cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Strange quark matter in explosive astrophysical systems
Creators: name: Sagert, I.
name: Fischer, T.
name: Hempel, M.
name: Pagliara, G.
name: Schaffner-Bielich, J.
name: Thielemann, F. -K.
name: Liebendörfer, M.
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Explosive astrophysical systems, such as supernovae or compact star binary mergers, provide conditions where strange quark matter can appear. The high degree of isospin asymmetry and temperatures of several MeV in such systems may cause a transition to the quark phase already around saturation density. Observable signals from the appearance of quark matter can be predicted and studied in astrophysical simulations. As input in such simulations, an equation of state with an integrated quark matter phase transition for a large temperature, density and proton fraction range is required. Additionally, restrictions from heavy ion data and pulsar observation must be considered. In this work we present such an approach. We implement a quark matter phase transition in a hadronic equation of state widely used for astrophysical simulations and discuss its compatibility with heavy ion collisions and pulsar data. Furthermore, we review the recently studied implications of the QCD phase transition during the early post-bounce evolution of core-collapse supernovae and introduce the effects from strong interactions to increase the maximum mass of hybrid stars. In the MIT bag model, together with the strange quark mass and the bag constant, the strong coupling constant $α_s$ provides a parameter to set the beginning and extension of the quark phase and with this the mass and radius of hybrid stars.
description: 6 pages, 5 figures, talk given at the International Conference on Strangeness in Quark Matter (SQM2009), Buzios, Brasil, September 28 - October 2, 2009, to be published in Journal Phys. G
Additional file 5 of Simplified plasmid cloning with a universal MCS design and bacterial in vivo assembly
Creators: name: Chen, Fan
name: Li, Yi-ya
name: Yu, Yan-li
name: Dai, Jie
name: Huang, Jin-ling
name: Lin, Jie
Publisher: name: figshare
Year: 2021
Subjects: subject: Biophysics
subject: Biochemistry
subject: Medicine
subject: Microbiology
subject: FOS: Biological sciences
subject: Genetics
subject: Molecular Biology
subject: Biotechnology
subject: Infectious Diseases
subject: FOS: Health sciences

description: Additional file 5 Figure S2. Assumed mechanism of bacterial in vivo assembly with nonhomologous regions.
Integration of ionic liquid biorefinery with constructed wetland remediation of wastewater
Creators: name: Firth, Anton Edward Josef
Publisher: name: Imperial College London
Year: 2021

description: Constructed wetland remediation has significant potential as a low-cost and low-maintenance water treatment technology. The high growth rates and yields of wetland species mean that constructed wetlands can also serve as a source of lignocellulosic biomass, which can be fractionated and processed into a wide range of useful fuels, chemicals, and materials. The work presented in this thesis investigates the potential for the widespread adoption of constructed wetlands for wastewater remediation, and for the valorisation of the generated biomass through an ionic liquid biorefinery. Firstly, this work investigates the effect of varying the degree of substitution of the cation in aqueous alkylammonium hydrogen sulfate ionic liquids. A decreasing degree of substitution was found to significantly enhance solution acidity in a way that differed from addition of excess sulfuric acid. The effects of this acidity were tested for the ionic liquid pretreatment of Miscanthus, through which a promising new pretreatment solvent was identified. Methylbutylammonium hydrogen sulfate produced pulps with purities of up to 94%, in two-thirds of the time of current benchmark ionic liquids. Secondly, a desk study was carried out to quantify the economic potential for wetland remediation, for the removal of organic and nutrient contamination, and for the remediation of Acid Mine Drainage, relative to conventional technologies. Constructed wetlands were found to be comparatively economically favourable at a wide range of conditions, particularly those with lower flow rates and/or contamination. Valorisation of the wetland biomass was found to be able to offset a significant proportion of total costs, but may require mixing with other feedstocks due to areal requirements. Valorisation of wetland feedstocks through ionic liquid pretreatment was then investigated experimentally. Feedstock independence was validated by pretreating 7 common wetland species. Large improvements in digestibility and pulp purity were observed (to around 80% and 70% respectively), with low variability between species. These feedstocks’ high extractives content was found to increase the rate of pseudolignin formation, but this could be avoided through pre-extraction with ethanol and water. Recycling performance was found to decrease with each cycle, although this was offset to a certain degree through biomass pre-extraction and through addition of acid between cycles. Finally, a novel fractionation process was suggested and developed using duckweed as a feedstock, allowing the full range of its promising features to be utilised. Ionic liquid interactions with pure starch were probed, allowing conditions amenable to starch processing to be determined. Pretreatment of duckweed with ionic liquids at mild conditions allowed near-quantitative sugar release to be achieved in 8 hours of hydrolysis, while a protein-enriched post-saccharification residue was also generated.
Semileptonic $D_{q}\to K_{1}\ell ν$ and nonleptonic $D\to K_1 π$ decays in three--point QCD sum rules and factorization approach
Creators: name: Khosravi, R.
name: Azizi, K.
name: Ghahramany, N.
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We analyze the semileptonic $D_{q}\to K_1 \ellν$ transition with $q=u, d, s$, in the framework of the three--point QCD sum rules and the nonleptonic $D\to K_1 π$ decay within the QCD factorization approach. We study $D_{q}$ to $K_1(1270)$ and $K_1(1400)$ transition form factors by separating the mixture of the $K_1(1270)$ and $K_1(1400)$ states. Using the transition form factors of the $D\to K_1 $, we analyze the nonleptonic $D\to K_1 π$ decay. We also present the decay amplitude and decay width of these decays in terms of the transition form factors. The branching ratios of these channel modes are also calculated at different values of the mixing angle $θ_{K_1}$ and compared with the existing experimental data for the nonleptonic case.
description: 28 Pages, 20 Figures and 9 Tables
A Construction Morphology Approach to Yoruba Numerals
Creators: name: Ajibade, Matthew
Publisher: name: Constructions
Year: 2023

