cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
The role of mTOR signalling in primordial germ cell development
Creators: name: Schoenherr, Theresa
Publisher: name: Imperial College London
Year: 2018

description: Primordial germ cells (PGCs) are the embryonic precursors of mature egg and sperm cells. In the mouse, following specification at embryonic day (E) 7.25, PGCs proliferate and migrate through the embryonic hindgut towards the genital ridges (future gonads). At E10.5, upon genital ridge entry, developing PGCs undergo epigenetic reprogramming followed by sex differentiation, committing to either oogenesis or spermatogenesis. Signalling cross-talk between PGCs and soma is a key feature of germ cell development. However, to what extent extrinsic signals emanating from the gonadal environment influence key germ cell processes is still not well understood. Here, I describe for the first time a crucial role of a key nutrient and hormone sensing pathway (mTOR) during PGC development. mTOR signals via two distinct multi-protein complexes, mTORC1 and mTORC2. Most of the presented work focuses on mTORC1 and its downstream translational regulators 4E-binding proteins (4E-BPs) and S6 kinases (S6Ks), respectively. Using an immunofluorescence-based approach, I show that in mouse PGCs, mTORC1 signals mainly via 4E-BP1, rather than the S6K1-S6 signalling axis. Interestingly, the observed activation of mTORC1-4E-BP1 signalling in PGCs shortly follows their entry into the genital ridge, suggesting a possible role at this developmental transition. However, global deletion of either 4E-BPs or S6Ks revealed only a minor phenotype in PGCs. Further, my results also point towards activation of AKT, a potential upstream mTORC1 activator in PGCs. This indicates a possible link to mTORC2 signalling. In view of that, I carried out a germline specific conditional deletion of Mtor (using a newly generated Blimp1-iCre mouse line), that leads to the loss of mTORC1 and mTORC2. Preliminary observations show a strong phenotype of very few germ cells surviving at E13.5. In summary, my results suggest a critical role for mTOR signalling during PGC development.
Effective biotreatment of acidic mine water and hospital wastewater using fluidized-bed reactors
Creators: name: Makhathini, Thobeka Pearl
name: Mulopo, Jean
name: Bakareb, Babatunde Femi
Publisher: name: Mangosuthu University of Technology (MUT)
Year: 2022
Subjects: subject: 90403 Chemical Engineering Design
subject: FOS: Chemical engineering

description: A laboratory-scale sulfate-reducing fluidized bed reactor at a controlled mesophilic condition of ± 28 °C ex?amined the biotreatment process of real acid mine drainage and hospital wastewater. In an attempt to substitute the carbon source, the study used the hospital wastewater in this regard. In this study, there was no supplement of carbon source during the treatment, but only the hospital wastewater provided the dissolved organic carbon. The process evaluated a biological treatment efficiency in stepwise phases, monitoring the effect of retention time, influent pH, and sulfates. The overall removal for the effluent COD concentrations and sulfate were be?tween 39.5 mg/l and 42 mg/l at COD/SO4 2− ratio of 0.68 and hydraulic retention time of 8 h. The overall COD oxidation and sulfate reduction performance of the reactor was recorded as an average of 96 % and 97 %, correspondingly. The sulfide concentration averaged 235 mg/l, and the alkalinity generated in sulfidogenic organic from hospital wastewater neutralized the acid in mine water. The metal removal efficiencies docu?mented at HRT of 8 h, were all above 98 %. The biological treatment further recorded the removal efficiencies of 44 % for naproxen and 55 % for ibuprofen pharmaceutical compounds as an additional advantage to the system.
The radial velocity curve of HD153919 (4U1700-37) revisited
Creators: name: Hammerschlag-Hensberge, G.
name: van Kerkwijk, M. H.
name: Kaper, L.
Publisher: name: arXiv
Year: 2003
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We have re-analysed all available high-resolution ultraviolet IUE spectra of the high-mass X-ray binary HD153919/4U1700-37. The radial velocity semi-amplitude of 20.6 +/- 1.0 km/s and orbital eccentricity of 0.22 +/- 0.04 agree very well with the values obtained earlier from optical spectra. They disagree with earlier conclusions for the same data reduced by Heap & Corcoran (1992) and by Stickland & Lloyd (1993).
description: 6 pages, latex, figure included, Astronomy & Astrophysics, in press
Pseudodiplorchis americanus
Creators: name: Mendoza-Garfias, Berenit
name: García-Prieto, Luis
name: León, Gerardo Pérez-Ponce De
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Platyhelminthes
Monogenea
Polystomatidea
Polystomatidae
Pseudodiplorchis
Pseudodiplorchis americanus

