cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Source of radio emissions induced by the Galilean moons Io, Europa and Ganymede: in situ measurements by Juno
Creators: name: Louis, C. K.
name: Louarn, P.
name: Collet, B.
name: Clément, N.
name: Saati, S. Al
name: Szalay, J. R.
name: Hue, V.
name: Lamy, L.
name: Kotsiaros, S.
name: Kurth, W. S.
name: Jackman, C. M.
name: Wang, Y.
name: Blanc, M.
name: Allegrini, F.
name: Connerney, J. E. P.
name: Gershman, D.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: At Jupiter, part of the auroral radio emissions are induced by the Galilean moons Io, Europa and Ganymede. Until now, except for Ganymede, they have been only remotely detected, using ground-based radio-telescopes or electric antennas aboard spacecraft. The polar trajectory of the Juno orbiter allows the spacecraft to cross the range of magnetic flux tubes which sustain the various Jupiter-satellite interactions, and in turn to sample in situ the associated radio emission regions. In this study, we focus on the detection and the characterization of radio sources associated with Io, Europa and Ganymede. Using electric wave measurements or radio observations (Juno/Waves), in situ electron measurements (Juno/JADE-E), and magnetic field measurements (Juno/MAG) we demonstrate that the Cyclotron Maser Instability (CMI) driven by a loss-cone electron distribution function is responsible for the encountered radio sources. We confirmed that radio emissions are associated with Main (MAW) or Reflected Alfvén Wing (RAW), but also show that for Europa and Ganymede, induced radio emissions are associated with Transhemispheric Electron Beam (TEB). For each traversed radio source, we determine the latitudinal extension, the CMI-resonant electron energy, and the bandwidth of the emission. We show that the presence of Alfvén perturbations and downward field aligned currents are necessary for the radio emissions to be amplified.
Synthetic incorporation of Nile Blue into DNA using 2′-deoxyriboside substitutes: Representative comparison of (R)- and (S)-aminopropanediol as an acyclic linker
Creators: name: Lachmann, Daniel
name: Berndl, Sina
name: Wolfbeis, Otto S.
name: Wagenknecht, Hans-Achim
Publisher: name: Universität Regensburg
Year: 2010
Subjects: subject: cycloaddition; fluorescence; glycol; oligonucleotide; phenoxazinium; phosphoramidite
subject: 540 Chemie

description: Open AccessThe Nile Blue chromophore was incorporated into oligonucleotides using “click” chemistry for the postsynthetic modification of oligonucleotides. These were synthesized using DNA building block 3 bearing an alkyne group and reacted with the azide 4. (R)-3-amino-1,2-propanediol was applied as the linker between the phosphodiester bridges. Two sets of DNA duplexes were prepared. One set carried the chromophore in an A-T environment, the second set in a G-C environment. Both were characterized by optical spectroscopy. Sequence-dependent fluorescence quenching was applied as a sensitive tool to compare the stacking interactions with respect to the chirality of the acyclic linker attachment. The results were compared to recent results from duplexes that carried the Nile Blue label in a sequentially and structurally identical context, except for the opposite chirality of the linker ((S)-3-amino-1,2-propandiol). Only minor, negligible differences were observed. Melting temperatures, UV–vis absorption spectra together with fluorescence quenching data indicate that Nile Blue stacks perfectly between the adjacent base pairs regardless of whether it has been attached via an S- or R-configured linker. This result was supported by geometrically optimized DNA models.
description: Open access
How Literature and Film Shape and Reflect Public Attitudes toward Genetics
Creators: name: Clayton, Jay
Publisher: name: Center for ELSI Resources and Analysis
Year: 2022
Subjects: subject: Genetics
subject: FOS: Biological sciences
subject: Ethics
subject: Science
subject: ELSI
subject: film
subject: literature
subject: public attitudes
subject: genetic enhancement

description: Powerful works of art enrich our understanding of the issues that matter most in our lives—not least in controversial areas of the biosciences. By exploring the dense cultural networks that shape science and technology, they help us see multiple dimensions of policy issues that might be opaque to other forms of analysis. Novels, from Frankenstein to Never Let me Go, have provided a space for reflection, for deepening and expanding our awareness of the impact of genetics on society. Thinking about narrative can be of special value to bioethics because of the power stories possess to immerse readers in richly imagined worlds, worlds in which the complexity of issues can be explored on multiple levels. Equally important is attending to the genre of stories, because the conventions, characters, and images that cluster around a topic both shape and reflect the assumptions shared by different communities. Tracing shifts in genre conventions can be a powerful way of revealing how people are responding to a scientific discovery. The social consequences of science depend not only on how the population at large understands genetics research but also on cultural concerns that may have little or nothing to do with the science. Literature and other symbolic forms are a guide to the hopes and fears that surround genetics. Members of the ELSI community do not have to be persuaded that language can be slippery, that buried metaphors can influence how messages are received, and that different communities often interpret texts in different ways. The ability to read critically what people write, both what they explicitly mean and what may lie beneath the surface of their words, is a valuable asset for bioethics and public policy, one that draws on the specialized training of literary scholars. This is especially true when exploring popular narratives with little claim to nuance or artistry. Distortions of the science are an ever-present problem, and it is important to urge scientists to find ways to communicate their results clearly. But long experience has shown that media hype, internet memes, personal stories, cultural myths, fictitious monsters, dystopian novels, post-apocalyptic tales, and literary slogans like “Frankenfood” and “brave new biology” can overwhelm any amount of careful language about the limitations of a research finding. The articles and chapters below have been chosen to illustrate some of the ways humanities scholarship can enrich bioethics. They are drawn from an increasingly prominent emphasis in literary and film studies on texts that engage with genetics and bioethics. Most not only provide insights into stories about genetics but also foreground how and why the analysis of cultural texts should play a role in bioethical inquiry.
Deep reinforcement learning approaches for process control
Creators: name: Pon Kumar, Steven Spielberg
Publisher: name: University of British Columbia
Year: 2017

