cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Machine Learning Models in Stock Market Prediction
Creators: name: Singh, Gurjeet
Publisher: name: arXiv
Year: 2022
Subjects: subject: Statistical Finance (q-fin.ST)
subject: Machine Learning (cs.LG)
subject: FOS: Economics and business
subject: FOS: Computer and information sciences

description: The paper focuses on predicting the Nifty 50 Index by using 8 Supervised Machine Learning Models. The techniques used for empirical study are Adaptive Boost (AdaBoost), k-Nearest Neighbors (kNN), Linear Regression (LR), Artificial Neural Network (ANN), Random Forest (RF), Stochastic Gradient Descent (SGD), Support Vector Machine (SVM) and Decision Trees (DT). Experiments are based on historical data of Nifty 50 Index of Indian Stock Market from 22nd April, 1996 to 16th April, 2021, which is time series data of around 25 years. During the period there were 6220 trading days excluding all the non trading days. The entire trading dataset was divided into 4 subsets of different size-25% of entire data, 50% of entire data, 75% of entire data and entire data. Each subset was further divided into 2 parts-training data and testing data. After applying 3 tests- Test on Training Data, Test on Testing Data and Cross Validation Test on each subset, the prediction performance of the used models were compared and after comparison, very interesting results were found. The evaluation results indicate that Adaptive Boost, k- Nearest Neighbors, Random Forest and Decision Trees under performed with increase in the size of data set. Linear Regression and Artificial Neural Network shown almost similar prediction results among all the models but Artificial Neural Network took more time in training and validating the model. Thereafter Support Vector Machine performed better among rest of the models but with increase in the size of data set, Stochastic Gradient Descent performed better than Support Vector Machine.
Race, area deprivation index, and access to surgical burn care in a pediatric population in North Carolina
Creators: name: Holloway, Alexa
name: Akinkuotu, Adesola
name: Charles, Anthony
name: Gallaher, Jared R
name: Williams, Felicia
Publisher: name: Elsevier
Year: 2023

description:
BACKGROUND: Burns represent a leading cause of morbidity and mortality for children. This study explores the intersecting effects of social deprivation and race in pediatric burn patients. METHODS: We performed a retrospective review of all pediatric patients (<18 years old) admitted to a tertiary burn center in North Carolina from 2009 to 2019. We used bivariate analysis to compare patients based on reported race, comparing African Americans (AA) to all others. Modified Poisson regression was used to model the probability of undergoing autologous skin grafting based on AA race. RESULTS: Of 4227 children admitted, AA children were disproportionally represented, comprising 33.7% of patients versus a state population of 22.3%. AA patients had larger %TBSA with a median of 3% (IQR 1-6) compared to 2% (IQR 1-5, p < 0.001) and longer median length of stay at 5.8 days (SD 13.6) versus 4.9 days (SD 13.8). AA patients were more likely to have autologous skin grafting compared to other races, with an adjusted RR of 1.49 (95% CI 1.22-1.83) when controlling for Area Deprivation Index (ADI) national rank, age, %TBSA, and burn type. CONCLUSIONS: AA children were disproportionately represented and had larger burns, even when controlling for ADI. They had longer hospital stays and were more likely to have autologous skin grafting, even accounting for burn size and type. The intersection between social deprivation and race creates a unique risk for AA patients. Further investigation into this phenomenon and factors underlying surgical intervention selection are indicated to inform best treatment practices and future preventative strategies.
Dynamic vacuum variable and equilibrium approach in cosmology
Creators: name: Klinkhamer, F. R.
name: Volovik, G. E.
Publisher: name: arXiv
Year: 2008
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Astrophysics (astro-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: A modified-gravity theory is considered with a four-form field strength F, a variable gravitational coupling parameter G(F), and a standard matter action. This theory provides a concrete realization of the general vacuum variable q as the four-form amplitude F and allows for a study of its dynamics. The theory gives a flat Friedmann-Robertson-Walker universe with rapid oscillations of the effective vacuum energy density (cosmological "constant"), whose amplitude drops to zero asymptotically. Extrapolating to the present age of the Universe, the order of magnitude of the average vacuum energy density agrees with the observed near-critical vacuum energy density of the present universe. It may even be that this type of oscillating vacuum energy density constitutes a significant part of the so-called cold dark matter in the standard Friedmann-Robertson-Walker framework.
description: 24 (not 25) pages, v7(=v6 with latex problem corrected): published version in preprint style
NI4OS-Europe First report on provider and repository integration
Creators: name: Dusan Vudragovic
name: Klemencic, Brina
name: Athenodorou, Andreas
name: Jovanovic, Petar
name: Mishev, Anastas
name: Prnjat, Ognjen
name: Koumantaros, Kostas
name: Radonjic, Milutin
Publisher: name: Zenodo
Year: 2021

description: First report on provider and repository integration - presents the current resource and provider on-boarding status. The deliverable gives details on the on-boarding procedure and reports fully and partially integrated repositories, thematic and generic services, as well as services from the pre-production environment.
