the characteristic polynomial of the directed graphs representing Weyl invariants. The proof relies on a combinatorial interpretation of a recursive formula due to M. Englis and A. Loi.
description: 25 pages, final version, Comm. Math. Phys