cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Formation of hot Jupiters through disk migration and evolving stellar tides
Creators: name: Heller, René
Publisher: name: arXiv
Year: 2018
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Here we address the hot Jupiter (hJ) pile-up at 0.05 AU around young solar-type stars observed in stellar radial velocity surveys, the hJ longterm orbital stability in the presence of stellar tides, and the hJ occurrence rate of 1.2 (+-0.38)% in one framework. We calculate the combined torques on the planet from the stellar dynamical tide and from the protoplanetary disk in the type II migration regime. We model a 2D nonisothermal viscous disk parameterized to reproduce the minimum-mass solar nebula and simulate an inner disk cavity at various radial positions near the star. We choose stellar rotation periods according to observations of young star clusters. The planet is on a circular orbit in the disk midplane and in the star's equatorial plane. We show that the torques can add up to zero beyond the corotation radius around young stars and stop inward migration. Monte Carlo simulations predict hot Jupiter survival rates between ~3% (alpha disk viscosity of 1e-1) and 15% (alpha = 1e-3). Once the protoplanetary disk has been fully accreted, the surviving hJs are pushed outward from their tidal migration barrier and pile up near 0.05 AU, as we demonstrate using a numerical implementation of a stellar dynamical tide model. Orbital decay is negligible on a one-billion-year timescale due to the contraction of the highly dissipative convective envelopes in young Sun-like stars. We find that the higher pile-up efficiency around metal-rich stars can at least partly explain the observed positive correlation between stellar metallicity and hJ occurrence. Combined with the observed hJ occurrence rate, our results for the survival rate imply that <8 % (alpha = 1e-3) to <43 % (alpha = 1e-1) of sun-like stars initially encounter an inward migrating hJ. This reconciles models and observations of young spinning stars with the observed hJ pile up and hJ occurrence rates.
description: accepted by A&A (30 June 2019), 14 pages, 12 figures (6 col, 6 b/w)
Negating the Galvin Property
Creators: name: Benhamou, Tom
name: Garti, Shimon
name: Poveda, Alejandro
Publisher: name: arXiv
Year: 2021
Subjects: subject: Logic (math.LO)
subject: FOS: Mathematics
subject: 03E35, 03E55

description: We prove that Galvin's property consistently fails at successors of strong limit singular cardinals. We also prove the consistency of this property failing at every successor of a singular cardinal. In addition, the paper analyzes the effect of Prikry-type forcings on the strong failure of the Galvin property and explores stronger forms of this property in the context of large cardinals
The Ray Bundle method for calculating weak magnification by gravitational lenses
Creators: name: Fluke, C. J.
name: Webster, R. L.
name: Mortlock, Daniel J.
Publisher: name: arXiv
Year: 1998
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present here an alternative method for calculating magnifications in gravitational lensing calculations -- the Ray Bundle method. We provide a detailed comparison between the distribution of magnifications obtained compared with analytic results and conventional ray-shooting methods. The Ray Bundle method provides high accuracy in the weak lensing limit, and is computationally much faster than (non-hierarchical) ray shooting methods to a comparable accuracy. The Ray Bundle method is a powerful and efficient technique with which to study gravitational lensing within realistic cosmological models, particularly in the weak lensing limit.
description: 9 pages Latex, 8 figures, submitted to MNRAS
Data and Supplementary materials - Evidence for a vocal signature in the rat and its reinforcing effects; a key role for the subthalamic nucleus
Creators: name: Vielle, Cassandre
name: Montanari, Christian
name: Pelloux, Yann
name: Baunez, Christelle
Publisher: name: figshare
Year: 2021
Subjects: Behavioral Neuroscience

description: Supplementary materials:This section contains detailed descriptions of:- the apparatus- the experimental procedure used to assess the effect of Playback display of USV during cocaine self-administration (before the baseline)- the accoustic stimuli used (recording conditions, analyses, figures)
- the 2 RE-PLM Tables
Data:This section contains data and RE-PLM codes used in the article
title: ADCO, Sixième cartulaire de Saint-Étienne de Dijon (1662), Cart. 30 (G 133), 441 folios, f. 873
Creators: name: de la Côte d'Or, Archives départementales
name: Archives Départementales De La Côte-D'Or
name: Petot, Frédérique
name: Projet CBMA
name: CG21/F.PETOT/2012
name: Petot, Frédéric
Publisher: name: NAKALA - https://nakala.fr (Huma-Num - CNRS)
publisherIdentifier: https://ror.org/04ces3204
publisherIdentifierScheme: ROR
Year: 2020
Subjects: subject: Chartes de la Bourgogne du Moyen Âge
subject: LaMOP
subject: Laboratoire de Médiévistique Occidentale de Paris
subject: Corpus Burgundiae Medii Aevi
subject: cartulaire

description: Sixième cartulaire de Saint-Étienne de Dijon (1662), Archives départementales de la Côte-d'Or, Cart. 30 (G 133), 441 folios, f. 873, Numérisation en mode image.
description: Relation: http://www.cbma-project.eu/
description: Bibliographic citation: Sixième cartulaire de Saint-Étienne de Dijon (1662), Archives départementales de la Côte-d'Or, Cart. 30 (G 133), 441 folios, f. 873, in Projet CBMA - Corpus Burgundiae Medii Aevi [Ressource en ligne], https://manuscrits.cbma-project.eu/
description: Provenance: abbaye Saint-Étienne de Dijon
description: Provenance: http://www.wikidata.org/entity/Q15945019
Investigation of porcine interferons as a metaphylactic intervention against classical swine fever virus
Creators: name: Crudgington, Bentley
Publisher: name: Imperial College London
Year: 2017