description: Pseudodiplorchis americanus (Rodgers & Kuntz, 1940)
 Diplorchis americanus Rodgers & Kuntz, 1940: 37.
 Pseudodiplorchis americanus – Yamaguti 1963: 291.
HOSTS. — Anura; Urinary bladder.
 GEOGRAPHIC DISTRIBUTION. — Baja California Sur. La Paz: Scaphiopus couchii (Lamothe-Argumedo 1985).
 Nuevo León. Río Salinas (El Carmen): S. couchii (León-Règagnon et al. 2005) **.
SPECIMENS IN COLLECTIONS. — CNHE (1334, 4335).
 Riojatrema bravoae Lamothe-Argumedo, 1963 (Fig. 5F)
 Riojatrema bravoae Lamothe-Argumedo, 1963b: 74.
HOSTS. — Anura; Urinary bladder.
 GEOGRAPHIC DISTRIBUTION. — Morelos. Cerro del Tepozteco (Tepoztlán): Eleutherodactylus nitidus, “ Bufo simus ” (Lamothe - Argumedo 1963b).
SPECIMENS IN COLLECTIONS. — CNHE (182-83) (H, P).
REMARK
 Bufo simus (currently Chiromantis simus [Annandale]) is distributed in Northeastern India (Assam, Mizoram, and West Bengal) as well as in intervening Bangladesh (Chittagong and Moulvibazar District); then, the record as host of R. bravoae in Mexico is doubful.
description: Published as part of Mendoza-Garfias, Berenit, García-Prieto, Luis & León, Gerardo Pérez-Ponce De, 2017, Checklist of the Monogenea (Platyhelminthes) parasitic in Mexican aquatic vertebrates, pp. 501-598 in Zoosystema 39 (4) on pages 559-560, DOI: 10.5252/z2017n4a5, http://zenodo.org/record/4578694
$Λ\rm{K}$ femtoscopy in Pb-Pb collisions at $\sqrt{s_{\rm{NN}}}$ = 2.76 TeV
Creators: name: ALICE Collaboration
Publisher: name: arXiv
Year: 2020
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: The first measurements of the scattering parameters of $Λ$K pairs in all three charge combinations ($Λ$K$^{+}$, $Λ$K$^{-}$, and $Λ\mathrm{K^{0}_{S}}$) are presented. The results are achieved through a femtoscopic analysis of $Λ$K correlations in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 2.76 TeV recorded by ALICE at the LHC. The femtoscopic correlations result from strong final-state interactions, and are fit with a parametrization allowing for both the characterization of the pair emission source and the measurement of the scattering parameters for the particle pairs. Extensive studies with the THERMINATOR 2 event generator provide a good description of the non-femtoscopic background, which results mainly from collective effects, with unprecedented precision. Furthermore, together with HIJING simulations, this model is used to account for contributions from residual correlations induced by feed-down from particle decays. The extracted scattering parameters indicate that the strong force is repulsive in the $Λ\rm{K}^{+}$ interaction and attractive in the $Λ\rm{K}^{-}$ interaction. The data hint that the and $Λ\rm{K}^{0}_{S}$ interaction is attractive, however the uncertainty of the result does not permit such a decisive conclusion. The results suggest an effect arising either from different quark-antiquark interactions between the pairs ($\rm s\overline{s}$ in $Λ$K$^{+}$ and $\rm u\overline{u}$ in $Λ$K$^{-}$) or from different net strangeness for each system (S = 0 for $Λ$K$^{+}$, and S = $-2$ for $Λ$K$^{-}$). Finally, the $Λ$K systems exhibit source radii larger than expected from extrapolation from identical particle femtoscopic studies. This effect is interpreted as resulting from the separation in space-time of the single-particle $Λ$ and K source distributions.
description: 32 pages, 10 captioned figures, 5 tables, authors from page 23, published version, figures at http://alice-publications.web.cern.ch/node/6221
title: Investigating whether male sexual offenders in a high security hospital show an attentional bias towards offence related stimuli
Creators: name: Lumbard, Darren John
Publisher: name: The Open University
Year: 2002

description: This study was the first time a paradigm used to investigate attentional bias in emotional disorders had been applied to a sexually offending population within a high security hospital. The aims were to investigate whether sexual and non-sexual offenders display an attentional bias towards stimuli related to offending, and to explore whether sexual offenders differ from controls in the way their attention is allocated to non-offending sexual stimuli. Sixty participants (15 sexual offenders against children, 15 sexual offenders against adult women, 15 non-sexual offenders, and 15 male members of staff) completed the probe detection task. Their task was to press a key to indicate the position of a dot probe that followed a neutral word or a 'target' word on a computer screen. The five categories of 'target' word were: stimuli related to sexual offending; stimuli related to non-sexual offending; stimuli related to non-offending sexual behaviour; stimuli related to sexual anatomy; and a 'neutral' set of stimuli related to travel. All three groups of offenders showed non-significant attentional biases towards sexual offending stimuli. Considerable differences in individual participants' attentional bias scores were observed. The combined group of offenders displayed a trend, approaching significance, of 'attentional avoidance' of stimuli related to non-sexual offending. There was limited evidence that sexual offenders differ from male staff in their attentional processing of nonoffending sexual stimuli. The findings are interpreted, noting the significant methodological limitations of this pilot study. Clinical implications and ideas for future research are discussed. There is some potential for future clinical use of the dot probe paradigm but further research is required to facilitate the generalisation of findings to broader populations of sexual offenders.
High Density Effective Theory Confronts the Fermi Liquid
Creators: name: Hands, Simon
Publisher: name: arXiv
Year: 2003
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Lattice (hep-lat)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The high density effective theory recently introduced by Hong and Hsu to describe ultradense relativistic fermionic matter is used to calculate the tree-level forward scattering amplitude between two particles at the Fermi surface. While the direct term correctly reproduces that of the underlying gauge theory, the exchange term has the wrong sign. The physical consequences are discussed in the context of Landau's theoretical description of the Fermi liquid.
description: 15 pages, 2 figures; conclusion expanded, reference added
The use of Shigella flexneri to study bacterial cell biology during infection of host cells
Creators: name: Krokowski, Sina Katharina
Publisher: name: Imperial College London
Year: 2018

