cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Enabling large-scale seismic data acquisition, processing and waveform-inversion via rank-minimization
Creators: name: Kumar, Rajiv
Publisher: name: University of British Columbia
Year: 2017

description: In this thesis, I adapt ideas from the field of compressed sensing to mitigate the computational and memory bottleneck of seismic processing workflows such as missing-trace interpolation, source separation and wave-equation based inversion for large-scale 3- and 5-D seismic data. For interpolation and source separation using rank-minimization, I propose three main ingredients, namely a rank-revealing transform domain, a subsampling scheme that increases the rank in the transform domain, and a practical large-scale data-consistent rank-minimization framework, which avoids the need for expensive computation of singular value decompositions. We also devise a wave-equation based factorization approach that removes computational bottlenecks and provides access to the kinematics and amplitudes of full-subsurface offset extended images via actions of full extended image volumes on probing vectors, which I use to perform the amplitude-versus- angle analyses and automatic wave-equation migration velocity analyses on complex geological environments. After a brief overview of matrix completion techniques in Chapter 1, we propose a singular value decomposition (SVD)-free factorization based rank-minimization approach for large-scale matrix completion problems. Then, I extend this framework to deal with large-scale seismic data interpolation problems, where I show that the standard approach of partitioning the seismic data into windows is not required, which use the fact that events tend to become linear in these windows, while exploiting the low-rank structure of seismic data. Carefully selected synthetic and realistic seismic data examples validate the efficacy of the interpolation framework. Next, I extend the SVD-free rank-minimization approach to remove the seismic cross-talk in simultaneous source acquisition. Experimental results verify that source separation using the SVD-free rank-minimization approaches are comparable to the sparsity-promotion based techniques; however, separation via rank-minimization is significantly faster and memory efficient. We further introduce a matrix-vector formulation to form full-subsurface extended image volumes, which removes the storage and computational bottleneck found in the convention methods. I demonstrate that the proposed matrix-vector formulation is used to form different image gathers with which amplitude-versus-angle and wave-equation migration velocity analyses is performed, without requiring prior information on the geologic dips. Finally, I conclude the thesis by outlining potential future research directions and extensions of the thesis work.
Curvature as a Measure of the Thermodynamic Interaction
Creators: name: Quevedo, Hernando
name: Sanchez, Alberto
name: Taj, Safia
name: Vazquez, Alejandro
Publisher: name: arXiv
Year: 2010
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We present a systematic and consistent construction of geometrothermodynamics by using Riemannian contact geometry for the phase manifold and harmonic maps for the equilibrium manifold. We present several metrics for the phase manifold that are invariant with respect to Legendre transformations and induce thermodynamic metrics on the equilibrium manifold. We review all the known examples in which the curvature of the thermodynamic metrics can be used as a measure of the thermodynamic interaction.
Application of Volcano Plots in Analyses of mRNA Differential Expressions with Microarrays
Creators: name: Li, Wentian
Publisher: name: arXiv
Year: 2011
Subjects: subject: Quantitative Methods (q-bio.QM)
subject: Genomics (q-bio.GN)
subject: FOS: Biological sciences

description: Volcano plot displays unstandardized signal (e.g. log-fold-change) against noise-adjusted/standardized signal (e.g. t-statistic or -log10(p-value) from the t test). We review the basic and an interactive use of the volcano plot, and its crucial role in understanding the regularized t-statistic. The joint filtering gene selection criterion based on regularized statistics has a curved discriminant line in the volcano plot, as compared to the two perpendicular lines for the "double filtering" criterion. This review attempts to provide an unifying framework for discussions on alternative measures of differential expression, improved methods for estimating variance, and visual display of a microarray analysis result. We also discuss the possibility to apply volcano plots to other fields beyond microarray.
description: 8 figures
Phone Proxies: Effortless Content Sharing Between Smartphones and Interactive Surfaces
Creators: name: Bazo, Alexander
name: Echtler, Florian
Publisher: name: Universität Regensburg
Year: 2014
Subjects: subject: casual interaction, interactive surface, mobile device, nfc, smartphone
subject: 004 Informatik

description: We present Phone Proxies, a technique for effortless content sharing between mobile devices and interactive surfaces. In such a scenario, users often have to perform a lengthy setup process before the actual exchange of content can take place. Phone Proxies uses a combination of custom NFC (near-field communication) tags and optical markers on the interactive surface to reduce the user interaction required for this setup process to an absolute minimum. We discuss two use cases: "pickup", in which the user wants to transfer content from the surface onto their device, and "share", in which the user transfers device content to the surface for shared viewing. We introduce three possible implementations of Phone Proxies for each of these use cases and discuss their respective advantages.
Religious Freedom and Dominant Religion
Creators: name: Mojica, Conrad
Publisher: name: University of Chicago
Year: 2022

