cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Estimating effective population size from genetic data: the past, present, and the future
Creators: name: Hui, Tin-Yu Jonathan
Publisher: name: Imperial College London
Year: 2017

description: Effective population size (𝑁𝑒) is an important statistic in conservation science and in the broader topics of evolutionary genetics. 𝑁𝑒 is often used to quantify the rate of evolutionary events such as losses in genetic diversity. Estimating and interpreting such quantity can however be challenging. Chapter 2 focuses on the change in allele frequency between two or more time points due to genetic drift. A new likelihood-based estimator 𝑁𝐵̂ for contemporary 𝑁𝑒 estimation is proposed by adopting a hidden Markov algorithm and continuous approximations. 𝑁𝐵̂ is found to be several-fold faster than the existing methods without sacrificing accuracy. It also relaxes the upper bound of 𝑁𝑒 to several million and which is currently limited to about 50000 due to computing limitations. Chapter 3 extends 𝑁𝐵̂ to handle multialleleic loci through using Dirichlet-multinomial distributions. An R package is also provided and available for download. Chapter 4 explores the signatures of linkage disequilibrium (LD) between a pair of loci induced by genetic drift as a function of recombination rate and historical population sizes. 𝐸[𝑟2] can be expressed as the weighted sum of the probability of coalescent at different time points of which information about 𝑁𝑒 is contained. This relationship is verified by computer simulation and then applied to historical 𝑁𝑒 estimation as illustrated in an example of Anopheles coluzzii population. A new likelihood-based routine Constrained ML is suggested in chapter 5 to estimate haplotype frequencies and 𝑟2 from genotypes under Hardy-Weinberg Equilibrium. It is shown to be identical to existing EM algorithm under normal conditions but far less sensitive to initial conditions. A new “unbiased” sample size correction is also proposed to estimate 𝑟2. To summarise, this work pushes the 𝑁𝑒 estimation to its current boundary and more importantly provides suitable tools to analyse the ever-growing datasets.
Finite $n$-quandles of torus and two-bridge links
Creators: name: Crans, Alissa S.
name: Hoste, Jim
name: Mellor, Blake
name: Shanahan, Patrick D.
Publisher: name: arXiv
Year: 2018
Subjects: subject: Geometric Topology (math.GT)
subject: FOS: Mathematics

description: We compute Cayley graphs and automorphism groups for all finite $n$-quandles of two-bridge and torus knots and links, as well as torus links with an axis.
description: 16 pages; version 2 is the final version to appear in Journal of Knot Theory and its Ramifications
Andrew Fielding Huxley - Bibliography from Sir Andrew Fielding Huxley OM. 22 November 1917 — 30 May 2012
Creators: name: Simmons, Robert Malcolm
Publisher: name: The Royal Society
Year: 2018
Subjects: subject: Physiology
subject: FOS: Biological sciences