description: The discussions on Yoruba numerals, described as one of the most complicated numeral systems of the world (Hurford, 1975), center on the array of arithmetic operations involved in their computation. These complex computational processes result in phonological variations for some numbers in isolation and when such numbers are stems for the derivation of complex numerals, thereby constituting a challenge to the identification of numerical meaning from phonological forms. In recent years, Booij (2010) developed Construction Morphology (CxM) to provide a systematic pair of linguistic forms and meanings of complex words. This approach uses constructional schema to account for the morphological structure and properties of existing complex words, even when such patterns lack generative power, and how existing templates can be used to create new words (Booij, 2010, 2018; Jackendoff, 2022). Following the CxM approach, this paper provides a form-meaning account of Yoruba numerals through a systematic structural examination of each group of numerals with similar arithmetic operations. By this systematic examination, the paper shows that numbers with similar numerical operations have feature commonalities that set them apart from other groups of numerals. These commonalities show how Yoruba users make form-meaning representations of numbers with different allomorphs, whether phonologically governed or idiosyncratic. The paper concludes that presenting holistic properties of Yoruba numerals through constructional schemas shows a direct way to identify their mathematical properties from phonological forms.
description: Constructions, Bd. 15 (2023)
The analytical and phenomenological sensitivity study of the flow-induced instabilities about a hinged circular cylinder with a splitter plate
Creators: name: Basso, Robin Lucas Guillaume
Publisher: name: Imperial College London
Year: 2021

description: This thesis investigates the origin of flow-induced instabilities and their sensitivities in a flow over a rotationally flexible circular cylinder with a rigid splitter plate. A linear stability and sensitivity problem are formulated in the two-dimensional Eulerian frame by considering the geometric nonlinearity arising from the translations and rotational motion of an arbitrary geometry (cross-sectional structure's shape), which is not present in the stationary or purely translating stability methodology. This nonlinearity needs careful and consistent treatment in the linearised problem, particularly when considering the Eulerian frame of reference adopted in this study and not so widely considered. Considering the one degree of freedom problem of the rotationally flexible circular cylinder with a rigid splitter plate, two types of instabilities arising from the fluid-structure interaction are found. The first type of instability is the stationary symmetry-breaking mode, which was well reported in previous studies. This instability exhibits a strong correlation with the length of the recirculation zone. A detailed analysis of the instability mode and its sensitivity reveals the importance of the flow near the tip region of the plate for the generation and control of this instability mode. The second type is an oscillatory torsional flapping mode, which has not been well reported. This instability typically emerges when the length of the splitter plate is sufficiently long. Unlike the symmetry breaking mode, it is not so closely correlated with the length of the recirculation zone. However, the sensitivity analysis also reveals the crucial role played by the flow near the tip region in this instability. Finally, it is found that many physical features of this instability are reminiscent of those of the flapping (or flutter instability) observed in a flow over a flexible plate or a flag, suggesting that these instabilities share the same physical origin. The sensitivity analysis of both the symmetry breaking and flapping instability is also compared to the results obtained from a stationary circular cylinder fitted to a splitter plate of the same lengths. Physically meaningful analogies are noted between the sensitivity regions of the three instabilities.
Optimum Pilot Overhead in Wireless Communication: A Unified Treatment of Continuous and Block-Fading Channels
Creators: name: Jindal, Nihar
name: Lozano, Angel
Publisher: name: arXiv
Year: 2009
Subjects: subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: The optimization of the pilot overhead in single-user wireless fading channels is investigated, and the dependence of this overhead on various system parameters of interest (e.g., fading rate, signal-to-noise ratio) is quantified. The achievable pilot-based spectral efficiency is expanded with respect to the fading rate about the no-fading point, which leads to an accurate order expansion for the pilot overhead. This expansion identifies that the pilot overhead, as well as the spectral efficiency penalty with respect to a reference system with genie-aided CSI (channel state information) at the receiver, depend on the square root of the normalized Doppler frequency. Furthermore, it is shown that the widely-used block fading model is only a special case of more accurate continuous fading models in terms of the achievable pilot-based spectral efficiency, and that the overhead optimization for multiantenna systems is effectively the same as for single-antenna systems with the normalized Doppler frequency multiplied by the number of transmit antennas.
description: Submitted to IEEE Trans. Wireless Communications
Fracture behaviour of SiC/SiC ceramic matrix composite
Creators: name: Delage, Justine
Publisher: name: Imperial College London
Year: 2022

