cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
The role of male color in darter speciation
Creators: name: Williams, Tory Holland
Publisher: name: Maryland Shared Open Access Repository
Year: 2013
Subjects: association preference
behavioral isolation
color
Etheostoma
mate choice
sexual selection

description: "This doctoral research examines the role of male nuptial coloration in the maintenance of species boundaries of darters (Percidae: Etheostoma). The two main goals were to identify how conspicuous male colors contribute to pre-mating isolation and to determine the relative importance of such pre-mating isolation in the maintenance of two sympatric species. The focal pair of sympatric species, E. zonale and E. barrenense, allow an examination of conspecific male coloration as a critical factor by which females select mates. According to speciation via sexual selection theory, if species-specific color leads to pre-mating isolation and pre-mating isolation is stronger than other forms of reproductive barriers, then that nuptial coloration plays a key role in maintaining species boundaries. Although conventional wisdom holds that conspicuous male coloration has evolved to attract conspecific female mates and that species-specific colors serve as a prominent cue maintaining species boundaries, this notion has been explicitly tested only rarely. Importantly, nuptial color may not be driven by female choice; alternatively, color cues may function in male-male competition to improve access to female mates. Therefore it is critical to test the precise role of nuptial coloration in speciation.   	Darters provide an excellent system for examining the role of nuptial coloration in speciation. Darters comprise the most diverse genus of North American freshwater fish, and nearly every species is characterized by unique nuptial coloration. Multiple darter species co-exist in sympatric populations, indicating that reproductive barriers are tantamount to maintaining these extraordinarily diverse color patterns. 	This doctoral research demonstrates that male coloration plays a role in female choice both within and between the focal species. Additionally, these species exhibit complete behavioral isolation influenced by female preference for conspecific male coloration. I compared the relative strengths of multiple reproductive barriers and found that behavioral isolation is the strongest measured barrier to gene flow between the focal species. These results present empirical evidence for speciation driven by sexual selection and provide insight into the maintenance of diversity among naturally occurring sympatric species."
description: Includes 1 .mov video file.
Non-Abelian coset string backgrounds from asymptotic and initial data
Creators: name: Petropoulos, P. M.
name: Sfetsos, K.
Publisher: name: arXiv
Year: 2006
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We describe hierarchies of exact string backgrounds obtained as non-Abelian cosets of orthogonal groups and having a space--time realization in terms of gauged WZW models. For each member in these hierarchies, the target-space backgrounds are generated by the ``boundary'' backgrounds of the next member. We explicitly demonstrate that this property holds to all orders in $α'$. It is a consequence of the existence of an integrable marginal operator build on, generically, non-Abelian parafermion bilinears. These are dressed with the dilaton supported by the extra radial dimension, whose asymptotic value defines the boundary. Depending on the hierarchy, this boundary can be time-like or space-like with, in the latter case, potential cosmological applications.
description: 26 pages
Gravitational decoupling for axially symmetric systems and rotating black holes
Creators: name: Contreras, E.
name: Ovalle, J.
name: Casadio, R.
Publisher: name: arXiv
Year: 2021
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We introduce a systematic and direct procedure to generate hairy rotating black holes by deforming a spherically symmetric seed solution. We develop our analysis in the context of the gravitational decoupling approach, without resorting to the Newman-Janis algorithm. As examples of possible applications, we investigate how the Kerr black hole solution is modified by a surrounding fluid with conserved energy-momentum tensor. We find non-trivial extensions of the Kerr and Kerr-Newman black holes with primary hair. We prove that a rotating and charged black hole can have the same horizon as Kerr's, Schwarzschild's or Reissner-Nordström's, thus showing possible observational effects of matter around black holes.
description: 11 pages, 4 figures
Climate Modelling in Low-Precision: Effects of both Deterministic & Stochastic Rounding
Creators: name: Paxton, E. Adam
name: Chantry, Matthew
name: Klöwer, Milan
name: Saffin, Leo
name: Palmer, Tim
Publisher: name: arXiv
Year: 2021
Subjects: subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: FOS: Physical sciences