description: Classical Swine Fever (CSF) is an important viral disease of swine. The application of Interferon (IFN) via viral vectors could be a beneficial intervention strategy against CSFV. Unlike type I and II IFN, the anti-CSFV activity of type III IFNs is unknown. Type III IFNs have similar antiviral actions to type I IFNs, but their specific receptors have limited tissue distribution and may be important as very early defences against infection at epithelial surfaces. PoIFN (type I (α, β) type II (γ) and type III (λ1, 3)) were cloned into a mammalian expression vector, expressed in porcine tracheal (NpTr) cells and the induction of an immune response and anti-CSFV activity examined. PoIFNs were subsequently expressed using adenovirus and MVA viral vectors and their antiviral activity assessed. All three types of vectored IFN upregulated expression of the interferon stimulated gene MxA and significantly reduced CSFV infection in the NpTr cell line and in porcine primary cells. Inoculation of NpTr cells with adenovirus and MVA vectors expressing all three types of IFN inhibited CSFV infection, with the Ad_IFNα/β and λ constructs inducing a greater anti- CSFV effect than the Ad_IFNγ constructs. Intranasal and intramuscular inoculations with MVA vectors did not induce ISG upregulation in the tonsils or protect monocytes against an ex vivo CSFV challenge. These outcomes are not likely to be true reflections on the potential of this vector system due to limitations in the preparation of inoculum. Intranasal inoculation with adeno vectors expressing type I and type III IFN did not induce any significant systemic or tissue specific antiviral responses and under these conditions would not be predicted to offer successful protection against CSFV infection. Intramuscular inoculation of Ad_IFNα into pigs induced upregulated serum IFNα levels and offered significant levels of protection against ex vivo CSFV challenge of isolated leukocytes and offers a promising candidate for metaphylactic intervention.
RR Lyrae Variables in the Globular Cluster M55. The First Evidence for Non Radial Pulsations in RR Lyr Stars
Creators: name: Olech, A.
name: Kaluzny, J.
name: Thompson, I. B.
name: Pych, W.
name: Krzeminski, W.
name: Schwarzenberg-Czerny, A.
Publisher: name: arXiv
Year: 1998
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present the results of a photometric study of RR Lyrae variables in the field of the globular cluster M55. We have discovered nine new RR Lyrae stars, increasing the number of known variables in this cluster to 15 objects. Five of the newly discovered variables belong to Bailey type RRc and two to type RRab. Two background RRab stars are probable members of the Sagittarius dwarf galaxy. Fourier decomposition of the light curves was used to derive basic properties of the present sample of RR Lyrae variables. From an analysis of the RRc variables we obtain a mean mass of $M=0.53\pm0.03 M_\odot$, luminosity $\log L=1.75\pm0.01$, effective temperature $T_{eff}=7193\pm27$ K, and helium abundance $Y=0.27\pm0.01$. Based on the $B-V$ colors, periods and metallicities of the RRab stars we estimate the value of the color excess for M55 to be equal to $E(B-V)=0.11\pm0.03$. Using this value we derive the colors of the blue and red edges of the instability strip in M55. The blue edge lies at $(B-V)_0=0.20$ mag and the red edge lies at $(B-V)_0=0.38$ mag. We estimate the values of the visual apparent and dereddened distance moduli to be $13.65\pm0.11$ and $13.31\pm0.11$, respectively. The light curves of three of the RRc variables exhibit changes in amplitude of over 0.1 mag on the time scale of less than a week, rather short for the Blazhko effect, but with no evidence for another radial pulsational frequency. However we do detect other periodicities which are clearly visible in the light curve after removing variations with the first overtone radial frequency. This is strong evidence for the presence of non-radial pulsations, a behavior common for $δ$ Scuti stars but not yet observed among RR Lyr variables.
description: submitted to Astronomical Journal, 33 pages with 11 figures
Observationally inferred dark matter phase-space distribution and direct detection experiments
Creators: name: Mandal, Sayan
name: Majumdar, Subhabrata
name: Rentala, Vikram
name: Thakur, Ritoban Basu
Publisher: name: arXiv
Year: 2018
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: We present a detailed analysis of the effect of an observationally determined dark matter (DM) velocity distribution function (VDF) of the Milky Way (MW) on DM direct detection rates. We go beyond local kinematic tracers and use rotation curve data up to 200 kpc to construct a MW mass model and self-consistently determine the local phase-space distribution of DM. This approach mitigates any incomplete understanding of local dark matter-visible matter degeneracies that can affect the determination of the VDF. Comparing with the oft used Standard Halo Model (SHM), which assumes an isothermal VDF, we look at how the tail of the empirically determined VDF alters our interpretation of the present direct detection WIMP DM cross section exclusion limits. While previous studies have suggested a very large difference (of more than an order of magnitude) in the bounds at low DM masses, we show that accounting for the detector response at low threshold energies, the difference is still significant although less extreme. The change in the number of signal events, when using the empirically determined DM VDF in contrast to the SHM VDF, is most prominent for low DM masses for which the shape of the recoil energy spectrum depends sensitively on the detector threshold energy as well as detector response near the threshold. We demonstrate that these trends carry over to the respective DM exclusion limits, modulo detailed understanding of the experimental backgrounds. With the unprecedented precision of astrometric data in the GAIA era, use of observationally determined DM phase-space will become a critical and necessary ingredient for DM searches. We provide an accurate fit to the current best observationally determined DM VDF (and self-consistent local DM density) for use in analyzing current DM direct detection data by the experimental community.
description: 13 pages, 10 figures, 4 tables, version accepted by PRD
title: ADCO, Septième cartulaire de Saint-Étienne de Dijon (1661-1665), Cart. 29 (G 134), 996 folios, f. 0669
Creators: name: de la Côte d'Or, Archives départementales
name: Archives Départementales De La Côte-D'Or
name: Petot, Frédérique
name: Projet CBMA
name: CG21/F.PETOT/2012
name: Petot, Frédéric
Publisher: name: NAKALA - https://nakala.fr (Huma-Num - CNRS)
publisherIdentifier: https://ror.org/04ces3204
publisherIdentifierScheme: ROR
Year: 2020
Subjects: subject: LaMOP
subject: Laboratoire de Médiévistique Occidentale de Paris
subject: Corpus Burgundiae Medii Aevi
subject: Chartes de la Bourgogne du Moyen Âge
subject: cartulaire