description: Andrew Huxley was a physiologist, possessing a combination of practical skill, invention and mathematical ability that has few parallels, and is famous for his contributions to the understanding of how nerve and muscle work. He came from an illustrious family: his paternal grandfather was Thomas Henry Huxley, and Julian Huxley and Aldous Huxley were his half-brothers. After completing his undergraduate degree in Cambridge in 1939, he joined Alan Hodgkin in his research on the squid giant axon and they made the first intracellular recording of a nerve action potential. Together, they used the voltage clamp technique to elucidate the ionic mechanism of the action potential; for this they were awarded a share of the Nobel Prize in Physiology or Medicine in 1963. Turning to research on muscle, he elucidated the sliding filament mechanism of contraction (in parallel with Hugh Huxley), and went on to formulate a quantitative account of the steady state properties of muscle based on the interaction between myosin crossbridges and actin sites. Moving to University College London (UCL) in 1960 as Jodrell Professor of Physiology, he provided quantitative evidence for the sliding filament theory through a study of the length–tension relation. His final studies were on the transient mechanical properties of muscle, resulting in a theory of force-generation by crossbridges. During the war, Huxley was engaged in operational research on anti-aircraft artillery and naval gunnery. He was President of the Royal Society in 1980–85, and Master of Trinity College Cambridge in 1984–90.
A low frequency radio telescope at Mauritius for a Southern sky survey
Creators: name: Golap, K.
name: Shankar, N. Udaya
name: Sachdev, S.
name: Dodson, R.
name: Sastry, Ch. V.
Publisher: name: arXiv
Year: 1998
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: A new, meter-wave radio telescope has been built in the North-East of Mauritius, an island in the Indian ocean, at a latitude of -20.14 deg. The Mauritius Radio Telescope (MRT) is a Fourier Synthesis T-shaped array, consisting of a 2048 m long East-West arm and a 880 m long South arm. In the East-West arm 1024 fixed helices are arranged in 32 groups and in the South arm 16 trolleys, with four helices on each, which move on a rail are used. A 512 channel digital complex correlation receiver is used to measure the visibility function. At least 60 days of observing are required for obtaining the visibilities up to 880 m spacing. The Fourier transform of the calibrated visibilities produces a map of the area of the sky under observation with a synthesized beam width 4'X 4.6'sec(dec+20.14) at 151.5 MHz. The primary objective of the telescope is to produce a sky survey in the declination range -70 deg to -10 deg with a point source sensitivity of about 200 mJy (3-sigma level). This will be the southern sky equivalent of the Cambridge 6C survey. In this paper we describe the telescope, discuss the array design and the calibration techniques used, and present a map made using the telescope.
description: Contains postscript figure files + jaa.sty (needed for lateXing) Accepted for publication in J. Astrop. Astr. (July 1998)
Henry E. Hall - Bibliography from Henry Edgar Hall. 28 September 1928 — 4 December 2015
Creators: name: A. I. Golov
name: W. F. Vinen
Publisher: name: The Royal Society
Year: 2018
Subjects: subject: 20203 Particle Physics
subject: FOS: Physical sciences

description: Henry Edgar Hall was a leading experimental and theoretical low temperature physicist of his generation, who, working first in Cambridge and then in Manchester, made important contributions to our knowledge and understanding of superfluidity in both liquid 4He and liquid 3He. His work focused significantly, but not exclusively, on the role of topological defects, such as quantized vortex filaments, in superfluid behaviour. He also contributed in important ways to the development of the 3He–4He dilution refrigerator, which has since played a vital role in experimental work requiring temperatures below 1 K.
Vultur gryphus Linnaeus, 1758, spec. nov.
Creators: name: Linnaeus, Carolus
Publisher: name: Laurentius Salvius
Year: 1758
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Aves
Accipitriformes
Cathartidae
Vultur
Vultur gryphus

description: Vultur gryphus [spec. nov.]
V. maximus, caruncula verticali longitudine capitis. �
Vultur Gryps Gryphus. Klein. av. 45.
Cuntur. Raj. av. 11.
Habitare fertur Chili.
Rara avis in terris; mihi ignota; videsis Kleinium.
description: Published as part of Linnaeus, Carolus, 1758, Systema Naturae per regna tria naturae: secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis, Stockholm :Laurentius Salvius on page 86, DOI: 10.5962/bhl.title.542, http://zenodo.org/record/3922206
High energy density magnetic reconnection experiments in colliding carbon plasma flows
Creators: name: Hare, Jack Davies
Publisher: name: Imperial College London
Year: 2017