description: The fracture behaviour of SiC/BN/SiC CMC have been assessed using different approaches. The toughening mechanisms responsible for the enhanced fracture toughness have been identified. Apparent KIC have been measured. KIC values of 3.05-3.27 and 4.13-5.44 MPa.m1/2 were measured in-situ for the in-plane and out-of-plane orientations, respectively. A second KIC of 26.6 ± 3.37 MPa.m1/2 was measured using the proportional limit. However, this method was found to overestimate the fracture toughness as the matrix cracking initiates significantly before the proportional limit. KIC represents the resistance to crack propagation at low crack extensions and does not fully describe the composite’s fracture toughness. An equivalent fracture toughness Keq that reflect to some extent the contribution of toughening mechanisms has been measured and found to be notch sensitive: it increases from 16.3 MPa.m1/2 to a plateau of 27.7 MPa.m1/2. Resistance-curves were measured using a J-integral approach. JR-curve initiates at 0.11-0.17 kJ.m-2 but never reached a steady-state plateau. Finally, a fracture energy approach was used to measure the fracture matrix energy of 72-186 J.m-2 which corresponds to the energy required for fracture initiation and work of fracture that correspond to the energy absorbed during the whole fracture process. The work of fracture was found to be strain rate sensitive: it decreases with increasing displacement rate. The notch and size-sensitivity of the composite was investigated. Strength were found to be unsensitive, but the opposite was observed concerning the fracture nature and the work of fracture. Finally, the effect of degradation environment on the microstructure and flexural behaviour was investigated. These environments correspond to a humidity exposure at 65°C and a steam exposure at 800°C. The flexural behaviour was found to be considerably degraded after the humidity exposure, but significantly lower degradation was observed after the steam exposure.
3D system-circuit-device design methodologies for advanced CMOS
Creators: name: Mathur, Rahul
name: 0000-0002-8064-5612
Publisher: name: The University of Texas at Austin
Year: 2021
Subjects: 3D stacking
3D integration
3D SRAM
Energy-efficient
Systolic
Accelerators
Thermal
Buried power rail
BPR
SRAM
Interconnect
Resistance

description: The emergence of 5G, automotive, and AI-based applications are creating new capabilities and a huge amount of data that is driving the need for a broad expansion in energy-efficient compute capacities. At the same time, the typical gains in Power, Performance, Area, and Cost (PPAC) that dimensional scaling has brought over the past several decades are slowing down. To o set the slowdown in 2D scaling and continue the trajectory of PPAC improvements, coordinated innovations are needed across the system, circuit, and device abstraction levels. 3D integration may offer complementary gains to transistor density scaling. Meanwhile, 3D expands the design space of SoC adding considerations like partitioning, power delivery, signaling, and thermal management. This dissertation studies these considerations in detail. The work spans thermal analysis of a 3D CPU, system-level design space exploration of 3D ML accelerators, circuit design of a 3D-Split SRAM macro, and novel use of device-level 3D construct of Buried Power Rail (BPR) for SRAM signaling to enable next-generation computing systems in advanced CMOS.
A new X-ray census of rotation powered pulsars
Creators: name: Xu, Yu-Jing
name: Peng, Han-Long
name: Weng, Shan-Shan
name: Zhang, Xiao
name: Ge, Ming-Yu
Publisher: name: arXiv
Year: 2025
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: To date, over 4000 pulsars have been detected. In this study, we identify 231 X-ray counterparts of Australia Telescope National Facility (ATNF) pulsars by performing a spatial cross match across the Chandra, XMM-Newton observational catalogs. This dataset represents the largest sample of X-ray counterparts ever compiled, including 98 normal pulsars (NPs) and 133 millisecond pulsars (MSPs). Based on this significantly expanded sample, we re-establish the correlation between X-ray luminosity and spin-down power, given by $L_{\rm X} \propto \dot{E}^{0.85\pm0.05}$ across the whole X-ray band. The strong correlation is also observed in hard X-ray band, while in soft X-ray band there is no significant correlation. Furthermore, $L_{\rm X}$ shows a strong correlation with spin period and characteristic age for NPs. For the first time, we observe a strongly positive correlation between $L_{\rm X}$ and the light cylinder magnetic field ($B_{\rm lc}$) for MSPs, with both NPs and MSPs following the relationship $L_{\rm X} \propto B_{\rm lc}^{1.14}$, consistent with the outer-gap model of pulsars that explains the mechanism of X-ray emission. Additionally, we investigate potential X-ray counterparts for Galactic Plane Pulsar Snapshot pulsars, finding a lower likelihood of detection compared to ATNF pulsars.
description: 13 pages, 4 figures, and 3 tables; published in ApJ; X-ray pulsar catalog will be updated regularly online
Additional file 6 of Simplified plasmid cloning with a universal MCS design and bacterial in vivo assembly
Creators: name: Chen, Fan
name: Li, Yi-ya
name: Yu, Yan-li
name: Dai, Jie
name: Huang, Jin-ling
name: Lin, Jie
Publisher: name: figshare
Year: 2021
Subjects: subject: Biophysics
subject: Biochemistry
subject: Medicine
subject: Microbiology
subject: FOS: Biological sciences
subject: Genetics
subject: Molecular Biology
subject: Biotechnology
subject: Infectious Diseases
subject: FOS: Health sciences