description: Shigella flexneri is a facultative intracellular bacterium and a paradigm to address key issues in cell biology and cell-autonomous immunity. Cell-autonomous immunity is a system of host defence that senses invading pathogens and mobilises anti-pathogen mechanisms, including autophagy. Recently, it has become clear that the cytoskeleton is directly linked to cell-autonomous immunity. During my PhD, I used S. flexneri to investigate bacterial factors that mediate interactions with the cytoskeleton and cell-autonomous immunity. Bacteria have counterparts to the host cytoskeleton components actin (e.g. MreB), microtubules (e.g. FtsZ), intermediate filaments (e.g. CreS) and septins (MinCD). However, rearrangements of the bacterial cytoskeleton have never been followed in pathogenic bacteria during infection of host cells. In Chapter 1, I generate new tools to follow the Shigella MreB, FtsZ and MinC cytoskeleton during infection of host cells using fluorescence microscopy. S. flexneri can exploit the host actin cytoskeleton to form ‘actin tails’ for its own motility. Actin-based motility enables bacterial cell-to-cell spread and evasion of the immune system. Polar localisation of the autotransporter IcsA is required for efficient actin tail formation, yet how IcsA is targeted to the bacterial cell pole was not fully known. In Chapter 2, I use Shigella MreB-msfGFPsw to reveal that MreB targets IcsA to the bacterial cell pole to promote actin tail formation and autophagy escape. To entrap Shigella for autophagy, the host septin cytoskeleton forms cage-like structures around actin polymerising bacteria. How septins recognise bacteria is poorly understood. In Chapter 3, I report that septins sense micron-scale curvature, cardiolipin and cell growth of dividing bacterial cells to inhibit Shigella cell division via autophagy and lysosome fusion. Therefore, the host septin cytoskeleton offers great potential to boost the recognition and restriction of dividing bacterial cells. Overall, the findings in this thesis have discovered that by controlling bacterial cell polarity, morphology and division, the bacterial cytoskeleton shapes host-pathogen interactions. Moreover, they highlight that investigation of the bacterial cytoskeleton during infection can inspire the development of new therapeutic regimes for infection control.
A quantum mechanical study of the phase stability and phase transition mechanisms in CaCO3 at finite temperature and pressure
Creators: name: Carrasco De Busturia, David
Publisher: name: Imperial College London
Year: 2018

description: First-principles calculations have been performed to explore the temperature-pressure phase diagram of calcium carbonate (CaCO3) in a range of temperatures and pressures up to 1000 K and 10 GPa respectively. The calcite I - calcite II and calcite I - aragonite phase boundaries have been obtained. Imaginary phonon modes in the aragonite phase suggest pathways to three distinct alternative phases that involve symmetry breaking and distortion of the unit cell. The variation of the Gibbs free energy with pressure and temperature has been computed in the quasi-harmonic approximation. Several approaches have been discussed in this thesis for the most accurate determination of the temperature - pressure phase boundary. A method for determining the calcite I - calcite II second order phase boundary has been described in this work. Hybrid exchange and GGA density functional theory in the all-electron linear combination of atomic orbitals approximation have been exploited, as well as the effect of the inclusion of van der Waals dispersion corrections. The resultant theoretical phase diagram is compared to the available measurements. The detailed theoretical understanding of the phase transitions mechanisms developed in this thesis sets the basis for a future exploration of the thermodynamic stability phase of CaCO3. In this respect, the methodology described in this work could be used to predict the temperature - pressure phase boundaries of the rest of the polymorphs of this complex system, e.g. phase transitions occurring in calcite III, IIIb, IV, V and VI.
title: Conceptualisations of Educational Technology in Distance Education: with special reference to the British Open University, the Spanish Universidad Nacional de Educacion a Distancia, and the Portuguese Universidade Aberta
Creators: name: González Estepa, Francisco Javier
Publisher: name: The Open University
Year: 2002