description: Motivated by recent advances in operational weather forecasting, we study the efficacy of low-precision arithmetic for climate simulations. We develop a framework to measure rounding error in a climate model which provides a stress-test for a low-precision version of the model, and we apply our method to a variety of models including the Lorenz system; a shallow water approximation for flow over a ridge; and a coarse resolution global atmospheric model with simplified parameterisations (SPEEDY). Although double precision (52 significant bits) is standard across operational climate models, in our experiments we find that single precision (23 sbits) is more than enough and that as low as half precision (10 sbits) is often sufficient. For example, SPEEDY can be run with 12 sbits across the entire code with negligible rounding error and this can be lowered to 10 sbits if very minor errors are accepted, amounting to less than 0.1 mm/6hr for the average grid-point precipitation, for example. Our test is based on the Wasserstein metric and this provides stringent non-parametric bounds on rounding error accounting for annual means as well as extreme weather events. In addition, by testing models using both round-to-nearest (RN) and stochastic rounding (SR) we find that SR can mitigate rounding error across a range of applications. Thus our results also provide evidence that SR could be relevant to next-generation climate models. While many studies have shown that low-precision arithmetic can be suitable on short-term weather forecasting timescales, our results give the first evidence that a similar low precision level can be suitable for climate.
Energy extremals and Nonlinear Stability in a Variational theory of Barotropic Fluid - Rotating Sphere System
Creators: name: Lim, Chjan C.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: A new variational principle - extremizing the fixed frame kinetic energy under constant relative enstrophy - for a coupled barotropic flow - rotating solid sphere system is introduced with the following consequences. In particular, angular momentum is transfered between the fluid and the solid sphere through a modelled torque mechanism. The fluid's angular momentum is therefore not fixed but only bounded by the relative enstrophy, as is required of any model that supports super-rotation. The main results are: At any rate of spin $Ω$ and relative enstrophy, the unique global energy maximizer for fixed relative enstrophy corresponds to solid-body super-rotation; the counter-rotating solid-body flow state is a constrained energy minimum provided the relative enstrophy is small enough, otherwise, it is a saddle point. For all energy below a threshold value which depends on the relative enstrophy and solid spin $Ω$, the constrained energy extremals consist of only minimizers and saddles in the form of counter-rotating states$.$ Only when the energy exceeds this threshold value can pro-rotating states arise as global maximizers. Unlike the standard barotropic vorticity model which conserves angular momentum of the fluid, the counter-rotating state is rigorously shown to be nonlinearly stable only when it is a local constrained minima. The global constrained maximizer corresponding to super-rotation is always nonlinearly stable.
description: 30 p, 8 figs
The MHC class II associated invariant chain limits the immunogenicity of genetically modified human tumor cell vaccines
Creators: name: Thompson, James Andrew
Publisher: name: Maryland Shared Open Access Repository
Year: 2007
Subjects: Cancer
vaccine
Class II Major Histocompatibility Complex
MHC II
invariant chain
RNAi

description: Activation of tumor-reactive T lymphocytes is a promising approach for the treatment of patients with metastatic cancers.  CD8+ T cells can have cytotoxicity and specificity for tumor cells and optimal CD8+ T cell activity and memory requires CD4+ T cell co-activation.  Therefore, we are developing MHC-II vaccines that activate tumor-reactive CD4+ T cells.  MHC-II vaccines are MHC class I+ tumor cells transduced with costimulatory molecules and MHC-II alleles syngeneic to the prospective recipient.   In previous studies mouse MHC-II vaccines were therapeutic for established mouse tumors, provided they did not co-express the class II-associated Invariant chain (Ii), an accessory molecule coordinately regulated with MHC II.  A major goal of my thesis has been to develop human MHC-II vaccines.   I hypothesized that in the absence of Ii, MHC-II presents novel endogenously synthesized tumor peptides not presented by professional Ii+ antigen presenting cells (APC), thereby circumventing existing antigen-specific tumor-induced tolerance. To express a single MHC-II allele in the absence of Ii, MHC-II-Ii- cells were transduced with a bicistronic retroviral vector which expresses the MHC-II a and ? genes.  To express multiple MHC-II alleles and to facilitate presentation of a broader repertoire of tumor antigens, tumor cells were transduced with the MHC-II transactivator (CIITA), a regulatory gene that coordinately increases expression of all MHC-II alleles.  RNAi expression vectors silenced Ii >95% in CIITA/CD80/siRNA transductants. Down-regulation of Ii did not affect MHC-II expression or stability, and Ii+ and Ii-  transductants activate human CD4+ T cells to DRB1*0701-restricted HER2/neu epitopes.  HER2/neu+ MHC-II+ non-malignant cells (MCF10A) did not activate HER2/neu specific CD4+ T cells, suggesting tumor vaccines may not affect non-malignant tissues.  MHC-II vaccines are more efficient than Ii+ APC for priming and boosting tumor-specific Type 1 CD4+ T cells, and they induce greater expansion of CD4+ T cells which secrete more IFN? and activate an overlapping, but distinct, repertoire of CD4+ T cells. Therefore, MHC-II vaccines facilitate a robust CD4+ T cell response that includes the presentation of peptides that are uniquely presented by Ii- cells. These vaccines may be unique agents which induce a strong tumor-specific immune response in patients.
ปัญญาประดิษฐ์กับการสอนวิชาศิลปะ
Creators: name: ขวัญใจ ทวนดำ
Publisher: name: สาขาวิชาคอมพิวเตอร์ศึกษา คณะวิทยาศาสตร์และเทคโนโลยี มหาวิทยาลัยราชภัฏสุรินทร์
Year: 2023
Subjects: ปัญญาประดิษฐ์
การสอนศิลปะ
ความคิดสร้างสรรค์
ปัญหาและอุปสรรค

description: วารสารคอมพิวเตอร์และเทคโนโลยีสร้างสรรค์, 1, 3, 33-39
The role of visual sampling in obstacle compensation
Creators: name: Vienneau, Opal Yvette
Publisher: name: University of British Columbia
Year: 2009