description: Spearheaded by the United States, many countries have taken an interest in incorporating international religious freedom into their foreign policies. Assessments of religious freedom conditions are well-documented, but there is no consensus on what factors explain the variation in religious freedom between the world’s countries. This project posits that a government’s relationship with its dominant religion is crucial to shaping its religious freedom conditions. Since no sources have quantified the many dimensions of a government’s relationship with its dominant religion, I construct an index to measure this relationship. Within this index, I categorize the different aspects of this relationship as (1) the dominant religion’s control of laws, (2) the presence of religious members in government, (3) the presence of pro-dominant religion legislation, (4) the government’s funding of the dominant religion, and (5) the government’s control over the dominant religion. Through regression analysis, I find a negative correlation between a government’s tie to the dominant religion and its religious freedom score. However, the strength of this correlation greatly varies between the categories of the government’s relationship with its dominant religion, with the most significant negative correlation with religious freedom being with the government’s control of the dominant religion. This study suggests that international actors interested in improving the religious freedom conditions should adopt a country-specific approach that considers the country’s government’s relationship with its dominant religion. These actors should tolerate these existing relationships and only seek to change the specific aspects detrimental to religious freedom.
Rómverja saga : an introduction and a translation.
Creators: name: Birnudóttir, Svala Lind
Publisher: name: University of British Columbia
Year: 2017

description: Rómverja saga (‘The Saga of the Romans’) is an Old Icelandic translation of three Latin works by Sallust and Lucan on historical themes from the classical period. In this thesis, I provide the first English translation of this little-known text in the hope that it might prove a tool for scholars interested in the reception of Latin literature in the medieval period. The saga is a free rendition of its models, and as such it gives us a glimpse into what elements a culture removed in both time and place valued and appropriated from Classical Rome. In the introduction, I will start by placing Rómverja saga in its literary context. I will then review the modern scholarship on the saga, focusing on its two different versions. Following that, I will list features and key terms that show how the redactor has adapted the text to his native context. The introduction ends with an overview of my translation choices. The translation of the second version of Rómverja saga follows
Microsolvation of Molecules in Superfluid Helium Nanodroplets Revealed by Means of Electronic Spectroscopy
Creators: name: Slenczka, Alkwin
name: Premke, Tobias
name: Wirths, Eva-Maria
name: Pentlehner, Dominik
name: Lehnig, Rudolf
name: Richers, Ricarda
name: Vdovin, Alexander
Publisher: name: Universität Regensburg
Year: 2014
Subjects: subject: electronic spectroscopy, Molecules, molecular complexes, microsolvation, Helium droplets, zero phonon line, phonon wing
subject: 615 Pharmazie

description: The empirical model explaining microsolvation of molecules in superfluid helium droplets proposes a non-superfluid helium solvation layer enclosing the dopant molecule. This model warrants an empirical explanation of any helium induced substructure resolved for electronic transitions of molecules in helium droplets. Despite a wealth of such experimental data, quantitative modeling of spectra is still in its infancy. The theoretical treatment of such many-particle systems dissolved into a quantum fluid is a challenge. Moreover, the success of theoretical activities relies also on the accuracy and self-critical communication of experimental data. This will be elucidated by a critical resume of our own experimental work done within the last ten years. We come to the conclusion that spectroscopic data and among others in particular the spectral resolution depend strongly on experimental conditions. Moreover, despite the fact that none of the helium induced fine structure speaks against the empirical model for solvation in helium droplets, in many cases an unequivocal assignment of the spectroscopic details is not possible. This ambiguity needs to be considered and a careful and critical communication of experimental results is essential in order to promote success in quantitatively understanding microsolvation in superfluid helium nanodroplets.
TYPE II DNA: when the interfacial energy becomes negative
Creators: name: Sadhukhan, Poulomi
name: Maji, Jaya
name: Bhattacharjee, Somendra M.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: An important step in transcription of a DNA base sequence to a protein is the initiation from the exact starting point, called promoter region. We propose a physical mechanism for identification of the promoter region, which relies on a new classification of DNAs into two types, Type-I and Type-II, like superconductors, depending on the sign of the energy of the interface separating the zipped and the unzipped phases. This is determined by the energies of helical ordering and stretching over two independent length scales. The negative interfacial energy in Type II DNA leads to domains of helically ordered state separated by defect regions, or blobs, enclosed by the interfaces. The defect blobs, pinned by non-coding promoter regions, would be physically distinct from all other types of bubbles. We also show that the order of the melting transition under a force is different for Type I and Type II.
description: 4 pages, 2 figures, Eq.(4) corrected in 4th version
Multifaceted Defense against Antagonistic Microbes in Developing Offspring of the Parasitoid Wasp Ampulex compressa (Hymenoptera, Ampulicidae)
Creators: name: Weiss, Katharina
name: Parzefall, Christopher
name: Herzner, Gudrun
Publisher: name: Universität Regensburg
Year: 2014
Subjects: subject: 590 Tiere (Zoologie)