description: This research addresses the question of what is the concept and role of educational technology in relation to distance education. This question is approached through an examination of three distance teaching universities: the British Open University (OU), the Spanish Universidad Nacional de Educación a Distancia (UNED), and the Portuguese Universidade Aberta (UA). A socio-cultural analysis explores the history, philosophical assumptions and applications of educational technology at each of the universities. Thus educational technology and distance education are discussed as interdependent and overlapping concepts. The socio-cultural approach is applied within a multi-modal systems theoretical framework. Along with these, the concept of world-view in intercultural communication is of central importance. On the basis of this theoretical scaffolding the research has sought to avoid any comparative judgements of the relative 'superiority vs. inferiority' of the various distance teaching universities that might hinder meaningful interactions among them. As a qualitative inquiry the research rejects models and attitudes of assimilation ('cultural domination' or 'sub-cultural imperialism') and seeks to show the value of dialogue between, and the recognition of diversity among, the participating institutions. Field work, including interviews and documentary analysis, has been conducted at the three major sites: Lisbon, Madrid and Milton Keynes. The interview data has been analysed using the GABEK (Ganzheitliche Bewaltigung von Komplexität - Holistic Processing of Linguistically Represented Complexity) method. The analysis not only identified a number of key issues about educational technology and distance education, from a multicultural perspective, but it also gave rise to a new definition of educational technology in terms of curriculum and power. The social function, along with the academic raison d'etre of these institutions, has been further explored and contextualised. Among the prominent topics that emerge from the various analyses is that of ethics: a relatively unexamined area in the field of distance education and educational technology. An effort has been made to introduce ethical concerns on the agenda for reflection among educational technologists and distance educational practitioners. I suggest that this topic has special relevance both to international collaborations and to the current engagement of the three universities in question with the promotion of distance education in developing countries. Finally, a proposal for the building up of communities of discourse in distance education in the various languages of this research is discussed.
A new alternative model to dark energy
Creators: name: Gong, Yungui
name: Chen, Xi-Ming
name: Duan, Chang-Kui
Publisher: name: arXiv
Year: 2004
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The recent observations of type Ia supernovae strongly support that the universe is accelerating now and decelerated in the recent past. This may be the evidence of the breakdown of the standard Friedmann equation. Instead of a linear function of the matter density, we consider a general function of the matter density to modify the Freidmann equation. We propose a new model which explains the recent acceleration and the past deceleration. Furthermore, the new model also gives a decelerated universe in the future. The new model gives $Ω_{m0}=0.46$ and $z_T=0.44$.
description: 4 pages, 4 figures,changed to use ws-mpla class, accepted for publication by Mod. Phys. Lett. A
Generative Adversarial Networks for LHCb Fast Simulation
Creators: name: Ratnikov, Fedor
Publisher: name: arXiv
Year: 2020
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: Machine Learning (cs.LG)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: LHCb is one of the major experiments operating at the Large Hadron Collider at CERN. The richness of the physics program and the increasing precision of the measurements in LHCb lead to the need of ever larger simulated samples. This need will increase further when the upgraded LHCb detector will start collecting data in the LHC Run 3. Given the computing resources pledged for the production of Monte Carlo simulated events in the next years, the use of fast simulation techniques will be mandatory to cope with the expected dataset size. In LHCb generative models, which are nowadays widely used for computer vision and image processing are being investigated in order to accelerate the generation of showers in the calorimeter and high-level responses of Cherenkov detector. We demonstrate that this approach provides high-fidelity results along with a significant speed increase and discuss possible implication of these results. We also present an implementation of this algorithm into LHCb simulation software and validation tests.
description: Proceedings for 24th International Conference on Computing in High Energy and Nuclear Physics
title: Italian Communist Party cultural policies during the post-war period 1944-1951
Creators: name: Gómez Gutiérrez, Juan José
Publisher: name: The Open University
Year: 2002