description: Most obstacle avoidance studies have identified the importance of visual information in choosing obstacle avoidance strategies and of kinesthetic information for successful clearance of obstacles. The intent of this investigation was to determine on what and how visual information is utilized when an obstacle is encountered in our travel path and on some of the subsequent gait adaptations made to accommodate it. Accommodation strategies are based on movement goals and, in the case of this experiment, the goal was to step up onto a platform of set height and width but placed at varying distances from the subject's start position. Twelve volunteers completed seven walking trials for each of four obstacle placement conditions. The kinematic properties of their gait and the corresponding eye movements were recorded and analyzed to determine whether there was an inherent pattern in accommodating obstacles. Subjects were found to slow down in mid path and make changes to their stride length. Smaller adjustments were applied within the last two strides before the obstacle. Stride length change was the primary method of adaptation. Subjects focussed primarily on the obstacle throughout the trials, however gaze time on the obstacle decreased as the subjects approached the point of step-up. The normal condition, set at a natural right-foot step-up position, presented the least change in stride and exhibited patterns similar to those observed in the control situation where there was no obstacle. The greatest effect of stride was observed for the close obstacle placement, while for the far obstacle placement participants displayed similar patterns that were less pronounced. The results of the present experiment indicated that multiple visual sampling was necessary in all strides to apply adaptations to gait.
Cell Response to Hydrogel Tissue Scaffolds
Creators: name: Vargo, Shelby
Publisher: name: Maryland Shared Open Access Repository
Year: 2012

description: Tissue Engineering is evolving as one of the most promising therapies in regenerative medicine. Biomaterials are attractive substrates for tissue-engineering applications because they are biocompatible, can be biodegradable, and can be fabricated from a variety of materials. The ideal biomaterial substrate mimics native extracellular matrices to regulate cellular function, provide physical structure, and allow the diffusion of vital solutes.  Cell morphology, proliferation, and differentiation are linked to substrate geometry and physical properties. We show that the dimensionality (2D vs 3D) of a substrate more strongly influences neuronal morphology than substrate stiffness.  We also correlated GRGDY-modified alginate gel composition with gel stiffness and cell behavior: increased GRGDY and alginate concentrations resulted in increased gel stiffness and density of adherent cells. While increased calcium also increased gel stiffness, cell density was optimal at an intermediate calcium concentration. This work adds towards our understanding of optimizing scaffold properties to direct cell response.
The Evolution of Carotenoid Coloration and Pigmentation in the New World Blackbirds
Creators: name: Friedman, Nicholas R.
Publisher: name: Maryland Shared Open Access Repository
Year: 2013
Subjects: Bird Coloration
Carotenoids
Convergent Evolution
Icteridae

description: Plumage color evolution in birds has been the focus of theoretical and empirical research on sexual selection since Darwin. Many of the yellow, orange, and red hues seen in bird plumage are the result of carotenoid pigmentation. While a great number of recent studies have examined the functions of carotenoid-based plumage coloration in a single species, few have examined the evolutionary history of this trait in a comparative phylogenetic context. Using the New World blackbirds as a model clade, I focus on two questions that a comparative phylogenetic approach can uniquely address. First, what is the history of evolutionary change in carotenoid color that led to the colors seen in extant blackbird taxa? Second, by what proximate mechanisms have carotenoid pigments evolved? In Chapter 1, I present an ancestral state reconstruction of carotenoid-based plumage coloration across the Icterid phylogeny, based on reflectance measurements of museum skins. My results show robust evidence that red coloration was gained repeatedly from a yellow common ancestor. In Chapter 2, I used pigment biochemistry of meadowlark (Sturnella<>) and Cacique (Cacicus<>) feathers to test whether independent gains of red coloration are the result of parallel or convergent metabolic mechanisms. Meadowlarks have evolved red coloration using a different set of carotenoids than caciques, but the caciques have evolved the same set of carotenoids twice. This suggests that red coloration evolved by convergent evolution among different blackbird clades, but evolved by parallel evolution within the caciques. Lastly, in Chapter 3 I examine the relationship between color and carotenoid pigmentation in orioles, a blackbird clade in which orange has been gained at least twice independently from a yellow common ancestor. I found red-producing keto-carotenoids only in orange species and never in yellow species. This result is a striking contrast to our expectation for a continuous gradient of a carotenoid pigment concentration. These results suggest that repeated gains of C4-oxygenation ability best explain evolutionary changes in orange coloration in orioles. To summarize, I showed using phylogenetic comparative methods that blackbirds have repeatedly evolved towards redder carotenoid coloration. Using HPLC biochemistry, I showed that each of these gains of orange and red coloration is likely the result of a gain of C4-oxygenation ability. The prevalence of gains of orange and red coloration suggests that there may be a directional bias towards evolving longer-wavelength carotenoid plumage. The research presented in these chapters provides the phylogenetic framework necessary for future studies to examine the functional causes underlying the repeated evolution of carotenoid-based coloration.
Influence of atomic polarization and horizontal illumination on the Stokes profiles of the He I 10830 multiplet
Creators: name: Bueno, J. Trujillo
name: Ramos, A. Asensio
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The polarization observed in the spectral lines of the He I 10830 multiplet carries valuable information on the dynamical and magnetic properties of plasma structures in the solar chromosphere and corona, such as spicules, prominences, filaments, emerging magnetic flux regions, etc. Here we investigate the influence of atomic level polarization on the emergent Stokes profiles for a broad range of magnetic field strengths, in both 90 degree and forward scattering geometry. We show that, contrary to a widespread belief, the selective emission and absorption processes caused by the presence of atomic level polarization may have an important influence on the emergent linear polarization, even for magnetic field strengths as large as 1000 G. Consequently, the modeling of the Stokes Q and U profiles should not be done by taking only into account the contribution of the transverse Zeeman effect within the framework of the Paschen-Back effect theory, unless the magnetic field intensity of the observed plasma structure is sensibly larger than 1000 G. We point out also that in low-lying optically thick plasma structures, such as those of active region filaments, the (horizontal) radiation field generated by the structure itself may substantially reduce the positive contribution to the anisotropy factor caused by the (vertical) radiation field coming from the underlying solar photosphere, so that the amount of atomic level polarization may turn out to be negligible. Only under such circumstances may the emergent linear polarization of the He I 10830 multiplet in such regions of the solar atmosphere be dominated by the contribution caused by the transverse Zeeman effect.
description: Accepted for publication in The Astrophysical Journal (It is tentatively scheduled for the ApJ January 20, 2007 issue)
Astrocyte response to 3D microenvironments
Creators: name: Balasubramanian, Swarnalatha
Publisher: name: Maryland Shared Open Access Repository
Year: 2014
Subjects: 3D collagen
Astrocyte
ECM
FGF
heterogeneity
Radial glia