description: Additional file 6 Figure S3. Efficiency evaluation of UMCS based subcloning for Top10 and BL21(DE3).
Expression profile and functional interrogation of G protein-coupled receptors in endometrial cancer
Creators: name: Sayers, Sarah Niamh
Publisher: name: Imperial College London
Year: 2022

description: Endometrial cancer (EC) is the sixth most diagnosed cancer in women and unlike most other cancers the incidence of this disease is rising; women are being diagnosed at an earlier age; and mortality is increasing, highlighting an urgent need for novel therapies. Tumours are multicellular units working in concert to achieve the hallmarks of cancer, communicating through autocrine and paracrine factors. G protein-coupled receptors (GPCRs) are the largest family of cell surface receptors that are involved in transducing extracellular signals into intracellular cascades, ultimately altering the trajectory of the cell. Gonadotrophin hormone receptors are prototypical GPCRs, that demonstrate multi-dimensional signalling capacity, and play key roles in reproduction, however, have also been reported to promote EC cell growth. Newer concepts in GPCR biology such as oligomerisation and endomembrane signalling have highlighted greater complexity in signalling and how GPCRs achieve diverse functional effects through the same receptor. Therefore, this thesis sought to identify GPCRs highly expressed in EC, through mining RNA sequencing databases; delineate gonadotrophin hormone receptor signalling and functional consequences in EC cells; and probe the regulation of the gonadotrophin receptor, follicle-stimulating hormone receptor (FSHR), through oligomerisation and endomembrane signalling. This thesis found 16 overexpressed GPCR genes in EC using differential expression analysis of matched normal and tumour samples. FSHR was found to preferentially activate non-classical Gαi/o signalling in Ishikawa EC cells, and induce lipid droplet accumulation via Gαi/o and β-arrestins, highlighting a novel function for β-arrestins in FSHR action. Using super-resolution imaging technique, PD-PALM, FSHR heterologously expressed in HEK293 cells was visualised on the plasma membrane and was demonstrated to exist as monomers and higher-order oligomers. Interestingly, FSHR complexes were altered after ligand stimulation and density-dependent effects were found. Together, this thesis has demonstrated that through system bias, the function and regulation of GPCRs are altered.
title: Unterschiedliche Sterblichkeit von Menschen mit und ohne Schweizer Pass während der COVID-19-Pandemie
title: Differences in Mortality Between People with and without a Swiss Passport During the COVID-19 Pandemic
titleType: AlternativeTitle
Creators: name: Plümecke, Tino
name: Mikosch, Heiner
name: Mohrenberg, Steffen
name: Supik, Linda
name: Razum, Oliver
name: Bartram, Isabelle
name: Ellebrecht, Nils
name: Schnieder, Laura
name: Schönberger, Hannah
name: Schulze-Marmeling, Charlotte
name: zur Nieden, Andrea
name: Gutzeit, Andreas
Publisher: name: Universität Bielefeld
Year: 2022
Subjects: subject: 610

description: Menschen ohne Schweizer Pass verzeichneten in der Schweiz während der COVID-19-Pande-mie eine höhere Zunahme der Sterblichkeit als Menschen mit Schweizer Pass. Dieser bisher nicht ausreichend beachtete Befund zeigt sich in einer Analyse der Todesfallstatistik aus dem Zeitraum 2020 bis Mai 2021 im Vergleich mit den zehn Vorjahren. 2020 fällt die Zunahme aller Todesfälle gegenüber dem Vorjahr bei Menschen ohne Schweizer Pass mit 21,2 Prozent fast doppelt so hoch aus, wie bei jenen mit Schweizer Pass, bei denen der Anstieg bei 11,4 Prozent lag. In einer detaillierten Auswertung der Wochendaten und der Aufteilung nach Altersklassen werden ein früherer und stärkerer Anstieg der Todesfallzahlen bei Menschen ohne Schweizer Pass sowie ein bis zu zehnfach höherer Anstieg (in der Altersklasse 65- bis 74-Jährige) der Todesfälle im Vergleich zum Vorjahr sichtbar. Unsere Analyse macht damit erhebliche gesundheitliche Ungleichheiten in verschiedenen Bevölkerungsteilen der Schweiz sichtbar.
Experimental evidence of chemical-pressure-controlled superconductivity in cuprates
Creators: name: Sanna, S.
name: Agrestini, S.
name: Zheng, K.
name: De Renzi, R.
name: Saini, N. L.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: X-ray absorption spectroscopy (XAS) and high resolution X-ray diffraction are combined to study the interplay between electronic and lattice structures in controlling the superconductivity in cuprates with a model charge-compensated CaxLa1-xBa1.75-xLa0.25+xCu3Oy (0
description: Accepted for publication in EPL
Protocorks and monopole Floer homology
Creators: name: Ladu, Roberto
Publisher: name: Imperial College London
Year: 2022