description: Effective antimicrobial strategies are essential adaptations of insects to protect themselves, their offspring, and their foods from microbial pathogens and decomposers. Larvae of the emerald cockroach wasp, Ampulex compressa, sanitize their cockroach hosts, Periplaneta americana, with a cocktail of nine antimicrobials comprising mainly (R)-(-)-mellein and micromolide. The blend of these antimicrobials has broad-spectrum antimicrobial activity. Here we explore the spatiotemporal pattern of deployment of antimicrobials during the development from egg to adult as well as their physicochemical properties to assess how these aspects may contribute to the success of the antimicrobial strategy. Using gas chromatography/mass spectrometry (GC/MS) we show that larvae start sanitizing their food as soon as they have entered their host to feed on its tissue. Subsequently, they impregnate the cockroach carcass with antimicrobials to create a hygienic substrate for cocoon spinning inside the host. Finally, the antimicrobials are incorporated into the cocoon. The antimicrobial profiles on cockroach and wasp cocoon differed markedly. While micromolide persisted on the cockroaches until emergence of the wasps, solid-phase microextraction sampling and GC/MS analysis revealed that (R)-(-)-mellein vaporized from the cockroaches and accumulated in the enclosed nest. In microbial challenge assays (R)-(-)-mellein in the headspace of parasitized cockroaches inhibited growth of entomopathogenic and opportunistic microbes (Serratia marcescens, Aspergillus sydowii, Metarhizium brunneum). We conclude that, in addition to food sanitation, A. compressa larvae enclose themselves in two defensive walls by impregnating the cocoon and the cockroach cuticle with antimicrobials. On top of that, they use vaporous (R)-(-)-mellein to sanitize the nest by fumigation. This multifaceted antimicrobial defense strategy involving the spatially and temporally coordinated deployment of several antimicrobials in solution and vapor form has apparently evolved to reliably protect the larvae themselves and their food against a broad range of antagonistic microbes.
Spectral rigidity of automorphic orbits in free groups
Creators: name: Francaviglia, Stefano
name: Carette, Mathieu
name: Kapovich, Ilya
name: Martino, Armando
Publisher: name: arXiv
Year: 2011
Subjects: subject: Group Theory (math.GR)
subject: Geometric Topology (math.GT)
subject: FOS: Mathematics
subject: Primary 20F, Secondary 57M, 37D

description: It is well-known that a point $T\in cv_N$ in the (unprojectivized) Culler-Vogtmann Outer space $cv_N$ is uniquely determined by its \emph{translation length function} $||.||_T:F_N\to\mathbb R$. A subset $S$ of a free group $F_N$ is called \emph{spectrally rigid} if, whenever $T,T'\in cv_N$ are such that $||g||_T=||g||_{T'}$ for every $g\in S$ then $T=T'$ in $cv_N$. By contrast to the similar questions for the Teichmüller space, it is known that for $N\ge 2$ there does not exist a finite spectrally rigid subset of $F_N$. In this paper we prove that for $N\ge 3$ if $H\le Aut(F_N)$ is a subgroup that projects to an infinite normal subgroup in $Out(F_N)$ then the $H$-orbit of an arbitrary nontrivial element $g\in F_N$ is spectrally rigid. We also establish a similar statement for $F_2=F(a,b)$, provided that $g\in F_2$ is not conjugate to a power of $[a,b]$. We also include an appended corrigendum which gives a corrected proof of Lemma 5.1 about the existence of a fully irreducible element in an infinite normal subgroup of of $Out(F_N)$. Our original proof of Lemma 5.1 relied on a subgroup classification result of Handel-Mosher, originally stated by Handel-Mosher for arbitrary subgroups $H\le Out(F_N)$. After our paper was published, it turned out that the proof of the Handel-Mosher subgroup classification theorem needs the assumption that $H$ be finitely generated. The corrigendum provides an alternative proof of Lemma~5.1 which uses the corrected, finitely generated, version of the Handel-Mosher theorem and relies on the 0-acylindricity of the action of $Out(F_N)$ on the free factor complex (due to Bestvina-Mann-Reynolds). A proof of 0-acylindricity is included in the corrigendum.
description: Included a corrigendum which gives a corrected proof of Lemma 5.1 about the existence of a fully irreducible element in an infinite normal subgroup of of Out(F_N). Note that, because of the arXiv rules, the corrigendum and the original article are amalgamated into a single pdf file, with the corrigendum appearing first, followed by the main body of the original article
Demographic characteristics of participants in graduate college professional and sociocultural development programming
Creators: name: Schram, Laura
name: Flores-Scott, Emma
name: Clasing-Manquian, Paula
Publisher: name: My University
Year: 2023
Subjects: Professional development
graduate school
graduate college
Master's and doctoral students
Sociocultural development