description: The conventional and optimization based controllers have been used in process industries for more than two decades. The application of such controllers on complex systems could be computationally demanding and may require estimation of hidden states. They also require constant tuning, development of a mathematical model (first principle or empirical), design of control law which are tedious. Moreover, they are not adaptive in nature. On the other hand, in the recent years, there has been significant progress in the fields of computer vision and natural language processing that followed the success of deep learning. Human level control has been attained in games and physical tasks by combining deep learning with reinforcement learning. They were also able to learn the complex go game which has states more than number of atoms in the universe. Self-Driving cars, machine translation, speech recognition etc started to gain advantage of these powerful models. The approach to all of them involved problem formulation as a learning problem. Inspired by these applications, in this work we have posed process control problem as a learning problem to build controllers to address the limitations existing in current controllers.
Safety first portfolio choice based on financial and sustainability returns
Creators: name: Dorfleitner, Gregor
name: Utz, Sebastian
Publisher: name: Universität Regensburg
Year: 2012
Subjects: subject: Finance, Socially Responsible Investing, Sustainability Value, Safety First Investor
subject: 330 Wirtschaft

description: The aim of this paper is to expand the methodological spectrum of socially responsible investing by introducing stochastic sustainability returns into safety first models for portfolio choice. We provide a foundation of the notion of sustainability in portfolio theory and establish a general model for generalized safety first portfolio management with probabilistic constraints and three specializations of it. Moreover, we prove theorems about conditions for unique optimal solutions and for the constraints of one model being more restrictive than those of another. In an empirical part, we calculate the costs of investing according to our approach in terms of less financial return.
Reuse-Aware Cache Partitioning Framework for Data-Sharing Multicore Systems
Creators: name: Ghosh, Soma N.
name: Sahula, Vineet
name: Bhargava, Lava
Publisher: name: arXiv
Year: 2022
Subjects: subject: Hardware Architecture (cs.AR)
subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: FOS: Computer and information sciences
subject: C.1.4; D.4.2

description: Multi-core processors improve performance, but they can create unpredictability owing to shared resources such as caches interfering. Cache partitioning is used to alleviate the Worst-Case Execution Time (WCET) estimation by isolating the shared cache across each thread to reduce interference. It does, however, prohibit data from being transferred between parallel threads running on different cores. In this paper we present (SRCP) a cache replacement mechanism for partitioned caches that is aware of data being shared across threads, prevents shared data from being replicated across partitions and frequently used data from being evicted from caches. Our technique outperforms TA-DRRIP and EHC, which are existing state-of-the-art cache replacement algorithms, by 13.34% in cache hit-rate and 10.4% in performance over LRU (least recently used) cache replacement policy.
description: 2 pages. 7th IEEE International Symposium on Smart Electronic Systems (iSES) 2021
Determination of 228Ra in human bone ash containing significant quantities of 40K and Ca2+
Creators: name: Kandlbinder, Robert
name: Schupfner, Robert
name: Wolfbeis, Otto S.
Publisher: name: Universität Regensburg
Year: 2010
Subjects: subject: Ra-228 - Coprecipitation - Calcium - Potassium
subject: 540 Chemie

description: The determination of 228Ra by means of γ-spectrometry, in material containing significant quantities of 40K and Ca2+ such as bone ash results in increased values of counting uncertainty and lower limit of detection (LLD) because of a significant contribution from the Compton continuum of 40K. However, 40K is widely removed from bone ash if 228Ra is coprecipitated with barium sulfate. As a result, the counting uncertainty and LLD are significantly reduced. A method is presented for determination of very low activity concentrations of 228Ra. Impurities introduced by precipitation are negligible when applying high resolution γ-spectrometry.
Teleamplification on the Borealis boson-sampling device
Creators: name: Goldberg, Aaron Z.
name: Heshami, Khabat
Publisher: name: arXiv
Year: 2023
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: A recent theoretical proposal for teleamplification requires preparation of Fock states, programmable interferometers, and photon-number resolving detectors to herald the teleamplification of an input state. These enable teleportation and heralded noiseless linear amplification of a photonic state up to an arbitrarily large energy cutoff. We report on adapting this proposal for Borealis and demonstrating teleamplification of squeezed-vacuum states with variable amplification factors. The results match the theoretical predictions and exhibit features of amplification in the teleported mode, with fidelities from 50 to 93%. This demonstration motivates the continued development of photonic quantum computing hardware for noiseless linear amplification's applications across quantum communication, sensing, and error correction.
description: 9+5 pages, 6+7 figures; close to published version
Surface XRF mapping for intraparticle heterogeneity assessment and particle grade estimation
Creators: name: Seiler, Santiago
Publisher: name: University of British Columbia
Year: 2017