description: This thesis considers the cultural politics of the Italian Communist Party (PCI) during the immediate post-war period in the context of Italian History, the artistic developments of the first half of the 20th Century and the ideological basis of the PCI. The text has been divided in two parts: The first part focuses on the cultural policy of the PCI from 1944 to 1951 and its relationship with contemporary Italian culture. In the second part, I discuss the influence of Communist cultural politics in post-war Italian art. I have identified two phases of the cultural politics of the PCI which correspond to two phases of the political developments in Italy after World War II: From 1944, the Italian Communists pursued a policy of alliances with nonproletarianised sectors of society and the other Italian anti-Fascist parties. This policy of alliances collapsed in 1947, when the PCI was expelled from the Government of national unity, which was controlled by the Christian Democrats. In the second part of the thesis, I explain how, similarly, Italian artists were heavily influenced by political allegiances in the wake of Fascism. But, precisely, anti-Fascism was a cornerstone for collaboration and understanding between representatives of disparate trends, and associations of artists from a broad political spectrum were organised. Artists with a PCI card were fully involved with such associations. After 1947, however, as a result of its marginalisation from government, the PCI Politics hardened in all fields, including culture. Party officials began to ask artists to put their skills at the service of the Communist's wider political programme and express Communist contents through their work in every case, with an 'understandable' style aimed to ideologically shape the uneducated proletariat. Nevertheless, this policy seemed unacceptable for those artists who equated Communism with political anti-fascism and free intellectual enquiry. The prestige of the PCI among intellectuals accordingly underwent a quick decline, and Communist officials had to develop a more relaxed cultural line from 1951. This substantially meant the return to the policy pursued in the wake of the war. After this, the relationship of the PCI with fine artists was recomposed. However, the political influence of this collective was fading away in the early 1950s, when new means of mass communication, such as cinema, radio and magazines, appeared in Italy and succeeded in shaping public opinion in a far more effective way than the fine arts.
New symmetry current for massive spin-3/2 fields
Creators: name: Pilling, Terry
Publisher: name: arXiv
Year: 2004
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We present several new results which will be of value to theorists working with massive spin-3/2 vector-spinor fields as found, for example, in low and intermediate energy hadron physics and also linearized supergravity. The general lagrangian and propagator for a vector-spinor field in d-dimensions is given. It is shown that the observables of the theory are invariant under a novel continuous symmetry group which is also extended to an algebra. A new technique is developed for exploring the consequences of the symmetry and a previously unknown conserved vector current and charge are found. The current leads to new interactions involving spin-3/2 particles and may have important experimental consequences.
description: 9 pages, references updated and minor changes
Probing triple Higgs coupling with machine learning at the LHC
Creators: name: Abdughani, Murat
name: Wang, Daohan
name: Wu, Lei
name: Yang, Jin Min
name: Zhao, Jun
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: Measuring the triple Higgs coupling is a crucial task in the LHC and future collider experiments. We apply the Message Passing Neural Network (MPNN) to the study of the non-resonant Higgs pair production process $pp \to hh$ in the final state with $2b + 2\ell + E_{\rm T}^{\rm miss}$ at the LHC. Although the MPNN can improve the signal significance, it is still challenging to observe such a process at the LHC. We find that a $2σ$ upper bound (including a 10\% systematic uncertainty) on the production cross section of the Higgs pair is 3.7 times the predicted SM cross section at the LHC with the luminosity of 3000 fb$^{-1}$, which will limit the triple Higgs coupling to the range of $[-3,11.5]$.
description: 23 pages, discussions added, version accepted by PRD
Role of Delay in Brain Dynamics
Creators: name: Meir, Yuval
name: Tevet, Ofek
name: Tzach, Yarden
name: Hodassman, Shiri
name: Kanter, Ido
Publisher: name: arXiv
Year: 2024
Subjects: subject: Biological Physics (physics.bio-ph)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: Significant variations of delays among connecting neurons cause an inevitable disadvantage of asynchronous brain dynamics compared to synchronous deep learning. However, this study demonstrates that this disadvantage can be converted into a computational advantage using a network with a single output and M multiple delays between successive layers, thereby generating a polynomial time-series outputs with M. The proposed role of delay in brain dynamics (RoDiB) model, is capable of learning increasing number of classified labels using a fixed architecture, and overcomes the inflexibility of the brain to update the learning architecture using additional neurons and connections. Moreover, the achievable accuracies of the RoDiB system are comparable with those of its counterpart tunable single delay architectures with M outputs. Further, the accuracies are significantly enhanced when the number of output labels exceeds its fully connected input size. The results are mainly obtained using simulations of VGG-6 on CIFAR datasets and also include multiple label inputs. However, currently only a small fraction of the abundant number of RoDiB outputs is utilized, thereby suggesting its potential for advanced computational power yet to be discovered.
description: 18 pages, 3 figures, 2 tables
Enzyme and temperature dual-responsive polymer nanostructures towards the treatment of osteoarthritis
Creators: name: Massi, Lucia
Publisher: name: Imperial College London
Year: 2018