Supersymmetric Wilson Loops in N=6 Super Chern-Simons-matter theory
Creators: name: Chen, Bin
name: Wu, Jun-Bao
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study supersymmetric Wilson loop operators in ABJM theory from both sides of the AdS_4/CFT_3 correspondence. We first construct some supersymmetric Wilson loops. The perturbative computations are performed in the field theory side at the first two orders. A fundamental string solution ending on a circular loop is also studied.
description: 21 pages, 6 figures; v2: minor changes; v3, 21 pages, 4 figures, major revisions, published version
Biaxial nematic and smectic phases of parallel particles with different cross sections
Creators: name: Martinez-Raton, Yuri
name: Varga, Szabolcs
name: Velasco, Enrique
Publisher: name: arXiv
Year: 2008
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We have calculated the phase diagrams of one--component fluids made of five types of biaxial particles differing in their cross sections. The orientation of the principal particle axis is fixed in space, while the second axis is allowed to freely rotate. We have constructed a free-energy density functional based on fundamental--measure theory to study the relative stability of nematic and smectic phases with uniaxial, biaxial and tetratic symmetries. Minimization of the density functional allows us to study the phase behavior of the biaxial particles as a function of the cross-section geometry. For low values of the aspect ratio of the particle cross section, we obtain smectic phases with tetratic symmetry, although metastable with respect to the crystal, as our MC simulation study indicates. For large particle aspect ratios and in analogy with previous work [Phys. Chem. Chem. Phys. 5, 3700 (2003)], we have found a four--phase point where four spinodals, corresponding to phase transitions between phases with different symmetries, meet together. The location of this point is quite sensitive to particle cross section, which suggests that optimizing the particle geometry could be a useful criterion in the design of colloidal particles that can exhibit an increased stability of the biaxial nematic phase with respect to other competing phases with spatial order.
description: 13 pages, 12 figures, submitted to PRE
Impacts of natural disasters on supply chain performance
Creators: name: Burkhardt, Mariana
Publisher: name: KIT Scientific Publishing
Year: 2021
Subjects: Risiko
Risikomanagement
Naturkatastrophen
Supply Chains
Perfomance
Risk
Risk Management
Natural Disasters
Performance

description: Considering the increasing importance of natural disaster events it is inevitable to also focus on their impacts on supply chains as well as their performance impacts on them. The developed approach SCperformND (Supply Chain performance impact assessment of Natural Disasters) demonstrates a methodology to assess those impacts and gives implications for supply chain designs and procurement decisions.
GeV-radio correlation in Markarian 421
Creators: name: Sliusar, Vitalii
name: Walter, Roland
name: Balbo, Matteo
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Markarian 421 (Mrk 421) is a high-synchrotron-peaked blazar showing relentless variability across the electromagnetic spectrum from radio to gamma-rays. We use over 7-years of radio and GeV observations to study the correlation and connected variability in radio and GeV bands. Radio data was obtained in a 15GHz band by the OVRO 40-m radio telescope, and GeV data is from Fermi Large Area Telescope. To determine the location of the gamma-ray emission regions in Mrk 421 we correlate GeV and radio light curves. We found that GeV light curve varies independently and accurately leads the variations observed in radio. Using a fast-rise-slow-decay profile derived for shock propagation within a conical jet, we manage to reproduce the radio light curve from GeV variations. The profile rise time is comparable with the Fermi-LAT binning the decay time is about 7.6 days. The best-fit value for the response profile also features a 44 days delay between the GeV and radio, which is compatible with the wide lag range obtained from the correlation. Such a delay corresponds to $10^{17}$ cm/c, which is comparable with the apparent light crossing time of the Mrk 421 radio core. Generally, the observed variability matches the predictions of the leptonic models and suggests that the physical conditions vary in the jet. The emitting region moving downstream the jet, while the environment becomes first transparent to gamma rays and later to the radio.
description: 7 pages, 3 figures, 1 table
Axions and the cooling of white dwarf stars
Creators: name: Isern, J.
name: Garcia-Berro, E.
name: Torres, S.
name: Catalan, S.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: White dwarfs are the end-product of the lifes of intermediate- and low-mass stars and their evolution is described as a simple cooling process. Recently, it has been possible to determine with an unprecedented precision their luminosity function, that is, the number of stars per unit volume and luminosity interval. We show here that the shape of the bright branch of this function is only sensitive to the averaged cooling rate of white dwarfs and we propose to use this property to check the possible existence of axions, a proposed but not yet detected weakly interacting particle. Our results indicate that the inclusion of the emission of axions in the evolutionary models of white dwarfs noticeably improves the agreement between the theoretical calculations and the observational white dwarf luminosity function. The best fit is obtained for m_a cos^2 β~ 5 meV, where m_a is the mass of the axion and cos^2 βis a free parameter. We also show that values larger than 10 meV are clearly excluded. The existing theoretical and observational uncertainties do not allow yet to confirm the existence of axions, but our results clearly show that if their mass is of the order of few meV, the white dwarf luminosity function is sensitive enough to detect their existence.
