cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Self-Supervised Hyperboloid Representations from Logical Queries over Knowledge Graphs
Creators: name: Choudhary, Nurendra
name: Rao, Nikhil
name: Katariya, Sumeet
name: Subbian, Karthik
name: Reddy, Chandan K.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Machine Learning (cs.LG)
subject: Computation and Language (cs.CL)
subject: Information Retrieval (cs.IR)
subject: FOS: Computer and information sciences

description: Knowledge Graphs (KGs) are ubiquitous structures for information storagein several real-world applications such as web search, e-commerce, social networks, and biology. Querying KGs remains a foundational and challenging problem due to their size and complexity. Promising approaches to tackle this problem include embedding the KG units (e.g., entities and relations) in a Euclidean space such that the query embedding contains the information relevant to its results. These approaches, however, fail to capture the hierarchical nature and semantic information of the entities present in the graph. Additionally, most of these approaches only utilize multi-hop queries (that can be modeled by simple translation operations) to learn embeddings and ignore more complex operations such as intersection and union of simpler queries. To tackle such complex operations, in this paper, we formulate KG representation learning as a self-supervised logical query reasoning problem that utilizes translation, intersection and union queries over KGs. We propose Hyperboloid Embeddings (HypE), a novel self-supervised dynamic reasoning framework, that utilizes positive first-order existential queries on a KG to learn representations of its entities and relations as hyperboloids in a Poincaré ball. HypE models the positive first-order queries as geometrical translation, intersection, and union. For the problem of KG reasoning in real-world datasets, the proposed HypE model significantly outperforms the state-of-the art results. We also apply HypE to an anomaly detection task on a popular e-commerce website product taxonomy as well as hierarchically organized web articles and demonstrate significant performance improvements compared to existing baseline methods. Finally, we also visualize the learned HypE embeddings in a Poincaré ball to clearly interpret and comprehend the representation space.
description: Accepted at the Web Conference 2021 (WWW '21)
Pottmeyer, Hermann Josef: Unfehlbarkeit und Souveränität im System der ultramontanen Ekklesiologie des 19. Jahrhunderts
Creators: name: Urban, Hans Jörg
Publisher: name: Ökumenische Rundschau
Year: 2025

description: Ökumenische Rundschau, Bd. 26 Nr. 3 (1977): Ökumenische Rundschau, Band 26, Heft 3
The Conformal Penrose Limit and the Resolution of the pp-curvature Singularities
Creators: name: Gueven, R.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We consider the exact solutions of the supergravity theories in various dimensions in which the space-time has the form M_{d} x S^{D-d} where M_{d} is an Einstein space admitting a conformal Killing vector and S^{D-d} is a sphere of an appropriate dimension. We show that, if the cosmological constant of M_{d} is negative and the conformal Killing vector is space-like, then such solutions will have a conformal Penrose limit: M^{(0)}_{d} x S^{D-d} where M^{(0)}_{d} is a generalized d-dimensional AdS plane wave. We study the properties of the limiting solutions and find that M^{(0)}_{d} has 1/4 supersymmetry as well as a Virasoro symmetry. We also describe how the pp-curvature singularity of M^{(0)}_{d} is resolved in the particular case of the D6-branes of D=10 type IIA supergravity theory. This distinguished case provides an interesting generalization of the plane waves in D=11 supergravity theory and suggests a duality between the SU(2) gauged d=8 supergravity of Salam and Sezgin on M^{(0)}_{8} and the d=7 ungauged supergravity theory on its pp-wave boundary.
description: 20 pages, LaTeX; typos corrected, journal version
Memory-two zero-determinant strategies in repeated games
Creators: name: Ueda, Masahiko
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computer Science and Game Theory (cs.GT)
subject: FOS: Computer and information sciences

description: Repeated games have provided an explanation how mutual cooperation can be achieved even if defection is more favorable in a one-shot game in prisoner's dilemma situation. Recently found zero-determinant strategies have substantially been investigated in evolutionary game theory. The original memory-one zero-determinant strategies unilaterally enforce linear relations between average payoffs of players. Here, we extend the concept of zero-determinant strategies to memory-two strategies in repeated games. Memory-two zero-determinant strategies unilaterally enforce linear relations between correlation functions of payoffs and payoffs at the previous round. Examples of memory-two zero-determinant strategy in the repeated prisoner's dilemma game are provided, some of which generalize the Tit-for-Tat strategy to memory-two case. Extension of zero-determinant strategies to memory-$n$ case with $n\geq 2$ is also straightforward.
description: 14 pages, 5 figures
Internal migration and mobile communication patterns among pairs with strong ties
Creators: name: Fudolig, Mikaela Irene D.
name: Monsivais, Daniel
name: Bhattacharya, Kunal
name: Jo, Hang-Hyun
name: Kaski, Kimmo
Publisher: name: arXiv
Year: 2020
Subjects: subject: Social and Information Networks (cs.SI)
subject: Computers and Society (cs.CY)
subject: Physics and Society (physics.soc-ph)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences

description: Using large-scale call detail records of anonymised mobile phone service subscribers with demographic and location information, we investigate how a long-distance residential move within the country affects the mobile communication patterns between an ego who moved and a frequently called alter who did not move. By using clustering methods in analysing the call frequency time series, we find that such ego-alter pairs are grouped into two clusters, those with the call frequency increasing and those with the call frequency decreasing after the move of the ego. This indicates that such residential moves are correlated with a change in the communication pattern soon after moving. We find that the pre-move calling behaviour is a relevant predictor for the post-move calling behaviour. While demographic and location information can help in predicting whether the call frequency will rise or decay, they are not relevant in predicting the actual call frequency volume. We also note that at four months after the move, most of these close pairs maintain contact, even if the call frequency is decreased.
description: published version in EPJ Data Science
Inflationary spectra and partially decohered distributions
Creators: name: Campo, David
name: Parentani, Renaud
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: It is generally expected that decoherence processes will erase the quantum properties of the inflationary primordial spectra. However, given the weakness of gravitational interactions, one might end up with a distribution which is only partially decohered. Below a certain critical change, we show that the inflationary distribution retains quantum properties. We identify four of these: a squeezed spread in some direction of phase space, non-vanishing off-diagonal matrix elements, and two properties used in quantum optics called non-$P$-representability and non-separability. The last two are necessary conditions to violate Bell's inequalities. The critical value above which all these properties are lost is associated to the `grain' of coherent states. The corresponding value of the entropy is equal to half the maximal (thermal) value. Moreover it coincides with the entropy of the effective distribution obtained by neglecting the decaying modes. By considering backreaction effects, we also provide an upper bound for this entropy at the onset of the adiabatic era.
description: 42 pages, 9 figures; 1 ref. added
Tempestuous life beyond R_500: X-ray view on the Coma cluster with SRG/eROSITA. I. X-ray morphology, recent merger, and radio halo connection
Creators: name: Churazov, E.
name: Khabibullin, I.
name: Lyskova, N.
name: Sunyaev, R.
name: Bykov, A. M.
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: This is the first paper in a series of studies of the Coma cluster using the SRG/eROSITA X-ray data obtained in course of the Calibration and Performance Verification observations. The data cover $\sim3^\circ\times 3^\circ$ area around the cluster with a typical exposure time of more than 20 ks. The stability of the instrumental background and operation of the SRG Observatory in the scanning mode provided us with an excellent data set for studies of the diffuse emission up to a distance of $\sim 1.5R_{200}$ from the Coma center. In this study, we discuss the rich morphology revealed by the X-ray observations (also in combination with the SZ data) and argue that the most salient features can be naturally explained by a recent (on-going) merger with the NGC 4839 group. In particular, we identify a faint X-ray bridge connecting the group with the cluster, which is convincing proof that NGC 4839 has already crossed the main cluster. The gas in the Coma core went through two shocks, first through the shock driven by NGC 4839 during its first passage through the cluster some Gyr ago, and, more recently, through the "mini-accretion shock" associated with the gas settling back to quasi-hydrostatic equilibrium in the core. After passing through the primary shock, the gas should spend much of the time in a rarefaction region, where radiative losses of electrons are small, until the gas is compressed again by the mini-accretion shock. Unlike "runway" merger shocks, the mini-accretion shock does not feature a rarefaction region downstream and, therefore, the radio emission can survive longer. Such a two-stage process might explain the formation of the radio halo in the Coma cluster.
description: accepted for publication in A&A
Instantons and the infrared behavior of the fermion propagator in the Schwinger Model
Creators: name: Radozycki, Tomasz
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Fermion propagator of the Schwinger Model is revisited from the point of view of its infrared behavior. The values of anomalous dimensions are found in arbitrary covariant gauge and in all contributing instanton sectors. In the case of a gauge invariant, but path dependent propagator, the exponential dependence, instead of power law one, is established for the special case when the path is a straight line. The leading behavior is almost identical in any sector, differing only by the slowly varying, algebraic prefactors. The other kind of the gauge invariant function, which is the amplitude of the dressed Dirac fermions, may be reduced, by the appropriate choice of the dressing, to the gauge variant one, if Landau gauge is imposed.
description: 9 pages, in REVTEX
Bose-glass to Superfluid transition in the three-dimensional Bose-Hubbard Model
Creators: name: Hitchcock, Peter
name: Sorensen, Erik S.
Publisher: name: arXiv
Year: 2006
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We present a Monte Carlo study of the Bose-glass to superfluid transition in the three-dimensional Bose-Hubbard model. Simulations are performed on the classical (3 + 1) dimensional link-current representation using the geometrical worm algorithm. Finite-size scaling analysis (on lattices as large as 16x16x16x512 sites) of the superfluid stiffness and the compressibility is consistent with a value of the dynamical critical exponent z = 3, in agreement with existing scaling and renormalization group arguments that z = d. We find also a value of $ν= 0.70(12)$ for the correlation length exponent, satisfying the relation $ν>= 2/d$. However, a detailed study of the correlation functions, C(r, tau), at the quantum critical point are not consistent with this value of z. We speculate that this discrepancy could be due to the fact that the correlation functions have not reached their true asymptotic behavior because of the relatively small spatial extent of the lattices used in the present study.
description: 9 pages, 8 figures, submitted to PRB
Bioactive nanoparticle incorporation into inorganic/organic hybrids
Creators: name: Li, Zhenlun
Publisher: name: Imperial College London
Year: 2018

