cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Profile and scaling of the fractal exponent of percolations in complex networks
Creators: name: Hasegawa, Takehisa
name: Nogawa, Tomoaki
name: Nemoto, Koji
Publisher: name: arXiv
Year: 2010
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Physics and Society (physics.soc-ph)
subject: FOS: Physical sciences

description: We propose a novel finite size scaling analysis for percolation transition observed in complex networks. While it is known that cooperative systems in growing networks often undergo an infinite order transition with inverted Berezinskii-Kosterlitz-Thouless singularity, it is very hard for numerical simulations to determine the transition point precisely. Since the neighbor of the ordered phase is not a simple disordered phase but a critical phase, conventional finite size scaling technique does not work. In our finite size scaling, the forms of the scaling functions for the order parameter and the fractal exponent determine the transition point and critical exponents numerically for an infinite order transition as well as a standard second order transition. We confirm the validity of our scaling hypothesis through Monte-Carlo simulations for bond percolations in some network models: the decorated (2,2)-flower and the random attachment growing network, where an infinite order transition occurs, and the configuration model, where a second order transition occurs.
description: 6 pages
Calcitonin gene-related peptide is a stimulator of renin secretion
Creators: name: Kurtz, Armin
name: Muff, R.
name: Born, W.
name: Lundberg, J. M.
name: Millberg, B. I.
name: Gnädinger, M. P.
name: Uehlinger, D. E.
name: Weidmann, P.
name: Hökfelt, T.
name: Fischer, J. A.
Publisher: name: Universität Regensburg
Year: 1988
Subjects: subject: 570 Biowissenschaften, Biologie
subject: 610 Medizin
subject: Animals
subject: Calcitonin/genetics
subject: Calcitonin Gene-Related Peptide
subject: Cyclic AMP/metabolism
subject: Fluorescent Antibody Technique
subject: Humans
subject: Infusions, Intravenous
subject: Juxtaglomerular Apparatus/cytology
subject: Kidney Cortex/metabolism
subject: Male
subject: Nerve Fibers/analysis
subject: Neuropeptides/pharmacology
subject: Rats
subject: Renin/secretion

description: Calcitonin gene-related peptide (CGRP) was found to stimulate renin secretion in vivo in normal human volunteers. Moreover, CGRP stimulated the release of renin in vitro from isolated rat renal juxtaglomerular cells (half-maximal effective concentration [EC50] 100 nM) concomitant with stimulation of cAMP production (EC50 60 nM). Immunoreactive CGRP was recognized in rat renal cortical nerve fibers, and intact rat CGRP was identified in extracts of the rat renal cortex. Because CGRP containing sensory nerve fibers are seen in the region of the juxtaglomerular apparatus, it would seem that the release of CGRP from these afferent nerves may be involved in the physiological control of renin secretion.
Lamb Shift in Light Muonic Atoms - Revisited
Creators: name: Borie, E.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: In connection with recent and proposed experiments, and new theoretical results, my previous calculations of the Lamb shift in muonic hydrogen will be reviewed and compared with other work. In addition, numerical results for muonic deuterium and helium will be presented. Some previously neglected (but very small) effects are included.
description: 41 pages. This paper has appeared in Annals of Physics, vol. 327, pp 733-763 (2012). The present version has corrected several misprints, and updated some references to take into account new results
Fast separations by capillary electrophoresis hyphenated to electrospray ionization time-of-flight mass spectrometry as a tool for arsenic speciation analysis
Creators: name: Niegel, Claudia
name: Pfeiffer, Simon A.
name: Grundmann, Marco
name: Arroyo-Abad, Uriel
name: Mattusch, Jürgen
name: Matysik, Frank-Michael
Publisher: name: Universität Regensburg
Year: 2012
Subjects: subject: 540 Chemie

description: Fast capillary electrophoresis (CE) hyphenated to time-of-flight mass spectrometry (TOF-MS) of four organoarsenic species (glycerol oxoarsenosugar, sulfate oxoarsenosugar, arsenobetaine, arsenocholine) are presented using short length CE capillaries under high electric field strengths of up to 1.3 kV cm−1 with small inner diameter (ID). The separation of arsenosugars by CE is demonstrated for the first time. An aqueous formic acid solution was employed as the background electrolyte (BGE) for the separation. Various acid concentrations were evaluated for their influence on migration times, separation efficiency as well as with regard to controlling the charge of the arsenic species. A 0.1 M formic acid/ammonium formate buffer (pH 2.8) proved to be suitable for the separation of the four species. A non-aqueous BGE was tested as an alternative buffer system for fast speciation analysis. Separation of arsenobetaine and arsenocholine could even be achieved within 10 s by pressure-assisted CE. Application of the optimized method for the analysis of extracts of a seagrass and a Wakame algae sample as well as the brown algae homogenate reference material IAEA-140/TM revealed a clear signal for the glycerol arsenosugar.
title: Extrapolationsmethoden zur Lösung parabolischer Gleichungen
Creators: name: Schneider, Stefan-Alexander
Publisher: name: Hochschule für angewandte Wissenschaften Kempten
Year: 2024
Subjects: subject: 51 Mathematik