description: 4 pages, 4 figures, replaced with version accepted by The Astrophysical Journal Letters
Port impact studies : comparison and evaluation of existing methods
Creators: name: Kaufmann, Gabriele
Publisher: name: University of British Columbia
Year: 2010

description: Since the early 1960's, a great number of port impact studies have been conducted. Little assessment has been done of the methodologies used to conduct the port impact studies. This thesis compares and evaluates the main aspects of the methodology of port impact studies using two criteria: 1) the informational value of the results obtained with different methods; 2) comparison of relative costs for the implementation of the different methods. The thesis reviews twenty port impact studies to determine the main methodological approaches to port impact analysis. The thesis then discusses four main aspects of the methodology used in the individual port impact studies. The first of these aspects is the determination of the size and regional and personal incidence of transportation cost savings occurring in the regional economy (due to the utilization of low cost water-transportation services). An assessment follows of the measures used in the individual port impact studies to measure primary and secondary port impacts. The study then discusses the determination of the primary impact. The last aspect of the methodology discussed is the determination of the multiplier effect initiated by the primary port impact activities (i.e. secondary port impact). The conclusion of this thesis evaluates the use of information obtained in a port impact study for the establishment of a port policy. The studies reviewed were conducted between 1961 and 1976. Eighteen of the twenty port impact studies were carried out in the United States, one in Canada, and one in West Germany. Nineteen of the port impact studies had similar methodologies, while one of them differed significantly. This thesis isolates both theoretical and practical problems in the conduct of a port impact study. The thesis identifies two prime areas of research to improve the informational value of port impact studies. They are: 1) opportunity cost; and 2) external economies.
ALMA Observations of Lyman-alpha Blob 1: Multiple major-mergers and widely distributed interstellar media
Creators: name: Umehata, Hideki
name: Smail, Ian
name: Steidel, Charles C.
name: Hayes, Matthew
name: Scott, Douglas
name: Swinbank, A. M.
name: Ivison, R. J.
name: Nagao, Toru
name: Kubo, Mariko
name: Nakanishi, Kouichiro
name: Matsuda, Yuichi
name: Ikarashi, Soh
name: Tamura, Yoichi
name: Geach, J. E.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We present observations of a giant Lyman-alpha blob in the SSA22 proto-cluster at z=3.1, SSA22-LAB1, taken with the Atacama Large Millimeter/submillimeter Array (ALMA). Dust continuum, along with [C II]158um, and CO(4-3) line emission have been detected in LAB1, showing complex morphology and kinematics across a ~100 kpc central region. Seven galaxies at z=3.0987-3.1016 in the surroundings are identified in [C II] and dust continuum emission, with two of them potential companions or tidal structures associated with the most massive galaxies. Spatially resolved [C II] and infrared luminosity ratios for the widely distributed media (L[C II]/LIR~0.01-0.001) suggest that the observed extended interstellar media are likely to have originated from star-formation activity and the contribution from shocked gas is probably not dominant. LAB1 is found to harbour a total molecular gas mass Mmol=(8.7+/-2.0)e+10 Msun, concentrated in the core region of the Ly-alpha-emitting area. While (primarily obscured) star-formation activity in the LAB1 core is one of the most plausible power sources for the Ly-alpha emission, multiple major-mergers found in the core may also play a role in making LAB1 exceptionally bright and extended in Ly-alpha as a result of cooling radiation induced by gravitational interactions.
description: 23 pages, 11 figures, accepted for publication in ApJ
Phase diagram and complexity of mode-locked lasers: from order to disorder
Creators: name: Leuzzi, L.
name: Conti, C.
name: Folli, V.
name: Angelani, L.
name: Ruocco, G.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Optics (physics.optics)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: We investigate mode-locking processes in lasers displaying a variable degree of structural randomness, from standard optical cavities to multiple-scattering media. By employing methods mutuated from spin-glass theory, we analyze the mean-field Hamiltonian and derive a phase-diagram in terms of the pumping rate and the degree of disorder. Three phases are found: i) paramagnetic, corresponding to a noisy continuous wave emission, ii) ferromagnetic, that describes the standard passive mode-locking, and iii) the spin-glass in which the phases of the electromagnetic field are frozen in a exponentially large number of configurations. The way the mode-locking threshold is affected by the amount of disorder is quantified. The results are also relevant for other physical systems displaying a random Hamiltonian, like Bose-Einstein condensates and nonlinear optical beams.
description: 4 pages, 2 figures
Superconductivity in a Hubbard-Froehlich Model and in cuprates
Creators: name: Hardy, T. M.
name: Hague, J. P.
name: Samson, J. H.
name: Alexandrov, A. S.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Using the variational Monte-Carlo method we find that a relatively weak long-range electron-phonon interaction induces a d-wave superconducting state of doped Mott-Hubbard insulators and/or strongly-correlated metals with a condensation energy significantly larger than can be obtained with Coulomb repulsion only. Moreover, the superconductivity is shown to exist for infinite on-site Coulomb repulsion, removing the requirement for additional mechanisms such as spin fluctuations to mediate d-wave superconductivity. We argue that the superconducting state is robust with respect to a more intricate choice of the trial function and that the true origin of high-temperature superconductivity lies in a proper combination of strong electron-electron correlations with poorly screened Froehlich electron-phonon interaction.