description: This thesis presents a detailed study of magnetic reconnection in a quasi-two-dimensional pulsed-power driven laboratory experiment. These experiments were performed at the 1.4 MA, 240 ns rise time Magpie facility at Imperial College London. Initial experiments are presented which demonstrate the viability of carbon as a wire material, and the use of exploding wire arrays as a platform for laboratory astrophysics. In the reconnection experiments, two exploding carbon wire arrays are placed side-by-side and driven in parallel by the Magpie current pulse. The carbon wires become plasma, creating super-sonic, sub-Alfvénic flows which advect anti-parallel magnetic fields towards the mid-plane between the two arrays, where the fields mutually annihilate inside a thin current sheet. A suite of temporally and spatially resolved diagnostics are used to study the reconnection process, including optical fast-framing, laser interferometry, Faraday Rotation imaging and Thomson Scattering. These detailed measurements allow the structure and dynamics of the reconnection layer to be determined, along with the nature of the inflows and outflows and the detailed energy partition during the reconnection process. The layer is unstable, exhibiting the repeated formation and ejection of plasmoids which have an associated magnetic structure measured by magnetic probes. The number and growth rate of these plasmoids agrees well with the predictions of semi-collisional tearing instability theory, and represent the first experimental observation of plasmoids in this regime. High electron and ion temperatures are observed, far in excess of what can be attributed to classical (Spitzer--Braginskii) resistivity or viscosity. Some possible anomalous heating mechanisms are discussed, including kinetic turbulence, and the plasmoid instability. Preliminary measurements of the out-of-plane velocity and magnetic field are presented along with the outlook for future experiments.
Different routes towards triplet states in organic semiconductors: direct S0→T excitation probed by time-resolved EPR spectroscopy
Creators: name: Matt, Clemens
name: Meyer, Deborah L.
name: Lombeck, Florian
name: Sommer, Michael
name: Biskup, Till
Publisher: name: Taylor & Francis
Year: 2018
Subjects: subject: Biophysics
subject: Biochemistry
subject: 29999 Physical Sciences not elsewhere classified
subject: FOS: Physical sciences
subject: Biotechnology
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: 69999 Biological Sciences not elsewhere classified
subject: FOS: Biological sciences
subject: 110309 Infectious Diseases
subject: FOS: Health sciences

description: Understanding the electronic structure of semiconducting polymers and their respective building blocks is an essential prerequisite to develop efficient materials for organic electronics. Due to its molecular resolution and capability to directly probe and assign triplet states, (time-resolved) electron paramagnetic resonance spectroscopy is particularly suited. We present here evidence for a direct S0→T optical excitation of distinct triplet states in the small molecule TBT, often used as building block for semiconducting polymers. These states are subtly different in their electronic structure from those populated via intersystem crossing from excited singlet states. With these results, we extend our previous investigations of CbzTBT, the repeat unit of the polymer PCDTBT comprising the TBT and an additional carbazole moiety. Hence, the strong acceptor unit TBT seems responsible for this additional triplet route. Due to the widespread use of TBT as an acceptor unit in many different co-polymers, this has potentially high impact on the efficiency of organic electronic devices.
Kinetic energy densities based on the fourth order gradient expansion: performance in different classes of materials and improvement via machine learning
Creators: name: Golub, Pavlo
name: Manzhos, Sergei
Publisher: name: arXiv
Year: 2018
Subjects: subject: Computational Physics (physics.comp-ph)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We study the performance of fourth-order gradient expansions of the kinetic energy density (KED) in semi-local kinetic energy functionals depending on the density-dependent variables. The formal fourth-order expansion is convergent for periodic systems and small molecules but does not improve over the second-order expansion (Thomas-Fermi term plus one-ninth of von Weizsäcker term). Linear fitting of the expansion coefficients somewhat improves on the formal expansion. The tuning of the fourth order expansion coefficients allows for better reproducibility of Kohn-Sham kinetic energy density than the tuning of the second-order expansion coefficients alone. The possibility of a much more accurate match with the Kohn-Sham kinetic energy density by using neural networks trained using the terms of the 4th order expansion as density-dependent variables is demonstrated. We obtain ultra-low fitting errors without overfitting. Small single hidden layer neural networks can provide good accuracy in separate KED fits of each compound, while for joint fitting of KEDs of multiple compounds multiple hidden layers were required to achieve good fit quality. The critical issue of data distribution is highlighted. We also show the critical role of pseudopotentials in the performance of the expansion, where in the case of a too rapid decay of the valence density at the nucleus with some pseudopotentials, numeric instabilities arise.
description: 37 pages, 20 figures
A cloth can hear your heartbeat
Creators: name: Rumon, md abdullah al
Publisher: name: figshare
Year: 2021
Subjects: subject: 90699 Electrical and Electronic Engineering not elsewhere classified
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: 91205 Functional Materials
subject: FOS: Materials engineering
subject: 91299 Materials Engineering not elsewhere classified
subject: 90609 Signal Processing
subject: 91012 Textile Technology

description: Technical Textile is becoming a roaring field nowadays. Fiber, yarn, fabrics and other structures with functional and technical properties engaged as an alternative material with a limitless range of applications. Generally the word “smart material” that refers those that can sense and response in a controlled and predicted manner to environment stimuli that may got from mechanical, chemical, thermal, magnetic or other form. Photo plethysmography principle was applied in this experiment. A Nano rigid sensor combined with ordinary woven fabric and then signal was analyzed to get a cumulative and observable sketch.