description: Mesoporous silica nanoparticles have a great therapeutic potential as they can deliver active ions and they also have been made to nanocomposites with polymers for bone regeneration. Hybrids are co-networks of inorganic and organic components that can be produced with interconnected pores, matching mechanical properties to the host tissue and controlled biodegradability. Both silica nanoparticles and hybrids can be made from the sol–gel process. Calcium incorporated mesoporous silica nanoparticles (MCE) have been developed as a bioactive cation carrier. In this thesis, a PTHF/PCL/MCE/SiO2 nano-hybrid network was achieved. For the first time, (3-Glycidyloxypropyl)trimethoxysilane (GPTMS) functionalized MCEs were incorporated into a hybrid and covalently bonded to the silicate network. Dense calcium containing silica nanoparticles were found not to be suitable for GPTMS grafting because of the low concentration of hydroxyl groups on the particle surface. Calcium incorporated mesoporous silica nanoparticles proved themselves to be a better choice for the functionalization as they had larger surface area and higher -OH surface density. In a Tris buffer dissolution study, the existence of covalent bonds between MCEs and the polymer network made them to release calcium at a slightly slower rate compared with unfunctionalized samples. In SBF dissolution, only a small amount of HCA formation was captured on specific samples after 3 weeks. This suggested the amount of calcium incorporated into particles were too low. Because of the suspected release of remained BF3OEt2, which caused a significant pH drop in solution, samples failed to pass cytotoxicity tests unless they were washed in water for 24 h prior to the test. Finally, porous scaffolds were fabricated by using 3D extrusion printing and the ink rheology profile showed a shear thinning behaviour. The concept of using nanoparticles as a bioactive cation carrier covalently bonded to the hybrid network was proven to be feasible. This nano-hybrid system also has potential for incorporating other cations for different applications, such as lithium for cartilage and strontium for bone regeneration.
Minnesota Farm Real Estate Sales: 1990-2005
Creators: name: Taff, Steven J.
name: Taff, Steven J.
Publisher: name: Unknown
Year: 2006
Subjects: Land Economics/Use

description: This publication is a snapshot of the Minnesota Farm Real Estate Sales web site (http://www.apec.umn.edu/faculty/sjtaff/salesstudy) as of May 31, 2006. It will be formally "reissued" (the web site will be recaptured) each Spring, as new sales data become available. We no longer distribute a separate farm real estate report in the Minnesota Agricultural Economist (now the Minnesota Applied Economist. The site consists largely of graphs and tables summarizing sales over the past fifteen years. It provides averages at the multi-county region and at the statewide levels of aggregation. Individual transaction data are available for downloading and analysis at Minnesota Land Economics (MLE) web site, located at http://www.apec.umn.edu/landeconomics. Electronic versions of this document are presented in fully navigable portable document format (pdf).
Interferometric 4D-STEM for Lattice Distortion and Interlayer Spacing Measurements in Bilayer and Trilayer Two-dimensional Materials
Creators: name: Zachman, Michael J
name: Madsen, Jacob
name: Zhang, Xiang
name: Ajayan, Pulickel M
name: Susi, Toma
name: Chi, Miaofang
Publisher: name: arXiv
Year: 2020
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Van der Waals materials composed of stacks of individual atomic layers have attracted considerable attention due to their exotic electronic properties that can be altered by, for example, manipulating the twist angle of bilayer materials or the stacking sequence of trilayer materials. To fully understand and control the unique properties of these few-layer materials, a technique that can provide information about their local in-plane structural deformations, twist direction, and out-of-plane structure is needed. In principle, interference in overlap regions of Bragg disks originating from separate layers of a material encodes three-dimensional information about the relative positions of atoms in the corresponding layers. Here, we describe an interferometric four-dimensional scanning transmission electron microscopy technique that utilizes this phenomenon to extract precise structural information from few-layer materials with nm-scale resolution. We demonstrate how this technique enables measurement of local pm-scale in-plane lattice distortions as well as twist direction and average interlayer spacings in bilayer and trilayer graphene, and therefore provides a means to better understand the interplay between electronic properties and precise structural arrangements of few-layer 2D materials.
Quark-model study of few-baryon systems
Creators: name: Valcarce, A.
name: Garcilazo, H.
name: Fernandez, F.
name: Gonzalez, P.
Publisher: name: arXiv
Year: 2005
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We review the application of non-relativistic constituent quark models to study one, two and three non-strange baryon systems. We present results for the baryon spectra, potentials and observables of the NN, N$Δ$, $ΔΔ$ and NN$^*(1440)$ systems, and also for the binding energies of three non-strange baryon systems. We make emphasis on observable effects related to quark antisymmetry and its interplay with quark dynamics.
description: 82 pages, 36 figures, 18 tables. Accepted for publication in Reports on Progress in Physics
The evolutionary ecology of root-associated bacteria
Creators: name: Matthews, Andrew Charles
Publisher: name: Imperial College London
Year: 2018