description: Septième cartulaire de Saint-Étienne de Dijon (1661-1665), Archives départementales de la Côte-d'Or, Cart. 29 (G 134), 996 folios, f. 0669, Numérisation en mode image.
description: Relation: http://www.cbma-project.eu/
description: Bibliographic citation: Septième cartulaire de Saint-Étienne de Dijon (1661-1665), Archives départementales de la Côte-d'Or, Cart. 29 (G 134), 996 folios, f. 0669, in Projet CBMA - Corpus Burgundiae Medii Aevi [Ressource en ligne], https://manuscrits.cbma-project.eu/
description: Provenance: abbaye Saint-Étienne de Dijon
description: Provenance: http://www.wikidata.org/entity/Q15945019
Fast Camouflaged Object Detection via Edge-based Reversible Re-calibration Network
Creators: name: Ji, Ge-Peng
name: Zhu, Lei
name: Zhuge, Mingchen
name: Fu, Keren
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: FOS: Computer and information sciences

description: Camouflaged Object Detection (COD) aims to detect objects with similar patterns (e.g., texture, intensity, colour, etc) to their surroundings, and recently has attracted growing research interest. As camouflaged objects often present very ambiguous boundaries, how to determine object locations as well as their weak boundaries is challenging and also the key to this task. Inspired by the biological visual perception process when a human observer discovers camouflaged objects, this paper proposes a novel edge-based reversible re-calibration network called ERRNet. Our model is characterized by two innovative designs, namely Selective Edge Aggregation (SEA) and Reversible Re-calibration Unit (RRU), which aim to model the visual perception behaviour and achieve effective edge prior and cross-comparison between potential camouflaged regions and background. More importantly, RRU incorporates diverse priors with more comprehensive information comparing to existing COD models. Experimental results show that ERRNet outperforms existing cutting-edge baselines on three COD datasets and five medical image segmentation datasets. Especially, compared with the existing top-1 model SINet, ERRNet significantly improves the performance by $\sim$6% (mean E-measure) with notably high speed (79.3 FPS), showing that ERRNet could be a general and robust solution for the COD task.
description: 35 pages, 7 figures, 5 tables (Accepted by Pattern Recognition 2022)
The Impact of India’s Janani Suraksha Yojana Conditional Cash Transfer Programme: A Replication Study
Creators: name: Carvalho, Natalie
name: Rokicki, Slawa
Publisher: name: Taylor & Francis
Year: 2018
Subjects: subject: Medicine
subject: Cell Biology
subject: Sociology
subject: FOS: Sociology
subject: Cancer

description: In 2005 the government of India established Janani Suraksha Yojana (JSY), a conditional cash transfer programme to increase deliveries in health facilities. We re-examine an influential study published in 2010 on the effect of JSY on reproductive health coverage indicators and perinatal and neonatal mortality. We find the original authors’ results to be replicable and robust to various changes in model specifications and analysis. Through the use of multilevel models, we find meaningful heterogeneity across states and districts in the effects of JSY on the probabilities of in-facility delivery and skilled birth attendance, and neonatal mortality rates.
Phase self-aligned continuous-variable measurement-device-independent quantum key distribution
Creators: name: Yin, Hua-Lei
name: Zhu, Wei
name: Fu, Yao
Publisher: name: arXiv
Year: 2018
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Continuous-variable measurement-independent-device quantum key distribution (CV-MDI-QKD) can offer high secure key rate at metropolitan distance and remove all side channel loopholes of detection as well. However, there is no complete experimental demonstration of CV-MDI-QKD due to the remote distance phase-locking techniques challenge. Here, we present a new optical scheme to overcome this difficulty and also removes the requirement of two identical independent lasers. We anticipate that our new scheme can be used to demonstrate the in-field CV-MDI-QKD experiment and build the CV-MDI-QKD network with untrusted source.
description: 26 pages, 3 figures
Globular Clusters in Blue Compact Galaxies as Tracers of the Starburst History
Creators: name: Östlin, G.
Publisher: name: arXiv
Year: 1998
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Representing single stellar populations, globular clusters (GCs) are relatively easy to model, thus providing powerful tools for studying the evolution of galaxies. This has been demonstrated for the blue compact galaxy ESO338-IG04. GC systems in galaxies may be fossils of starbursts and mergers. Thus studies of GCs in the local universe may add to our understanding of the formation and evolution of galaxies and the distant universe.
description: 4 pages, 2 figures. To be published in "Galaxy evolution: Connecting the distant Universe with the local fossil record", proceedings from conference at Observatoire de Paris-Meudon, 21-25 september 1998, eds M. Spite et al., Kluwer
Monte Carlo algorithms for hypothesis testing and for hidden markov models
Creators: name: Ding, Dong
Publisher: name: Imperial College London
Year: 2018