Full paper: https://www.textiletoday.com.bd/cloth-can-hear-heartbeat/
Fibre-reinforced composites with nacre-inspired interphase: a route towards high performance toughened hierarchical composites
Creators: name: De Luca, Francois
Publisher: name: Imperial College London
Year: 2017

description: Conventional fibre-reinforced polymer composite materials are well known for their high strength, stiffness, low weight and chemical resistance but composites do fail catastrophically, in a brittle manner, with little prior warning. When a fibre breaks in tension, shear stresses transfer load previously carried by the broken fibre to neighbouring fibres through the matrix, leading to local stress concentrations. As tensile loading continues, fibre breaks accumulate in the composite, eventually leading to the formation of a critical cluster, which triggers the failure of the composite. The aim of this research was to develop a novel hierarchical composite architecture consisting of fibres decorated with a nanostructured coating embedded in a matrix. A high performance and tough nanostructured composite interphase, inspired by nacre, should provide additional toughness in tension. A Layer-by-Layer assembly method was used to assemble inorganic nanometre-wide platelets and a polyelectrolyte into a well-organised nanostructure, mimicking the “brick-and-mortar” architecture of nacre, which was developed and characterised. The nanostructure was successfully deposited around conventional reinforcing-fibres, such as carbon and glass fibres, and allowed for absorption of the energy arising from fibre breaks and substantial increase in debonding toughness in single fibre composite models. Impregnated fibre bundle composites were manufactured and tested in tension, which exhibited an increased tensile strength, strain to failure and work of fracture when the nanostructured composite interphase was incorporated. This work was part of the HiPerDuCT programme grant, collaboration between the departments of Aeronautics, Chemical Engineering, Chemistry and Mechanical Engineering of Imperial College London and the University of Bristol.
Bandgap states in solution-processed semiconductors
Creators: name: Mottram, Alexander David
Publisher: name: Imperial College London
Year: 2017

description: The field of plastic electronics has opened up a new material set with which to produce microelectronics including metal oxides, polymers and small molecules. These materials are versatile in properties and processing techniques, already outmatching amorphous silicon. Thin film transistors (TFTs) produced from these materials state mobility as the highest figure of merit; while ignoring the effect that trap states on charge transport. The two are inextricably linked though as regularly observed in the gate dependence of measured field effect mobilities. This thesis presents an in-depth analysis of bandgap trap states within low-temperature, and solution-processed, high performance phototransistors and low voltage TFTs. This thesis first discusses the Grünewald bandgap analysis method used to calculate semiconductor bandgap states from a single TFT measurement. The second section demonstrates solution-processed, low temperature (≤ 200 °C) dyed-sensitized thin-film phototransistors consisting of indium oxide (In2O3) and the organic dye D102. Devices exhibit an ultrahigh photosensitivity of 10^6 and responsivity of 2x10^3 A/W. Bandgap analysis identified photoinduced n-doping of the channel as the likely mechanism. The final section presents a direct comparison of four high-k dielectric layers used as insulators within In2O3 based TFTs. An identical low-temperature (≤ 200 °C), solution-processed route was used to produce aluminium oxide (AlOx), hafnium oxide (HfOx), yttrium oxide (YOx), and zirconium oxide (ZrOx) films. The usage of AlOx, HfOx & ZrOx dielectric layers resulted in functioning TFTs with on/off ratios of 10^5, operating below 3 V. The In2O3 mobility exhibited a dielectric dependence with average values of 2.0, 6.4, and 18.7 cm2/Vs for AlOx, HfOx and ZrOx respectively. The bandgap analysis was used to eliminate trap states as a possible cause for this dielectric dependent mobility. In conclusion, bandgap analysis of current semiconducting materials greatly improves the understanding of potential candidates for future high performance solution processed microelectronics.
Cost effectiveness analysis of hepatitis C case finding strategies using direct linkage into care
Creators: name: Selvapatt, Nowlan
Publisher: name: Imperial College London
Year: 2016