description: Sensor-based sorting is perceived as a feasible solution for some of the most critical aspects of mineral processing. There are two basic classes of sensors, 1. those that measure a property characteristic of the bulk of a particle; and 2. those that measure a property of the surface of a particle. For the second class, the surface measurement is then correlated to the bulk property of interest. The correlation does not only depend on how well the sensors can analyze the surface, but also on how well the surface correlates to the volume of the rock. The correlation is even more complex since only part of the rock surface is scanned by an actual sorter. Thus, the heterogeneity within each particle, defined as intraparticle heterogeneity, is an important variable to be characterized. The main objective of this work was to design and develop a method for rock surface mapping to assess intraparticle heterogeneity and to evaluate the correlation between surface grade and bulk grade for run of the mine or primary crushed rocks. The XRF mapping technique developed, and the procedure selected to analyze the mapping data, were described and applied to two porphyry copper ore samples. According to an univariate statistical analysis, for the samples analyzed, copper and iron data distributions did not follow either normal or lognormal distribution. Median and median absolute deviation were proposed as the best parameters to summarize the surface grade and the intraparticle heterogeneity, respectively. The median value of the surface grade data showed the best correlation to the bulk grade of the rock for both elements. For the copper ore used in this work, with mainly vein type mineralization, the one-dimensional heterogeneity assessment showed a high degree of intraparticle heterogeneity. This characteristic of the ore might generate poor reproducibility in the results of an XRF sorter when sensing only one face of each rock. The variogram was evaluated as a measure of heterogeneity in two dimensions. Two-color mapping method was selected to display the data collected in the XRF mapping for both samples analyzed.
Dynamic Critical Behavior of the Chayes-Machta Algorithm for the Random-Cluster Model. I. Two Dimensions
Creators: name: Garoni, Timothy M.
name: Ossola, Giovanni
name: Polin, Marco
name: Sokal, Alan D.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: High Energy Physics - Lattice (hep-lat)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We study, via Monte Carlo simulation, the dynamic critical behavior of the Chayes-Machta dynamics for the Fortuin-Kasteleyn random-cluster model, which generalizes the Swendsen-Wang dynamics for the q-state Potts ferromagnet to non-integer q \ge 1. We consider spatial dimension d=2 and 1.25 \le q \le 4 in steps of 0.25, on lattices up to 1024^2, and obtain estimates for the dynamic critical exponent z_{CM}. We present evidence that when 1 \le q \lesssim 1.95 the Ossola-Sokal conjecture z_{CM} \ge β/νis violated, though we also present plausible fits compatible with this conjecture. We show that the Li-Sokal bound z_{CM} \ge α/νis close to being sharp over the entire range 1 \le q \le 4, but is probably non-sharp by a power. As a byproduct of our work, we also obtain evidence concerning the corrections to scaling in static observables.
description: LaTeX2e, 75 pages including 26 Postscript figures
Diffusive modes of two-band fermions under number-conserving dissipative dynamics
Creators: name: Lyublinskaya, A. A.
name: Burmistrov, I. S.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Gases (cond-mat.quant-gas)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Driven-dissipative protocols are proposed to control and create nontrivial quantum many-body correlated states. Protocols conserving the number of particles stand apart. As well-known, in quantum systems with the unitary dynamics the particle number conservation and random scattering yield diffusive behavior of two-particle excitations (diffusons and cooperons). Existence of diffusive modes in the particle-number-conserving dissipative dynamics is not well studied yet. We explicitly demonstrate the existence of diffusons in a paradigmatic model of a two-band system, with dissipative dynamics aiming to empty one fermion band and to populate the other one. The studied model is generalization of the model introduced in F. Tonielli, J. C. Budich, A. Altland, and S. Diehl, Phys. Rev. Lett. 124, 240404 (2020). We find how the diffusion coefficient depends on details of a model and the rate of dissipation. We discuss how the existence of diffusive modes complicates engineering of macroscopic many-body correlated states.
description: 6 pages, 2 figures, to appear in JETP Letters
Dual sensing of pO2 and temperature using a water-based and sprayable fluorescent paint
Creators: name: Fischer, Lorenz H.
name: Borisov, Sergej M.
name: Schäferling, Michael
name: Klimant, Ingo
name: Wolfbeis, Otto S.
Publisher: name: Universität Regensburg
Year: 2010
Subjects: subject: 540 Chemie