description: Monte Carlo methods are useful tools to approximate the numerical result of a problem by random sampling when its analytic solution is intractable or computationally intensive. The main focus of this work is to investigate Monte Carlo methods in two areas of inference problems: hypothesis testing and posterior analysis in a hidden Markov model (HMM). The first part of this thesis focuses on the decision of the p-value with respect to a fixed threshold via Monte Carlo simulations in a statistical hypothesis test. We wish to control the resampling risk, which is the probability of obtaining a different test decision from the true one based on the unknown p-value. We present confidence sequence method (CSM), a simple Monte Carlo testing procedure which bounds the resampling risk uniformly. CSM is useful due to its simple implementation and comparable performance to its competitors. The second part of the thesis focuses on two posterior distributions of an HMM: smoothing and parameter estimation. We apply a divide-and-conquer strategy (Lindsten et al., 2017) to develop Monte Carlo algorithms that which provide sample approximation of the target distribution. We propose an algorithm called tree-based particle smoothing algorithm (TPS) to estimate the joint smoothing distribution. We then assume an unknown parameter in the HMM, and extend TPS to approximate its posterior, which we refer to as tree-based parameter estimation algorithm (TPE). TPS and TPE both construct an auxiliary tree for recursively splitting model into sub-models. The root of the tree stands for the target distribution of the model. We propose different forms of intermediate target distributions of the sub-models associated to the non-root nodes, which are crucial to sampling quality. For the sampling process, we generate initial samples independently between the leaf nodes. Then we recursively merge these samples along the tree until reaching the root. Each merging step involves importance sampling for the (intermediate) target distribution. A more adaptive design of the algorithms and an improved accuracy compared to their competitors make them useful alternatives in practice.
Mapping of dopaminergic networks in vivo in parkinson’s patients: a multimodal imaging study
Creators: name: Li, Weihua
Publisher: name: Imperial College London
Year: 2018

description: Position emission tomography (PET) provides non-invasive quantifications of brain glucose metabolism and neuroreceptor binding that enabling greater understanding of the pathophysiology of Parkinson’s disease (PD). However, PET studies have often been conducted separately from studies using magnetic resonance imaging (MRI) exploring connectivity and functional network. The aim of this thesis is to map in vivo dopaminergic and serotonergic networks in patients with PD by using advanced MRI and PET with the tracer 18F-DOPA assessing Aromatic-L-Amino-Acid-Decarboxylase (AADC), 11C-PE2I and 11C-DASB, targeting dopamine transporter (DAT) and serotonin transporter (SERT) respectively The main findings are as follows: (1) Longitudinal comparison of 11C-PE2I and 18F-DOPA PET for assessing rate of disease progression in early-moderate PD patients indicate that DAT decline is closely associated with motor progression over time, whereas no such relationship was found with AADC. (2) The combined resting-state functional MRI (fMRI) and 11C-PE2I PET study demonstrates that (a) Functional connectivity of the striatum with substantia nigra (SN) was significantly positively correlated with striatal 11C-PE2I uptake. (b) Longitudinally, reduced functional connectivity of posterior putamen with SN was significantly associated with decreases in posterior putamen 11C-PE2I uptake. (3) The combined diffusion tensor imaging (DTI) and 11C-DASB PET shows that the amygdalar 11C-DASB uptake was significantly correlated with mean diffusivity (MD) value in the amygdala. Taken together, the findings suggest that 11C-PE2I PET is an objective biomarker for investigating the effects of novel interventions on the rate of nigrostriatal degeneration in PD, and it is more effective to evaluate efficacy of neuroprotective treatments in PD. This thesis also identifies the importance of using multi-model neuroimaging to better assess underlying PD pathology and explain PD-related clinical measures. In some circumstances where cost, accessibility and scan duration are an issue; resting-state fMRI and DTI may supersede PET in the investigation of functional and structural changes in PD.
Reionization of the Inhomogeneous Universe
Creators: name: Miralda-Escude, Jordi
name: Haehnelt, Martin
name: Rees, Martin J.
Publisher: name: arXiv
Year: 1998
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: A model of the density distribution in the intergalactic medium, motivated by that found in numerical simulations, is used to demonstrate the effect of a clumpy IGM and discrete sources on the reionization of the universe. In an inhomogeneous universe reionization occurs outside-in, starting in voids and gradually penetrating into overdense regions. Reionization should not be sudden but gradual, with a continuous rise of the photon mean free path over a fair fraction of the Hubble time as the emissivity increases. We show that a hydrogen Gunn-Peterson trough should be present at $z\simeq 6$ unless the emissivity increases with redshift at $z>4$. However, the epoch of overlap of cosmological \hii regions could have occurred at a higher redshift if sources of low luminosity reionized the IGM; the Gunn-Peterson trough at $z\sim 6$ would then appear because even the most underdense voids have a large enough neutral fraction in ionization equilibrium to be optically thick to \lya photons. Cosmological \hii regions near the epoch of overlap can produce gaps of transmitted flux only if luminous quasars contributed to the reionization. Despite the clumpiness of the matter distribution, recombinations are not very important during the reionization of hydrogen because the high density gas is not ionized until a late time. We show that the \heii reionization was most likely delayed relative to the hydrogen reionization, but should be completed by $z\sim 3$, the redshift where observations are available. The reported large optical depth fluctuations of \heii are probably not due to an incomplete \heii reionization, but arise from a combination of density fluctuations and the variations in the intensity of the ionizing background due to luminous QSO's.
description: to be published in The Astrophysical Journal
Deletion Robust Submodular Maximization over Matroids
Creators: name: Dütting, Paul
name: Fusco, Federico
name: Lattanzi, Silvio
name: Norouzi-Fard, Ashkan
name: Zadimoghaddam, Morteza
Publisher: name: arXiv
Year: 2022
Subjects: subject: Data Structures and Algorithms (cs.DS)
subject: Machine Learning (cs.LG)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences

description: Maximizing a monotone submodular function is a fundamental task in machine learning. In this paper, we study the deletion robust version of the problem under the classic matroids constraint. Here the goal is to extract a small size summary of the dataset that contains a high value independent set even after an adversary deleted some elements. We present constant-factor approximation algorithms, whose space complexity depends on the rank $k$ of the matroid and the number $d$ of deleted elements. In the centralized setting we present a $(3.582+O(\varepsilon))$-approximation algorithm with summary size $O(k + \frac{d \log k}{\varepsilon^2})$. In the streaming setting we provide a $(5.582+O(\varepsilon))$-approximation algorithm with summary size and memory $O(k + \frac{d \log k}{\varepsilon^2})$. We complement our theoretical results with an in-depth experimental analysis showing the effectiveness of our algorithms on real-world datasets.
Mechanistic modelling methodologies for microstructurally-sensitive crack growth in ductile metals
Creators: name: Wilson, David Joel
Publisher: name: Imperial College London
Year: 2018

description: A physically-based methodology for modelling microstructurally-sensitive fatigue crack growth has been developed and shown to capture many of the experimentally observed effects associated with microstructurally-sensitive fatigue crack growth, which currently contribute to the high levels of uncertainty in lifing models. Behaviours predicted by the model cover changes in rate and path due to interactions with local microstructural features including rate changes due to local crystal orientations, deflections and retardation at grain boundaries and crack path tortuosity within grains. The ability of the model to accurately capture these key behaviours has enabled their rationalisation within a physically-based, mechanistic framework.
Poster IODP-ITALIA 2018
Creators: name: IODP-ITALIA Commissione IODP-Italia-Commissione Per Il Coordinamento Della Partecipazione Italiana All'International Ocean Discovery Program (IODP)
Publisher: name: figshare
Year: 2018
Subjects: subject: 50203 Environmental Education and Extension
subject: FOS: Earth and related environmental sciences
subject: 40402 Geodynamics
subject: Geology
subject: Geophysics
subject: 40305 Marine Geoscience
subject: Oceanography
subject: 40605 Palaeoclimatology
subject: 40308 Palaeontology (incl. Palynology)
subject: 40309 Petroleum and Coal Geology
subject: 40310 Sedimentology
subject: Solid Earth Sciences
subject: 40311 Stratigraphy (incl. Biostratigraphy and Sequence Stratigraphy)

description: Summary of IODP-Italia activities
Thin film composite membranes and their derivatives in desalination by reverse osmosis
Creators: name: Abdulsalam Ebrahim, Mahmood
Publisher: name: Imperial College London
Year: 2019