description: It is estimated that more than 50% of persons with hepatitis C in the UK remain undiagnosed, which should be considered a failure of current screening processes. Further, treatment uptake is poor and linkage and retention to care is a significant barrier to virus elimination. In this thesis we demonstrate the impact of long term linkage to care using the example of hepatocellular carcinoma surveillance. We demonstrate that in scenarios where patients are required to followed up long term, there are currently significant shortfalls in maintaining linkage to specialist services. In at least 40% of cases, lack of linkage was not due to patient related factors and were institutional failures. We also evaluated the impact of hepatitis C cirrhosis on hospital admissions. Patients who did not achieve SVR were associated with more frequent admission events and more days of admission. Whilst it is unclear if this was primarily associated with greater likelihood of advanced liver disease solely it does provide a compelling argument for treatment at earlier stages of disease. After demonstrating the burden of disease, health economic evaluation was performed comparing real-life screening and treatment outcomes in a drug-treatment unit, antenatal screening service and a homeless shelter. In all scenarios the screening was followed by direct linkage into specialist services aiming to increase retention. Finally a exploratory analysis was performed on a UK birth cohort screening programme using real-world age distributions of hepatitis C patients. All health economic analysis was performed using a validated hepatitis C natural history Markov modelling model. Hepatitis C screening at varying viraemic prevalences as seen in the drug treatment unit (41%) and antenatal screening (0.16%) are demonstrably cost-effective as long as patients are appropriately linked up to care with specialist services to reap the benefits of SVR at earlier stages of disease and minimise onward virus related liver complications.
When things stop falling, chaos is suppressed
Creators: name: Ageev, Dmitry S.
name: Aref'eva, Irina Ya.
Publisher: name: arXiv
Year: 2018
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: This note is devoted to the investigation of Susskind's proposal(arXiv:1802.01198) concerning the correspondence between the operator growth in chaotic theories and the radial momenta of the particle falling in the AdS black hole. We study this proposal and consider the simple example of an operator with the global charge described by the charged particle falling to the Reissner-Nordstrom-AdS black hole. Different charges of the particle lead to qualitatively different behavior of the particle momenta and consequently change of the operator size behavior. This holographic result is supported by different examples of chaotic models at a finite chemical potential where the suppression of chaos has been observed.
description: v1: 7 pages, 2 figures; v2: formula 3.4 is corrected; v3: discussion is enlarged; v4: new chapter, v5: published version
Search for the rare decay Λ0b → pπ −μ+ μ−
Creators: name: Smith, Eluned
Publisher: name: Imperial College London
Year: 2017

description: This thesis reports the branching fraction measurement of the rare Cabibbo-suppressed decay Λ0 b → pπ −μ+ μ− . The decay is observed for the first time with a 5.5σ deviation from the background-only hypothesis. This is the first observation of a b→ d quark transition in the baryon sector. The dataset used for the measurement corresponds to 3 fb−1 of pp collisions collected at the LHCb experiment at CERN. The branching fraction is measured using Λ0 b →J/ψ (→μ+ μ−)pπ − as a normalisation channel and is measured as B(Λ0 b → pπ−μ+ μ−) = (6.9 ± 1.9 ± 1.1+1.3 −1.0 ) × 10−8 , where the first error is the statistical uncertainty, the second is the systematic uncertainty and the third is the uncertainty on B(Λ0 b → J/ψ pπ−). The measurement of B(Λ0 b → pπ −μ+ μ− ) can be combined with the branching fraction measurement for Λ0 b → pK − μ+μ− to give constraints on the ratio of CKM matrix elements |Vtd/Vts|. Such a determination of |Vtd/Vts| requires a theory prediction for the ratio of the relevant form factors. This thesis also reports the ratio of tracking efficiencies, [epsilon_{rel}] , between data and simulation for Ks 0 → π +π− decays occurring within the LHCb detector acceptance. As Ks 0 particles are long-lived, their associated tracking efficiencies are less precisely determined compared to those of shorter-lived particles. The average value of [epsilon_{rel}] for Ks 0 → π+ π − decays, where the Ks 0 has a flight distance of > 1 m, is found to be ∼[ epsilon_{rel}] = 0.70 ± 0.02. To perform this calibration measurement a novel technique was developed which has the potential to be used in measuring the value of [epsilon_{rel}] for other decays involving long-lived particles.
title: An Evaluation of an Electromagnetic Current Meter for Study of Water Particle Motion
Creators: name: Hecker, George Milton
Publisher: name: Old Dominion University
publisherIdentifier: https://ror.org/04zjtrb98
publisherIdentifierScheme: ROR
Year: 1970