description: Complex communities are formed by association of plant roots with microbes in soil, and signiﬁcantly determine plant nutrition, stress tolerance, and pathogen resistance. These communities are potentially shaped by diﬀerential microbial colonisation of roots, competition between colonizing strains, and selective recruitment of microbes by plants - all these processes are poorly understood. To better understand community assembly in the root and how it can aﬀect plant growth and health, this thesis explored experimentally the ecological factors shaping microbial communities. I found that plant host species rather than soils deﬁned microbial communities, although community assembly appears to diﬀer between plant species, as both relatively invariant and dynamic assembly patterns are observed. Phenotypic characterization of rhizobacteria isolates indicated that bacterial functions deﬁne root-associated bacteria beyond phylogenetic identities, so that diﬀerential colonization and selection are plausible mechanisms for assembly. Nevertheless, isolate host origin was not an important predictor of colonization ability in a gnotobiotic in planta experimental system, although competitive or mutualistic interactions could be very important for colonization and plant growth outcomes. An additional chapter exploring the microbial ecology of a ‘replant’ disease in a commercial orchard conﬁrmed that disease risk associated with soil legacy was associated with changes in diversity and abundance of unculturable phyla. This project highlights the potential of culture-independent approaches, but also their limitations. Microbial function and microbe-microbe interactions are clearly important for rhizobacterial community assembly, but their elucidation may require more data-intensive approaches. In terms of predicting which microbes might colonize particular plants and whether colonization is likely to be beneﬁcial, this thesis only scratched the surface of the problem. Perhaps not surprisingly, environmental context is very important for understanding when rhizobacteria are likely to be beneﬁcial, while the complexities of bacterial competition and mutualism suggest that stochasticity is important in determining which microbes are successful on which plant.
A structure-preserving, operator splitting scheme for reaction-diffusion equations with detailed balance
Creators: name: Liu, Chun
name: Wang, Cheng
name: Wang, Yiwei
Publisher: name: arXiv
Year: 2020
Subjects: subject: Numerical Analysis (math.NA)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: In this paper, we propose and analyze a positivity-preserving, energy stable numerical scheme for certain type reaction-diffusion systems involving the Law of Mass Action with the detailed balance condition. The numerical scheme is constructed based on a recently developed energetic variational formulation, in which the reaction part is reformulated in terms of reaction trajectories. The fact that both the reaction and the diffusion parts dissipate the same free energy opens a path of an energy stable, operator splitting scheme for these systems. At the reaction stage, we solve equations of reaction trajectories by treating all the logarithmic terms in the reformulated form implicitly due to their convex nature. The positivity-preserving property and unique solvability can be theoretically proved, based on the singular behavior of the logarithmic function around the limiting value. Moreover, the energy stability of this scheme at the reaction stage can be proved by a careful convexity analysis. Similar techniques are used to establish the positivity-preserving property and energy stability for the standard semi-implicit solver at the diffusion stage. As a result, a combination of these two stages leads to a positivity-preserving and energy-stable numerical scheme for the original reaction-diffusion system. To our best knowledge, it is the first time to report an energy-dissipation-law-based operator splitting scheme to a nonlinear PDE with variational structures. Several numerical examples are presented to demonstrate the robustness of the proposed operator splitting scheme.
Detection of TeV gamma-ray Emission from the Shell-Type Supernova Remnant RX J0852.0-4622 with H.E.S.S
Creators: name: collaboration, H. E. S. S.
name: :
name: Aharonian, F.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We report the detection of TeV gamma-rays from the shell-type supernova remnant RX J0852.0-4622 with data of 3.2 h of live time recorded with H.E.S.S. in February 2004. An excess of (700 +/- 60) events from the whole remnant with a significance of 12 sigma was found. The observed emission region is clearly extended with a radius of the order of 1 degree and the spatial distribution of the signal correlates with X-ray observations. The spectrum in the energy range between 500 GeV and 15 TeV is well described by a power law with a photon index of 2.1 +/- 0.1(stat) +/- 0.2(syst) and a differential flux at 1 TeV of (2.1 +/- 0.2(stat) +/- 0.6(syst)) 10^{-11} cm^{-2} s^{-1} TeV^{-1}. The integral flux above 1 TeV was measured to be (1.9 +/- 0.3(stat) +/- 0.6(syst)) 10^{-11} cm^{-2} s^{-1}, which is at the level of the flux of the Crab nebula at these energies. More data are needed to draw firm conclusions on the magnetic field in the remnant and the type of the particle population creating the TeV gamma-rays.
description: 5 pages, 3 figures, accepted for publication in A&A letters
Bulk-edge correspondence with generalized chiral symmetry
Creators: name: Kawarabayashi, Tohru
name: Hatsugai, Yasuhiro
Publisher: name: arXiv
Year: 2020
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The bulk-edge correspondence in topological phases is extended to systems with the generalized chiral symmetry, where the conventional chiral symmetry is broken. In such systems, we find that the edge state exhibits an unconventional behavior in the presence of the symmetry breaking by the mass, which is explored explicitly in the case of a deformed Su-Schrieffer-Heeger model. The localization length of the edge states diverges at a certain critical mass, where the edge state touches to the bulk band. The edge state is specified by an imaginary wave vector that becomes real at the touching energy.
description: 11 pages, 9 figures
Confinement of Fermions in Tachyon Matter at Finite Temperature
Creators: name: Issifu, Adamu
name: Rocha, Julio C. M.
name: Brito, Francisco A.
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study a phenomenological model that mimics the characteristics of QCD theory at finite temperature. The model involves fermions coupled with a modified Abelian gauge field in a tachyon matter. It reproduces some important QCD features such as, confinement, deconfinement, chiral symmetry and quark-gluon-plasma (QGP) phase transitions. The study may shed light on both light and heavy quark potentials and their string tensions. Flux-tube and Cornell potentials are developed depending on the regime under consideration. Other confining properties such as scalar glueball mass, gluon mass, glueball-meson mixing states, gluon and chiral condensates are exploited as well. The study is focused on two possible regimes, the ultraviolet (UV) and the infrared (IR) regimes.
description: 25 pages, 13 figures, version published in AHEP
Società e stato
per una identità borghese