description: Purpose The USA’s higher education leaders and professional organizations have called for increased professional development programming at graduate colleges to better prepare US graduate students for their future careers. This study aims to investigate the demographic characteristics of graduate students participating in co-curricular professional development (PD) and sociocultural development (SD) programming at a graduate college at a large, selective and research-intensive public university in the Midwestern USA. Design/methodology/approach Using institutional data from six semesters, the authors examined the characteristics of students that attended the graduate college’s programs at one university. The authors analyzed which students were most likely to attend PD and SD programs using multinomial logistic regression models. Findings Female students, students from US historically marginalized racial groups, and US Pell Grant recipients (low-income students) were found to have a higher likelihood of attending both PD and SD programs at the centralized graduate college. Practical implications The findings will be of interest to graduate deans and educators who support graduate students. Further evaluative research on the usefulness of such programs at other institutions would help graduate colleges better understand the role they play in meeting graduate students’ needs. Originality/value The findings contribute to the understanding of the important role of the US graduate college in the development of graduate students. To the best of the authors’ knowledge, it is the first study to evaluate the backgrounds of graduate students who pursue co-curricular PD and SD opportunities.
Anti-aggressive effects of neuropeptide S independent of anxiolysis in male rats
Creators: name: Beiderbeck, Daniela Ingeborg
name: Lukas, Michael
name: Neumann, Inga D.
Publisher: name: Universität Regensburg
Year: 2014
Subjects: subject: Aggression, Hypothalamus, Nucleus Accumbens, Social Behavior, Anxiety, neuropeptide S
subject: 590 Tiere (Zoologie)

description: Neuropeptide S (NPS) exerts robust anxiolytic and memory enhancing effects, but only in a non-social context. In order to study whether NPS affects aggressive behavior we used Wistar rats bred for low (LAB) and high (HAB) levels of innate anxiety-related behaviour, respectively, which were both described to display increased levels of aggression compared with Wistar rats not selectively bred for anxiety (NAB). Male LAB, HAB and NAB rats were tested for aggressive behavior towards a male intruder rat within their home cage (10 min, resident-intruder [RI] test). Intracerebroventricular (icv) infusion of NPS (1 nmol) significantly reduced inter-male aggression in LAB rats, and tended to reduce aggression in HAB and NAB males. However, local infusion of NPS (0.2 or 0.1 nmol NPS) into either the nucleus accumbens or the lateral hypothalamus did not influence aggressive behavior. Social investigation in the RI test and general social motivation assessed in the social preference paradigm were not altered by icv NPS. The anti-aggressive effect of NPS is most likely not causally linked to its anxiolytic properties, as intraperitoneal administration of the anxiogenic drug pentylenetetrazole decreased aggression in LAB rats whereas the anxiolytic drug diazepam did not affect aggression of HAB rats. Thus, although NPS has so far only been shown to exert effects on non-social behaviors, our results are the first demonstration of anti-aggressive effects of NPS in male rats.
Global dynamics above the ground state for the nonlinear Klein-Gordon equation without a radial assumption
Creators: name: Nakanishi, Kenji
name: Schlag, Wilhelm
Publisher: name: arXiv
Year: 2010
Subjects: subject: Analysis of PDEs (math.AP)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 35L70, 35Q55

description: We extend our previous result on the focusing cubic Klein-Gordon equation in three dimensions to the non-radial case, giving a complete classification of global dynamics of all solutions with energy at most slightly above that of the ground state.
description: 40 pages
supplementary.docx from Virtual manipulation of tail postures of a gliding barn owl (Tyto alba) demonstrates drag minimization when gliding
Creators: name: Song, Jialei
name: Cheney, Jorn A.
name: Bomphrey, Richard J.
name: Usherwood, James R.
Publisher: name: The Royal Society
Year: 2022
Subjects: subject: 110601 Biomechanics
subject: FOS: Health sciences

description: Supplementary figures
Self-organized criticality in a network of economic agents with finite consumption
Creators: name: da Cruz, João P.
name: Lind, Pedro G.
Publisher: name: arXiv
Year: 2010
Subjects: subject: General Finance (q-fin.GN)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: Physics and Society (physics.soc-ph)
subject: FOS: Economics and business
subject: FOS: Physical sciences

description: We introduce a simple model for addressing the controversy in the study of financial systems, sometimes taken as brownian-like processes and other as critical systems with fluctuations of arbitrary magnitude. The model considers a collection of economical agents which establish trade connections among them according to basic economical principles properly translated into physical properties and interaction. With our model we are able to reproduce the evolution of macroscopic quantities (indices) and to correctly retrieve the common exponent value characterizing several indices in financial markets, relating it to the underlying topology of connections.
Emotion and affect in mental imagery: Do fear and anxiety manipulate mental rotation performance?
Creators: name: Kaltner, Sandra
name: Jansen, Petra
Publisher: name: Universität Regensburg
Year: 2014
Subjects: subject: Fear, Anxiety, mental rotation, Embodied Cognition, object-based and egocentric transformations
subject: 796 Sport