description: A new sophisticated electromagnetic current meter was laboratory and field tested in a wide variety of applications, ranging from measurement of net bottom currents (primarily tidal origin) on the continental shelf, to horizontal and vertical components of wave induced orbital motion of waves with periods as small as one second.

These tests indicate that this instrument is capable of performing to at least the following specifications, subject to the comments which follow:

Speed range: Accuracy: Threshold: 0 to + 5 knots + 0.2 knots + 0.02 knots Response time: 0.25 sec. Direction: -+ 7 degrees Depth: '0 to 42 feet

A single check of 7.5 knots was made in the 0 to 10 knot range. This was within specifications.

The sensing probe has no moving parts. It senses two orthogonal components of the average instantaneous current (in a plane perpendicular to the axis of the probe) in an area approximately 4.5 inches in radius. Each of the two pairs of sensing plates will give an essentially undistorted cosine response of flow not parallel to the plane of the plates.

Because of the great sensitivity and rapid response of the meter, the design of the mount must minimize structural responant frequencies (in situ) within the spectrum of interest. When this is not possible, on site observations can be made to record natural resonant frequencies of the mounting system.

The output level of the equipment. is virtually independent of temperature and salinity, although when employed in fresh water the signal to noise ratio decreases noticeably. There is no noticeable effect of the presence of local electrolytic potentials, but there is an indication that some factor in the local environment can create a zero offset. that must be detected and measured by 180 rotation of the sensor. A computer program easily normalizes such data.

Measurements made less than three feet from a sharp magnetic discontinuity will be unreliable. However measurements within one foot of the surface and one-half foot of a sand bottom remain within specified accuracy.

Input power variations of ± 20 volts or less do not affect the output. Minor (5%) variations from 60 cycles similarly cause no problem except perhaps in ancillary recording equipment.
The origin of imprinting defects in Temple syndrome and comparison with other imprinting disorders
Creators: name: Beygo, Jasmin
name: Mertel, Claudia
name: Kaya, Sabine
name: Gillessen-Kaesbach, Gabriele
name: Eggermann, Thomas
name: Horsthemke, Bernhard
name: Buiting, Karin
Publisher: name: Taylor & Francis
Year: 2018
Subjects: subject: Medicine
subject: Genetics
subject: FOS: Biological sciences
subject: 59999 Environmental Sciences not elsewhere classified
subject: FOS: Earth and related environmental sciences
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: Sociology
subject: FOS: Sociology
subject: Developmental Biology
subject: Science Policy

description: Temple syndrome (TS14) is a rare imprinting disorder caused by genetic and epigenetic alterations on chromosome 14q32. A subset of these patients shows an imprinting defect (ID) where the paternal allele harbors a maternal epigenotype thus silencing the paternally expressed genes and leading to an increased expression of the maternally expressed genes. We investigated the grandparental origin of the incorrectly imprinted chromosome 14 in a cohort of 13 TS14 ID patients and their families. In seven families grandmaternal and, in six families, grandpaternal inheritance was observed. These results indicate that the ID occurred after imprint erasure in the paternal germ line. While the complete lack of methylation as observed in the majority of TS14 ID patients may be due to an imprint establishment error in the paternal germ line, cases with methylation mosaicism suggest that in general many IDs (TS14, AS, BWS, and SRS) are in fact of somatic origin in the early or late embryo.
Weyl and Browder S-spectrums in a right quaternionic Hilbert space
Creators: name: Muraleetharan, B.
name: Thirulogasanthar, K.
Publisher: name: arXiv
Year: 2018
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences
subject: 47A10, 47A53