description: Das vorliegende Arbeit ist die abschließende Zusammenfassug der Diplomarbeit mit dem Titel Extrapolationsmethoden zur Lösung parabolischer Gleichungen.
High-pressure structural phase transitions in CuWO4
Creators: name: Ruiz-Fuertes, J.
name: Errandonea, D.
name: Lacomba-Perales, R.
name: Segura, A.
name: Gonzalez, J.
name: Rodriguez, F.
name: Manjon, F. J.
name: Ray, S.
name: Rodriguez-Hernandez, P.
name: Munoz, A.
name: Zhu, Zh.
name: Tu, C. Y.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: We study the effects of pressure on the structural, vibrational, and magnetic behavior of cuproscheelite. We performed powder x-ray diffraction and Raman spectroscopy experiments up to 27 GPa as well as ab initio total-energy and lattice-dynamics calculations. Experiments provide evidence that a structural phase transition takes place at 10 GPa from the low-pressure triclinic phase (P-1) to a monoclinic wolframite-type structure (P2/c). Calculations confirmed this finding and indicate that the phase transformation involves a change in the magnetic order. In addition, the equation of state for the triclinic phase is determined: V0 = 132.8(2) A3, B0 = 139 (6) GPa and = 4. Furthermore, experiments under different stress conditions show that non-hydrostatic stresses induce a second phase transition at 17 GPa and reduce the compressibility of CuWO4, B0 = 171(6) GPa. The pressure dependence of all Raman modes of the triclinic and high-pressure phases is also reported and discussed.
description: 33 pages, 9 figures, 5 tables
Increased plasma viscosity as a reason for inappropriate erythropoietin formation
Creators: name: Singh, A.
name: Eckardt, Kai-Uwe
name: Zimmermann, A.
name: Götz, Karlheinz
name: Hamann, M.
name: Ratcliffe, P. J.
name: Kurtz, Armin
name: Reinhart, W. H.
Publisher: name: Universität Regensburg
Year: 1993
Subjects: subject: 570 Biowissenschaften, Biologie
subject: 610 Medizin
subject: Adult
subject: Aged
subject: Animals
subject: Blood Pressure
subject: Blood Viscosity
subject: Erythropoietin/genetics
subject: Exchange Transfusion, Whole Blood
subject: Female
subject: Hematocrit
subject: Humans
subject: Kidney/metabolism
subject: Male
subject: Middle Aged
subject: Multiple Myeloma/blood
subject: Oxygen/blood
subject: RNA, Messenger/metabolism
subject: Rats
subject: Rats, Sprague-Dawley
subject: Rats, Wistar
subject: Waldenstrom Macroglobulinemia/blood

description: The aim of this study was to examine whether altered plasma viscosity could contribute to the inappropriately low production rate of erythropoietin (EPO) observed in patients suffering from hypergammaglobulinemias associated with multiple myeloma or Waldenström's disease. We found that the EPO formation in response to anemia in these patients was inversely related to plasma viscosity. A similar inverse relationship between plasma viscosity and EPO production was seen in rats in which EPO formation had been stimulated by exchange transfusion and the plasma viscosity of which was thereby altered by using exchange solutions of different composition to alter plasma viscosity and thus whole blood viscosity independently from hematocrit. Raising the gammaglobulin concentration to approximately 40 mg/ml plasma in the rats almost totally blunted the rise in serum EPO levels despite a fall of the hematocrit to 20%. Determination of renal EPO mRNA levels by RNase protection revealed that the reductions in serum EPO levels at higher plasma viscosities were paralleled by reductions in renal EPO mRNA levels. Taken together, our findings suggest that plasma viscosity may be a significant inhibitory modulator of anemia-induced EPO formation. The increased plasma viscosity in patients with hypergammaglobulinemias may therefore contribute to the inappropriate EPO production, which is a major reason for the anemia developing in these patients.
Investigating the influence of risky decision making on dopaminergic reward mechanisms
Creators: name: Ferland, Jacqueline-Marie N.
Publisher: name: University of British Columbia
Year: 2017

description: Addiction is a chronic relapsing psychiatric disorder affecting millions worldwide. Despite years of research investigating the etiology and phenomenology of substance abuse, there is no cure. Determining factors which promote the addictive phenotype may help to discover new therapeutics. Several clinical studies have shown addicts demonstrate poor cost/benefit decision making as measured by validated tasks such as the Iowa Gambling Task (IGT), a cognitive deficit maintained during periods of abstinence and associated with relapse risk. However, it is unclear whether disadvantageous choice precedes or is the consequence of drug abuse. Furthermore, dopaminergic signalling, actively recruited by drugs of abuse, has also been implicated in decision-making biases, and may contribute to choice deficits after drug exposure. The experiments here explored the role of disadvantageous choice in addiction susceptibility using rodent analogues of the IGT, the rat gambling task (rGT) and cued rat gambling task (crGT). These paradigms require the animal to choose between four different nose poke options which are associated with sugar wins, probabilities of winning, and timeouts. The crGT also includes salient reward-paired cues to enhance risky decision making. The first two experiments assessed whether baseline risk-preference on the rGT and crGT affected drug seeking as measured by cocaine self-administration, and whether drug exposure affected task performance. The third study examined the influence of task experience on the locomotor response to cocaine and responding for conditioned reinforcement, two dopamine-dependent behavioural assays associated with addiction risk. Basal and cocaine-induced nucleus accumbens dopamine release was also assessed using microdialysis after task training. The final study used chemogenetics to reduce nucleus accumbens dopamine to investigate the role of dopaminergic tone in choice biases. Our results show poor decision making precedes drug exposure, and is uniquely susceptible to drug-induced cognitive deficits. crGT rats showed greater drug seeking and sensitivity to cocaine-induced choice impairments, a phenotype linked to basal accumbal dopamine efflux. Finally, by reducing accumbens dopamine, animals showed marked reductions in risky choice. These data support the conclusion that poor decision making may serve as a cognitive endophenotype for addiction via aberrant dopaminergic signaling within the mesostriatal network.
Effectiveness of Large-Language Models in Recognizing Spatially Intensive Statistical Data
Creators: name: Tharatipyakul, Atima
name: Loh, Haw Yuh
name: Perrault, Simon T.
name: WANG, Yong
name: Gastner, Michael Thorsten
Publisher: name: Singapore Institute of Technology
Year: 2024
Subjects: classificationCode: 370402
subject: Earth and space science informatics