description: Little is known about the effects of fear as a basic emotion on mental rotation performance. We expected that the emotional arousal evoked by fearful stimuli presented prior to each mental rotation trial would enhance mental rotation performance. Regarding the influence of anxiety, high anxious participants are supposed to show slower responses and higher error rates in this specific visuo-spatial ability. Furthermore, with respect to the embodied cognition viewpoint we wanted to investigate if the influence of fear on mental rotation performance is the same for egocentric and object-based transformations. Results show that fear enhances mental rotation performance, expressed by a higher mental rotation speed. Interestingly, this influence is stimulus-specific: it is restricted to egocentric transformations. Both observation of emotional stimuli and egocentric strategies are associated with left hemisphere activation which could explain a stronger influence on this type of transformation during observation. Another possible notion is the conceptual link between visuo-spatial perspective taking and empathy based on the co-activation of parietal areas. Stronger responses in egocentric transformations could result from this specific link. Regarding the influence of anxiety, participants with high scores on the trait-anxiety scale showed poor results in both reaction time and mental rotation speed. Findings of impoverished recruitment of prefrontal attentional control in patients with high scores in trait anxiety could be the explanation for this reduced performance.
Multigrid preconditioning of linear systems for semismooth Newton methods applied to optimization problems constrained by smoothing operators
Creators: name: Draganescu, Andrei
Publisher: name: arXiv
Year: 2011
Subjects: subject: Numerical Analysis (math.NA)
subject: Optimization and Control (math.OC)
subject: FOS: Mathematics

description: This article is concerned with the question of constructing effcient multigrid preconditioners for the linear systems arising when applying semismooth Newton methods to large-scale linear-quadratic optimization problems constrained by smoothing operators with box-constraints on the controls. It is shown that, for certain discretizations of the optimization problem, the linear systems to be solved at each semismooth Newton iteration reduce to inverting principal minors of the Hessian of the associated unconstrained problem. As in the case when box-constraints on the controls are absent, the multigrid preconditioner introduced here is shown to increase in quality as the mesh-size decreases, resulting in a number of iterations that decreases with mesh-size. However, unlike the unconstrained case, the spectral distance between the preconditioners and the Hessian is shown to be of suboptimal order in general.
description: 34 pages, 5 figures, 4 tables
A D2-brane in the Penrose limits of AdS(4)x CP(3)
Creators: name: Ali-Akbari, M.
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We consider a D2-brane in the pp-wave backgrounds obtained from AdS$_4\times$CP$^3$ when electric and magnetic fields have been turned on. Upon fixing the light-cone gauge, light-cone Hamiltonian and BPS configurations are obtained. In particular we study BPS configurations with electric dipole on the two sphere giant and a giant graviton rotating in transverse directions. Moreover we show that the gauge field living on the D2-brane is replaced by a scalar field in the light-cone Hamiltonian. We also present a matrix model by regularizing (quantizing) 2-brane theory.
description: 14 pages
Biomass, productivity and allocation patterns in tropical old-growth and logged-over forests in Ghana
Creators: name: Addo-Danso, Shalom Daniel
Publisher: name: University of British Columbia
Year: 2017

description: Understanding how tropical forest structure and function change during the decades after logging is a key research challenge. This thesis reports functional traits, forest structure, biomass, net primary productivity (NPP) and allocation, as well as their controlling factors in an old-growth forest and a 54-year-old logged-over forest in Ghana. By analyzing root traits, I found fine-root biomass, root length, surface area, and root tissue density were higher in the logged-over forest, whereas the old-growth forest had higher specific root length and specific root area. I also found divergent exploitation strategies between the two forests; plants in the old-growth forest produced thinner roots, which increase resource uptake efficiency, while plants in the logged-over forest had thicker roots, which are associated with greater resource conservation. Through correlation analysis, I found that fine-root mass correlated positively to relative humidity, while absorbed photosynthetically active radiation and fine-root biomass were also positively correlated. Fine-root mass and soil K were also positively correlated, and fine-root necromass correlated positively with soil P. I then explored the relationships between leaf traits, taxonomic (e.g., species richness) or structural (e.g., tree diameter) variables and aboveground biomass (AGB) or coarse wood productivity (CWP) in the two forests. Leaf K related positively to tree biomass in the logged-over forest. Leaf N and P were significantly and positively related to tree productivity in the old-growth forest and logged-over forest. AGB and CWP were mostly explained by the structural variables. The shape and magnitude of the relationships between tree species richness and AGB or CWP differed between the two forests. In addition, I found that leaf area index, mean tree diameter and height were similar between the two forests, but stand density and basal area were higher in the logged-over forest than in the old-growth forest. Total biomass and annual NPP were comparable in both forests, but there was a shift in NPP allocation between wood and fine roots. I conclude that the forest structure, biomass and productivity of the logged-over forest have largely recovered, but the legacy of logging still persists, which is reflected in differences in functional traits and allocation patterns.
Ultrafast Laser Energy Density and Retinal Absorption Cross-Section Determination by Saturable Absorption Measurements
Creators: name: Penzkofer, Alfons
name: Luck, Meike
name: Mathes, Tilo
name: Hegemann, Peter
Publisher: name: Universität Regensburg
Year: 2014
Subjects: subject: Laser Pulse Peak Energy Density Determination, Ground-State Absorption Cross-Section Determination, Excited-State Absorption Cross-Section Determination, Saturable Absorption, ADS084BE Dye, Histidine Kinase Rhodopsin HKR1, Retinal Schiff Base RetA Cofactor, Number Density Determination
subject: 530 Physik