description: In this note first we study the Weyl operators and Weyl S-spectrum of a bounded right quaternionic linear operator, in the setting of the so-called S-spectrum, in a right quaternionic Hilbert space. In particular, we give a characterization for the S-spectrum in terms of the Weyl operators. In the same space we also study the Browder operators and introduce the Browder S-spectrum.
description: arXiv admin note: substantial text overlap with arXiv:1805.01461
The dynamics of vortical perturbations in viscoelastic shear flows
Creators: name: Page, Jacob
Publisher: name: Imperial College London
Year: 2015

description: Polymer additives have a striking impact on vortical motions in transitional and fully turbulent flows. Coherent structures which are familiar from Newtonian dynamics are altered in both strength and size while new, elasto-inertial phenomenology also emerges. In this work three canonical problems are used to explain the formation and evolution of particular flow structures in terms of the coupling between vorticity and polymer torque. Viscoelastic streak amplification is investigated first by forcing laminar Couette flow with a row of streamwise rolls. The streak response is shown to be determined by the ratio of the polymer relaxation time to the disturbance diffusion timescale in the solvent. When the timescales are disparate, quasi-Newtonian and elastic dynamics can be distinguished. When the timescales are commensurate, the fluid supports the propagation of vorticity waves whose reflection and superposition result in spanwise-travelling streaks which re- energise cyclically. In the second problem the receptivity of viscoelastic Couette flow to surface roughness on the lower wall is examined. The vorticity response is classified using a phase diagram, which is parameterised by the ratios of the channel depth and of the vorticity waves’ critical layer depth to the wavelength of the surface waviness. In shallow flows the bulk streamline distortion matches the topography of the lower wall, while large vorticity fluctuations are contained in an upper-wall solvent boundary layer. In deep channels, vorticity fluctuations are generated by a kinematic amplification mechanism at the critical layer. Finally, the evolution of a weak Gaussian vortex in a viscoelastic shear flow is computed to examine the dynamics of spanwise vorticity. Vorticity wave propagation along the tensioned mean streamlines causes the vortex to split into two as it is reoriented by the background flow. In addition, the analysis identifies the existence of a ‘reverse-Orr’ mechanism, whereby the vorticity amplifies as structures are tipped forward with the shear. The vorticity-polymer torque framework provides a unifying framework for studying these coherent motions. It also provides a grounding for understanding more complex, multiscale flows, such as elastic and inertial turbulence at low- and high-Reynolds numbers.
Vultur harpyja Linnaeus, 1758, spec. nov.
Creators: name: Linnaeus, Carolus
Publisher: name: Laurentius Salvius
Year: 1758
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Aves
Accipitriformes
Cathartidae
Vultur
Vultur harpyja

description: Vultur harpyja [spec. nov.]
V. occipite subcristato. �
Yzquauhtli. Hern. mex. pp. 34.
Aquilae cristatae genus. Raj. av. 161.
Habitat in Mexico.
Magnitudo arietis. Collum, Dorsum, Cauda, Crista surrecta nigra; Subtus nigro candidoque fulvo mixta. Homines etiam adoritur. Hernand.
Cfr. Aquila mexicana coronata. Rostrum Vulturis. Oculi membrana nictitante. Sub ingluvie pennae albae, quas iratus dimittit usque ad pedum digitos. Alae Caudaque subtus albo nigroque punctatae colore Tigridis. Erectus considet. Pennas occipitis saepius erigit in formam coronae. Fertur unico ictu cranium hominis iratus findere. Visus Madriti in Vivario Regio a Z. Hallman.
description: Published as part of Linnaeus, Carolus, 1758, Systema Naturae per regna tria naturae: secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis, Stockholm :Laurentius Salvius on page 86, DOI: 10.5962/bhl.title.542, http://zenodo.org/record/3922206
Cloud-droplet growth due to supersaturation fluctuations in stratiform clouds
Creators: name: Li, Xiang-Yu
name: Svensson, Gunilla
name: Brandenburg, Axel
name: Haugen, Nils E. L.
Publisher: name: arXiv
Year: 2018
Subjects: subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: FOS: Physical sciences