description: A statistical quantity associated with a geographic enumeration unit is termed “intensive” if its value is, at least approximately, independent of the unit’s spatial extent. This study evaluates the ability of large language models (LLMs) to identify whether a quantity is intensive. Overall, certain combinations of LLMs, intensiveness definitions, and data descriptions performed well in the classification.
On the characteristic polynomial of the Frobenius on étale cohomology
Creators: name: Elsenhans, Andreas-Stephan
name: Jahnel, Jörg
Publisher: name: arXiv
Year: 2011
Subjects: subject: Algebraic Geometry (math.AG)
subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 14F20, 14G15, 14J20, 14J35

description: Let $X$ be a smooth proper variety of even dimension $d$ over a finite field. We establish a restriction on the value at $(-1)$ of the characteristic polynomial of the Frobenius on the middle-dimensional étale cohomology of $X$ with coefficients in ${\mathbb Q}_l(d/2)$.
description: Revised version, several minor errors corrected
Design of PtZn nanoalloy catalysts for propane dehydrogenation through interface tailoring via atomic layer deposition
Creators: name: Ingale, Piyush
name: Knemeyer, Kristian
name: Preikschas, Phil
name: Ye, Mengyang
name: Geske, Michael
name: Naumann D’Alnoncourt, Raoul
name: Thomas, Arne
name: Rosowski, Frank
Publisher: name: Technische Universität Berlin
Year: 2020
Subjects: subject: 540 Chemie und zugeordnete Wissenschaften
subject: dehydrogenation
subject: propane
subject: Pt catalysts

description: Supported Pt nanoparticles are widely used for the catalytic dehydrogenation of propane to propene. Monometallic Pt catalysts are subject to fast deactivation. A successful strategy for stabilization is alloying Pt with a second metal. In this study, we present a novel approach for the precise formation of bimetallic nanoparticles via tailoring of the interface between metal nanoparticles and the support. An ultra-thin functional layer of ZnO is deposited via atomic layer deposition on SiO2. The supported Pt nanoparticles undergo a phase transformation and form Pt1Zn1 alloy nanoparticles under reductive thermal treatment. The resulting Pt1Zn1 catalyst showed a high and stable selectivity to propene over 12 hours of time on stream. The activity of the Pt1Zn1 catalyst was 1.5 times higher than that of a catalyst of the same composition prepared by incipient wetness impregnation. The nanoalloy formation causes electronic and geometric modification of Pt which reduces side reactions and leads to a stable and active propane dehydrogenation catalyst.
Hyperbolic surface subgroups of one-ended doubles of free groups
Creators: name: Kim, Sang-hyun
name: Oum, Sang-il
Publisher: name: arXiv
Year: 2010
Subjects: subject: Group Theory (math.GR)
subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 20F65 (Primary) 57M20, 05C70 (Secondary)

description: Gromov asked whether every one-ended word-hyperbolic group contains a hyperbolic surface group. We prove that every one-ended double of a free group has a hyperbolic surface subgroup if (1) the free group has rank two, or (2) every generator is used the same number of times in the amalgamating words. To prove this, we formulate a stronger statement on Whitehead graphs and prove its specialization by combinatorial induction for (1) and the characterization of perfect matching polytopes by Edmonds for (2).
description: 30 pages, 8 figures. This version has been accepted for publication by the Journal of Topology
Gate-controlled persistent spin helix state in (In,Ga)As quantum wells
Creators: name: Kohda, M.
name: Lechner, Vera
name: Kunihashi, Y.
name: Dollinger, Tobias
name: Olbrich, Peter
name: Schönhuber, Christoph
name: Caspers, Ines
name: Belkov, Vassilij
name: Golub, Leonid
name: Weiss, Dieter
name: Richter, Klaus
name: Nitta, J.
name: Ganichev, Sergey
Publisher: name: Universität Regensburg
Year: 2012
Subjects: subject: 530 Physik
subject: 71.70.Ej, 72.25.Fe, 72.25.Rb, 73.20.Fz