Scritti scelti
Creators: name: Schiera, Pierangelo
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2016
Subjects: SPS/02 Storia delle dottrine politiche

description: Questa terza raccolta degli scritti di Pierangelo Schiera riunisce testi usciti tra il 1976 e il 2013. Il volume riprende alcuni dei principali percorsi di ricerca che hanno finora caratterizzato la sua opera. In primo luogo quello centrato sul lungo processo di costituzione dello Stato moderno: esso viene indagato attraverso lo studio della ragion di Stato e del costituzionalismo. In questo terzo volume domina tuttavia l’attenzione per la costituzione della società moderna. All’interno di questo secolare processo la melancolia emerge come simbolo della condizione umana, ovvero di una individualità che deve costantemente inventarsi e disciplinarsi. La faticosa disciplina di questi individui mira a raggiungere una condotta di vita capace di esprimere una scelta etica. L’indagine storica di classici del pensiero politico, quali Christian Thomasius, Wilhelm von Humboldt e Max Weber, si affianca all’analisi di autori altrimenti considerati minori come Adolf Knigge e Madame de Staël, Sismonde de Sismondi o Joseph Arthur de Gobineau, ma restituisce anche la politica dell’arte di Ambrogio Lorenzetti e Johann Sebastian Bach. In tutti questi casi al centro dell’attenzione di Schiera è il carattere dottrinario delle loro produzioni intellettuali, ovvero il modo in cui tutte le loro diverse opere contribuiscono all’autoconsapevolezza della società. In questo laboratorio secolare, che fonde istituzioni, socialità e individuo, si forma lentamente ma inequivocabilmente l’identità borghese.
Polycaprolactone containing inorganic/organic hybrid biomaterials
Creators: name: Sang, Tian
Publisher: name: Imperial College London
Year: 2018

description: Bioactive glass and its associated products are able to stimulate bone regeneration but they are brittle and unable to be applied in load bearing sites. Improvements are needed so that they can share load with bone as well as promoting new bone growth and being biodegradable. Sol-gel hybrids can achieve this by having covalently coupled inorganic and organic networks. In order to form such intimate co-network, the choice of polymer is essential. Polycaprolactone (PCL) is a biodegradable polymer that has been widely used in tissue engineering due to its slow degradation rate, however it lacks functional groups that are critical to covalently bond to the silica network. In this thesis, new PCL/silica hybrids that have covalently bonded co-network were developed to toughen the glass content for the use in bone regeneration. In the first step, novel copolymer of caprolactone (CL) and 3-glycidoxypropyl trimethoxysilane (GPTMS) were synthesised to overcome the lack of functionality in conventional PCL. Hydrolysed silane part in the new poly(CL-co-GPTMS) are able to directly bond to the silica network without further functionalization. Hybrids were made homogeneously with poly(CL-co-GPTMS). Both weight percentage and repeating units of CL and GPTMS can be used to tailor the mechanical properties so that they obtain high compressive strength (64 MPa), strain to failure (20%) and deform elastically. Pre-osteoblast cells were found to adhere on the hybrids. Calcium was then incorporated into the glass using calcium methoxyethoxide (CME) in order to make the hybrid bioactive. The hybrids promoted hydroxycarbonate apatite (HCA) formation after 3 days immersion in stimulated body fluid (SBF). CME addition has also changed the mechanical properties of the hybrids depend on how CME was added to the hybrids. Inspired by the chemistry of polyurethane and poly(urethane-co-caprolactone) copolymer, hybrids were also made with cross-linked polymer content by the addition of methylene diphenyl diisocyanate (MDI). The MDI cross-linking effect has further toughed the hybrids without reducing their biological responses. Introducing such a new hybrid platform created a new way to fabricate biomaterials for bone repair.
The first coefficients of the asymptotic expansion of the Bergman kernel of the spin^c Dirac operator
Creators: name: Ma, Xiaonan
name: Marinescu, George
Publisher: name: arXiv
Year: 2005
Subjects: subject: Complex Variables (math.CV)
subject: Differential Geometry (math.DG)
subject: FOS: Mathematics