description: We introduce and study a class of compact 4-manifolds with boundary that we call protocorks. Any exotic pair of simply connected closed 4-manifolds is related by a protocork twist, moreover, any cork is supported by a protocork. We prove a theorem on the relative Seiberg-Witten invariants of a protocork before and after twisting and a splitting theorem on the Floer homology of protocork boundaries. As a corollary we improve a theorem by Morgan and Szab\'{o} regarding the variation of Seiberg-Witten invariants with an upper bound which depends only on the topology of the data. Moreover we show that for any cork, only the reduced Floer homology of its boundary contributes to the variation of the Seiberg-Witten invariants after a cork twist.
Additional file 4 of Simplified plasmid cloning with a universal MCS design and bacterial in vivo assembly
Creators: name: Chen, Fan
name: Li, Yi-ya
name: Yu, Yan-li
name: Dai, Jie
name: Huang, Jin-ling
name: Lin, Jie
Publisher: name: figshare
Year: 2021
Subjects: subject: Biophysics
subject: Biochemistry
subject: Medicine
subject: Microbiology
subject: FOS: Biological sciences
subject: Genetics
subject: Molecular Biology
subject: Biotechnology
subject: Infectious Diseases
subject: FOS: Health sciences

description: Additional file 4 Figure S1. Effects of insert/vector ratio on assembly efficiency for vector linearized by EcoRV digestion.
‘Did the speaker change?’: Temporal tracking for overlapping speaker segmentation in multi-speaker scenarios
Creators: name: Hogg, Aidan
Publisher: name: Imperial College London
Year: 2022

description: Diarization systems are an essential part of many speech processing applications, such as speaker indexing, improving automatic speech recognition (ASR) performance and making single speaker-based algorithms available for use in multi-speaker domains. This thesis will focus on the first task of the diarization process, that being the task of speaker segmentation which can be thought of as trying to answer the question ‘Did the speaker change?’ in an audio recording. This thesis starts by showing that time-varying pitch properties can be used advantageously within the segmentation step of a multi-talker diarization system. It is then highlighted that an individual’s pitch is smoothly varying and, therefore, can be predicted by means of a Kalman filter. Subsequently, it is shown that if the pitch is not predictable, then this is most likely due to a change in the speaker. Finally, a novel system is proposed that uses this approach of pitch prediction for speaker change detection. This thesis then goes on to demonstrate how voiced harmonics can be useful in detecting when more than one speaker is talking, such as during overlapping speaker activity. A novel system is proposed to track multiple harmonics simultaneously, allowing for the determination of onsets and end-points of a speaker’s utterance in the presence of an additional active speaker. This thesis then extends this work to explore the use of a new multimodal approach for overlapping speaker segmentation that tracks both the fundamental frequency (F0) and direction of arrival (DoA) of each speaker simultaneously. The proposed multiple hypothesis tracking system, which simultaneously tracks both features, shows an improvement in segmentation performance when compared to tracking these features separately. Lastly, this thesis focuses on the DoA estimation part of the newly proposed multimodal approach. It does this by exploring a polynomial extension to the multiple signal classification (MUSIC) algorithm, spatio-spectral polynomial (SSP)-MUSIC, and evaluating its performance when using speech sound sources.
One-Dimensional Diffusions That Eventually Stop Down-Crossing
Creators: name: Pinsky, Ross G.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 60J60

description: Consider a diffusion process corresponding to the operator $L=\frac12a\frac{d^2}{dx^2}+b\frac d{dx}$ and which is transient to $+\infty$. For $c>0$, we give an explicit criterion in terms of the coefficients $a$ and $b$ which determines whether or not the diffusion almost surely eventually stops making down-crossings of length $c$. As a particular case, we show that if $a=1$, then the diffusion almost surely stops making down-crossings of length $c$ if $b(x)\ge\frac1{2c}\log x+\fracγc\log\log x$, for some $γ>1$ and for large $x$, but makes down-crossings of length $c$ at arbitrarily large times if $b(x)\le\frac1{2c}\log x+\frac1c\log\log x$, for large $x$.
Learning and advancing local feature-based methods for 3D geometry systems
Creators: name: Barroso Laguna, Axel
Publisher: name: Imperial College London
Year: 2022