description: 4 pages, 4 figures
Stirring Strongly Coupled Plasma
Creators: name: Fadafan, Kazem Bitaghsir
name: Liu, Hong
name: Rajagopal, Krishna
name: Wiedemann, Urs Achim
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We determine the energy it takes to move a test quark along a circle of radius L with angular frequency w through the strongly coupled plasma of N=4 supersymmetric Yang-Mills (SYM) theory. We find that for most values of L and w the energy deposited by stirring the plasma in this way is governed either by the drag force acting on a test quark moving through the plasma in a straight line with speed v=Lw or by the energy radiated by a quark in circular motion in the absence of any plasma, whichever is larger. There is a continuous crossover from the drag-dominated regime to the radiation-dominated regime. In the crossover regime we find evidence for significant destructive interference between energy loss due to drag and that due to radiation as if in vacuum. The rotating quark thus serves as a model system in which the relative strength of, and interplay between, two different mechanisms of parton energy loss is accessible via a controlled classical gravity calculation. We close by speculating on the implications of our results for a quark that is moving through the plasma in a straight line while decelerating, although in this case the classical calculation breaks down at the same value of the deceleration at which the radiation-dominated regime sets in.
description: 27 pages LaTex, 5 figures
Patient sex, racial and ethnic disparities in emergency department triage: A multi-site retrospective study
Creators: name: Cheng, Qian
name: Argon, Nilay T
name: Murphy, Laura
name: Linthicum, Benjamin
name: Liu, Yufeng
name: Evans, Christopher S
name: Ziya, Serhan
name: Patel, Mehul D
name: Mehrotra, Abhi
name: Lin, Peter
Publisher: name: Elsevier
Year: 2023

description:
OBJECTIVES: There is limited evidence on sex, racial, and ethnic disparities in Emergency Department (ED) triage across diverse settings. We evaluated differences in the assignment of Emergency Severity Index (ESI) by patient sex and race/ethnicity, accounting for age, clinical factors, and ED operating conditions. METHODS: We conducted a multi-site retrospective study of adult patients presenting to high-volume EDs from January 2019-February 2020. Patient-level data were obtained and analyzed from three EDs (academic, metropolitan community, and rural community) affiliated with a large health system in the Southeastern United States. For the study outcome, ESI levels were grouped into three categories: 1-2 (highest acuity), 3, and 4-5 (lowest acuity). Multinomial logistic regression was used to compare ESI categories by patient race/ethnicity and sex jointly (referent = White males), adjusted for patient age, insurance status, ED arrival mode, chief complaint category, comorbidity score, time of day, day of week, and average ED wait time. RESULTS: We identified 186,840 eligible ED visits with 56,417 from the academic ED, 69,698 from the metropolitan community ED, and 60,725 from the rural community ED. Patient cohorts between EDs varied by patient age, race/ethnicity, and insurance status. The majority of patients were assigned ESI 3 in the academic and metropolitan community EDs (61% and 62%, respectively) whereas 47% were assigned ESI 3 in the rural community ED. In adjusted analyses, White females were less likely to be assigned ESI 1-2 compared to White males although both groups were roughly comparable in the assignment of ESI 4-5. Non-White and Hispanic females were generally least likely to be assigned ESI 1-2 in all EDs. Interactions between ED wait time and race/ethnicity-sex were not statistically significant. CONCLUSIONS: This retrospective study of adult ED patients revealed sex and race/ethnicity-based differences in ESI assignment, after accounting for age, clinical factors, and ED operating conditions. These disparities persisted across three different large EDs, highlighting the need for ongoing research to address inequities in ED triage decision-making and associated patient-centered outcomes.
Pulsations in the atmosphere of the rapidly oscillating Ap star 10 Aquilae
Creators: name: Sachkov, M.
name: Kochukhov, O.
name: Ryabchikova, T.
name: Huber, D.
name: Leone, F.
name: Bagnulo, S.