description: Core–shell particles (CSPs) composed of a polystyrene core and a poly(vinyl pyrrolidone) shell were dyed with a luminescent platinum(II) porphyrinprobe for oxygen. In parallel, microparticles were dyed with a luminescent iridium(II) complex acting as a probe for temperature. The particles were deposited (by spraying) on a surface to enable continuous imaging of the distribution of oxygen (and thus of barometric pressure) and temperature. Unlike most previous paints of this kind, a binder polymer is not needed and water can be used as a dispersant. This makes the paint environmentally friendly and reduces costs in terms of occupational health, clean-up, and disposal. Both indicatorprobes in the sensor paint can be excited at 405 nm using LEDs or diode lasers, whilst their emission maxima are spectrally separated by about 130 nm. Thus, two independent optical signals are obtained that allow for fluorescent imaging of barometric pressure (in fact oxygen partial pressure) and of temperature, and also to correct the oxygen signal for effects of temperature. The paint was calibrated at air pressures ranging from 50 mbar to 2000 mbar and at temperatures between 1 °C and 50 °C.
Determination of biogenic amines by capillary electrophoresis using a chameleon type of fluorescent stain
Creators: name: Steiner, Mark-Steven
name: Meier, Robert J.
name: Spangler, Christian
name: Dürkop, Axel
name: Wolfbeis, Otto S.
Publisher: name: Universität Regensburg
Year: 2009
Subjects: subject: Biogenic amines - Capillary electrophoresis - Chameleon label - Derivatization - Laser-induced fluorescence
subject: 540 Chemie

description: A method was developed for the determination of biogenic amines (BAs) via micellar electrokinetic chromatography along with laser induced fluorescence detection using the amino-reactive chameleon stain Py-1. A labeling protocol was established for seven primary BAs by optimizing the reaction conditions in terms of the amount of reagents, reaction temperature, reaction time and solvent. Derivatization was accomplished within 30 min and is visible by the naked eye because it is accompanied by a color change from blue to red. Separation of the labeled BAs was achieved within 15 min with a background buffer of pH 2.5 containing phosphate, Tween®80, and methanol. The LODs range from 0.1 to 0.9 µmol·L−1, with RSDs ranging from 1.1 to 4.2% at 10 µmol·L−1. The method was applied to the determination of histamine in various fish samples.
APEX at the QSO MUSEUM: molecular gas reservoirs associated with $z\sim$3 quasars and their link to the extended Ly$α$ emission
Creators: name: Muñoz-Elgueta, N.
name: Battaia, F. Arrigoni
name: Kauffmann, G.
name: De Breuck, C.
name: García-Vergara, C.
name: Zanella, A.
name: Farina, E. P.
name: Decarli, R.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Cool gas (T$\sim$10$^{4}$~K) traced by hydrogen Ly$α$ emission is now routinely detected around $z\sim3$ quasars, but little is known about their molecular gas reservoirs. Here, we present an APEX spectroscopic survey of the CO(6-5), CO(7-6) and [CI](2-1) emission lines for 9 quasars from the QSO MUSEUM survey which have similar UV luminosities, but very diverse Ly$α$ nebulae. These observations ($\langle~\rm rms~\rangle=2.6$~mJy in 300~km~s$^{-1}$) detected three CO(6-5) lines with 3.4$\leq I_{\rm CO(6-5)} \leq$5.1~Jy~km~s$^{-1}$, 620$\leq$FWHM$\leq$707~km~s$^{-1}$, and three [CI](2-1) lines with 2.3$\leq I_{\rm [CI](2-1)} \leq$15.7~Jy~km~s$^{-1}$, 329$\leq$FWHM$\leq$943~km~s$^{-1}$. For the CO and [CI] detected sources, we constrain the molecular gas reservoirs to be $\rm M_{H_{2}} = (0.4-6.9) \times 10^{11} M_{\odot}$, while the non-detections imply $\rm M_{H_{2}} < 1.1\times 10^{11} M_{\odot}$. We compare our observations with the extended Ly$α$ properties to understand the link between the cool and the molecular gas phases. We find large velocity shifts between the bulk of Ly$α$ and the molecular gas systemic redshift in five sources (from $\sim$-400 to $\sim+$1200~km~s$^{-1}$). The sources with the largest shifts have the largest Ly$α$ line widths in the sample, suggesting more turbulent gas conditions and/or large-scale inflows/outflows around these quasars. We also find that the brightest ($I_{\rm[CI](2-1)}=15.7\pm3.7~\rm Jy~km~s^{-1}$) and the widest (FWHM$\sim$900~km~s$^{-1}$) lines are detected for the smallest and dimmest Ly$α$ nebulae. From this, we speculate that host galaxy obscuration can play an important role in reducing the ionizing and Ly$α$ photons able to escape to halo scales, and/or that these systems are hosted by more massive halos.
description: Accepted on January 3, MNRAS. 25 pages, 17 figures
Colloidal silica nanoparticles for use in click chemistry-based conjugations and fluorescent affinity assays
Creators: name: Achatz, E.
name: Heiligtag, Florian J.
name: Li, Xiaohua
name: Link, Martin
name: Wolfbeis, Otto S.
Publisher: name: Universität Regensburg
Year: 2010
Subjects: subject: Silica nanoparticles; Surface chemistry; Fluorescence; Bioconjugation; Affinity sensing; Biotin; Click chemistry
subject: 540 Chemie