description: In layered semiconductors with spin-orbit interaction (SOI) a persistent spin helix (PSH) state with suppressed spin relaxation is expected if the strengths of the Rashba and Dresselhaus SOI terms, α and β, are equal. Here we demonstrate gate control and detection of the PSH in two-dimensional electron systems with strong SOI including terms cubic in momentum. We consider strain-free InGaAs/InAlAs quantum wells and first determine a ratio α/β≃1 for nongated structures by measuring the spin-galvanic and circular photogalvanic effects. Upon gate tuning the Rashba SOI strength in a complementary magnetotransport experiment, we monitor the complete crossover from weak antilocalization via weak localization to weak antilocalization, where the emergence of weak localization reflects a PSH-type state. A corresponding numerical analysis reveals that such a PSH-type state indeed prevails even in presence of strong cubic SOI, however no longer at α=β.
New formulae for the Hubble Constant in a Euclidean Static Universe
Creators: name: Zaninetti, Lorenzo
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: It is shown that the Hubble constant can be derived from the standard luminosity function of galaxies as well as from a new luminosity function as deduced from the mass-luminosity relationship for galaxies. An analytical expression for the Hubble constant can be found from the maximum number of galaxies (in a given solid angle and flux) as a function of the redshift. A second analytical definition of the Hubble constant can be found from the redshift averaged over a given solid angle and flux. The analysis of two luminosity functions for galaxies brings to four the new definitions of the Hubble constant. The equation that regulates the Malmquist bias for galaxies is derived and as a consequence it is possible to extract a complete sample. The application of these new formulae to the data of the two-degree Field Galaxy Redshift Survey provides a Hubble constant of $( 65.26 \pm 8.22 ) \mathrm{\ km\ s}^{-1}\mathrm{\ Mpc}^{-1}$ for a redshift lower than 0.042. All the results are deduced in a Euclidean universe because the concept of space-time curvature is not necessary as well as in a static universe because two mechanisms for the redshift of galaxies alternative to the Doppler effect are invoked.
description: 27 pages 10 Figures
Computer simulation of energy transfer: Application to the photoluminescence in CdMnTe
Creators: name: Kett, H.
name: Wünsch, Friedrich
name: Gebhardt, Wolfgang
Publisher: name: Universität Regensburg
Year: 1984
Subjects: subject: 530 Physik

description: The transfer is studied on an fcc-lattice filled at random with optically active ions. The computed results for time-resolved emission are compared with experimental data.
Monte Carlo simulation of Heisenberg spin glass on FCC lattice in external magnetic field
Creators: name: Mlodzki, J.
name: Wünsch, Friedrich
name: Galazka, R. R.
Publisher: name: Universität Regensburg
Year: 1990
Subjects: subject: 530 Physik

description: The simple but realistic model described by a Heisenberg Hamiltonian with nearest neighbours and next nearest neighbours interactions in an external magnetic field was investigated by use of the Monte Carlo method. Three-dimensional vector spins of length View the MathML source were distributed randomly on a fcc lattice. Different concentrations of spins, x = 0.05, 0.10,…,0.90, were studied. For low concentrations, simulated samples contained about 1000 spins. For higher values of x the size of system was about 8000. All the computations were done for high external magnetic fields of around 3 T. During simulation, physical quantities such as magnetization, energy, specific heat and magnetic susceptibility were determined. The results for magnetization differ for the zero-field-cooled (ZFC) and field-cooled (FC) cases for the whole range of concentrations. This difference, also typical for experimental data, seems to vanish after longer simulation. From critical temperatures for computer simulated magnetization, the magnetic phase diagram was obtained and compared to experimental data for Cd1-xMnxTe. Concentration dependent results for magnetization, specific heat and magnetic susceptibility allowed one to distinguish three different regions for the simulated system: x ≤ 0.20, 0.30 ≤ x ≤ 0.60, 0.70 ≤ x ≤ 0.90.
Post-spinel transformations and equation of state in ZnGa2O4: Determination at high-pressure by in situ x-ray diffraction
Creators: name: Errandonea, D.
name: Kumar, Ravhi S.
name: Manjon, F. J.
name: Ursaki, V. V.
name: Rusu, E. V.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Geophysics (physics.geo-ph)
subject: FOS: Physical sciences

description: Room temperature angle-dispersive x-ray diffraction measurements on spinel ZnGa2O4 up to 56 GPa show evidence of two structural phase transformations. At 31.2 GPa, ZnGa2O4 undergoes a transition from the cubic spinel structure to a tetragonal spinel structure similar to that of ZnMn2O4. At 55 GPa, a second transition to the orthorhombic marokite structure (CaMn2O4-type) takes place. The equation of state of cubic spinel ZnGa2O4 is determined: V0 = 580.1(9) A3, B0 = 233(8) GPa, B0'= 8.3(4), and B0''= -0.1145 GPa-1 (implied value); showing that ZnGa2O4 is one of the less compressible spinels studied to date. For the tetragonal structure an equation of state is also determined: V0 = 257.8(9) A3, B0 = 257(11) GPa, B0'= 7.5(6), and B0''= -0.0764 GPa-1 (implied value). The reported structural sequence coincides with that found in NiMn2O4 and MgMn2O4.
description: 20 pages, 4 figures, 2 Tables
title: PERIPHERAL NEUROPATHY  OF THE OLFACTORY NERVE IN COVID-19
Creators: name: Aliyeva, Merey B.
name: Ayaganov, Dinmukhamed N.
name: Saparbayev, Samat S.
Publisher: name: Astrakhan State Medical University
Year: 2021

description: Abstract. Sudden anosmia and/or ageusia is one of the first and significant symptoms of COVID-19, which are manifested in good health and a successful course of the disease. Purpose: to analyze neurological disorders in COVID-19 and present the results of peripheral neuropathy of the olfactory nerve. We present the results of 39 (32 %) patients with olfactory dysfunction obtained among 121 patients with a positive RT-PCR test for COVID-19. The data was collected through a sur-vey and questionnaire based on the AAO-HNS anosmia reporting tool. The majority of individuals (32 patients) did not have close contact with a positive case in the recent past. Most patients regained their sense of smell within 1-2 weeks of the onset of anosmia. To date, the mechanisms of anosmia in SARS-CoV-2 are not yet clear. It remains debatable whether anosmias are the result of nerve damage or inflammation of the olfactory nerves, which requires further research. Key words: anosmia, loss of smell, dysgeusia, neuroinflammation, olfactory dysfunction, SARS-COV-2, COVID-19.
Asymptotic Granularity Reduction and Its Application
Creators: name: Su, Shenghui
name: Lv, Shuwang
name: Fan, Xiubin
Publisher: name: arXiv
Year: 2011
Subjects: subject: Computational Complexity (cs.CC)
subject: FOS: Computer and information sciences