description: Laser pulse nonlinear transmission measurements through saturable absorbers of known absorption parameters allow the measurement of their energy density. On the other hand, nonlinear transmission measurements of laser pulses of known energy density through absorbing media allow their absorption parameter determination. The peak energy density w0P of second harmonic pulses of a mode-locked titanium sapphire laser at wavelength λP = 400 nm is determined by nonlinear energy transmission measurement TE through the dye ADS084BE (1,4-bis(9-ethyl-3-car-bazovinylene)-2-methoxy-5-(2’-ethyl-hexyloxy)-benzene) in tetrahydrofuran. TE(w0P) calibration curves are calculated for laser pulse peak energy density reading w0P from measured pulse energy transmissions TE. The ground-state absorption cross-section σP and the excited-state absorption cross-section σex at λP, and the number density N0 of the retinal Schiff base isoform RetA in pH 7.4 buffer of the blue-light adapted recombinant rhodopsin fragment of the histidine kinase rhodopsin HKR1 from Chlamydomonas reinhardtii were determined by picosecond titanium sapphire second harmonic laser pulse energy transmission measurement TE through RetA as a function of laser input peak energy density w0P. The complete absorption cross-section spectrum σ
Folk Theorems on the Correspondence between State-Based and Event-Based Systems
Creators: name: Reniers, M. A.
name: Willemse, T. A. C.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Logic in Computer Science (cs.LO)
subject: Formal Languages and Automata Theory (cs.FL)
subject: FOS: Computer and information sciences

description: Kripke Structures and Labelled Transition Systems are the two most prominent semantic models used in concurrency theory. Both models are commonly believed to be equi-expressive. One can find many ad-hoc embeddings of one of these models into the other. We build upon the seminal work of De Nicola and Vaandrager that firmly established the correspondence between stuttering equivalence in Kripke Structures and divergence-sensitive branching bisimulation in Labelled Transition Systems. We show that their embeddings can also be used for a range of other equivalences of interest, such as strong bisimilarity, simulation equivalence, and trace equivalence. Furthermore, we extend the results by De Nicola and Vaandrager by showing that there are additional translations that allow one to use minimisation techniques in one semantic domain to obtain minimal representatives in the other semantic domain for these equivalences.
description: Full version of SOFSEM 2011 paper
Complements and higher resonance varieties of hyperplane arrangements
Creators: name: Budur, Nero
Publisher: name: arXiv
Year: 2011
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics

description: Hyperplane arrangements form the geometric counterpart of combinatorial objects such as matroids. The shape of the sequence of Betti numbers of the complement of a hyperplane arrangement is of particular interest in combinatorics, where they are known, up to a sign, as Whitney numbers of the first kind, and appear as the coefficients of chromatic, or characteristic, polynomials. We show that certain combinations, some nonlinear, of these Betti numbers satisfy Schur positivity. At the same time, we study the higher degree resonance varieties of the arrangement. We draw some consequences, using homological algebra results and vector bundles techniques, of the fact that all resonance varieties are determinantal.
description: Erratum to Thm 1.1 added. Main results on deeper propagation, dimensional bounds for resonance varieties, and positivity results related to Betti numbers are unchanged
Subcanopy genetics – the relationship between canopy tree size and genetic variation of the savanna species Pollichia campestris Aiton (Illecebraceae)
Creators: name: Simmel, Josef
name: Poschlod, Peter
name: Reisch, Christoph
Publisher: name: Universität Regensburg
Year: 2014
Subjects: subject: Acacia, AFLP, Directed Dispersal, Frugivore, Kalahari, Nurse Tree
subject: 580 Pflanzen (Botanik)

description: In savanna vegetation, trees and their canopies provide an important, but scattered habitat. Seeds of plants growing under these nurse trees often are dispersed by animals, especially birds. In the present study, we investigated the influence of tree size and frugivore dispersal on the genetic variation of the subcanopy species Pollichia campestris, using amplified fragment length polymorphisms (AFLP). Considering the individuals under each nurse tree as subpopulations, we found the genetic variation within subpopulations to be positively correlated with the size of the respective canopy tree. Genetic variation was very low among, but high within subpopulations (ΦPT = 0.026, P = 0.18). We conclude that the low genetic variation among subpopulations is due to effective and directed dispersal (dispersal from one canopy to another) by legitimate and frugivorous dispersal agents.
title: "Statua di Eracle, tipo Albertini", arte romana, inv. CXIV (ITA/EN)
title: Scheda catalogo digitale Borghese
titleType: AlternativeTitle
Creators: name: di Fazio, Clara
name: Galleria Borghese
Publisher: name: Galleria Borghese
Year: 2024

description: Pubblicazione delle schede delle opere conservate nel museo ed estratte dal catalogo digitale di

Galleria Borghese, nelle due versioni esistenti online, in italiano e inglese.