description: Silica nanoparticles (SiNPs) with an average diameter of 25 nm were prepared by a one-pot method that involves the formation of a silica core that is subsequently covered with a shell functionalized with either azido groups or alkyne groups for use in copper(I)-catalyzed click reactions. Respective triethoxysilane reagents are presented. The SiNPs were (a) rendered fluorescent by click conjugation to fluorophores of various colors, and (b) made bioconjugatable by introducing maleimide groups (that covalently bind thiols) and biotin (a widely used bioaffinity reagent that binds streptavidin). Particles were characterized by transmission electron microscopy, infrared spectroscopy, fluorescence, and light scattering. The fluorescently labeled SiNPs carrying maleimido groups were conjugated to the thiol group of bovine serum albumin (BSA) labeled with a fluorophore, and fluorescence resonance energy transfer was shown to occur between the labeled SiNPs and the labeled BSA. This is considered to represent a new approach towards nanoparticle-based fluorescent bioassays.
Matryoshka Locally Resonant Sonic Crystal
Creators: name: Elford, Daniel P.
name: Chalmers, Luke
name: Kusmartsev, Feodor V.
name: Swallowe, Gerry M.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Classical Physics (physics.class-ph)
subject: FOS: Physical sciences

description: The results of numerical modelling of sonic crystals with resonant array elements are reported. The investigated resonant elements include plain slotted cylinders as well as various their combinations, in particular, Russian doll or Matryoshka configurations. The acoustic band structure and transmission characteristics of such systems have been computed with the use of finite element methods. The general concept of a locally resonant sonic crystal is proposed, which utilises acoustic resonances to form additional band gaps that are decoupled from Bragg gaps. An existence of a separate attenuation mechanism associated with the resonant elements, which increases performance in the lower frequency regime has been identified. The results show a formation of broad band gaps positioned significantly below the first Bragg frequency. For low frequency broadband attenuation a most optimal configuration is the Matryoshka sonic crystal, where each scattering unit is composed of multiple concentric slotted cylinders. This system forms numerous gaps in the lower frequency regime, below Bragg bands, whilst maintaining a reduced crystal size viable for noise barrier technology. The finding opens new perspectives for construction of sound barriers in the low frequency range usually inaccessible by traditional means including conventional sonic crystals.
description: 7 Pages, 12 Figures
Understanding Symmetry Breaking in Twisted Bilayer Graphene from Cluster Constraints
Creators: name: Astrakhantsev, Nikita
name: Wagner, Glenn
name: Westerhout, Tom
name: Neupert, Titus
name: Fischer, Mark H.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Twisted bilayer graphene is an exciting platform for exploring correlated quantum phases, extremely tunable with respect to both the single-particle bands and the interaction profile of electrons. Here, we investigate the phase diagram of twisted bilayer graphene as described by an extended Hubbard model on the honeycomb lattice with two fermionic orbitals (valleys) per site. Besides the special extended {\it cluster interaction} $Q$, we incorporate the effect of gating through an onsite Hubbard-interaction $U$. Within Quantum Monte Carlo (QMC), we find valence-bond-solid, Néel-valley antiferromagnetic or charge-density wave phases. Further, we elucidate the competition of these phases by noticing that the cluster interaction induces an exotic constraint on the Hilbert space, which we dub {\it the cluster rule}, in analogy to the famous pyrochlore spin-ice rule. Formulating the perturbative Hamiltonian by projecting into the cluster-rule manifold, we perform exact diagonalization and construct the fixed-point states of the observed phases. Finally, we compute the local electron density patterns as signatures distinguishing these phases, which could be observed with scanning tunneling microscopy. Our work capitalizes on the notion of cluster constraints in the extended Hubbard model of twisted bilayer graphene, and suggests a scheme towards realization of several symmetry-breaking insulating phases in a twisted-bilayer graphene sheet.
description: 10 pages, 6 figures
Photographing Oxygen Distribution
Creators: name: Wang, Xu-dong
name: Meier, Robert J.
name: Link, Martin
name: Wolfbeis, Otto S.
Publisher: name: Universität Regensburg
Year: 2010
Subjects: subject: fluorescence; imaging; oxygen; sensors; photography
subject: 540 Chemie

description: O2, where are you? The spatial distribution of oxygen can be imaged with a conventional digital camera by making use of a specially designed fluorescent sensor film containing a quenchable red-emitting probe for oxygen along with a green-emitting reference fluorophore. The technique exploits the RGB channels involved in digital photography (see picture) to deliver a simple method for quantitative sensing and imaging of this important species.
The canonical equilibrium of constrained molecular models
Creators: name: Echenique, Pablo
name: Cavasotto, Claudio N.
name: García-Risueño, Pablo
Publisher: name: arXiv
Year: 2011
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Quantitative Methods (q-bio.QM)
subject: FOS: Physical sciences
subject: FOS: Biological sciences