description: It is well known that the inverse function of y = x with the derivative y' = 1 is x = y, the inverse function of y = c with the derivative y' = 0 is inexistent, and so on. Hence, on the assumption that the noninvertibility of the univariate increasing function y = f(x) with x > 0 is in direct proportion to the growth rate reflected by its derivative, the authors put forward a method of comparing difficulties in inverting two functions on a continuous or discrete interval called asymptotic granularity reduction (AGR) which integrates asymptotic analysis with logarithmic granularities, and is an extension and a complement to polynomial time (Turing) reduction (PTR). Prove by AGR that inverting y = x ^ x (mod p) is computationally harder than inverting y = g ^ x (mod p), and inverting y = g ^ (x ^ n) (mod p) is computationally equivalent to inverting y = g ^ x (mod p), which are compatible with the results from PTR. Besides, apply AGR to the comparison of inverting y = x ^ n (mod p) with y = g ^ x (mod p), y = g ^ (g1 ^ x) (mod p) with y = g ^ x (mod p), and y = x ^ n + x + 1 (mod p) with y = x ^ n (mod p) in difficulty, and observe that the results are consistent with existing facts, which further illustrates that AGR is suitable for comparison of inversion problems in difficulty. Last, prove by AGR that inverting y = (x ^ n)(g ^ x) (mod p) is computationally equivalent to inverting y = g ^ x (mod p) when PTR can not be utilized expediently. AGR with the assumption partitions the complexities of problems more detailedly, and finds out some new evidence for the security of cryptosystems.
description: 13 pages
Localization in fractal and multifractal media
Creators: name: Garcia-Garcia, Antonio M.
name: Cuevas, Emilio
Publisher: name: arXiv
Year: 2010
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Classical Physics (physics.class-ph)
subject: FOS: Physical sciences

description: The propagation of waves in highly inhomogeneous media is a problem of interest in multiple fields including seismology, acoustics and electromagnetism. It is also relevant for technological applications such as the design of sound absorbing materials or the fabrication of optically devices for multi-wavelength operation. A paradigmatic example of a highly inhomogeneous media is one in which the density or stiffness has fractal or multifractal properties. We investigate wave propagation in one dimensional media with these features. We have found that, for weak disorder, localization effects do not arrest wave propagation provided that the box fractal dimension D of the density profile is D < 3/2. This result holds for both fractal and multifractal media providing thus a simple universal characterization for the existence of localization in these systems. Moreover we show that our model verifies the scaling theory of localization and discuss practical applications of our results.
description: 4 pages, 5 figures
High-Q exterior whispering gallery modes in a metal-coated microresonator
Creators: name: Xiao, Yun-Feng
name: Zou, Chang-Ling
name: Li, Bei-Bei
name: Li, Yan
name: Dong, Chun-Hua
name: Han, Zheng-Fu
name: Gong, Qihuang
Publisher: name: arXiv
Year: 2010
Subjects: subject: Optics (physics.optics)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We propose a kind of plasmonic whispering gallery modes highly localized on the exterior surface of a metal-coated microresonator. This exterior (EX) surface mode possesses high quality factors at room temperature, and can be efficiently excited by a tapered fiber. The EX mode can couple to an interior (IN) mode and this coupling produces a strong anti-crossing behavior, which not only allows conversion of IN to EX modes, but also forms a long-lived anti-symmetric mode. As a potential application, the EX mode could be used for a biosensor with a sensitivity high up to 500 nm per refraction index unit, a large figure of merit, and a wide detection range.
Effects of optical and surface polar phonons on the optical conductivity of doped graphene
Creators: name: Scharf, Benedikt
name: Perebeinos, Vasili
name: Fabian, Jaroslav
name: Avouris, Phaedon
Publisher: name: Universität Regensburg
Year: 2013
Subjects: subject: Condensed Matter - Mesoscale and Nanoscale Physics
subject: 530 Physik

description: Using the Kubo linear response formalism, we study the effects of intrinsic graphene optical and surface polar phonons (SPPs) on the optical conductivity of doped graphene. We find that inelastic electron-phonon scattering contributes significantly to the phonon-assisted absorption in the optical gap. At room temperature, this midgap absorption can be as large as 20-25% of the universal ac conductivity for graphene on polar substrates due to strong electron-SPP coupling. The midgap absorption, moreover, strongly depends on the substrates and doping levels used. With increasing temperature, the midgap absorption increases, while the Drude peak, on the other hand, becomes broader as inelastic electron-phonon scattering becomes more probable. Consequently, the Drude weight decreases with increasing temperature.
Identification of discrete concentration graph models with one hidden binary variable
Creators: name: Stanghellini, Elena
name: Vantaggi, Barbara
Publisher: name: arXiv
Year: 2010
Subjects: subject: Methodology (stat.ME)
subject: Statistics Theory (math.ST)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: Conditions are presented for different types of identifiability of discrete variable models generated over an undirected graph in which one node represents a binary hidden variable. These models can be seen as extensions of the latent class model to allow for conditional associations between the observable random variables. Since local identification corresponds to full rank of the parametrization map, we establish a necessary and sufficient condition for the rank to be full everywhere in the parameter space. The condition is based on the topology of the undirected graph associated to the model. For non-full rank models, the obtained characterization allows us to find the subset of the parameter space where the identifiability breaks down.
description: Published in at http://dx.doi.org/10.3150/12-BEJ435 the Bernoulli (http://isi.cbs.nl/bernoulli/) by the International Statistical Institute/Bernoulli Society (http://isi.cbs.nl/BS/bshome.htm)
Energy transfer by exciton-polarons in RbMnF3
Creators: name: Wünsch, Friedrich
name: Gerhardt, V.
name: Gebhardt, Wolfgang
Publisher: name: Universität Regensburg
Year: 1987
Subjects: subject: 530 Physik