name: Weiss, W. W.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The rapidly oscillating Ap (roAp) star 10 Aql shows one of the lowest photometric pulsation amplitudes and is characterized by an unusual spectroscopic pulsational behavior compared to other roAp stars. More than 1000 spectra were taken during 7 nights over a time span of 21 days with high-resolution spectrographs at the 8-m ESO VLT and 3.6-m TNG telescopes giving access to radial velocity variations of about 150 lines from different chemical species. A comparison of pulsation signatures in lines formed at different atmospheric heights allowed us to resolve the vertical structure of individual pulsation modes in 10 Aql which is the first time for a multiperiodic roAp star. The inferred propagation of pulsation waves in 10 Aql is qualitatively similar to other roAp stars: pulsation amplitudes become measurable in the layers where Y and Eu are concentrated, increase in layers where the Halpha core is formed, reach a maximum of 200-300 m/s in the layers probed by Ce, Sm, Dy lines and then decrease to 20-50 m/s in the layers where NdIII and PrIII lines are formed. A unique pulsation feature of 10 Aql is a second pulsation maximum indicated by TbIII lines which form in the uppermost atmospheric layers and oscillate with amplitudes of up to 350 m/s. The dramatic decline of pulsations in the atmospheric layers probed by the strong PrIII and NdIII lines accounts for the apparent peculiarity of 10 Aql when compared to other roAp stars. The phase-amplitude diagrams and bisector measurements of the NdIII 5102 A line reveal a rapid change of phase and amplitude with height for all three main pulsation modes, indicating the presence of a pulsation node in the stellar atmosphere. (abridged)
description: 17 pages, 10 figures; accepted for publication in MNRAS
Quantum Phase Diagram of Bosons in Optical Lattices
Creators: name: Santos, F. E. A. dos
name: Pelster, A.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We work out two different analytical methods for calculating the boundary of the Mott-insulator-superfluid (MI-SF) quantum phase transition for scalar bosons in cubic optical lattices of arbitrary dimension at zero temperature which improve upon the seminal mean-field result. The first one is a variational method, which is inspired by variational perturbation theory, whereas the second one is based on the field-theoretic concept of effective potential. Within both analytical approaches we achieve a considerable improvement of the location of the MI-SF quantum phase transition for the first Mott lobe in excellent agreement with recent numerical results from Quantum Monte-Carlo simulations in two and three dimensions. Thus, our analytical results for the whole quantum phase diagram can be regarded as being essentially exact for all practical purposes.
Dynamics of protein-protein encounter: a Langevin equation approach with reaction patches
Creators: name: Schluttig, Jakob
name: Alamanova, Denitsa
name: Helms, Volkhard
name: Schwarz, Ulrich S.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Biomolecules (q-bio.BM)
subject: Subcellular Processes (q-bio.SC)
subject: FOS: Biological sciences

description: We study the formation of protein-protein encounter complexes with a Langevin equation approach that considers direct, steric and thermal forces. As three model systems with distinctly different properties we consider the pairs barnase:barstar, cytochrome c:cytochrome c peroxidase and p53:MDM2. In each case, proteins are modeled either as spherical particles, as dipolar spheres or as collection of several small beads with one dipole. Spherical reaction patches are placed on the model proteins according to the known experimental structures of the protein complexes. In the computer simulations, concentration is varied by changing box size. Encounter is defined as overlap of the reaction patches and the corresponding first passage times are recorded together with the number of unsuccessful contacts before encounter. We find that encounter frequency scales linearly with protein concentration, thus proving that our microscopic model results in a well-defined macroscopic encounter rate. The number of unsuccessful contacts before encounter decreases with increasing encounter rate and ranges from 20-9000. For all three models, encounter rates are obtained within one order of magnitude of the experimentally measured association rates. Electrostatic steering enhances association up to 50-fold. If diffusional encounter is dominant (p53:MDM2) or similarly important as electrostatic steering (barnase:barstar), then encounter rate decreases with decreasing patch radius. More detailed modeling of protein shapes decreases encounter rates by 5-95 percent. Our study shows how generic principles of protein-protein association are modulated by molecular features of the systems under consideration. Moreover it allows us to assess different coarse-graining strategies for the future modelling of the dynamics of large protein complexes.
Self-consistent calculations within the Green's function method including particle-phonon coupling and the single-particle continuum
Creators: name: Lyutorovich, N.
name: Speth, J.
name: Avdeenkov, A.
name: Gruemmer, F.
name: Kamerdzhiev, S.
name: Krewald, S.
name: Tselyaev, V. I.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The Green's function method in the \emph{Quasiparticle Time Blocking Approximation} is applied to nuclear excitations in $^{132}$Sn and $^{208}$Pb. The calculations are performed self-consistently using a Skyrme interaction. The method combines the conventional RPA with an exact single-particle continuum treatment and considers in a consistent way the particle-phonon coupling. We reproduce not only the experimental values of low- and high-lying collective states but we also obtain fair agreement with the data of non-collective low-lying states that are strongly influenced by the particle-phonon coupling.
description: 6 pages, 9 figures, documentclass{svjour}
Basic properties of nonsmooth Hormander's vector fields and Poincare's inequality
Creators: name: Bramanti, Marco
name: Brandolini, Luca
name: Pedroni, Marco
Publisher: name: arXiv
Year: 2008
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 53C17, 46E35, 26D10

description: We consider a family of vector fields defined in some bounded domain of R^p, and we assume that they satisfy Hormander's rank condition of some step r, and that their coefficients have r-1 continuous derivatives. We extend to this nonsmooth context some results which are well-known for smooth Hormander's vector fields, namely: some basic properties of the distance induced by the vector fields, the doubling condition, Chow's connectivity theorem, and, under the stronger assumption that the coefficients belong to C^{r-1,1}, Poincare's inequality. By known results, these facts also imply a Sobolev embedding. All these tools allow to draw some consequences about second order differential operators modeled on these nonsmooth Hormander's vector fields.