Collegamento al catalogo digitale:

ITA: https://www.collezionegalleriaborghese.it/

EN: https://www.collezionegalleriaborghese.it/en
Slowly synchronizing automata and digraphs
Creators: name: Ananichev, Dmitry S.
name: Gusev, Vladimir V.
name: Volkov, Mikhail V.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Formal Languages and Automata Theory (cs.FL)
subject: Discrete Mathematics (cs.DM)
subject: FOS: Computer and information sciences
subject: 68Q45, 68R10

description: We present several infinite series of synchronizing automata for which the minimum length of reset words is close to the square of the number of states. These automata are closely related to primitive digraphs with large exponent.
description: 13 pages, 5 figures
Chromatin targeting signals nucleosome positioning mechanism and non-coding RNA mediated regulation of the chromatin remodeling complex NoRC
Creators: name: Längst, Gernot
name: Gross, Thomas
name: Strohner, Ralf
name: Manelyte, Laura
Publisher: name: Universität Regensburg
Year: 2014
Subjects: subject: 570 Biowissenschaften, Biologie

description: Active and repressed ribosomal RNA (rRNA) genes are characterised by specific epigenetic marks and differentially positioned nucleosomes at their promoters. Repression of the rRNA genes requires a non-coding RNA (pRNA) and the presence of the nucleolar remodeling complex (NoRC). ATP-dependent chromatin remodeling enzymes are essential regulators of DNA-dependent processes, and this regulation occurs via the modulation of DNA accessibility in chromatin. We have studied the targeting of NoRC to the rRNA gene promoter; its mechanism of nucleosome positioning, in which a nucleosome is placed over the transcription initiation site; and the functional role of the pRNA. We demonstrate that NoRC is capable of recognising and binding to the nucleosomal rRNA gene promoter on its own and binds with higher affinity the nucleosomes positioned at non-repressive positions. NoRC recognises the promoter nucleosome within a chromatin array and positions the nucleosomes, as observed in vivo. NoRC uses the release mechanism of positioning, which is characterised by a reduced affinity for the remodeled substrate. The pRNA specifically binds to NoRC and regulates the enzyme by switching off its ATPase activity. Given the known role of pRNA in tethering NoRC to the rDNA, we propose that pRNA is a key factor that links the chromatin modification activity and scaffolding function of NoRC.
title: A Neoliberalisation of Social Data? Big Data and the Future of Official Statistics
Creators: name: Takala, Ville
Publisher: name: Goldsmiths, University of London
Year: 2018

description: Many of the existing commentaries on enormous, interconnected, dynamic datasets, or Big Data, as they have become commonly known, have highlighted their technical qualities. It has for example been argued that what separates Big Data from previous forms of data are the so called 3Vs; Volume, Variety and Velocity. In contrast, based on a historical, conceptual and empirical analysis, I suggest that what is novel about Big Data is not just its technical composition, but more importantly the changing jurisdictions between the producers of data that its emergence entails. Its technical composition, I argue, is predicated upon how its production is organised.

I suggest that historically, statistics have emerged out of a co-constitutive interaction between methodological and technological developments and changes in the political and administrative world (Desrosières 1998). Further to this, I suggest that the production of data on which statistics have relied has often been monopolised by dominant institutions. By situating Big Data in the context of political economy, I argue that its emergence reflects broader processes of neoliberalisation that have swept over western polities in the past few decades, notably in the sense that it primarily accumulates in the private, rather than the public sector. 

By exploring responses to Big Data within National Statistical Institutes, I suggest that it signals not just an increasing privatisation of data production and related infrastructures, but also an increasing pressure to adopt neoliberal rationalities and values in the public sector. I suggest that at Statistics Finland, where my fieldwork was based, these processes are potentially undermining the social welfarist principles upon which the production of official statistics has for long been based. I argue that the social organisation of Big Data must be rethought based on Social Democratic principles and political imaginations and that the question about the future role of the NSI must form a central component of such considerations.
Spherical Tiling by 12 Congruent Pentagons
Creators: name: Gao, Honghao
name: Shi, Nan
name: Yan, Min
Publisher: name: arXiv
Year: 2010
Subjects: subject: Combinatorics (math.CO)
subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 05B45, 52C20

description: The tilings of the 2-dimensional sphere by congruent triangles have been extensively studied, and the edge-to-edge tilings have been completely classified. However, not much is known about the tilings by other congruent polygons. In this paper, we classify the simplest case, which is the edge-to-edge tilings of the 2-dimensional sphere by 12 congruent pentagons. We find one major class allowing two independent continuous parameters and four classes of isolated examples. The classification is done by first separately classifying the combinatorial, edge length, and angle aspects, and then combining the respective classifications together.
description: 53 pages, 40 figures, spherical geometry
Critical branching random walks, branching capacity and branching interlacements
Creators: name: Zhu, Qingsan
Publisher: name: University of British Columbia
Year: 2017