description: In order to increase the efficiency of the computer simulation of biological molecules, it is very common to impose holonomic constraints on the fastest degrees of freedom; normally bond lengths, but also possibly bond angles. However, as any other element that affects the physical model, the imposition of constraints must be assessed from the point of view of accuracy: both the dynamics and the equilibrium statistical mechanics are model-dependent, and they will be changed if constraints are used. In this review, we investigate the accuracy of constrained models at the level of the equilibrium statistical mechanics distributions produced by the different dynamics. We carefully derive the canonical equilibrium distributions of both the constrained and unconstrained dynamics, comparing the two of them by means of a "stiff" approximation to the latter. We do so both in the case of flexible and hard constraints, i.e., when the value of the constrained coordinates depends on the conformation and when it is a constant number. We obtain the different correcting terms associated with the kinetic energy mass-metric tensor determinants, but also with the details of the potential energy in the vicinity of the constrained subspace (encoded in its first and second derivatives). This allows us to directly compare, at the conformational level, how the imposition of constraints changes the thermal equilibrium of molecular systems with respect to the unconstrained case. We also provide an extensive review of the relevant literature, and we show that all models previously reported can be considered special cases of the most general treatments presented in this work. Finally, we numerically analyze a simple methanol molecule in order to illustrate the theoretical concepts in a practical case.
description: 51 pages, 7 figures, Springer LaTeX style
Structure Formation after Reheating: Supermassive Primordial Black Holes and Fermi Ball Dark Matter
Creators: name: Flores, Marcos M.
name: Lu, Yifan
name: Kusenko, Alexander
Publisher: name: arXiv
Year: 2023
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: In the presence of (relatively) long-range forces, structures can form even during the radiation dominated era, leading to compact objects, such as Fermi balls or primordial black holes (PBHs), which can account for all or part of dark matter. We present a detailed analysis of a model in which fermions are produced from the inflaton decay developing some particle-antiparticle asymmetry. These fermions undergo clustering and structure formation driven by a Yukawa interaction. The same interaction provides a cooling channel for the dark halos via scalar radiation, leading to rapid collapse and the formation of a compact object. We discuss the criteria for the formation of either PBHs and Fermi balls. In the PBH formation regime, supermassive PBHs can seed the active galactic nuclei or quasars found at high redshift. Alternatively, Fermi balls can account for all of the cold dark matter, while evading microlensing constraints.
description: 9 pages, 6 figures
Stability and evolution of synonyms and homonyms in signaling game
Creators: name: Lipowski, Dorota
name: Lipowski, Adam
Publisher: name: arXiv
Year: 2022
Subjects: subject: Physics and Society (physics.soc-ph)
subject: FOS: Physical sciences

description: Synonyms and homonyms appear in all natural languages. We analyse their evolution within the framework of the signaling game. Agents in our model use reinforcement learning, where probabilities of selection of a communicated word or of its interpretation depend on weights equal to the number of accumulated successful communications. When the probabilities increase linearly with weights, synonyms appear to be very stable and homonyms decline relatively fast. Such behaviour seems to be at odds with linguistic observations. A better agreement is obtained when probabilities increase faster than linearly with weights. Our results may suggest that a certain positive feedback, the so-called Metcalfe's Law, possibly drives some linguistic processes. Evolution of synonyms and homonyms in our model can be approximately described using a certain nonlinear urn model.
description: 17 pages
Non-monotoic fluctuation-induced interactions between dielectric slabs carrying charge disorder
Creators: name: Sarabadani, Jalal
name: Naji, Ali
name: Dean, David S.
name: Horgan, Ron R.
name: Podgornik, Rudolf
Publisher: name: arXiv
Year: 2010
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We investigate the effect of monopolar charge disorder on the classical fluctuation-induced interactions between randomly charged net-neutral dielectric slabs and discuss various generalizations of recent results (A. Naji et al., Phys. Rev. Lett. 104, 060601 (2010)) to highly inhomogeneous dielectric systems with and without statistical disorder correlations. We shall focus on the specific case of two generally dissimilar plane-parallel slabs, which interact across vacuum or an arbitrary intervening dielectric medium. Monopolar charge disorder is considered to be present on the bounding surfaces and/or in the bulk of the slabs, may be in general quenched or annealed and may possess a finite lateral correlation length reflecting possible `patchiness' of the random charge distribution. In the case of quenched disorder, the bulk disorder is shown to give rise to an additive long-range contribution to the total force, which decays as the inverse distance between the slabs and may be attractive or repulsive depending on the dielectric constants of the slabs. We show that in the case of two dissimilar slabs the net effect due to the interplay between the disorder-induced and the pure van der Waals interactions can lead to a variety of unusual non-monotonic interaction profiles between the dielectric slabs. In particular, when the intervening medium has a larger dielectric constant than the two slabs, we find that the net interaction can become repulsive and exhibit a potential barrier, while the underlying van der Waals force is attractive. On the contrary, when the intervening medium has a dielectric constant in between that of the two slabs, the net interaction can become attractive and exhibit a free energy minimum, while the pure van der Waals force is repulsive. Therefore, the charge disorder, if present, can drastically alter the effective interaction between net-neutral objects.
description: 13 pages, 8 figures
Luminescent Europium(III) Nanoparticles for Sensing and Imaging of Temperature in the Physiological Range
Creators: name: Peng, Hongshang
name: Stich, Matthias I. J.
name: Yu, Jiangbo
name: Sun, Li-ning
name: Fischer, Lorenz H.
name: Wolfbeis, Otto S.
Publisher: name: Universität Regensburg
Year: 2010
Subjects: subject: Europium chelates; Luminescence; Nanoparticles; Temperature sensing; Temperature imaging
subject: 540 Chemie