description: Thin film composite (TFC) membranes formed via the interfacial polymerisation of m-phenylenediamine (MPD) and trimesoyl chloride (TMC) on a polysulfone (PSf) or polyethersulfone ultrafiltration support are the most widely used membranes in desalination. This work aims to develop high flux seawater reverse osmosis (SWRO) membranes. An analogue TFC membrane formed via the interfacial reaction of MPD and TMC was fabricated; and its performance was compared to five commercial RO membranes. The influence of sodium chloride concentration in the feed solution on the transport properties of the membranes was evaluated by varying the feed concentration between 0 to 70 g.L^(-1) NaCl, in order to simulate the commonly encountered operating conditions of SWRO desalination at a recovery of 50%. The analogue membrane showed comparable performance to the commercial RO membranes over the experimental range. Mixed matrix ultrafiltration (MMUF) supports were prepared by incorporating titanium dioxide (TiO2) nanoparticles and nanotubes in the polysulfone support membrane. MMUF supports showed an increase in the pure water permeance by up to 200% relative to the pure PSf support. A selective polyamide layer was fabricated via interfacial polymerisation of MPD and TMC on the MMUF, and on the pure PSf support membranes; and their desalination performance was tested. TFC membranes made on TiO2 nanotubes incorporated MMUF showed around 8% improvement (up to 2.7 L.m^(-2).h^(-1).bar^(-1) at 60 bar) compared to the TFCs fabricated on pure PSf support and 99% rejection of NaCl at steady state. The results of this work and the recent advances in the development of graphene-based membranes suggest that the development of porous ultrathin carbon (UtC) nanofilms is a potential route to obtain high flux RO membranes. UtC nanofilms were obtained from pyrolysis of polyamide nanofilms made via interfacial polymerisation at 500 – 1100°C under an Ar/H2 atmosphere, to provide nanofilms with thicknesses down to 3 nm, and the properties of UtC nanofilm sheets and powders are reported. Ultrathin carbon nanofilms showed limited utility as reverse osmosis membranes, with water permeance of 0.01 L.m^(-2).h^(-1).bar^(-1) and low rejection of sodium chloride. Although the small pore width and hydrophobic nature of these films resulted in low water permeance, ultrathin carbon nanofilms could potentially be useful in different applications.
Graphene optical and microwave molecular sensing platforms
Creators: name: Black, Nicola Charlotte
Publisher: name: Imperial College London
Year: 2018

description: The unique electronic and physical structure of graphene is highly sensitive to its surroundings, producing a promising candidate for future sensor technologies. However, graphene responds equally to perturbations at both sides of its interface, such that tuning the chemical potential of the substrate at the graphene-solid interface impacts the sensor response at the graphene-gas/liquid interface. In this work, two distinct non-contact graphene sensing platforms are studied under various ambient conditions to assess their propensity towards molecular sensing. The different spectral enhancement mechanisms of graphene surface enhanced Raman spectroscopy platforms are studied through interfacing graphene to differently treated gold nanodisc substrates. Using statistical Raman analysis, the influence of the chemical enhancement mechanism with respect to the graphene Raman peaks is assessed. Moreover, Kelvin force microscopy shows that the locally enhanced electromagnetic field can induce surface chemical reactions which are dependent upon the sensor environment. Explicitly, laser illumination in an air/nitrogen ambient, p-/n-dopes the graphene sheet by -0.87 0.05 meV/ +0.75 0.07 meV. By measuring the change of resistivity of graphene upon gas adsorption using a microwave dielectric resonator, a contactless non-invasive gas sensing platform is demonstrated. This large area graphene measurement platform allows evaluation of the real time sorption processes of NO2 with graphene. Using a modified Langmuir adsorption model, the sticking coefficient is exponentially dependent upon NO2 occupancy. Consequently, the possible variation of the NO2 binding energy, which is frequently considered as the main parameter, plays only a secondary role compared to the rising adsorption energy barrier with increasing NO2 coverage. Finally, through preliminary temperature and electrical gating measurements the charge transfer affinity of graphene based NO2 sensors is explored. Interestingly, the sensor response can be hindered and/or enhanced by back gate control of the doping in graphene.
Strong Aperiodic X-ray Variability and Quasi-Periodic Oscillation in X-ray Nova XTE J1550-564
Creators: name: Cui, Wei
name: Zhang, S. N.
name: Chen, Wan
name: Morgan, E. H.
Publisher: name: arXiv
Year: 1998
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We report the discovery of strong aperiodic X-ray variability and quasi-periodic oscillation (QPO) in the X-ray light curves of a new X-ray Nova, XTE J1550-564, and the evolution of the observed temporal properties during the rise of the recent X-ray outburst. The power spectral analysis of the first observation reveals strong aperiodic X-ray variability of the source (~28%), as well as the presence of a QPO at ~82 mHz with fractional rms amplitude ~14% over the 2-60 keV energy range. Also apparent is the first harmonic of the QPO with the amplitude ~9%. As the X-ray flux increases, the source tends to become less variable, and the QPO frequency increases rapidly, from 82 mHz to 4 Hz, over the flux (2-50 keV) range of 1.73-5.75 x 10^{-8} ergs cm^{-2} s^{-1}. The amplitude of the fundamental component of the QPO varies little, while that of the harmonic follows a decreasing trend. The fundamental component strengthens toward high energies, while its harmonic weakens. Initially, the power spectrum is roughly flat at low frequencies and turns into a power law at high frequencies, with the QPO harmonic sitting roughly at the break. In later observations, however, the high-frequency portion of the continuum can actually be better described by a broken power law (as opposed to a simple power law). This effect becomes more apparent at higher energies. The overall amplitude of the continuum shows a similar energy dependence to that of the fundamental component of the QPO. Strong rapid X-ray variability, as well as hard energy spectrum, makes XTE J1550-564 a good black hole candidate. We compare its temporal properties with those of other black hole candidates.
description: 12 pages, including 5 figures. To appear in ApJ Letters, vol. 512 (1999)
Jenkins-Serrin graphs in $M\times\mathbb{R}$
Creators: name: Gama, Eddygledson S.
name: Heinonen, Esko
name: de Lira, Jorge H.
name: Martin, Francisco
Publisher: name: arXiv
Year: 2018
Subjects: subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 53C44, 53A10, 53C21, 53C42