description: Energy transfer in RbMnF3 was studied by time-resolved spectroscopy of the 4T1g-exciton luminescence. The threefold orbital degeneracy of the 4T1g-state is lifted by a Jahn-Teller coupling to eg-modes. The JT-effect leaves an orientational degeneracy of distorted MnF6-octahedra, which is lifted by application of uniaxial stress. The dynamics of exciton and trap luminescence after pulse excitation was investigated with and without stress. It was found that stress reduces the excitonic transfer rate considerably. The most striking effect was obtained with [110]-stress which produced a very slow nonexponential decay of the exciton luminescence. This behavior was interpreted as evidence for [110]-stress induced 2-dimensional energy transfer.
Quantum electrodynamics in a whispering-gallery microcavity coated with a polymer nanolayer
Creators: name: Xiao, Yun-Feng
name: Zou, Chang-Ling
name: Xue, Peng
name: Xiao, Lixin
name: Li, Yan
name: Dong, Chun-Hua
name: Han, Zheng-Fu
name: Gong, Qihuang
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quasi-transverse-electric and -transverse-magnetic fundamental whispering gallery modes in a polymer-coated silica microtoroid are theoretically investigated and demonstrated to possess very high-quality factors. The existence of a nanometer-thickness layer not only evidently reduces the cavity mode volume but also draws the maximal electric field's position of the mode to the outside of the silica toroid, where single quantum dots or nanocrystals are located. Both effects result in a strongly enhanced coherent interaction between a single dipole (for example, a single defect center in a diamond crystal) and the quantized cavity mode. Since the coated microtoroid is highly feasible and robust in experiments, it may offer an excellent platform to study strong-coupling cavity quantum electrodynamics, quantum information, and quantum computation.
Towards liver shear wave vibro-elastography : method repeatability and image registration technique
Creators: name: Hemily, Julie
Publisher: name: University of British Columbia
Year: 2017

description: Liver fibrosis is a largely prevalent concern in Canada and world-wide, due to high rates of Hepatitis, fatty liver disease, alcoholism, as well as several other possible causes. It is currently diagnosed and staged by performing biopsies or by tissue elasticity measurements referred to as elastography. Elastography methods are a relatively new means of measuring the mechanical properties of soft tissue non-invasively by measuring and processing the propagation of shear waves through the body. The Robotics and Control Laboratory at the University of British Columbia has developed an elastography technique, Vibro-elastography, that can quantitatively measure soft tissue stiffness in real time. It has previously been applied to prostate and breast pathologies. It is now being developed and optimized for liver applications. To validate Vibro-elastography as a new diagnostic tool, a comparison study should be performed on a clinical population. This work sets out to lay out the prerequisites needed to implement a full clinical study. It starts out with a repeatability study using a tissue phantom to ensure repeatable results and compare our results to manufacturer stiffness values. In this work, we compare the precision of several different implementations of Vibro-elastography including the placement of the excitation source, data acquisition techniques and single versus multi-frequency excitation. Most of the implementations resulted in good, repeatable results, regardless of exciter placement. The quality of wave propagation deteriorated with depth as expected, but elasticity results remained repeatable even at deeper regions of interest. The parameters are selected and designed for the use on the liver. Finally, a registration pipeline and initial case trial has been presented as a suggested means of comparing the elastography data obtained using Vibro-elastography and any elastography measures that can be obtained from a magnetic resonance system. Using manual fiducial vessel markers and applying an Iterative Closest Point registration process results in a quick alignment of the ultrasound and MRI volumes with registration error less than 20 mm.
ИЗУЧЕНИЕ И АНАЛИЗ РОЛИ КАЛЬЦИЕВОГО ОБМЕНА И КАЛЬЦИЕВОГО ТРАНСПОРТА В РЕГУЛЯЦИИ СОКРАТИМОСТИ МИОКАРДА
Creators: name: Мадалиев, Х.А.
name: Супхонов, У.У.
name: Бариева, М.К.
name: Абдурахманов, Диёр
Publisher: name: Zenodo
Year: 2024

description: Кальций (Ca2+) является важной сигнальной молекулой в активации мышц и регуляции сократимости миокарда. В данной статье мы рассмотрим роль кальциевого обмена и кальциевого транспорта в регуляции сократимости миокарда и обсудим последние достижения в данной области исследований, механизмы, отвечающие за взаимодействие кальция с мышечными белками, а также роль кальциевого обмена в контроле концентрации кальция внутри клеток миокарда. Далее, мы рассмотрим работы, исследующие молекулярные механизмы кальциевого транспорта и влияние ионов кальция на функционирование сердца. Наконец, проанализируем последние достижения в разработке новых терапевтических подходов, направленных на воздействие на кальциевый обмен и транспорт для лечения сердечных заболеваний.
Search for same-sign top-quark pair production at sqrt(s) = 7 TeV and limits on flavour changing neutral currents in the top sector
Creators: name: CMS Collaboration
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: An inclusive search for same-sign top-quark pair production in pp collisions at sqrt(s) = 7 TeV is performed using a data sample recorded with the CMS detector in 2010, corresponding to an integrated luminosity of 35 inverse picobarns. This analysis is motivated by recent studies of p p-bar to t t-bar reporting mass-dependent forward-backward asymmetries larger than expected from the standard model. These asymmetries could be due to Flavor Changing Neutral Currents (FCNC) in the top sector induced by t-channel exchange of a massive neutral vector boson (Z'). Models with such a Z' also predict enhancement of same-sign top-pair production in pp or p p-bar collisions. Limits are set as a function of the Z' mass and its couplings to u and t quarks. These limits disfavour the FCNC interpretation of the Tevatron results.
description: Replaced with published version
The concept of drift and operationalization of its detection in simulated data
Creators: name: Roded, Keren
Publisher: name: University of British Columbia
Year: 2017