description: Many diseases are associated with increased enzyme activities. Osteoarthritis (OA) is such an example where the over-expression of proteolytic enzymes leads to the erosion of the articular cartilage. These changes in the enzymatic environment offer inspiration for the design of smart drug delivery systems with triggered response to disease-specific conditions. In this context, self-assembled polymeric nanoparticles have come into focus due to their adaptable chemistry enabling the introduction of stimuli-responsive motifs to achieve triggered nanoparticle assembly and cargo release. Here, peptide-crosslinked, thermoresponsive polymer nanostructures cleavable by disease-associated enzymes are developed. More specifically, libraries of thermo-responsive N-isopropylacrylamide (NIPAM)- and N-cyclopropylacrylamide (NCPAM)-based triblock copolymers able to self-assemble across a range of temperatures were synthesized by controlled reversible addition-fragmentation chain-transfer (RAFT) polymerization. Two of the developed block copolymers were selected to be used for the construction of the enzyme-triggered delivery platform. By using copper-catalyzed click chemistry, these nanostructures were cross-linked with various peptide substrates sensitive to specific proteases. This approach confers improved system stability and controlled drug release kinetics. The morphology of both purely self-assembled and cross-linked nanostructures was investigated in detail by small angle neutron scattering (SANS) and cryogenic transmission electron microscopy (cryo-TEM). Further, loading capability towards multiple model cargos was demonstrated and enzyme-triggered release of a selected model protein was studied using fluorescence correlation spectroscopy (FCS). By accurate choice of the peptide cross-linker, nanoparticle degradation was achieved with various enzymes including MMP-13, which is the major enzyme causing cartilage degradation in OA. Finally, nanoparticle-cell interactions were studied using human OA chondrocytes and the synthesized copolymers / cross-linked nanoparticles did not reveal any cytotoxicity. Based on their fine control over the assembly temperature, chemical versatility, loading capabilities, enzyme-responsive properties and biocompatibility, these peptide cross-linked nanostructures are promising candidates as smart delivery systems for various diseases, including OA, where certain enzymes are over-expressed.
Simulating disordered quantum systems via dense and sparse restricted Boltzmann machines
Creators: name: Pilati, S.
name: Pieri, P.
Publisher: name: arXiv
Year: 2020
Subjects: subject: Computational Physics (physics.comp-ph)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: In recent years, generative artificial neural networks based on restricted Boltzmann machines (RBMs) have been successfully employed as accurate and flexible variational wave functions for clean quantum many-body systems. In this article we explore their use in simulations of disordered quantum spin models. The standard dense RBM with all-to-all inter-layer connectivity is not particularly appropriate for large disordered systems, since in such systems one cannot exploit translational invariance to reduce the amount of parameters to be optimized. To circumvent this problem, we implement sparse RBMs, whereby the visible spins are connected only to a subset of local hidden neurons, thus reducing the amount of parameters. We assess the performance of sparse RBMs as a function of the range of the allowed connections, and compare it with the one of dense RBMs. Benchmark results are provided for two sign-problem free Hamiltonians, namely pure and random quantum Ising chains. The RBM ansatzes are trained using the unsupervised learning scheme based on projective quantum Monte Carlo (PQMC) algorithms. We find that the sparse connectivity facilitates the training process and allows sparse RBMs to outperform the dense counterparts. Furthermore, the use of sparse RBMs as guiding functions for PQMC simulations allows us to perform PQMC simulations at a reduced computational cost, avoiding possible biases due to finite random-walker populations. We obtain unbiased predictions for the ground-state energies and the magnetization profiles with fixed boundary conditions, at the ferromagnetic quantum critical point. The magnetization profiles agree with the Fisher-de Gennes scaling relation for conformally invariant systems, including the scaling dimension predicted by the renormalization-group analysis.
description: 11 pages, 5 figures
Machine learning approaches to optimise the management of patients with sepsis
Creators: name: Komorowski, Matthieu
Publisher: name: Imperial College London
Year: 2018

description: The goal of this PhD was to generate novel tools to improve the management of patients with sepsis, by applying machine learning techniques on routinely collected electronic health records. Machine learning is an application of artificial intelligence (AI), where a machine analyses data and becomes able to execute complex tasks without being explicitly programmed. Sepsis is the third leading cause of death worldwide and the main cause of mortality in hospitals, but the best treatment strategy remains uncertain. In particular, evidence suggests that current practices in the administration of intravenous fluids and vasopressors are suboptimal and likely induce harm in a proportion of patients. This represents a key clinical challenge and a top research priority. The main contribution of the research has been the development of a reinforcement learning framework and algorithms, in order to tackle this sequential decision-making problem. The model was built and then validated on three large non-overlapping intensive care databases, containing data collected from adult patients in the U.S.A and the U.K. Our agent extracted implicit knowledge from an amount of patient data that exceeds many-fold the life-time experience of human clinicians and learned optimal treatment by having analysed myriads of (mostly sub-optimal) treatment decisions. We used state-of-the-art evaluation techniques (called high confidence off-policy evaluation) and demonstrated that the value of the treatment strategy of the AI agent was on average reliably higher than the human clinicians. In two large validation cohorts independent from the training data, mortality was the lowest in patients where clinicians’ actual doses matched the AI policy. We also gained insight into the model representations and confirmed that the AI agent relied on clinically and biologically meaningful parameters when making its suggestions. We conducted extensive testing and exploration of the behaviour of the AI agent down to the level of individual patient trajectories, identified potential sources of inappropriate behaviour and offered suggestions for future model refinements. If validated, our model could provide individualized and clinically interpretable treatment decisions for sepsis that may improve patient outcomes.
Chaos and Shadowing Around a Homoclinic Tube
Creators: name: Li, Yanguang Charles
Publisher: name: arXiv
Year: 2003
Subjects: subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: Let $F$ be a $C^3$ diffeomorphism on a Banach space $B$. $F$ has a homoclinic tube asymptotic to an invariant manifold. Around the homoclinic tube, Bernoulli shift dynamics of submanifolds is established through shadowing lemma. This work removes an uncheckable condition of Silnikov [Equation (11), page 625 of L. P. Silnikov, Soviet Math. Dokl., vol.9, no.3, (1968), 624-628]. Also, the result of Silnikov does not imply Bernoulli shift dynamics of a single map, rather only provides a labeling of all invariant tubes around the homoclinic tube. The work of Silnikov was done in ${\mathbb R}^n$, and the current work is done in a Banach space.
description: accepted, Abstract and Applied Analysis
Borromean states in discrete-time quantum walks
Creators: name: Markiewicz, Marcin
name: Karczewski, Marcin
name: Kurzynski, Pawel
Publisher: name: arXiv
Year: 2020
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In the right conditions, removing one particle from a multipartite bound state can make it fall apart. This feature, known as the "Borromean property", has been recently demonstrated experimentally in Efimov states. One could expect that such peculiar behavior should be linked with the presence of strong inter-particle correlations. However, any exploration of this connection is hindered by the complexity of the physical systems exhibiting the Borromean property. To overcome this problem, we introduce a simple dynamical toy model based on a discrete-time quantum walk of many interacting particles. We show that the particles described by it need to exhibit the Greenberger-Horne-Zeillinger (GHZ) entanglement to form Borromean bound states. As this type of entanglement is very prone to particle losses, our work demonstrates an intuitive link between correlations and Borromean properties of the system. Moreover, we discuss our findings in the context of the formation of composite particles.
description: 5+4 pages, 4 figures
Infrared photodissociation spectroscopy of D2-tagged CH3CO2−(H2O)0−2 anions
Creators: name: Jessalyn A. DeVine
name: Sreekanta Debnath
name: Ya-Ke Li
name: McCaslin, Laura M.
name: Schöllkopf, Wieland
name: Neumark, Daniel M.
name: Asmis, Knut R.
Publisher: name: Taylor & Francis
Year: 2020
Subjects: subject: Biochemistry
subject: 29999 Physical Sciences not elsewhere classified
subject: FOS: Physical sciences
subject: Cell Biology
subject: Biotechnology
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: Immunology
subject: FOS: Clinical medicine
subject: 69999 Biological Sciences not elsewhere classified
subject: FOS: Biological sciences
subject: Marine Biology
subject: Inorganic Chemistry
subject: Computational Biology