description: This thesis focuses on finding the geometric relationship between two views. Learning about the geometry of a scene is a pivotal part of modern 3D geometry systems, and it is a popular and active area of research. There are many methods to compute image geometry, and most of them rely on what we call image matching. Image matching aims at finding local correspondences between images, and although it involves multiple steps, image matching stages can be summarized into 1) finding characteristic local regions in the images, also known as keypoints, 2) calculating their mathematical representation, referred to as keypoint descriptors, and 3) searching the corresponding regions between the views. The first part of this thesis focuses on the detection of the keypoints. We study the similarities between handcrafted detectors and learned convolutional networks and propose a new architecture that combines handcrafted and learned filters, which achieves state-of-the-art results while being fast and lightweight. Then, we extend the idea of integrating handcrafted filters into the keypoint descriptor network and discuss its benefits in terms of matching capabilities. Moreover, we introduce a new objective function based on the discriminativeness of keypoint candidates, which guides the candidate keypoints toward easy-to-match regions and improves the robustness of our keypoint detector and descriptor. Finally, we study and isolate one geometric challenge in image matching, large scale changes between views. To deal with the scale challenge, we present a scale-aware matching pipeline that brings a solution to image pairs where previous multi-scale methods failed. Besides the ideas and experiments discussed in this manuscript, all the presented methods and datasets are publicly available on https://github.com/axelBarroso.
Fate of baby radio galaxies: Dead or Alive ?
Creators: name: Kawakatu, Nozomu
name: Nagai, Hiroshi
name: Kino, Motoki
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: In order to reveal the long-term evolution of relativistic jets in active galactic nuclei (AGNs), we examine the dynamical evolution of variously-sized radio galaxies [i.e., compact symmetric objects (CSOs), medium-size symmetric objects (MSOs), Fanaroff-Riley type II radio galaxies (FRIIs)]. By comparing the observed relation between the hot spot size and the linear size of radio source with a coevolution model of hot spot and cocoon, we find that the advance speed of hot spots and lobes inevitably show the deceleration phase (CSO-MSO phase) and the acceleration phase (MSO-FRII phase). The deceleration is caused by the growth of the cross-sectional area of the cocoon head. Moreover, by comparing the hot spot speed with the sound speed of the ambient medium, we predict that only CSOs whose initial advance speed is higher than 0.3-0.5c can evolve into FRIIs.
description: 5 pages and 3 figures, accepted for publication in Astronomische Nachrichten (issue dedicated to the Proceedings of "The 4th Workshop on Compact Steep Spectrum and GHz-Peaked Spectrum Radio Sources" held at Riccione, Italy, 26-29 May 2008)
NNLO corrections to B --> X_u l nu and the determination of |V_ub|
Creators: name: Greub, C.
name: Neubert, M.
name: Pecjak, B. D.
Publisher: name: arXiv
Year: 2009
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We study the impact of next-to-next-to-leading order (NNLO) QCD corrections on partial decay rates in B --> X_u l nu decays, at leading-order in the 1/m_b expansion for shape-function kinematics. These corrections are implemented within a modified form of the BLNP framework, which allows for arbitrary variations of the jet scale mu_i \sim 1.5 GeV. Our analysis includes a detailed comparison between resummed and fixed-order perturbation theory, and between the complete NNLO results and those obtained in the large-$β_0$ approximation. For the default choice mu_i=1.5 GeV used in current extractions of |V_ub| within the BLNP framework, the NNLO corrections induce significant downward shifts in the central values of partial decay rates with cuts on the hadronic variable P_+, the hadronic invariant mass, and the lepton energy. At the same time, perturbative uncertainties are reduced, especially those at the jet scale, which are the dominant ones at next-to-leading order (NLO). For higher values of mu_i and in fixed-order perturbation theory, the shifts between NLO and NNLO are more moderate. We combine our new results with known power-suppressed terms in order to illustrate the implications of our analysis on the determination of |V_ub| from inclusive decays.
description: 24 pages, 7 figures
Linear stability of ferrofluids in a non-uniform magnetic field
Creators: name: Ferguson Briggs, Sarah Helen
Publisher: name: Imperial College London
Year: 2022

description: The linear stability of Newtonian ferrofluids subject to non-uniform magnetic fields is consid- ered in different geometries. First, a ferrofluid column with constant magnetic susceptibility, centred on a current-carrying rigid wire and surrounded by another ferrofluid with a differ- ent susceptibility, is investigated. Ferrofluids with non-uniform susceptibilities are considered next. For a constant susceptibility the magnetic forcing is confined to the interface, but for a non-constant susceptibility the forcing is felt in the bulk of the fluid. It is postulated that a sta- tionary state of a ferrofluid with a non-uniform susceptibility in the presence of a non-uniform field, such that regions of highest susceptibility do not coincide with regions of highest field, may be unstable. An instability could be driven by the release of magnetic energy, since a minimum energy configuration may be reached when ferrofluid regions of high susceptibility and regions of high field coincide. This is explored for equilibria in a cylindrical domain, a planar domain and in a general three-dimensional domain. In a cylindrical domain, a stability condition is determined for a ferrofluid surrounding a current-carrying rigid wire, whose susceptibility varies radially. In a planar configuration, a stationary state of ferrofluid between two channel walls is found. The susceptibility and field vary normal to the wall, such that the regions of highest field and susceptibility do not coincide, and it is proven to be unstable. Methods of stabilising both systems are determined. For the cylindrical system, a constant axial field suffices, but for the planar domain it is shown that a rapidly rotating field is necessary to dampen unstable modes. Lastly, a stability condition is obtained for a general volume of ferrofluid, whose susceptibility varies slowly with position, subject to a non-uniform field.
Seven Conjectures in Geometry and Number Theory
Creators: name: Smarandache, Florentin
Publisher: name: arXiv
Year: 2009
Subjects: subject: General Mathematics (math.GM)
subject: FOS: Mathematics
subject: 11A41, 51F20

description: In this short paper we propose four conjectures in synthetic geometry that generalize Erdos-Mordell Theorem, and three conjectures in number theory that generalize Fermat Numbers.
description: 2 pages
Advanced robust control strategies of mechatronic suspensions for cars
Creators: name: Feng, Zilin
Publisher: name: Imperial College London
Year: 2022