description: In this paper, the phenomenon of changes in item characteristics over time (often referred to as drift) is discussed from several theoretical perspectives, and a new procedure for the detection of Item Parameter Drift (IPD) is proposed. An initial evaluation of the utility of the proposed procedure is conducted using simulated data modeled by the 2-Parameter Logistic (2PL) Item Response Theory (IRT) model. In addition to the proposed procedure, an IPD analysis of the simulated data is conducted using two known methods: Kim, Cohen, and Park's (1995) extension of Lord's (1980) Chi-square test of Differential Item Functioning (DIF) to multiple groups, and logistic regression. The results indicate high agreement and accuracy in the detection of true IPD using the two known methods, but poor performance of the proposed procedure. Possible explanations of the findings and future directions are discussed.
Dielectric function, screening, and plasmons of graphene in the presence of spin-orbit interactions
Creators: name: Scholz, Andreas
name: Stauber, Tobias
name: Schliemann, John
Publisher: name: Universität Regensburg
Year: 2012
Subjects: subject: 530 Physik
subject: 77.22.Ch
subject: 71.45.Gm
subject: 81.05.ue

description: We study the dielectric properties of graphene in the presence of Rashba and intrinsic spin-orbit interactions in their most general form, i.e., for arbitrary frequency, wave vector, doping, and spin-orbit coupling (SOC) parameters. The main result consists in the derivation of closed analytical expressions for the imaginary as well as for the real part of the polarization function. Several limiting cases, e.g., the case of purely Rashba or purely intrinsic SOC, and the case of equally large Rashba and intrinsic coupling parameters are discussed. In the static limit the asymptotic behavior of the screened potential due to charged impurities is derived. In the opposite limit (q=0, ω→0), an analytical expression for the plasmon dispersion is obtained and afterwards compared to the numerical result. Our result can also be applied to related systems such as bilayer graphene or topological insulators.
On the topological contents of eta invariants
Creators: name: Bunke, Ulrich
Publisher: name: arXiv
Year: 2011
Subjects: subject: Algebraic Topology (math.AT)
subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 58J28

description: We discuss an universal bordism invariant obtained from the Atiyah-Patodi-Singer eta-invariant from the analytic and homotopy theoretic point of view. Classical invariants like the Adams e-invariant, $ρ$-invariants and $String$-bordism invariants are derived as special cases. The main results are a secondary index theorem about the coincidence of the analytic and topological constructions and intrinsic expressions for the bordism invariants.
description: 85 pages, 5 figures Revisions: Definition 4.2 of a geometrisation is corrected since the cohomological character may not be unique (former Lemma 4.2 is not correct). A Section 6. on the K-theory of $K(\pi,n)$-bundles was added. Proposition 6.1 replaces the former Proposition 5.15 whose proof is not correct. The construction of a geometrisation of a string manifold is revised correspondingly
THE ROLE OF THE PHENOMENON OF BILINGUALISM IN THE DEVELOPMENT OF HUMANITARIAN SCIENCES
Creators: name: Babajanov, Khusan
Publisher: name: Zenodo
Year: 2024

description: In the past decade, research investigating bilingual effects on cognitive and linguistic development has increased significantly. Bilingualism is a field of continuous growth that covers a broad range of mental and linguistic achievements. Through most of the 20th century, bilingualism was assumed to threaten normal language development and impair cognitive achievement.
All-electrical measurements of direct spin Hall effect in GaAs with Esaki diode electrodes
Creators: name: Ehlert, Markus
name: Song, Cheng
name: Ciorga, Mariusz
name: Utz, Martin
name: Schuh, Dieter
name: Bougeard, Dominique
name: Weiss, Dieter
Publisher: name: Universität Regensburg
Year: 2012
Subjects: subject: 530 Physik
subject: 72.25.Dc, 72.25.Rb, 85.75.-d, 75.50.Pp

description: We report on measurements of direct spin Hall effect in a lightly n-doped GaAs channel with conductivity below 2000 Ω−1 m−1. As spin detecting contacts, we employed highly efficient ferromagnetic Fe/(Ga,Mn)As/GaAs Esaki diode structures. We investigate bias and temperature dependence of the measured spin Hall signal and evaluate the value of total spin Hall conductivity and its dependence on channel conductivity and temperature. From the results, we determine skew scattering and side-jump contribution to the total spin Hall conductivity and compare it with the results of experiments on higher conductive n-GaAs channels [ Garlid, Hu, Chan, Palmstrøm and Crowell Phys. Rev. Lett. 105 156602 (2010)]. As a result, we conclude that both skewness and side jump contribution cannot be treated as fully independent of the conductivity of the channel.
nnSVG for the identification of spatially variable genes and improved computational analyses of spatial transcriptomic data from postmortem brain tissue
Creators: name: Weber, Lukas M
Publisher: name: Zenodo
Year: 2023