description: Nerve injuries can be catastrophic as neurons in the adult human do not divide; therefore, neurons lost due to injury cannot be replaced by innate healing processes. Current therapeutic treatments to repair traumatic brain injury consist of rehabilitative, cellular and molecular therapies. However, these approaches target only some aspects of the injury and are not completely restorative. We propose a change in direction: to induce nerve regeneration, we focus on astrocytes, support cells in the central nervous system (CNS). We aim to harness immature astrocytes to recapitulate cues that were present in the developing brain but disrupted or lost in the adult brain injury environment. We characterized newborn mouse astrocytes in two conditions, traditional two-dimensional glass coverslips and three-dimensional (3D) hydrogels.  We present quantitative data supporting that 3D culture is critical for sustaining the heterogeneity of astrocytes. We also report that fibroblast growth factor induced astrocytes encapsulated in 3D hydrogels can recapitulate developmental cues and modify the hydrogel into an environment essential for neurite outgrowth and guidance.  This work is a major step towards understanding key parameters that guide astrocyte development and nerve regeneration and provides a foundation to design improved strategies for CNS injury and neurodegenerative disorders.
Correction to: A dual iterative substructuring method with a small penalty parameter
Creators: name: Lee, Chang-Ock
name: Park, Eun-Hee
name: Park, Jongho
Publisher: name: arXiv
Year: 2020
Subjects: subject: Numerical Analysis (math.NA)
subject: FOS: Mathematics
subject: 65F10, 65N30, 65N55

description: In this corrigendum, we offer a correction to [J. Korean. Math. Soc., 54 (2017), pp. 461--477]. We construct a counterexample for the strengthened Cauchy--Schwarz inequality used in the original paper. In addition, we provide a new proof for Lemma 5 of the original paper, an estimate for the extremal eigenvalues of the standard unpreconditioned FETI-DP dual operator.
description: 6 pages, 0 figure
Cavity nonlinear optics with few photons and ultracold quantum particles
Creators: name: Vukics, András
name: Niedenzu, Wolfgang
name: Ritsch, Helmut
Publisher: name: arXiv
Year: 2008
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The light force on particles trapped in the field of a high-Q cavity mode depends on the quantum state of field and particle. Different photon numbers generate different optical potentials anddifferent motional states induce different field evolution. Even for weak saturation and linear polarizability the induced particle motion leads to nonlinear field dynamics. We derive a corresponding effective field Hamiltonian containing all the powers of the photon number operator, which predicts nonlinear phase shifts and squeezing even at the few-photon level. Wave-function simulations of the full particle-field dynamics confirm this and show significant particle-field entanglement in addition.
description: 5 pages, 5 figures
title: Στοχαστικά μοντέλα Chain Ladder στις γενικές ασφαλίσεις
title: Stochastic Chain Ladder models in non-life insurance
titleType: AlternativeTitle
Creators: name: Μάντζαρη, Ελένη
Publisher: name: Πανεπιστήμιο Πειραιώς
Year: 2021
Subjects: subject: Στοχαστικά μοντέλα
subject: Chain Ladder