description: This thesis concerns critical branching random walks. We focus on supercritical (d ≥ 5 or higher) and critical (d=4) dimensions. In this thesis, we extend the potential theory for random walk to critical branching random walk. In supercritical dimensions, we introduce branching capacity for every finite subset of ℤ^d and construct its connections with critical branching random walk through the following three perspectives. 1. The visiting probability of a finite set by a critical branching random walk starting far away; 2. Branching recurrence and branching transience; 3. Local limit of branching random walk in torus conditioned on the total size. Moreover, we establish the model which we call 'branching interlacements' as the local limit of branching random walk in torus conditioned on the total size. In the critical dimension, we also construct some parallel results. On the one hand, we give the asymptotics of visiting a finite set and the convergence of the conditional hitting point. On the other hand, we establish the asymptotics of the range of a branching random walk conditioned on the total size. Also in this thesis, we analyze a small game which we call the Majority-Markov game and give an optimal strategy.
Negative parity tetraquarks with the open charm
Creators: name: Gerasyuta, S. M.
name: Kochkin, V. I.
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The relativistic four-quark equations are found in the framework of coupled-channel formalism. The dynamical mixing of the meson-meson states with the four-quark states is considered. The four-quark amplitudes of the negative parity tetraquarks including the quarks of three flavors (u, d, s) and the charmed quark are constructed. The poles of these amplitudes determine the masses of tetraquarks. The mass values of low-lying tetraquarks with the spin-parity JP=0-,1-,2-,3- are calculated.
description: 18 pages, pdf
Spin Hall voltages from a.c. and d.c. spin currents
Creators: name: Wei, Dahai
name: Obstbaum, Martin
name: Ribow, Mirko
name: Back, Christian
name: Woltersdorf, Georg
Publisher: name: Universität Regensburg
Year: 2014
Subjects: subject: 530 Physik

description: In spin electronics, the spin degree of freedom is used to transmit and store information. To this end the ability to create pure spin currents—that is, without net charge transfer—is essential. When the magnetization vector in a ferromagnet–normal metal junction is excited, the spin pumping effect leads to the injection of pure spin currents into the normal metal. The polarization of this spin current is time-dependent and contains a very small d.c. component. Here we show that the large a.c. component of the spin currents can be detected efficiently using the inverse spin Hall effect. The observed a.c.-inverse spin Hall voltages are one order of magnitude larger than the conventional d.c.-inverse spin Hall voltages measured on the same device. Our results demonstrate that ferromagnet–normal metal junctions are efficient sources of pure spin currents in the gigahertz frequency range.
Cooperative hydrolysis of aryl esters on functionalized membrane surfaces and in micellar solutions
Creators: name: Poznik, Michal
name: König, Burkhard
Publisher: name: Universität Regensburg
Year: 2014
Subjects: subject: 540 Chemie

description: Catalytic hydrolysis of peptides, proteins, phosphates or carboxylate esters in nature is catalysed by enzymes, which are efficient, fast and selective. Most of the hydrolytic chemical catalysts published so far mimic the active site of enzymes and contain metal complexes and amino acid residues. Their synthesis can be laborious, while the hydrolytic activity is still limited compared to enzymes. We present an approach that uses fluid membranes of vesicles and micelles as a support for amphiphilic additives, which cooperatively cleave aryl ester bonds. The membrane anchored bis-Zn(II)-complex 1 is hydrolytically active and hydrolyses fluorescein diacetate (FDA) with a second order rate constant (k2) of 0.9 M−1 s−1. The hydrolytic activity is modulated by co-embedded membrane additives, bearing common amino acid side chain functional groups. With this approach, the hydrolytic activity of the system is enhanced up to 16 fold in comparison with cyclen 1 (k2 = 14.7 M−1 s−1). DOPC and DSPC lipids form at room temperature fluid or gel phase membranes, respectively. Omitting the lipid, micellar solutions were obtained with hydrolytic activity reaching k2 = 13.4 M−1 s−1. It is shown that cooperative hydrolysis is favoured in fluid membranes and micelles, allowing the active moieties to arrange freely. The embedding and dynamic self-assembly of membrane active components in fluid membranes and micelles provide facile access to hydrolytically active soft interfaces.
description: Open-Access-Komponente aus der Allianzlizenz
Scalar Fields in BTZ Black Hole Spacetime and Entanglement Entropy
Creators: name: Singh, Dharm Veer
name: Siwach, Sanjay
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study the quantum scalar fields in background of BTZ black hole spacetime. We calculate the entanglement entropy using the discretized model, which resembles a system of coupled harmonic oscillators. The leading term of the entropy formula is standard Bakenstein-Hawking entropy and sub-leading corresponds to quantum corrections to black hole entropy. We calculate the co-efficent of sub-leading logarithmic corrections numerically.
description: journal version, numerical section on entropy revised
Spin of ground state baryons
Creators: name: Buchmann, A. J.
name: Henley, E. M.
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We calculate the quark spin contribution to the total angular momentum of flavor octet and flavor decuplet ground state baryons using a spin-flavor symmetry based parametrization method of quantum chromodynamics. We find that third order SU(6) symmetry breaking three-quark operators are necessary to explain the experimental result Sigma_1=0.32(10). For spin 3/2 decuplet baryons we predict that the quark spin contribution is Sigma_3=3.93(22), i.e. considerably larger than their total angular momentum.
description: 8 pages