description: Poster presented at the Annual Meeting of the American College of Neuropsychopharmacology (ACNP) 2023, Tampa, FL, USA, December 3-6, 2023
Mean curvature self-shrinkers of high genus: Non-compact examples
Creators: name: Kapouleas, Nikolaos
name: Kleene, Stephen J.
name: Møller, Niels Martin
Publisher: name: arXiv
Year: 2011
Subjects: subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 53C44, 35J15

description: We give the first rigorous construction of complete, embedded self-shrinking hypersurfaces under mean curvature flow, since Angenent's torus in 1989. The surfaces exist for any sufficiently large prescribed genus $g$, and are non-compact with one end. Each has $4g+4$ symmetries and comes from desingularizing the intersection of the plane and sphere through a great circle, a configuration with very high symmetry. Each is at infinity asymptotic to the cone in $\mathbb{R}^3$ over a $2π/(g+1)$-periodic graph on an equator of the unit sphere $\mathbb{S}^2\subseteq\mathbb{R}^3$, with the shape of a periodically "wobbling sheet". This is a dramatic instability phenomenon, with changes of asymptotics that break much more symmetry than seen in minimal surface constructions. The core of the proof is a detailed understanding of the linearized problem in a setting with severely unbounded geometry, leading to special PDEs of Ornstein-Uhlenbeck type with fast growth on coefficients of the gradient terms. This involves identifying new, adequate weighted Hölder spaces of asymptotically conical functions in which the operators invert, via a Liouville-type result with precise asymptotics.
description: 41 pages, 1 figure; minor typos fixed; to appear in J. Reine Angew. Math
Series Prediction based on Algebraic Approximants
Creators: name: Homeier, Herbert H. H.
Publisher: name: Universität Regensburg
Year: 2011
Subjects: subject: 510 Mathematik

description: It is described how the Hermite-Padé polynomials corresponding to an algebraic approximant for a power series may be used to predict coefficients of the power series that have not been used to compute the Hermite-Padé polynomials. A recursive algorithm is derived, and some numerical examples are given.
description: Article ID 958968
'In the future will people travel and live in space?' - Big Questions Investigation Card
Creators: name: Stone, Phil
name: Billingsley, Berry
Publisher: name: Zenodo
Year: 2022
Subjects: epistemic insight
primary science
primary education
multidisciplinary
cross-curricular learning

description: The Epistemic Insight “Investigating Big Questions” Discovery Bags contain a variety of scientific equipment and resources to help students ‘think like a scholar’. This Investigation Card focuses on space, in which students make a 'to scale' diagram of the solar system and consider whether humans could really travel deep into space to live and work. Students are encouraged to think about this scenario from a range of disciplines, including science, to determine the benefits and drawbacks put forward by different disciplinary perspectives.
Energy transfer between Jahn-Teller systems in RbMnF3
Creators: name: Wünsch, Friedrich
name: Gebhardt, Wolfgang
Publisher: name: Universität Regensburg
Year: 1989
Subjects: subject: 530 Physik
subject: 71.70.Ej
subject: 71.20.Ps
subject: 78.47.-p
subject: 63.20.-e
subject: 71.35.-y

description: Energy transfer in RbMnF3 was studied by time-resolved spectroscopy of 4T1g exciton and trap luminescence. Uniaxial stress was used to lift the orientational degeneracy of the Jahn-Teller distorted MnF6 octahedra. Stress also reduces the excitonic transfer rates considerably. The most drastic reduction of transfer and a nonexponential decay was observed with (110) stress. Evidence for two-dimensional transfer under (110) stress is given by computer simulation of random-walk processes and by a calculation of nearest-neighbour transfer integrals.
Clarithromycin, ein neues Makrolid-Antibiotikum. Wirksamkeit bei puerperalen Infektionen und Übertritt in die Muttermilch [Clarithromycin, a new macrolide antibiotic. Effectiveness in puerperal infections and pharmacokinetics in breast milk]
Creators: name: Sedlmayr, T.
name: Petersen, F.
name: Raasch, W.
name: Kees, Frieder K.
Publisher: name: Universität Regensburg
Year: 1993
Subjects: subject: 615 Pharmazie
subject: Administration, Oral
subject: Adult
subject: Clarithromycin/pharmacokinetics
subject: Endometritis/drug therapy
subject: Episiotomy
subject: Female
subject: Humans
subject: Milk, Human/metabolism
subject: Puerperal Infection/drug therapy
subject: Pyelonephritis/drug therapy
subject: Surgical Wound Infection/drug therapy

description: The aims of this study were, to determine the pharmacokinetic parameters of clarithromycin and to study the passage of the drug into breast milk. Twelve patients (age 24 to 38; weight 44 to 83 kg), suffering from puerperal infections, were treated orally with 250 mg clarithromycin b.i.d. for 6 days. Samples of blood and breast milk were taken at timed intervals. The specimens were assayed for clarithromycin and its active metabolite 14-hydroxy-clarithromycin by HPLC and electrochemical detection. Serum concentrations of clarithromycin in the investigated patients were higher than those reported in healthy volunteers. The mean peak concentrations of clarithromycin and 14-hydroxy-clarithromycin in breast milk were about 25%, and 75% respectively of the corresponding serum concentrations. All patients recovered within 2 to 4 days and no drug-associated side effects (eg. gastrointestinal) were noted. Clarithromycin appears to be an appropriate antibiotic for the treatment of puerperal infections and (because of its considerable concentrations in breast milk) for puerperal mastitis as well.