description: The so called Jenkins-Serrin problem is a kind of Dirichlet problem for graphs with prescribed mean curvature that combines, at the same time, continuous boundary data with regions of the boundary where the boundary values explodes either to $+\infty$ or to $-\infty.$ We give a survey on the development of Jenkins-Serrin type problems over domains on Riemannian manifolds. The existence of this type of graphs imposes restrictions on the geometry of the boundary of these domains. We also improve some earlier results by proving Theorem 1.8, and prove the existence of translating Jenkins-Serrin graphs (Theorem 1.9).
description: Revised version. To appear in the proceedings of the "M:IV winter workshop 2018" held at the University of Granada, January 9-12, 2018
Gamma Ray Bursts vs. Afterglows
Creators: name: Katz, J. I.
Publisher: name: arXiv
Year: 1998
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: When does a GRB stop and its afterglow begin? A GRB may be defined as emission by internal shocks and its afterglow as emission by an external shock, but it is necessary to distinguish them observationally. With these definitions irregularly varying emission (at any frequency) must be the GRB, but smoothly varying intensity is usually afterglow. The GRB itself and its afterglow may overlap in time and in frequency, and distinguishing them will, in general, require detailed modeling.
description: 2 pp., Proc. Conf. Gamma-Ray Bursts in the Afterglow Era, Astron. Ap. latex (needs files from ftp://ftp.edpsciences.com/pub/aas/)
Representation varieties of twisted Hopf links
Creators: name: González-Prieto, Ángel
name: Muñoz, Vicente
Publisher: name: arXiv
Year: 2022
Subjects: subject: Geometric Topology (math.GT)
subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 57K31, 14D20, 14C30

description: We study the representation theory of the fundamental group of the complement of a Hopf link with n twists. A general framework is described to analyze the $SL_r(C)$-representation varieties of these twisted Hopf links as byproduct of a combinatorial problem and equivariant Hodge theory. As application, close formulas of their E-polynomials are provided for ranks 2 and 3, both for the representation and character varieties.
description: 25 pages, 3 figures; v2. Corrected mistake in the E-polynomial in main theorem
The Structural Basis of Calvin-Benson Cycle Redox Regulation
Creators: name: McFarlane, Ciaran Rayan
Publisher: name: Imperial College London
Year: 2018

description: The Calvin-Benson cycle is the source of almost all the organic carbon in the biosphere. It uses the ATP and NADPH generated by the photosynthetic light-dependent reactions to fix carbon dioxide into organic carbon. In the dark, the light-dependent reactions are inactive and in response the Calvin-Benson cycle is down regulated. The small chloroplast protein CP12 is responsible for Calvin-Benson cycle down regulation; in the light it is intrinsically disordered and in the dark it becomes ordered due to the oxidation of two disulfide bridges. This oxidation causes CP12 to form an inhibited enzyme complex with Calvin- Benson cycle enzymes glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and phosphoribulokinase (PRK). I have expressed and purified complexes of CP12, GAPDH and PRK from the cyanobacterium Thermosynechococcus elongatus for structure and function studies. I solved structures of GAPDH and GAPDH-CP12 using X-ray crystallography producing structures of full length CP12 and in collaboration with Dr. Nita Shah and Dr. Doryen Bubeck we solved the first structure of the GAPDH-CP12-PRK complex using cryo-electron microscopy. In conjunction with enzyme assays, these structures reveal how CP12 inhibits enzyme activity and how it senses the nucleotide and redox state of the chloroplast to regulate GAPDH and PRK, furthering our understanding Calvin-Benson cycle regulation and carbon fixation as a whole.
Ergodic Sum Rate Capacity Achieving Transmit Design for Massive MIMO LEO Satellite Uplink Transmission
Creators: name: Li, Ke-Xin
name: Gao, Xiqi
name: Xia, Xiang-Gen
Publisher: name: arXiv
Year: 2022
Subjects: subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: In this paper, we investigate the ergodic sum rate (ESR) capacity achieving uplink (UL) transmit design for massive multiple-input multiple-output (MIMO) low-earth-orbit (LEO) satellite communications with statistical channel state information at the user terminals (UTs). The UL massive MIMO LEO satellite channel model with uniform planar array configurations at the satellite and UTs is presented. We prove that the rank of each UT's optimal transmit covariance matrix does not exceed that of its channel correlation matrix at the UT side, which reveals the maximum number of independent data streams transmitted from each UT to the satellite. We then prove that the transmit covariance matrix design can be transformed into the lower-dimensional matrix design without loss of optimality. We also obtain a necessary and sufficient condition when single data stream transmission from each UT to the satellite can achieve the ESR capacity. A conditional gradient (CG) method is developed to compute the ESR capacity achieving transmit covariance matrices. Furthermore, to avoid the exhaustive sample average, we utilize an asymptotic expression of the ESR and devise a simplified CG method to compute the transmit covariance matrices, which can approximate the ESR capacity. Simulations demonstrate the effectiveness of the proposed approaches.
description: 13 pages, double columns
Deep, Deep Learning with BART
Creators: name: Blumenthal, Moritz
name: Luo, Guanxiong
name: Schilling, Martin
name: Holme, H. Christian M.
name: Uecker, Martin
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Signal Processing (eess.SP)
subject: FOS: Computer and information sciences
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Purpose: To develop a deep-learning-based image reconstruction framework for reproducible research in MRI.
 Methods: The BART toolbox offers a rich set of implementations of calibration and reconstruction algorithms for parallel imaging and compressed sensing. In this work, BART was extended by a non-linear operator framework that provides automatic differentiation to allow computation of gradients. Existing MRI-specific operators of BART, such as the non-uniform fast Fourier transform, are directly integrated into this framework and are complemented by common building blocks used in neural networks. To evaluate the use of the framework for advanced deep-learning-based reconstruction, two state-of-the-art unrolled reconstruction networks, namely the Variational Network [1] and MoDL [2], were implemented.
 Results: State-of-the-art deep image-reconstruction networks can be constructed and trained using BART's gradient based optimization algorithms. The BART implementation achieves a similar performance in terms of training time and reconstruction quality compared to the original implementations based on TensorFlow.
 Conclusion: By integrating non-linear operators and neural networks into BART, we provide a general framework for deep-learning-based reconstruction in MRI.
description: Submitted to Magnetic Resonance in Medicine
Potential applications for additive manufacturing technology in forensic pathology practice
Creators: name: Biggs, Michael
Publisher: name: University of Leicester
Year: 2021
Subjects: Uncategorized