description: Infrared photodissociation spectroscopy of D2-tagged anions is used to obtain the vibrational spectra of microsolvated acetate, CH3CO2−(H2O)n (n = 0–2), in the CH/OH stretching (∼4000–2500 cm−1) and fingerprint (∼1800–800 cm−1) spectral regions. These results are analysed by comparison to anharmonic IR spectra from MP2 calculations as well as Born-Oppenheimer molecular dynamics (BOMD) simulations. In agreement with prior work, we find that the first water molecule adds to the acetate anion by donating two hydrogen bonds, yielding a symmetrical structure involving a six-membered hydrogen-bonded ring. Two nearly degenerate binding motifs that differ in energy by less than 1 kJ/mol are identified for n = 2 anion, where the lowest-energy geometry has two ion-water hydrogen bonds as well as a water-water hydrogen bond. The molecular dynamics simulations confirm that this lower-energy structure is preferred over a slightly higher-lying configuration possessing three ion-water hydrogen bonds and no water-water interactions. Analysis of the molecular motion contributing to peaks in the BOMD spectra via a generalised normal mode approach provides assignment of all observed transitions to the lower-energy structure, and enables distinction of the vibrational signatures associated with ion-water and water-water intermolecular motions.
Nothing really matters
Creators: name: Dibitetto, Giuseppe
name: Petri, Nicolò
name: Schillo, Marjorie
Publisher: name: arXiv
Year: 2020
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study non-perturbative instabilities of AdS spacetime in General Relativity with a cosmological constant in arbitrary dimensions. In this simple setup we explicitly construct a class of gravitational instantons generalizing Witten's bubble of nothing. We calculate the corresponding Euclidean action and show that its change is finite. The expansion of these bubbles is described by a lower-dimensional de Sitter geometry within a non-compact foliation of the background spacetime. Moreover we discuss the existence of covariantly constant spinors as a possible topological obstruction for such decays to occur. This mechanism is further connected to the stability of supersymmetric vacua in string theory.
description: 22 pages, 2 appendices
Circulating microvesicles as mediators of acute pulmonary vascular inflammation
Creators: name: Tan, Ying Ying
Publisher: name: Imperial College London
Year: 2020

description: Acute lung injury (ALI) resulting from remote ‘indirect’ causes is a major problem in sepsis and systemic inflammatory response syndrome (SIRS) but the underlying mechanisms are poorly understood. Circulating microvesicles (MVs) have been implicated as long-range mediators of vascular inflammation and their role as biomarkers in sepsis and SIRS has been widely investigated in clinical studies in recent years. However, the in vivo functional roles of MVs in sepsis and ALI have received less attention. Specifically, the role of in vivo MVs in the development of sepsis/SIRS-induced indirect ALI has not been previously evaluated. We hypothesised that circulating microvesicles (MVs) play a crucial role in propagating inflammation to the lungs, contributing to the development of pulmonary vascular inflammation in indirect ALI. The overall aims of this project were to: 1) evaluate MV uptake by pulmonary vascular cells and the mechanisms involved, 2) characterise the intravascular production of MVs in animal models of sepsis and sterile extrapulmonary organ injury, and 3) identify the contribution of in vivo-derived circulating MVs to the development of indirect ALI. The major findings of this work were that during sub-clinical endotoxaemia in mice, lung-marginated Ly6Chigh monocytes become a major target for circulating MV uptake via a phosphatidylserine receptor mechanism1. In mouse models of sepsis and extrapulmonary organ injury, neutrophil- and monocyte-derived MVs were the predominant MV subtypes being produced during endotoxaemia, while platelet- and endothelial-derived MVs were predominant during kidney ischaemia reperfusion injury. When MVs obtained from plasmas of endotoxaemic mice were adoptively transferred to isolated perfused lungs (IPLs), they induced significant increases in lung oedema. Depletion of intravascular lung monocytes by treatment with clodronate liposomes resulted in the reversal of the oedema, demonstrating the role of monocytes in MV-induced ALI. To investigate the contribution of different circulating MV subtypes, we immunoaffinity isolated myeloid (CD11b+) and platelet (CD41+) MVs from endotoxaemic mouse plasmas and transferred these to the IPL. We found that myeloid-MVs induced significant lung oedema and potent release of soluble mediators, whereas platelet-MVs produced a statistically significant, but much lower level of oedema and negligible release of soluble mediators. In summary, these findings indicate an important role of myeloid-derived MVs, particularly those derived from neutrophils and/or monocytes, and their interaction with lung-marginated monocytes in the pathogenesis of pulmonary vascular inflammation in indirect ALI. Further work to elucidate the specific MV molecular effectors mechanism involved will facilitate an enhanced understanding of ALI pathobiology.
Zusammenarbeit zwischen Lehrpersonen und Eltern von unterstützt kommunizierenden Kindern an der Heilpädagogischen Schule
Creators: name: Fäh, Karin
Publisher: name: Zenodo
Year: 2016
Subjects: Sonderpädagogik
Kommunikationshilfe
Schule
Kooperation
Lehrer
Masterarbeit