description: Η παρούσα διπλωματική εργασία διερευνά τις μεθόδους που χρησιμοποιούν οι ασφαλιστικές εταιρείες για να εκτιμήσουν τα απαραίτητα αποθέματα που πρέπει να διατηρούν για να εξασφαλίσουν την οικονομική τους ασφάλεια.
Microwave Dielectric Loss at Single Photon Energies and milliKelvin Temperatures
Creators: name: O'Connell, Aaron D.
name: Ansmann, M.
name: Bialczak, R. C.
name: Hofheinz, M.
name: Katz, N.
name: Lucero, Erik
name: McKenney, C.
name: Neeley, M.
name: Wang, H.
name: Weig, E. M.
name: Cleland, A. N.
name: Martinis, J. M.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: The microwave performance of amorphous dielectric materials at very low temperatures and very low excitation strengths displays significant excess loss. Here, we present the loss tangents of some common amorphous and crystalline dielectrics, measured at low temperatures (T < 100 mK) with near single-photon excitation energies, using both coplanar waveguide (CPW) and lumped LC resonators. The loss can be understood using a two-level state (TLS) defect model. A circuit analysis of the half-wavelength resonators we used is outlined, and the energy dissipation of such a resonator on a multilayered dielectric substrate is considered theoretically.
description: 4 pages, 3 figures, submitted to Applied Physics Letters
The Visual Ecology of Stomatopod Larvae
Creators: name: Feller, Kathryn Deborah
Publisher: name: Maryland Shared Open Access Repository
Year: 2014
Subjects: subject: Biological photonics
subject: Camouflage
subject: Crustacean
subject: Ecology
subject: FOS: Biological sciences
subject: Larvae
subject: Vision

description: Despite researchers' interest in adult stomatopod vision, only a handful of studies have investigated stomatopod larval visual ecology, the function of the larval compound eye, or its transition into the adult eye structures. In order to address this knowledge deficit, I tested several hypotheses surrounding larval eye physiology and ontogeny using microspectrophotometry (MSP) and electroretinography (ERG).  MSP was used to investigate visual pigment diversity in the retinas of different species of stomatopod larvae.  Together with data previously published, these data provide further support that larvae possess a single spectral class of photoreceptor.  Surprisingly, the peak spectral absorbance varied significantly among sympatric species, with four species falling into a short-wavelength and the remainder into a long-wavelength sensitivity class.  These results may be explained by differences in behavioral ecology or by different developmental stages of individual test subjects. To investigate ontogenetic changes in retinal function, ERG intensity responses were measured from different stage retinas of a single species, Squilla empusa. Initial MSP data from transitioning retinas found no evidence of visual pigment absorption in newly emerged adult retinas, implying a putative delay in photoreceptive function. Robust ERG responses to light stimuli, however, were observed from the earliest presence of emerging adult retinas, rejecting this hypothesis.  These data also suggest an increase in the response dynamics of stomatopod retinas with ontogeny as well as an increase in irradiance sensitivity during the double-retina phase.  To investigate the visual ecology of stomatopod larval light-reflecting structures, I characterized the function and structure of eyeshine overlying the retina. In situ photography of larvae eyeshine demonstrated its function as a contrast reducer, or camouflage.  Calculations of eyeshine reflectance spectra in their natural setting revealed novel, spectral matching with the background environment. Eyeshine structures were characterized via transmission electron microscopy (TEM) and identified as amorphous, three-dimensional photonic crystal arrays of spherical vesicles that coherently scatter light. The photonic mechanism of eyeshine production was tested using a modified Bragg-theory model and dimensions from TEM micrographs. These eyeshine data as well as data regarding the physiology of stomatopod larval vision provide a strong foundation for future investigations into the ontogeny of vision in stomatopod crustaceans.
Ultrafast Momentum-Resolved Probing of Plasmon Thermal Dynamics with Free Electrons
Creators: name: Mkhitaryan, Vahagn
name: Dias, Eduardo J. C.
name: Carbone, Fabrizio
name: de Abajo, F. Javier García
Publisher: name: arXiv
Year: 2020
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Current advances in ultrafast electron microscopy make it possible to combine optical pumping of a nanostructure and electron beam probing with subångstrom and femtosecond spatiotemporal resolution. We present a theory predicting that this technique can reveal a rich out-of-equilibrium dynamics of plasmon excitations in graphene and graphite samples. In a disruptive departure from the traditional probing of nanoscale excitations based on the identification of spectral features in the transmitted electrons, we show that measurement of angle-resolved, energy-integrated inelastic electron scattering can trace the temporal evolution of plasmons in these structures and provide momentum-resolved mode identification, thus avoiding the need for highly-monochromatic electron beams and the use of electron spectrometers. This previously unexplored approach to study the ultrafast dynamics of optical excitations can be of interest to understand and manipulate polaritons in 2D semiconductors and other materials exhibiting a strong thermo-optical response.
description: 24 pages, 13 figures, 101 references
Witten deformation and the equivariant index
Creators: name: Prokhorenkov, Igor
name: Richardson, Ken
Publisher: name: arXiv
Year: 2006
Subjects: subject: Differential Geometry (math.DG)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 58J20, 58J37, 58J50

description: Let $M$ be a compact Riemannian manifold endowed with an isometric action of a compact Lie group. The method of the Witten deformation is used to compute the virtual representation-valued equivariant index of a transversally elliptic, first order differential operator on $M$. The multiplicities of irreducible representations in the index are expressed in terms of local quantities associated to the isolated singular points of an equivariant bundle map that is locally Clifford multiplication by a Killing vector field near these points.
description: 26 pages, mistakes corrected, examples added
D2.2 Digital Twin
Creators: name: Ardebili, Mohsen Seyedkazemi
name: Bartolini, Andrea
Publisher: name: Zenodo
Year: 2024
Subjects: DECICE
Digital Twin