description: Additive manufacturing (i.e. 3D printing) processes have been in development since the 1980s. Medical practitioners were among the first to appreciate the value of this technology, but early industrial devices were prohibitively large and expensive, limiting access to all but a few. More recently, smaller scale “desktop” printers have become available, bringing this capability within the realistic reach of many.Computed tomography (x-ray) scanning has increasingly become routine in forensic pathological investigations in Leicester since its implementation in 2002. The obtained scan data has previously been used to produce graphical 3D representations of pathological evidence to assist jury comprehension in court. With the advent of smaller scale 3D printing, the possibility of further enhancing this court evidence with 3D printed anatomical models was considered a viable option.This thesis explains the overall concept and specific processes of 3D printing, and explores potential applications for this technology in the context of forensic pathology practice. Following acquisition of suitable hardware and software, the initial testing, calibration and accuracy checks are detailed. Strategies developed to overcome hurdles encountered during the early stages are also described. After completion of the technical evaluation phase, several practical applications were trialled and the results are illustrated. Acceptance of such 3D printed models for use within court is then demonstrated using a number of real case examples.By confirming that the recently-available, “desktop” 3D printing devices can be acquired and operated within the modest setting of a working forensic pathology department, this project contributes to the knowledge in this small but emerging field of practice. In addition, establishment of the provision of this technology represents a genuine improvement to the forensic pathology service offered within the East Midlands region
The kinematic Sunyaev Zeldovich effect and transverse cluster velocities
Creators: name: Audit, Edouard
name: Simmons, John F. L.
Publisher: name: arXiv
Year: 1998
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The polarization of the CMBR scattered by galaxy clusters in the kinematic Sunyaev Zeldovich effect depends on the transverse velocity of the cluster. This polarizing effect is proportional to the transverse velocity squared, and so weaker that the change in intensity due to the radial motion in the kinematic effect. The value given by Sunyaev and Zeldovich, and which is frequently cited, underestimates the polarizing effect by a factor of ten. We show furthermore that the polarization has a strong frequency dependence. This means that the polarization should be detectable with the new generation of CMBR probes, at least for some clusters. Thus this effect offers, almost uniquely, a method of obtaining the vectorial velocity of clusters.
description: Submitted to MNRAS letter. 5 pages using mnras file style. email: edouard.audit@obspm.fr
Application of an optical disdrometer to characterize simulated rainfall and measure drop-size distribution
Creators: name: Derege Tsegaye Meshesha
name: Tsunekawa, Atsushi
name: Nigussie Haregeweyen
Publisher: name: Taylor & Francis
Year: 2018
Subjects: subject: Biophysics
subject: Space Science
subject: 29999 Physical Sciences not elsewhere classified
subject: FOS: Physical sciences
subject: Medicine
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: 69999 Biological Sciences not elsewhere classified
subject: FOS: Biological sciences
subject: Developmental Biology

description: Knowledge of rainfall characteristics such as drop-size distribution is essential for the development of erosion-mitigation strategies and models. This research used an optical disdrometer to elucidate the relationships between raindrop-size distribution, median volume drop diameter (D50), kinetic energy and radar reflectivity (dBz) of simulated rainfall of different intensities. The D50 values were higher for the simulated rain than for natural rain at almost all rainfall intensities, perhaps due to variations in rainfall types and the turbulence in natural rain that breaks up large drops. The kinetic energy ranged from 26.67 to 5955.51 J m−2 h −1, while the median volume drop diameter (D50) was in the range 1.94–7.25 mm, for intensities between 1.5 and 202.6 mm h−1. The relationship between radar reflectivity (Z) and the intensity (R) of the simulated rain was best described by a power law function (Z = aRb), with a and b coefficients in the ranges 162–706 and 0.94–2.46, respectively, throughout the range of rainfall intensities (1.5–202.6 mm h−1).