description: We establish the existence of the asymptotic expansion of the Bergman kernel associated to the spin-c Dirac operators acting on high tensor powers of line bundles with non-degenerate mixed curvature (negative and positive eigenvalues) by extending the paper " On the asymptotic expansion of Bergman kernel " (math.DG/0404494) of Dai-Liu-Ma. We compute the second coefficient b_1 in the asymptotic expansion using the method of our paper "Generalized Bergman kernels on symplectic manifolds" (math.DG/0411559).
description: 21 pages, to appear in Internat. J. Math. Precisions added in the abstract
Do drugs prescribed to prevent hip fractures in fact cause bones to become weaker?
Creators: name: Ma, Shaocheng
Publisher: name: Imperial College London
Year: 2018

description: Osteoporosis is the most prevalent metabolic bone disorder worldwide, for which bisphosphonates are the first-line treatment. Bisphosphonates suppress normal bone remodelling and are effective at reducing fracture risk. However, bisphosphonate use is associated with fragility fractures in a small population of patients. This thesis comprises a series of studies designed to investigate the effects of bisphosphonates on the mechanical and structural properties of bone. The first study investigated the effects of bisphosphonate treatment on the microstructural and mechanical properties of bone. Bisphosphonate-treated bone exhibited increased frequency and size of microcracks, which corresponded to reduced tensile strength and stiffness. These findings suggest that the accumulation of microcracks occurring in bisphosphonate-treated bone comprises the microstructure leading to reduced mechanical strength. In the second study, the fracture mechanics of bisphosphonate-treated bone were evaluated. The propagation of cracks in the bisphosphonate group was significantly greater compared with osteoporotic and healthy bone, which highlights a reduction in fracture resistance. There is loss of protective mechanisms against fracture in bisphosphonate-treated bone, thus increasing susceptibility to low-energy fractures. The aim of the third study was to interrogate the effects of bisphosphonate treatment on bone mechanics at the nanoscale. Mineral strain reached a peak at the maximum tissue strain, preceding the onset of fibril sliding. There was initiation of fibril sliding at a higher tissue strain than that corresponding to ultimate tensile strength but at a lower tissue strain than that corresponding to fracture. Hence, the mechanisms contributing to reduced macroscopic strength observed in bisphosphonate-treated bone can be attributed to the effects the mineral’s ability to contribute to the load carrying capacity of the bone. The present findings suggest that there may be a population of patients in whom bisphosphonate therapy does not confer protective effects against fractures but is associated with micro- and nanostructural alternations and increased bone fragility instead.
Exports and FDI motivations: empirical evidence from
US foreign subsidiaries
Creators: name: Franco, Chiara
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2009
Subjects: SECS-P/01 Economia politica

description: The expected indirect benefits Foreign Direct Investments (FDI) are supposed to bring into the host countries are drawn mainly from studies at the microeconomic level. Empirical analyses examine whether FDI may be the source of productivity spillover effect on local firms and a new emerging literature analyses the effect with regard to the their export performance. However, conclusive results have not been reached so far. Two main shortcomings affect this literature: firstly, it is difficult to generalize results valid across countries; secondly, the role played by FDI motivations is largely disregarded. For these reasons, the aim of the paper is that of testing the effects of US FDI on export intensity at the sectoral level in 16 OECD countries over the period 1990-2001. Through these data, we are able to disentangle asset seeking and asset exploiting motivations and especially we are able to distinguish the channels through which the effect is going to occur. The findings show that taking into consideration the different motivations for which Multinational Enterprises (MNEs) invest abroad is relevant. The asset exploiting motivations, and in particular market seeking FDI, are those that affect export intensity to a greater extent.
THE COMPARATIVE STATICS OF THE FAUSTMANN MODEL OF FOREST MANAGEMENT
Creators: name: Graham-Tomasi, Theodore
name: Graham-Tomasi, Theodore
Publisher: name: Unknown
Year: 1983
Subjects: Resource /Energy Economics and Policy

description: The solution to the problem of how long a present valve maximizing forester should let trees grow has a long history in the literature of economics and forestry. Until recently, however, the comparative statics of the forestry problem when there are two decision variables, an initial input at the time of regeneration of the stand and the rotation period, had not been investigated. In this paper we offer a generalization, clarification, and extension of some recent works in this area.
Class elicitation session
Creators: name: Baclawski, Kenneth
name: Lamoureux, Spencer
name: Sande, Hannah Leigh
name: Skilton, Amalia Horan
name: Zapana Almanza, Hector
Publisher: name: California Language Archive, University of California, Berkeley
Year: 2016
Subjects: Aymara language