description: 60 pages, LaTeX; Section 6 added and Section 7 (6 in the previous version) changed. Some references added
Sharp change over from compound nuclear fission to shape dependent quasi fission
Creators: name: Ghosh, T. K.
name: Banerjee, K.
name: Bhattacharya, C.
name: Bhattacharya, S.
name: Kundu, S.
name: Mali, P.
name: Meena, J. K.
name: Mukherjee, G.
name: Mukhopadhyay, S.
name: Rana, T. K.
name: Bhattacharya, P.
name: Golda, K. S.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: Fission fragment mass distribution has been measured from the decay of $^{246}$Bk nucleus populating via two entrance channels with slight difference in mass asymmetries but belonging on either side of the Businaro Gallone mass asymmetry parameter. Both the target nuclei were deformed. Near the Coulomb barrier, at similar excitation energies the width of the fission fragment mass distribution was found to be drastically different for the $^{14}$N + $^{232}$Th reaction compared to the $^{11}$B + $^{235}$U reaction. The entrance channel mass asymmetry was found to affect the fusion process sharply.
description: 4 pages,6 figures
The very massive binary NGC3603-A1
Creators: name: Schnurr, O.
name: Moffat, A. F. J.
name: St-Louis, N.
name: Casoli, J.
name: Chené, A. -N.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Using VLT/SINFONI, we have obtained repeated AO-assisted, NIR spectroscopy of the three central WN6ha stars in the core of the very young (~1 Myr), massive and dense Galactic cluster NGC3603. One of these stars, NGC3603-A1, is a known 3.77-day, double-eclipsing binary, while another one, NGC3603-C, is one of the brightest X-ray sources among all known Galactic WR stars, which usually is a strong indication for binarity. Our study reveals that star C is indeed an 8.9-day binary, although only the WN6ha component is visible in our spectra; therefore we temporarily classify star C as an SB1 system. A1, on the other hand, is found to consist of two emission-line stars of similar, but not necessarily of identical spectral type, which can be followed over most the orbit. Using radial velocities for both components and the previously known inclination angle of the system, we are able to derive absolute masses for both stars in A1. We find M_1 = (116 \pm 31) Mo for the primary and M_2 = (89 \pm 16) Mo for the secondary component of A1. While uncertainties are large, A1 is intrinsically half a magnitude brighter than WR20a, the current record holder with 83 and 82 Mo, respectively; therefore, it is likely that the primary in A1 is indeed the most massive star weighed so far.
description: 5 pages, 4 figures; accepted for MNRAS Letters
Time-dependent version of cryptohermitian quantum theory
Creators: name: Znojil, Miloslav
Publisher: name: arXiv
Year: 2008
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: For many quantum models an apparent non-Hermiticity of observables corresponds to their hidden Hermiticity in another, physical Hilbert space. For these models we show that the existence of observables which are manifestly time-dependent may require the use of a manifestly time-dependent representation of the physical Hilbert space of states.
description: 14 pp
Context and Research Timeline: Acoustic Electronica - Engineering and Producing a New Jazz Aesthetic
Creators: name: Williams, Brendan
Publisher: name: University of Salford
Year: 2019
Subjects: subject: 190406 Music Composition
subject: FOS: Arts (arts, history of arts, performing arts, music)
subject: 109999 Technology not elsewhere classified
subject: FOS: Other engineering and technologies

description: Context and timeline illustrating research activities around the outputs.
Comparison of coronagraphs for high contrast imaging in the context of Extremely Large Telescopes
Creators: name: Martinez, P.
name: Boccaletti, A.
name: Kasper, M.
name: Cavarroc, C.
name: Yaitskova, N.
name: Fusco, T.
name: Verinaud, C.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We compare coronagraph concepts and investigate their behavior and suitability for planet finder projects with Extremely Large Telescopes (ELTs, 30-42 meters class telescopes). For this task, we analyze the impact of major error sources that occur in a coronagraphic telescope (central obscuration, secondary support, low-order segment aberrations, segment reflectivity variations, pointing errors) for phase, amplitude and interferometric type coronagraphs. This analysis is performed at two different levels of the detection process: under residual phase left uncorrected by an eXtreme Adaptive Optics system (XAO) for a large range of Strehl ratio and after a general and simple model of speckle calibration, assuming common phase aberrations between the XAO and the coronagraph (static phase aberrations of the instrument) and non-common phase aberrations downstream of the coronagraph (differential aberrations provided by the calibration unit). We derive critical parameters that each concept will have to cope with by order of importance. We evidence three coronagraph categories as function of the accessible angular separation and proposed optimal one in each case. Most of the time amplitude concepts appear more favorable and specifically, the Apodized Pupil Lyot Coronagraph gathers the adequate characteristics to be a baseline design for ELTs.