description: Europium(III) Nanoparticles are fabricated for sensing and imaging of physiological temperatures (see image). The material shows visible-light excitation, line-like emission, inertness to external perturbers (such as oxygen in air), and a dynamic range that covers temperatures encountered in medicine and (cellular) biology. The resolution is ±0.3 °C. The nanoparticles may also be incorporated into a (conceivably sprayable) sensor film.
Detection, estimation and control in online social media
Creators: name: Aprem, Anup
Publisher: name: University of British Columbia
Year: 2017

description: Due to large scale use of online social media there has been growing interest in modeling and analysis of data from online social media. The unifying theme of this thesis is to develop a set of mathematical tools for detection, estimation and control in online social media. The following are the main contributions of this thesis: Chapter 2 deals with nonparametric change detection for dynamic utility maximization agents. Using the revealed preference framework, necessary and sufficient conditions for detecting the change point are derived. In the presence of noisy measurements, we construct a decision test to check for dynamic utility maximization behaviour and the change point. Experiments on the Yahoo! Tech Buzz dataset show that the framework can be used to detect changes in ground truth using online search data. Chapter 3 studies engagement dynamics and sensitivity analysis of YouTube videos. Using machine learning and sensitivity analysis techniques it is shown that the video view count is sensitive to 5 meta-level features. In addition, changing the meta-level after the video has been posted increases the popularity of the video. In addition, we examine how the social dynamics of a YouTube channel affect it's popularity. The results are empirically validated on a real-world data consisting of about 6 million videos spread over 25 thousand channels. Chapter 4 considers the problem of scheduling advertisements in live personalized online social media. Broadcasters aim to opportunistically schedule advertisements (ads) so as to generate maximum revenue. The problem is formulated as a multiple stopping problem and is addressed in a partially observed Markov decision process (POMDP) framework. Structural results are provided on the optimal ad scheduling policy. By exploiting the structure of the optimal policy, optimum linear threshold policies are computed using a stochastic gradient algorithm. The proposed model and framework are validated on a Periscope dataset and it was found that the revenue can be improved by 25% in comparison to currently employed periodic scheduling.
The third (3rd) newsletter of the Patient Empowerment through Predictive Personalized Decision Support System (PEPPER) project
Creators: name: Pepper
Publisher: name: Zenodo
Year: 2019

description: Welcome to the third issue of the PEPPER Project newsletter. We have had an exciting few months since the last issue. You will find news here about the clinical feasibility studies, now in progress in both centres: Imperial College Healthcare NHS Trust, London, UK and Institut d'Investigació Biomèdica de Girona Dr. Josep Trueta, Spain. Participants have been enrolled to both the PEPPER platforms: the smartphone platform to guide those who use multiple daily injections, and the next generation Cellnovo System, which features a Bluetooth and Android-enabled micro-pump. You can watch a video about the project (http://bit.ly/2BNwU2j). If you would like to offer us any feedback please contact contact_pepper@googlegroups.com
Dynamics of pinned quantized vortices in superfluid $^4$He in a microelectromechanical oscillator
Creators: name: Nakagawa, Tomo
name: Tsubota, Makoto
name: Gunther, Keegan
name: Lee, Yoonseok
Publisher: name: arXiv
Year: 2023
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: We numerically studied the vortex dynamics at zero temperature in superfluid $^4$He confined between two parallel rough solid boundaries, one of which oscillates in a shear mode. This study was motivated by the experimental work by Barquist $et$ $al.$ which employed a microelectromechanical systems (MEMS) oscillator operating in superfluid $^4$He at a near-zero temperature. Their experiments suggest that the motion of the MEMS oscillator is damped by quantized vortices. In our study, we postulated that this damping effect was closely associated with vortex pinning phenomena and developed pinning models. Our primary objective is to understand the vortex dynamics in the presence of pinning and to provide insight into the experimental observations regarding the damping mechanism. We confirmed that Kelvin waves were excited in the pinned vortices when the oscillation frequency of the solid boundary matched with the mode frequency of the Kelvin wave. Additionally, we examined the formation and evolution of vortex tangles between the boundaries. The vortex tangle was suppressed in the presence of pinning, while the absence of pinning allowed to form well developed vortex tangle resulting in turbulence. Finally, by evaluating the tension of pinned vortices we extracted the damping force acting on the solid boundaries.
description: 11 pages + supplement, 17 figures
Fitting functions for a disk-galaxy model with different LCDM-halo profiles
Creators: name: Darriba, L.
name: Solanes, J. M.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We present an adaptation of the standard scenario of disk-galaxy formation to the concordant LCDM cosmology aimed to derive analytical expressions for the scale length and rotation speed of present-day disks that form within four different, cosmologically motivated protogalactic dark matter halo-density profiles. We invoke a standard galaxy-formation model that includes virial equilibrium of spherical dark halos, specific angular momentum conservation during gas cooling, and adiabatic halo response to the gas inflow. The mean mass-fraction and mass-to-light ratio of the central stellar disk are treated as free parameters whose values are tuned to match the zero points of the observed size-luminosity and circular speed-luminosity relations of galaxies. We supply analytical formulas for the characteristic size and rotation speed of disks built inside Einasto r^{1/6}, Hernquist, Burkert, and Navarro-Frenk-White dark matter halos. These expressions match simultaneously the observed zero points and slopes of the different correlations that can be built in the RVL space of disk galaxies from plausible values of the galaxy- and star-formation efficiencies.
A new weakly basic amino-reactive fluorescent label for use in isoelectric focusing and chip electrophoresis
Creators: name: Schulze, Philipp
name: Link, Martin
name: Schulze, Marcel
name: Thürmann, Sebastian
name: Wolfbeis, Otto S.
name: Belder, Detlev
Publisher: name: Universität Regensburg
Year: 2010
Subjects: subject: CIEF; Fluorescence marker; MCE; Luminescence detection; Protein labeling
subject: 540 Chemie