description: Negation and focus (HL); case stacking (KB); case on complex NPs and more focus issues (SL); uvular and palatal assimilation effects (AS)
Heinz, Gerhard: Das Problem der Kirchenentstehung in der deutschen protestantischen Theologie des 20. Jahrhunderts : Tübinger Theologische Studien Band 4
Creators: name: Urban, Hans Jörg
Publisher: name: Ökumenische Rundschau
Year: 2025

description: Ökumenische Rundschau, Bd. 26 Nr. 3 (1977): Ökumenische Rundschau, Band 26, Heft 3
The Foucault shift in sociological theory : from epistemological to ontological critique
Creators: name: Soleiman-Panah, Sayyed Mohammad
Publisher: name: University of British Columbia
Year: 2009

description: Sociology has always been forced to establish its "scientific" legitimacy, but this need has never been more strongly felt than today. Constant theoretical shifts and disciplinary fragmentation are viewed as symptoms of some fundamental problems. Assuming the precariousness of the present condition of sociology, this dissertation seeks to understand and explain the driving force behind theoretical shifts in sociology, for they are blamed for many of the problems in the discipline. Through a close reading of Michel Foucault's works, I argue that sociology, like many other forms of knowledge, has attempted to shape the modern person as an ethical subject. Pursuant to this objective, early sociologists attempted to establish a balance between two different kinds of orientation within the discipline, one of which was epistemological and scientific while the other was ontological and discursive. This position was in line with the critical attitude of the time and the emancipatory promises of the Enlightenment, which were nurtured by the early sociologists. In other words, the dual characteristic of sociology was due to a critical interest in changing and shaping the modern social subject. However, this duality gave rise to a tension within the discipline that was extremely difficult to manage, if not impossible. This dissertation examines the tension between the two orientations that has shaped the history of sociology. I read classical sociologists such as Auguste Comte, Emile Durkheim, and Max Weber to show that even these positivistic sociologists' theories can best be understood as a form of critique. In particular, I explain how they sought to manage the tension between the epistemological and the ontological aspects of their theories. I also examine Karl Popper's critical philosophy as a more recent attempt to keep science politically relevant. However, I will show that the dilemmas created in sociology are mainly due to a strong epistemological orientation beyond which most contemporary sociologists are not able to move. Sociology may avoid some of its present dilemmas by shifting its critical interest to an ontological path. To show the possibility and merits o f the ontological approach to politics, I read Karl Marx as a classical sociologist whose theory exhibits a strong ontological tendency. I above all discuss Michel Foucault's work extensively in order to both explain the nature of sociological theories and to explore the possibility and the prospects of the separation of the epistemological and the ontological sociologies more systematically. My aim is to show that while scientific sociology tries to advance without becoming intrinsically political, an explicitly discursive or ontological approach to contemporary political questions can be adopted by interested political actors and sociologists alike.
Canonical moments and random spectral measures
Creators: name: Gamboa, Fabrice
name: Rouault, Alain
Publisher: name: arXiv
Year: 2008
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 15A52, 60G57, 60F10

description: We study some connections between the random moment problem and the random matrix theory. A uniform draw in a space of moments can be lifted into the spectral probability measure of the pair (A,e) where A is a random matrix from a classical ensemble and e is a fixed unit vector. This random measure is a weighted sampling among the eigenvalues of A. We also study the large deviations properties of this random measure when the dimension of the matrix grows. The rate function for these large deviations involves the reversed Kullback information.
description: 32 pages. Revised version accepted for publication in Journal of Theoretical Probability
Eny2: a novel epigenetic regulator of senescence
Creators: name: Barkway, Aimee Rhian
Publisher: name: Imperial College London
Year: 2018