description: 12 pages, 6 figures, Accepted for publication in A&A
Site-specific symmetry sensitivity of angle-resolved photoemission spectroscopy in layered palladium diselenide
Creators: name: Cattelan, M.
name: Sayers, C. J.
name: Wolverson, D.
name: Carpene, E.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Two-dimensional (2D) materials with puckered layer morphology are promising candidates for next-generation opto-electronics devices owing to their anisotropic response to external perturbations and wide band gap tunability with the number of layers. Among them, PdSe2 is an emerging 2D transition-metal dichalcogenide with band gap ranging from 1.3 eV in the monolayer to a predicted semimetallic behavior in the bulk. Here we use angle-resolved photoemission spectroscopy to explore the electronic band structure of PdSe2 with energy and momentum resolution. Our measurements reveal the semiconducting nature of the bulk. Furthermore, constant binding-energy maps of reciprocal space display a remarkable site-specific sensitivity to the atomic arrangement and its symmetry. Supported by density functional theory calculations, we ascribe this effect to the inherent orbital character of the electronic band structure. These results not only provide a deeper understanding of the electronic configuration of PdSe2, but also establish additional capabilities of photoemission spectroscopy.
Localized states with non-trivial symmetries: localized labyrinthine patterns
Creators: name: Clerc, Marcel G.
name: Echeverría-Alar, Sebastián
name: Tlidi, Mustapha
Publisher: name: arXiv
Year: 2021
Subjects: subject: Pattern Formation and Solitons (nlin.PS)
subject: FOS: Physical sciences

description: The formation of self-organized patterns and localized states are ubiquitous in Nature. Localized states containing trivial symmetries such as stripes, hexagons, or squares have been profusely studied. Disordered patterns with non-trivial symmetries such as labyrinthine patterns are observed in different physical contexts. Here we report stable localized disordered patterns in spatially extended dissipative systems. These 2D and 3D localized structures consist of an isolated labyrinth embedded in a homogeneous steady state. Their partial bifurcation diagram allows us to explain this phenomenon as a manifestation of a pinning-depinning transition. We illustrate our findings on Swift-Hohenberg type of equations and other well-established models for plant ecology, nonlinear optics, and reaction-diffusion systems.
Symmetry-enforced topological band crossings in orthorhombic crystals: Classification and materials discovery
Creators: name: Leonhardt, Andreas
name: Hirschmann, Moritz M.
name: Heinsdorf, Niclas
name: Wu, Xianxin
name: Fabini, Douglas H.
name: Schnyder, Andreas P.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We identify all symmetry-enforced band crossings in nonmagnetic orthorhombic crystals with and without spin-orbit coupling and discuss their topological properties. We find that orthorhombic crystals can host a large number of different band degeneracies, including movable Weyl and Dirac points with hourglass dispersions, fourfold double Weyl points, Weyl and Dirac nodal lines, almost movable nodal lines, nodal chains, and topological nodal planes. Interestingly, spin-orbit coupled materials in the space groups 18, 36, 44, 45, and 46 can have band pairs with only two Weyl points in the entire Brillouin zone. This results in a simpler connectivity of the Fermi arcs and more pronounced topological responses than in materials with four or more Weyl points. In addition, we show that the symmetries of the space groups 56, 61, and 62 enforce nontrivial weak $\mathbb{Z}_2$ topology in materials with strong spin-orbit coupling, leading to helical surface states. With these classification results in hand, we perform extensive database searches for orthorhombic materials crystallizing in the relevant space groups. We find that Sr$_2$Bi$_3$ and Ir$_2$Si have bands crossing the Fermi energy with a symmetry-enforced nontrivial $\mathbb{Z}_2$ invariant, CuIrB possesses nodal chains near the Fermi energy, Pd$_7$Se$_4$ and Ag$_2$Se exhibit fourfold double Weyl points, the latter one even in the absence of spin-orbit coupling, whereas the fourfold degeneracies in AuTlSb are made up from intersecting nodal lines. For each of these examples we compute the ab-initio band structures, discuss their topologies, and for some cases also calculate the surface states.
description: 26 pages, 14 figures, supplemental material
Quark Schwinger-Dyson equation in temporal Euclidean space
Creators: name: Sauli, V.
name: Batiz, Z.
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present an elementary nonperturbative method to obtain Green's functions (GFs) for timelike momenta. We assume there are no singularities in the first and third quadrants of the complex plane of space momentum components and perform a 3d analogue of Wick rotation. This procedure defines Greens functions in a timelike Euclidean space. As an example we consider the quark propagator in QCD. While for weak coupling, this method is obviously equivalent to perturbation theory, for a realistic QCD coupling a complex part of the quark mass and renormalization wave function has been spontaneously generated even below the standard perturbative threshold. Therefore, our method favors a confinement mechanism based on the lack of real poles.