description: In this study, we present a novel amino-reactive fluorescence marker (referred to as UR-431), which is well suited for electrophoretic techniques. A main feature of this marker is its weakly basic behavior when conjugated to analytes. Labeled primary amines exhibit a positive net charge and accordingly a cathodic mobility below a pH of 2.4. The label features a pH-independent fluorescence emission and is thus very interesting for electrophoretic applications such as IEF. The absorption maximum of this yellow daylight chromophore is at 431 nm, whereas fluorescence emission peaks at 537 nm (quantum yield≈0.1). The label was successfully conjugated to amines, peptides and proteins and separated via CE and MCE. The on-chip detection limit of labeled lysine using a mercury-lamp-based fluorescence microscope was determined as 12 nM. An important feature of the new label is that it effects only a subtle change of the pI of proteins compared with common anionic labels, e.g. FITC. pI values of proteins were investigated by comparing native proteins and labeled proteins in CIEF. UR-431 was also applied to sensitive detection of amines and peptides in MCE.
OtherTube: Facilitating Content Discovery and Reflection by Exchanging YouTube Recommendations with Strangers
Creators: name: Bhuiyan, Md Momen
name: Isaza, Carlos Augusto Bautista
name: Mitra, Tanushree
name: Lee, Sang Won
Publisher: name: arXiv
Year: 2022
Subjects: subject: Human-Computer Interaction (cs.HC)
subject: FOS: Computer and information sciences

description: To promote engagement, recommendation algorithms on platforms like YouTube increasingly personalize users' feeds, limiting users' exposure to diverse content and depriving them of opportunities to reflect on their interests compared to others'. In this work, we investigate how exchanging recommendations with strangers can help users discover new content and reflect. We tested this idea by developing OtherTube -- a browser extension for YouTube that displays strangers' personalized YouTube recommendations. OtherTube allows users to (i) create an anonymized profile for social comparison, (ii) share their recommended videos with others, and (iii) browse strangers' YouTube recommendations. We conducted a 10-day-long user study (n=41) followed by a post-study interview (n=11). Our results reveal that users discovered and developed new interests from seeing OtherTube recommendations. We identified user and content characteristics that affect interaction and engagement with exchanged recommendations; for example, younger users interacted more with OtherTube, while the perceived irrelevance of some content discouraged users from watching certain videos. Users reflected on their interests as well as others', recognizing similarities and differences. Our work shows promise for designs leveraging the exchange of personalized recommendations with strangers.
description: CHI 2022, 17 pages
An Empirical Study of Spam and Spam Vulnerable email Accounts
Creators: name: Dhinakaran, Cynthia
name: Nagamalai, Dhinaharan
name: Lee, Jae Kwang
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cryptography and Security (cs.CR)
subject: Networking and Internet Architecture (cs.NI)
subject: FOS: Computer and information sciences

description: Spam messages muddle up users inbox, consume network resources, and build up DDoS attacks, spread malware. Our goal is to present a definite figure about the characteristics of spam and spam vulnerable email accounts. These evaluations help us to enhance the existing technology to combat spam effectively. We collected 400 thousand spam mails from a spam trap set up in a corporate mail server for a period of 14 months form January 2006 to February 2007. Spammers use common techniques to spam end users regardless of corporate server and public mail server. So we believe that our spam collection is a sample of world wide spam traffic. Studying the characteristics of this sample helps us to better understand the features of spam and spam vulnerable e-mail accounts. We believe that this analysis is highly useful to develop more efficient anti spam techniques. In our analysis we classified spam based on attachment and contents. According to our study the four years old heavy users email accounts attract more spam than four years oldlight users mail accounts. The 14 months old relatively new email accounts don't receive spam. In some special cases like DDoS attacks, the new email accounts receive spam. During DDoS attack 14 months old heavy users email accounts have attracted more number of spam than 14 months old light users mail accounts.
description: 6 pages, 5 Figures, FGCN 2007, IEEE CS