description: Senescence is a form of irreversible growth arrest, induced in response to cell stresses such as DNA damage, telomere erosion, and oncogenic shock. Senescent cells are associated with many different pathologies. Understanding the regulatory mechanisms controlling the induction of senescence can facilitate the study of associated diseases, particularly cancer and age-related diseases. Epigenetic pathways play a crucial role in regulating the induction and maintenance of senescence, and we need a better understanding of the epigenetic mechanisms controlling senescence. In a genetic screen for epigenetic factors controlling senescence, our lab identified ENY2- a highly conserved protein found in two different complexes: SAGA, a histone-modifying complex, and TREX2, involved in mRNA export. This investigation aimed to characterise the mechanism through which ENY2 regulates senescence. shRNAs knocking down ENY2 prevented the growth arrest observed in IMR90 ER: RAS, a model of oncogene-induced senescence. Knockdown of multiple components of SAGA, but not the TREX2 complex, also blunted the senescence growth arrest. In accordance, ENY2 was thought to control senescence through the SAGA complex at the level of histone modification. On ENY2 knockdown, there were profound changes in global H2BUb levels and a reduction in SAHF formation. Understanding that these global chromatin changes could affect transcription, I explored the impact of ENY2 knockdown on gene expression during entry to senescence. RNA-seq showed upregulation of key transcripts involved in the G1 to S transition in senescent cells depleted of ENY2. These cells escaped senescence growth arrest and displayed increased BrdU incorporation and Rb phosphorylation, while other aspects of the senescence phenotype such as the SASP and persistent DDR remained unchanged. Further investigation will elucidate the precise mechanism by which ENY2 controls senescence.
Multiparticle Entanglement Dynamics of Quantum Chaos in a Bose-Einstein condensate
Creators: name: Li, Sheng-Chang
name: Pezzè, Luca
name: Smerzi, Augusto
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We study the particle-entanglement dynamics witnessed by the quantum Fisher information (QFI) of a trapped Bose-Einstein condensate governed by the kicked rotor Hamiltonian. The dynamics is investigated with a beyond mean-field approach. We link the time scales of the validity of this approximation in, both, classical regular and chaotic regions, with the maximum Lyapunov exponents of the classical system. This establishes an effective connection between the classical chaos and the QFI. We finally study the critical point of a quantum phase transition using the beyond mean-field approximation by considering a two-mode bosonic Josephson junction with attractive interparticle interaction.
On the Discrete Spectrum of Generalized Quantum Tubes
Creators: name: Lin, Christopher
name: Lu, Zhiqin
Publisher: name: arXiv
Year: 2006
Subjects: subject: Differential Geometry (math.DG)
subject: Mathematical Physics (math-ph)
subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: In this paper, we study the spectrum of quantum tubes. Under certain intrinsic assumptions of the asymptotically flat submanifold of the Euclidean space, we prove the existence of the ground state of the quantum tube. The work is a generalization of Duclos, Exner and Krejcirik (CMP, 223(1), 13-28, 2001) and ourselves(math.DG/0402252).
Pair production and ionizing radiation from superconductors
Creators: name: Hirsch, J. E.
Publisher: name: arXiv
Year: 2005
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We show that an alternative theory of superconductivity recently proposed (theory of hole superconductivity) leads to the surprising consequence that real electron-positron pair production will occur for superconductors larger than a critical size. High frequency radiation with frequencies up to $0.511MeV/\hbar$ is predicted to be emitted from superconductors out of equilibrium. Attention to the possibility of harmful consequences is called for.
description: 2 sections added - title expanded
WATER INSTITUTIONS AND ECONOMIC INCENTIVES TO AMELIORATE MARKET AND GOVERNMENT FAILURES
Creators: name: Easter, K. William
name: Feder, Gershon
name: Easter, K. William
name: Feder, Gershon
Publisher: name: Unknown
Year: 1996
Subjects: Resource /Energy Economics and Policy

description: At the macro level, the way water resources are managed results in major misallocations as well as quality deterioration. It has become apparent in many cases that current practices and policies are not sustainable, and that reforms are needed. The present paper focuses on some of these reforms. It starts by reviewing and analyzing the sources of the market failures as well as government failures in water resources management. Recognizing the inevitability and desirability of some form of public action in many circumstances, it seeks to identify forms of interventions that utilize, to the extent possible, individual or private incentives by providing the institutional and legal framework in which these incentives can best complement the interventions. Examples from various countries are provided to illustrate the feasibility and merits of the proposed reforms.
Accuracy of ab initio methods in predicting the crystal structures of metals: review of 80 binary alloys
Creators: name: Curtarolo, Stefano
name: Morgan, Dane
name: Ceder, Gerbrand
Publisher: name: arXiv
Year: 2005
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Predicting and characterizing the crystal structure of materials is a key problem in materials research and development. We report the results of ab initio LDA/GGA computations for the following systems: AgAu, AgCd, AgMg, AgMo*, AgNa, AgNb*, AgPd, AgRh*, AgRu*, AgTc*, AgTi, AgY, AgZr, AlSc, AuCd, AuMo*, AuNb, AuPd, AuPt*, AuRh*, AuRu*, AuSc, AuTc*, AuTi, AuY, AuZr, CdMo*, CdNb*, CdPd, CdPt, CdRh, CdRu*, CdTc*, CdTi, CdY, CdZr, CrMg*, MoNb, MoPd, MoPt, MoRh, MoRu, MoTc*, MoTi, MoY*, MoZr, NbPd, NbPt, NbRh, NbRu, NbTc, NbY*, NbZr*, PdPt, PdRh*, PdRu*, PdTc, PdTi, PdY, PdZr, PtRh, PtRu, PtY, PtTc, PtTi, PtZr, RhRu, RhTc, RhTi, RhY, RhZr, RuTi, RuTc, RuY, RuZr, TcTi, TcY, TcZr, TiZr*, YZr* (*= systems in which the ab initio method predicts that no compounds are stable). A detailed comparison to experimental data confirms the high accuracy with which ab initio methods can predict ground states. Keywords: Binary Alloys, Ab initio, Intermetallics, Transition Metals, StructureAluminum, Cadmium, Gold, Magnesium, Molybdenum, Niobium, Palladium, Platinum, Rhodium, Ruthenium, Scandium, Silver, Sodium, Titanium, Technetium, Yttrium, Zirconium.
description: 60 pages, many pics. in press in calphad