description: Eltern von unterstützt kommunizierenden Kindern an Heilpädagogischen Schulen sind häufig sehr belastet. Einerseits sind sie selber emotional betroffen. Andererseits müssen sie ein innerfamiliäres Verständigungssystem aufbauen und die Anliegen ihres Kindes vertreten. Damit das Kind über das häusliche Umfeld hinaus ein multimodales Kommunikationssystem aufbauen kann, ist die gute Zusammenarbeit zwischen Lehrperson und Eltern zentral. Im Rahmen der Masterarbeit wurden qualitative Interviews mit Eltern von unterstützt kommunizierenden Kindern durchgeführt und zu ihren Erfahrungen befragt. Welche Faktoren haben nach Meinung dieser Eltern einen Einfluss auf die gute Zusammenarbeit? Verglichen mit dem theoretischen Hintergrund zeigen die Ergebnisse auf, dass Wertschätzung und Akzeptanz, die Gestaltung des Kontakts, die Kompetenzen und das Engagement der Lehrperson stark gewichtet werden.
PIT – Programm für Individuelle Tagespläne Ein Programm zur Tages- und Unterrichtsstrukturierung für Kinder mit besonderem Förderbedarf
Creators: name: Halbenleib, Claudia
Publisher: name: Zenodo
Year: 2016
Subjects: Sonderpädagogik
Strukturierung
Unterricht
Kind
Masterarbeit

description: no abstract
A different look at the spin state of Co$^{3+}$ ions in CoO$_{5}$ pyramidal coordination
Creators: name: Hu, Z.
name: Wu, Hua
name: Haverkort, M. W.
name: Hsieh, H. H.
name: Lin, H. -J.
name: Lorenz, T.
name: Baier, J.
name: Reichl, A.
name: Bonn, I.
name: Felser, C.
name: Tanaka, A.
name: Chen, C. T.
name: Tjeng, L. H.
Publisher: name: arXiv
Year: 2003
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Using soft-x-ray absorption spectroscopy at the Co-$L_{2,3}$ and O-$K$ edges, we demonstrate that the Co$^{3+}$ ions with the CoO$_{5}$ pyramidal coordination in the layered Sr$_2$CoO$_3$Cl compound are unambiguously in the high spin state. Our result questions the reliability of the spin state assignments made so far for the recently synthesized layered cobalt perovskites, and calls for a re-examination of the modeling for the complex and fascinating properties of these new materials.
description: 5 pages 3 figures
Bayesian inference on the number of recurrent events: A joint model of recurrence and survival
Creators: name: Boom, Willem van den
name: De Iorio, Maria
name: Tallarita, Marta
Publisher: name: arXiv
Year: 2020
Subjects: subject: Methodology (stat.ME)
subject: FOS: Computer and information sciences

description: The number of recurrent events before a terminating event is often of interest. For instance, death terminates an individual's process of rehospitalizations and the number of rehospitalizations is an important indicator of economic cost. We propose a model in which the number of recurrences before termination is a random variable of interest, enabling inference and prediction on it. Then, conditionally on this number, we specify a joint distribution for recurrence and survival. This novel conditional approach induces dependence between recurrence and survival, which is often present, for instance due to frailty that affects both. Additional dependence between recurrence and survival is introduced by the specification of a joint distribution on their respective frailty terms. Moreover, through the introduction of an autoregressive model, our approach is able to capture the temporal dependence in the recurrent events trajectory. A non-parametric random effects distribution for the frailty terms accommodates population heterogeneity and allows for data-driven clustering of the subjects. A tailored Gibbs sampler involving reversible jump and slice sampling steps implements posterior inference. We illustrate our model on colorectal cancer data, compare its performance with existing approaches and provide appropriate inference on the number of recurrent events.
description: 56 pages, 11 figures