description: Two novel mechatronic suspensions for road vehicles are studied in this thesis: the Series Active Variable Geometry Suspension (SAVGS) and the Parallel Active Link Suspension (PALS). The SAVGS and the PALS complement each other in terms of the vehicle categories they serve, which range from light high-performance vehicles (the Grand Tourer) to heavy SUV vehicles, respectively, based on the sprung mass and the passive suspension stiffness. Previous work developed various control methodologies for these types of suspension. Compared to existing active suspension solutions, both the SAVGS and the PALS are capable of low-frequency chassis attitude control and high-frequency ride comfort and road holding enhancement. In order to solve the limitation of both SAVGS and PALS robustness, mu-synthesis control methodologies are first developed for SAVGS and PALS, respectively, to account for structured uncertainties arising from changes to system parameters within realistic operating ranges. Subsequently, to guarantee robustness of both low-frequency and high-frequency vehicle dynamics for PALS, the mu-synthesis scheme is combined with proportional-integral-derivative (PID) control, employing a frequency separation paradigm. Moreover, as an alternative robustness guaranteeing scheme that captures plant nonlinearities and road unevenness as uncertainties and disturbances, a novel robust model predictive control (RMPC) based methodology is proposed for the SAVGS, motivated by the promise shown by RMPC in other industrial applications. Finally, aiming to provide further performance stability and improvements, feedforward control is developed for the PALS. Nonlinear simulations with a set of ISO driving situations are performed to evaluate the efficiency and effectiveness of the proposed control methods in this thesis.
N=4 Yang--Mills theory as a complexification of the N=2 theory
Creators: name: Baulieu, Laurent
Publisher: name: arXiv
Year: 2009
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: A complexification of the twisted $\N=2$ theory allows one to determine the N=4 Yang--Mills theory in its third twist formulation. The imaginary part of the gauge symmetry is used to eliminate two scalars fields and create gauge covariant longitudinal components for the imaginary part of the gauge field. The latter becomes the vector field of the thirdly twisted $\N=4$ theory. Eventually, one gets a one to one correspondence between the fields of both theories. Analogous complexifications can be done for topological 2d-gravity and topological sigma models.
Differential methylation of expression-associated CpG loci in an enhancer region is associated with morning cancer-related fatigue severity
Creators: name: Le, Caroline
name: Lewis, Maureen
name: Berger, Liam
name: Roy, Ritu
name: Yom, Sue
name: Cho, Nam Woo
name: Olshen, Adam
name: Miaskowski, Christine
name: Kober, Kord M
Publisher: name: F1000 Research Limited
Year: 2023

description: Cancer-related fatigue (CRF) is the most common symptom associated with cancer and its treatment. A lack of knowledge of the underlying mechanisms limits the development of efficacious interventions. By utilizing multiple types of complementary omics data (i.e., transcriptomics, epigenomics), we aim to identify molecular characteristics associated with morning CRF (AM CRF) severity to increase understanding of the mechanisms underlying AM CRF. The first aim of this study is to identify expression-associated (eCpG) loci in one group oncology patients receiving CTX. Our second aim is to evaluate for differential methylation of distal regions of eCpG loci (identified in aim 1) associated with AM CRF severity in an independent group. Patients completed questionnaires during the week prior to the next treatment. AM CRF severity was evaluated using the Lee Fatigue Scale. RNA and DNA methylation were measured in peripheral blood of two distinct groups of oncology patients (n=115; n=584). Distal eCpG’s (n=25,310) were identified using eQTM mapping in the first group. Differential methylation of these distal eCpGs was evaluated in the second group of patients (n=224 High, n=360 Low AM CRF). The final model included significant demographic and clinical characteristics and three surrogate variables. Differentially methylated distal regions were identified using a sliding window approach. Using Fisher’s method, one region was found to be significantly differentially methylation (FDR < 0.0002). CpGs in this region mapped to the expression of three genes (ONECUT1, CLIP, and SLCO3A1). ONECUT1 is a transcription factor involved in gene transcription, glucose metabolism, and cell cycle regulation. Genetic variation in SLCO3A1 is associated with the occurrence with chronic fatigue syndrome. These findings can be useful to identify novel therapeutic targets. These methods may be generalizable to other symptoms and patient-reported outcomes associated with cancer (e.g., sleep disturbance, depression, anxiety, dyspnea, pain) and its treatment (e.g., combined CTX and radiation).
Spatial transcriptomics inference for the elucidation of disease pathogenesis across large scale histopathology cohorts: A preliminary analysis in skin photoaging
Creators: name: Gokul Srinivasan
name: Davis, Matthew
name: LeBoeuf, Matthew
name: Levy, Joshua
Publisher: name: F1000 Research Limited
Year: 2023

description: Background: Spatial transcriptomics (ST) technologies have revolutionized our understanding of tissue biology, offering spatially resolved insights into diverse tissues and processes, from cancer to embryonic development. Though various ST methods have been developed – each with differing multiplexing and spatial resolution – all have contributed to our burgeoning knowledge regarding human disease and development. ST methods have helped illustrate spatial molecular diversity within tumors and uncovered disease pathways in conditions like diabetic foot ulcers and muscular dystrophy. In development, ST methods have enhanced our grasp of embryology, revealing gene regulation patterns that drive early-life cellular differentiation. However, high costs, the need for skilled technicians, and complex analysis have limited ST's broader application.