description: This deliverable describes the implementation of the DECICE Digital Twin core components.The deliverable describes the initial implementation of the Digital Twin and the interfaces for interconnecting with other DECICE components, showcasing its core elements. It delineates the various technological options applicable to different facets of the Digital Twin, offering a nuanced understanding of its capabilities.A detailed examination of data flow between these subcomponents is also presented.
Rapidity window dependence of ridge correlations in the glasma
Creators: name: Zhang, Donghai
name: Zhao, Yeyin
name: Xu, Mingmei
name: Pan, Xue
name: Wu, Yuanfang
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We study ridge correlations of the glasma in pp collisions at $\sqrt{s_{\mathrm{NN}}}=7$ TeV by using the color glass condensate (CGC) formalism. The azimuthal collimation at long range rapidity is intrinsic to glasma dynamics and is reproduced here. When rapidity window enlarges, ridge correlations in two dimensional $Δy$-$Δϕ$ distribution and one dimensional $Δϕ$ distribution at long range rapidity gap are enhanced. The enhancements are demonstrated to be the contributions of source gluons. The quantum evolution of the gluons presents unique correlation patterns in differential correlation function. These characters of two gluon correlations open a way of testing the production mechanism from experimental measurements.
description: 8 pages, 5 figures
Airbnb: μελέτη των κινήτρων και αξιολόγηση της εμπειρίας Ελλήνων τουριστών
Creators: name: Λαγκαδιανού, Χριστίνα
Publisher: name: Πανεπιστήμιο Πειραιώς
Year: 2021
Subjects: subject: Οικονομία διαμοιρασμού
subject: Airbnb
subject: Κίνητρα χρηστών
subject: Ποιότητα υπηρεσιών