description: 11 pages, grammar and typos corrected
The role of central noradrenergic systems in morphine tolerance development
Creators: name: Klonoff, Pamela Susan
Publisher: name: University of British Columbia
Year: 2010

description: The role of noradrenaline (NA) in the behavioural and pharmacological effects of morphine was evaluated in rats. Animals received specific injections of 6-hydroxydopamine (6-OHDA) into the dorsal noradrenergic bundle (DB) resulting in selective depletion of telencephalic NA levels and increased levels of noradrenaline in the spinal cord and cerebellum. Employing changes in the hypoactive phase of morphine-induced locomotor activity as an index of tolerance development, it was observed that injection of 6-OHDA into the dorsal noradrenergic bundle resulted in a slower rate and a lesser degree of tolerance development to morphine. The effect of the DB-6-0HDA lesion on physical dependence was assessed by measuring naltrexone-induced withdrawal in lesioned and control animals who had received chronic morphine treatment. Results indicate that although NA is important in tolerance development, it does not mediate a dominant role in withdrawal, although behavioural evidence suggesting a secondary or modulatory role is presented. The interaction of amphetamine and morphine with the dopamine (DA) system was also assessed by studying the behavioural effects of amphetamine in animals following either acute or chronic morphine treatment. It was observed that amphetamine potentiated the spontaneous locomotor hyperactivity following both acute and chronic morphine treatment. The DB-6-OHDA lesion did not affect the locomotor potentiation of amphetamine in morphine pre-treated animals, and the hypothesis that another transmitter system mediates this effect, specifically DA, is discussed.
Characterizing the free-energy landscapes of DNA origamis
Creators: name: Wong, Chak Kui
name: Tang, Chuyan
name: Schreck, John S.
name: Doye, Jonathan P. K.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We show how coarse-grained modelling combined with umbrella sampling using distance-based order parameters can be applied to compute the free-energy landscapes associated with mechanical deformations of large DNA nanostructures. We illustrate this approach for the strong bending of DNA nanotubes and the potentially bistable landscape of twisted DNA origami sheets. The homogeneous bending of the DNA nanotubes is well described by the worm-like chain model; for more extreme bending the nanotubes reversibly buckle with the bending deformations localized at one or two "kinks". For a twisted one-layer DNA origami, the twist is coupled to the bending of the sheet giving rise to a free-energy landscape that has two nearly-degenerate minima that have opposite curvatures. By contrast, for a two-layer origami, the increased stiffness with respect to bending leads to a landscape with a single free-energy minimum that has a saddle-like geometry. The ability to compute such landscapes is likely to be particularly useful for DNA mechanotechnology and for understanding stress accumulation during the self-assembly of origamis into higher-order structures.
description: main (17 pages, 7 figures); Supporting Information (14 pages, 11 figures)
Supporting reproductive health among birthing persons with chronic conditions in the United States: A qualitative multilevel study using systems thinking to inform action
Creators: name: Bryant, Katherine
name: McClain, Erin
name: Verbiest, Sarah
name: Fatima, Hiba
name: Lich, Kristen Hassmiller
name: Smith, Cambray
Publisher: name: Wiley
Year: 2023

description:
OBJECTIVE (STUDY QUESTION): To use systems thinking with diverse system actors to (a) characterize current problems at the intersection of chronic conditions (CCs) and reproductive health (RH) care and their determinants, (b) determine necessary system actors for change, and (c) document cross-system actions that can improve identified problems in the United States. DATA SOURCES/STUDY SETTING: Data were collected from six groups of system actors via online focus groups. STUDY DESIGN: This is a qualitative multilevel study using the iceberg systems thinking framework. DATA COLLECTION/EXTRACTION METHODS: Data were collected by note-taking and recording six focus groups; analysis incorporated perspective triangulation using the systems thinking iceberg and system mapping to visualize interconnected system challenges, actors, and action ideas. PRINCIPAL FINDINGS: Participants described eight necessary system actors: health care institutions, medical leaders, medical providers, patient advocates and foundations, patients and families, payors, policy makers, and research funders. Forty pain points were identified, spread across each of the four levels of the systems thinking iceberg: undesirable outcomes (6), concerning trends (9), system structure flaws (15), and problematic mental models (10). In response to these pain points, a set of 46 action ideas was generated by participants and mapped into nine action themes: (1) adjust QI metrics, incentives, and reimbursement, (2) bolster RH medical education and training, (3) break down medical silos, (4) enrich patient education, (5) expand the health care team, (6) improve holistic health care, (7) modify research and programmatic funding to prioritize RH and CC, (8) spur innovation for patient visits, and (9) support professional champions and leaders. CONCLUSIONS: By embracing system complexity, creating visual maps, and pushing participants to identify actionable strategies for improvement, this study generates a set of specific actions that can be used to address pain points across the multiple system levels that make improving reproductive care for people with CCs so challenging.
A database application
Creators: name: Cyphus, Peter
Publisher: name: Loughborough University
Year: 2021
Subjects: subject: 89999 Information and Computing Sciences not elsewhere classified
subject: FOS: Computer and information sciences

description: This project is intended to satisfy several different functions. It was my intention to design a software package which would be easily understood by a wide variety of students of differing interests attending courses at a College Of Further Education. [Continues.]