Methods: To address these challenges, our research presents a cost-effective ST inference method using standard H&E slides, employing a vision transformer model that shows promising cross-validation results in gene expression prediction across 1000 genes with a median Spearman’s Correlation of 0.600 (CI: 0.580-0.610) across four-fold cross-validation. Inference on unseen slides involves automatic tissue masking, data patching, and model inference, followed by reconstruction of the ST data object. We applied this workflow to 261 skin tissue slides annotated by pathologists.



Results: Our approach successfully recapitulates genetic heterogeneity and histological features, allowing downstream methods to achieve high accuracy in classifying various histomorphologies given the synthetic data. We report a macro-averaged class-specific accuracy of 0.934, 0.986, 0.999, 0.934, 0.666, 0.970, 0.837, 0.900 across the following histological categories: eccrine gland, epidermis, fat, hair follicle, nerve, sebaceous gland, smooth muscle, vessel.



Conclusions: These findings indicate the potential of ST inference by enabling the prediction of histological identity from synthetic gene expression data, identifying relevant genes. Study limitations include homogenous training set and a limited set of gene targets, yet this work offers the potential to democratize access to high resolution ST data.
Homologically maximizing geodesics in conformally flat tori
Creators: name: Suhr, Stefan
Publisher: name: arXiv
Year: 2010
Subjects: subject: Differential Geometry (math.DG)
subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics

description: We study homologically maximizing timelike geodesics in conformally flat tori. A causal geodesic $γ$ in such a torus is said to be homologically maximizing if one (hence every) lift of $γ$ to the universal cover is arclength maximizing. First we prove a compactness result for homologically maximizing timelike geodesics. This yields the Lipschitz continuity of the time separation of the universal cover on strict sub-cones of the cone of future pointing vectors. Then we introduce the stable time separation $\mathfrak{l}$. As an application we prove relations between the concavity properties of $\mathfrak{l}$ and the qualitative behavior of homologically maximizing geodesics.
description: 16 pages, submitted to Adv. in Lor. geometry
Three-dimensional Resonance in superconducting BaFe$_{1.9}$Ni$_{0.1}$As$_2$
Creators: name: Chi, Songxue
name: Schneidewind, Astrid
name: Zhao, Jun
name: Harriger, Leland W.
name: Li, Linjun
name: Luo, Yongkang
name: Cao, Guanghan
name: Xu, Zhu'an
name: Loewenhaupt, Micheal
name: Hu, Jiangping
name: Dai, Pengcheng
Publisher: name: arXiv
Year: 2008
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: We use inelastic neutron scattering to study magnetic excitations of the FeAs-based superconductor BaFe$_{1.9}$Ni$_{0.1}$As$_2$ above and below its superconducting transition temperature $T_c=20$ K. In addition to gradually open a spin gap at the in-plane antiferromagnetic ordering wavevector $(1,0,0)$, the effect of superconductivity is to form a three dimensional resonance with clear dispersion along the c-axis direction. The intensity of the resonance develops like a superconducting order parameter, and the mode occurs at distinctively different energies at $(1,0,0)$ and $(1,0,1)$. If the resonance energy is directly associated with the superconducting gap energy $Δ$, then $Δ$ is dependent on the wavevector transfers along the c-axis. These results suggest that one must be careful in interpreting the superconducting gap energies obtained by surface sensitive probes such as scanning tunneling microscopy and angle resolved photoemission.
description: 5 pages, 4 figures
Additional file 3 of Simplified plasmid cloning with a universal MCS design and bacterial in vivo assembly
Creators: name: Chen, Fan
name: Li, Yi-ya
name: Yu, Yan-li
name: Dai, Jie
name: Huang, Jin-ling
name: Lin, Jie
Publisher: name: figshare
Year: 2021
Subjects: subject: Biophysics
subject: Biochemistry
subject: Medicine
subject: Microbiology
subject: FOS: Biological sciences
subject: Genetics
subject: Molecular Biology
subject: Biotechnology
subject: Infectious Diseases
subject: FOS: Health sciences

description: Additional file 3 Table S3. List of the primers and oligonucleotides used throughout this study.
Direct multiscale coupling of a transport code to gyrokinetic turbulence codes
Creators: name: Barnes, M.
name: Abel, I. G.
name: Dorland, W.
name: Goerler, T.
name: Hammett, G. W.
name: Jenko, F.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: Direct coupling between a transport solver and local, nonlinear gyrokinetic calculations using the multiscale gyrokinetic code TRINITY [M. Barnes, Ph.D. thesis, arxiv:0901.2868] is described. The coupling of the microscopic and macroscopic physics is done within the framework of multiscale gyrokinetic theory, of which we present the assumptions and key results. An assumption of scale separation in space and time allows for the simulation of turbulence in small regions of the space-time grid, which are embedded in a coarse grid on which the transport equations are implicitly evolved. This leads to a reduction in computational expense of several orders of magnitude, making first-principles simulations of the full fusion device volume over the confinement time feasible on current computing resources. Numerical results from TRINITY simulations are presented and compared with experimental data from JET and ASDEX Upgrade plasmas.
description: 12 pages, 13 figures, invited paper for 2009 APS-DPP meeting, submitted to Phys. Plasmas