description: Με τον τουρισμό να αποτελεί διεθνώς τον μεγαλύτερο και τον πιο ταχέως αναπτυσσόμενο κλάδο της οικονομίας, η προσπάθεια δραστηριοποίησης σε αυτόν έχει οδηγήσει στην εμφάνιση καινοτόμων προϊόντων και υπηρεσιών. Όπως είναι φυσικό, η διάδοση των επιχειρήσεων που εμπίπτουν σε μοντέλα οικονομίας διαμοιρασμού έχει επηρεάσει και τον τουρισμό σε παγκόσμιο επίπεδο. Χάρη στις δυνατότητες που προσφέρει το διαδίκτυο, όλο και περισσότερα επιχειρηματικά μοντέλα με βάση τον διαμοιρασμό έχουν κάνει την εμφάνισή τους. Η Airbnb αποτελεί το πιο επιτυχημένο παράδειγμα. Λαμβάνοντας υπόψη ότι πρόκειται την σχετικά πρόσφατη εμφάνιση της πλατφόρμας, έχει ιδιαίτερο ενδιαφέρον να μελετηθούν οι όλες οι πτυχές του θέματος. Σκοπός της έρευνας στην παρούσα διπλωματική είναι να διερευνηθούν τα κίνητρα που ωθούν τους Έλληνες τουρίστες στην επιλογήτηςAirbnb για τη διαμονή τους και να αξιολογηθεί η συνολική τους εμπειρία, εστιάζοντας σε συγκεκριμένες παραμέτρους. Για την επίτευξη του συγκεκριμένου σκοπού δημιουργήθηκε ερωτηματολόγιο που απαντήθηκε από 135 συμμετέχοντες. Η ανάλυση των αποτελεσμάτων έγινε σε Excel και χρησιμοποιήθηκε ο συντελεστής συσχέτισης Pearson r. Αξιοσημείωτο είναι πως οι βασικοί λόγοι επιλογής της πλατφόρμας έναντι ενός ξενοδοχείου είναι η συγκριτικά καλύτερη σχέση ποιότητας τιμής και οι παροχές των δωματίων/ διαμερισμάτων, οι οποίες πλησιάζουν τις ανέσεις σπιτιού. Ταυτόχρονα, σύμφωνα με τα αποτελέσματα, προκύπτει πως η πλειοψηφία του δείγματος αξιολογεί με θετικό πρόσημο την ποιότητα των υπηρεσιών σε σχέση με τις μεταβλητές οικοδεσπότης-κατάλυμα και ιστοσελίδα. Ακόμη, τα επίπεδα συνολικής ικανοποίησης και πιθανότητας επανάληψης της διαμονής, σύστασης σε τρίτους ή διαφήμισης της πλατφόρμας είναι υψηλά. Τέλος, από τη συσχέτιση των παραμέτρων της ποιότητας με την ικανοποίηση και τις επιμέρους μεταβλητές συμπεραίνουμε την ύπαρξη θετικής συσχέτισης.
Effects of non-local initial conditions in the Quantum Walk on the line
Creators: name: Abal, G.
name: Donangelo, R.
name: Romanelli, A.
name: Siri, R.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We report an enhancement of the decay rate of the survival probability when non-local initial conditions in position space are considered in the Quantum Walk on the line. It is shown how this interference effect can be understood analytically by using previously derived results. Within a restricted position subspace, the enhanced decay is correlated with a maximum asymptotic entanglement level while the normal decay rate corresponds to initial relative phases associated to a minimum entanglement level.
description: 5 pages, 1 figure, Elsevier style, to appear in Physica A
Image feature extraction and galaxy classification: a novel and efficient approach with automated machine learning
Creators: name: Tarsitano, F.
name: Bruderer, C.
name: Schawinski, K.
name: Hartley, W. G.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: In this work we explore the possibility of applying machine learning methods designed for one-dimensional problems to the task of galaxy image classification. The algorithms used for image classification typically rely on multiple costly steps, such as the Point Spread Function (PSF) deconvolution and the training and application of complex Convolutional Neural Networks (CNN) of thousands or even millions of parameters. In our approach, we extract features from the galaxy images by analysing the elliptical isophotes in their light distribution and collect the information in a sequence. The sequences obtained with this method present definite features allowing a direct distinction between galaxy types, as opposed to smooth Sérsic profiles. Then, we train and classify the sequences with machine learning algorithms, designed through the platform Modulos AutoML, and study how they optimize the classification task. As a demonstration of this method, we use the second public release of the Dark Energy Survey (DES DR2). We show that by applying it to this sample we are able to successfully distinguish between early-type and late-type galaxies, for images with signal-to-noise ratio greater then 300. This yields an accuracy of $86\%$ for the early-type galaxies and $93\%$ for the late-type galaxies, which is on par with most contemporary automated image classification approaches. Our novel method allows for galaxy images to be accurately classified and is faster than other approaches. Data dimensionality reduction also implies a significant lowering in computational cost. In the perspective of future data sets obtained with e.g. Euclid and the Vera Rubin Observatory (VRO), this work represents a path towards using a well-tested and widely used platform from industry in efficiently tackling galaxy classification problems at the peta-byte scale.
description: 9 pages, 7 figures
Detecting "Temperate" Jupiters: The Prospects of Searching for Transiting Gas Giants in Habitability Zones
Creators: name: Fleming, S. W.
name: Kane, S. R.
name: McCullough, P. R.
name: Chromey, F. R.
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: This paper investigates the effects of observing windows on detecting transiting planets by calculating the fraction of planets with a given period that have zero, one (single), two (double), or $\ge$3 (multiple) transits occurring while observations are being taken. We also investigate the effects of collaboration by performing the same calculations with combined observing times from two wide-field transit survey groups. For a representative field of the 2004 observing season, both XO and SuperWASP experienced an increase in single and double transit events by up to 20-40% for planets with periods 14 < P < 150 days when collaborating by sharing data. For the XO Project using its data alone, between 20-40% of planets with periods 14-150 days should have been observed at least once. For the SuperWASP Project, 50-90% of planets with periods between 14-150 days should have been observed at least once. If XO and SuperWASP combined their observations, 50-100% of planets with periods less than 20 days should be observed three or more times. We find that in general wide-field transit surveys have selected appropriate observing strategies to observe a significant fraction of transiting giant planets with semimajor axes larger than the Hot Jupiter regime. The actual number of intermediate-period transiting planets that are detected depends upon their true semimajor axis distribution and the signal-to-noise of the data.
description: 14 pages, 12 figures, 4 tables, accepted to MNRAS
Gravitational instantons and anomalous chiral symmetry breaking
Creators: name: Hamada, Yu
name: Pawlowski, Jan M.
name: Yamada, Masatoshi
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We study anomalous chiral symmetry breaking in two-flavour QCD induced by gravitational and QCD-instantons within asymptotically safe gravity within the functional renormalisation group approach. Similarly to QCD-instantons, gravitational ones, associated to a K3-surface connected by a wormhole-like throat in flat spacetime, generate contributions to the 't~Hooft coupling proportional to $\exp(-1/g_N)$ with the dimensionless Newton coupling $g_N$. Hence, in the asymptotically safe gravity scenario with a non-vanishing fixed point coupling $g_N^*$, the induced 't Hooft coupling is finite at the Planck scale, and its size depends on the chosen UV-completion. Within this scenario the gravitational effects on anomalous $U(1)_A$-breaking at the Planck scale may survive at low energy scales. In turn, fermion masses of the order of the Planck scale cannot be present. This constrains the allowed asymptotically safe UV-completion of the Gravity-QCD system. We map-out the parameter regime that is compatible with the existence of light fermions in the low-energy regime.
description: 14 pages, 7 figures
Nationale Kirche, Volkskirche oder Öffentlichkeitskirche?
Creators: name: Adamiak, Elżbieta
Publisher: name: Ökumenische Rundschau
Year: 2025

description: Ökumenische Rundschau, Bd. 66 Nr. 2 (2017): Ökumenische Rundschau, Band 66, Heft 2
Bayesian Single-Epoch Photometric Classification of Supernovae
Creators: name: Poznanski, Dovi
name: Maoz, Dan
name: Gal-Yam, Avishay
Publisher: name: arXiv
Year: 2006
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: (abridged) Ongoing supernova (SN) surveys find hundreds of candidates, that require confirmation for their use. Traditional classification based on followup spectroscopy of all candidates is virtually impossible for these large samples. We present an automatic Bayesian classifying algorithm for supernovae, the SN-ABC. We rely solely on single-epoch multiband photometry and host-galaxy (photometric) redshift information to sort SN candidates into the two major types, Ia and core-collapse supernovae. We test the SN-ABC performance on published samples of SNe from the SNLS and GOODS projects that have both broad-band photometry and spectroscopic classification (so the true type is known). The SN-ABC correctly classifies up to 97% (85%) of the type Ia (II-P) SNe in SNLS, and similar fractions of the GOODS SNe, depending on photometric redshift quality. Using simulations with large artificial samples, we find similarly high success fractions for type Ia and II-P, and reasonable (~75%) success rates in classifying type Ibc SNe as core-collapse. Type IIn SNe, however, are often misclassified as Ia's. In deep surveys, SNe Ia are best classified at redshifts z >~ 0.6, or when near maximum, with success rates of the order of 95%. Core-collapse SNe are best recognized several weeks after maximum, or at z
description: AJ, accepted
Weak Alfvénic turbulence in relativistic plasmas. Part 1. Dynamical equations and basic dynamics of interacting resonant triads
Creators: name: TenBarge, J. M.
name: Ripperda, B.
name: Chernoglazov, A.
name: Bhattacharjee, A.
name: Mahlmann, J. F.
name: Most, E. R.
name: Juno, J.
name: Yuan, Y.
name: Philippov, A. A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Plasma Physics (physics.plasm-ph)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: Alfvén wave collisions are the primary building blocks of the non-relativistic turbulence that permeates the heliosphere and low-to-moderate energy astrophysical systems. However, many astrophysical systems such as gamma-ray bursts, pulsar and magnetar magnetospheres, and active galactic nuclei have relativistic flows or energy densities. To better understand these high energy systems, we derive reduced relativistic MHD equations and employ them to examine weak Alfvénic turbulence, dominated by three-wave interactions, in reduced relativistic magnetohydrodynamics, including the force-free, infinitely magnetized limit. We compare both numerical and analytical solutions to demonstrate that many of the findings from non-relativistic weak turbulence are retained in the relativistic system. But, an important distinction in the relativistic limit is the inapplicability of a formally incompressible limit, i.e, there exists finite coupling to the compressible fast mode regardless of the strength of the magnetic field. Since fast modes can propagate across field lines, this mechanism provides a route for energy to escape strongly magnetized systems, e.g., magnetar magnetospheres. However, we find that the fast-Alfvén coupling is diminished in the limit of oblique propagation.
description: Accepted
Correlated Detection of sub-mHz Gravitational Waves by Two Optical-Fiber Interferometers
Creators: name: Cahill, Reginald T
name: Stokes, Finn
Publisher: name: arXiv
Year: 2008
Subjects: subject: General Physics (physics.gen-ph)
subject: FOS: Physical sciences

description: Results from two optical-fiber gravitational-wave interferometric detectors are reported. The detector design is very small, cheap and simple to build and operate. Using two detectors has permitted various tests of the design principles as well as demonstrating the first simultaneous detection of correlated gravitational waves from detectors spatially separated by 1.1km. The frequency spectrum of the detected gravitational waves is sub-mHz with a strain spectral index a=-1.4 +/- 0.1. As well as characterising the wave effects the detectors also show, from data collected over some 80 days in the latter part of 2007, the dominant earth rotation effect and the earth orbit effect. The detectors operate by exploiting light speed anisotropy in optical-fibers. The data confirms previous observations of light speed anisotropy, earth rotation and orbit effects, and gravitational waves.
description: 15 pages, 17 colored figures
Picomolar FKBP inhibitors enabled by a single water-displacing methyl group in bicyclic [4.3.1] aza-amides
Creators: name: Kolos, Jürgen M.
name: Pomplun, Sebastian
name: Jung, Sascha
name: Rieß, Benedikt
name: Purder, Patrick L.
name: Voll, Andreas M.
name: Merz, Stephanie
name: Gnatzy, Monika
name: Jatzlau, Jerome
name: Knaus, Petra
Publisher: name: Freie Universität Berlin
Year: 2021
Subjects: subject: methyl groups
subject: FK506-binding proteins
subject: bone morphogenic protein
subject: 500 Naturwissenschaften und Mathematik::540 Chemie::540 Chemie und zugeordnete Wissenschaften

description: Methyl groups can have profound effects in drug discovery but the underlying mechanisms are diverse and incompletely understood. Here we report the stereospecific effect of a single, solvent-exposed methyl group in bicyclic [4.3.1] aza-amides, robustly leading to a 2 to 10-fold increase in binding affinity for FK506-binding proteins (FKBPs). This resulted in the most potent and efficient FKBP ligands known to date. By a combination of co-crystal structures, isothermal titration calorimetry (ITC), density-functional theory (DFT), and 3D reference interaction site model (3D-RISM) calculations we elucidated the origin of the observed affinity boost, which was purely entropically driven and relied on the displacement of a water molecule at the protein–ligand–bulk solvent interface. The best compounds potently occupied FKBPs in cells and enhanced bone morphogenic protein (BMP) signaling. Our results show how subtle manipulation of the solvent network can be used to design atom-efficient ligands for difficult, solvent-exposed binding pockets.