description: Condensational growth of cloud droplets due to supersaturation fluctuations is investigated by solving the hydrodynamic and thermodynamic equations using direct numerical simulations with droplets being modeled as Lagrangian particles. The supersaturation field is calculated directly by simulating the temperature and water vapor fields instead of being treated as a passive scalar. Thermodynamic feedbacks to the fields due to condensation are also included for completeness. We find that the width of droplet size distributions increases with time, which is contrary to the classical theory without supersaturation fluctuations, where condensational growth leads to progressively narrower size distributions. Nevertheless, in agreement with earlier Lagrangian stochastic models of the condensational growth, the standard deviation of the surface area of droplets increases as $t^{1/2}$. Also, for the first time, we explicitly demonstrate that the time evolution of the size distribution is sensitive to the Reynolds number, but insensitive to the mean energy dissipation rate. This is shown to be due to the fact that temperature fluctuations and water vapor mixing ratio fluctuations increases with increasing Reynolds number, therefore the resulting supersaturation fluctuations are enhanced with increasing Reynolds number. Our simulations may explain the broadening of the size distribution in stratiform clouds qualitatively, where the mean updraft velocity is almost zero.
description: 17 pages, 2 tables, 4 figures, submitted to Atmosph. Chem. Phys
Bypassing the gatekeeper: incidental negative cues stimulate choices with negative outcomes
Creators: name: Strohmaier, Niek
name: Veling, Harm
Publisher: name: Taylor & Francis
Year: 2018
Subjects: subject: Medicine
subject: Neuroscience
subject: 69999 Biological Sciences not elsewhere classified
subject: FOS: Biological sciences
subject: Science Policy
subject: 111714 Mental Health
subject: FOS: Health sciences
subject: 110309 Infectious Diseases

description: The Theory of Event Coding (TEC) predicts that exposure to affective cues can automatically trigger affectively congruent behaviour due to shared representational codes. An intriguing hypothesis from this theory is that exposure to aversive cues can automatically trigger actions that have previously been learned to result in aversive outcomes. Previous work has indeed found such a compatibility effect on reaction times in forced-choice tasks, but not for action selection in free-choice tasks. Failure to observe this compatibility effect for aversive cues in free choice tasks suggests that control processes aimed at directing behaviour toward positive outcomes may overrule the automatic activation of affectively congruent responses in case of aversive cues. The present study tested whether minimising such control could cause selection of actions that have been learned to result in aversive outcomes. Results showed incidental exposure to aversive cues biased selection of behaviours with learned aversive outcomes over behaviours with positive outcomes, despite a preference to execute the positive- over the negative-outcome actions evidenced by a separate behaviour measurement and self-reports. These results suggest motivational processes to select actions with positive consequences may sometimes be bypassed. Data and Materials: http://doi.org/10.17605/osf.io/ym7qu
E-textile: A New Sensation in Textiles
Creators: name: Rumon, md abdullah al
name: Sarker, Jahid
Publisher: name: figshare
Year: 2021
Subjects: subject: 91205 Functional Materials
subject: FOS: Materials engineering
subject: 91012 Textile Technology
subject: 90699 Electrical and Electronic Engineering not elsewhere classified
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: Electronic Textiles (e-textiles) are fabrics that feature electronics and interconnections woven into them, presenting physical flexibility and typical size that cannot be achieved with other existing electronic manufacturing techniques. E-textiles, refers to fabrics that can function electrically as electronics and behave physically as textiles Electronic-textile research is closely related to wearable computing research, but in many ways its own distinct field. Wearable computing explores technologies that are portable and attached to or carried on the body, but e-textile research has a slightly different focus: investigating electronic and computational technology that is imbedded into textiles. E-textile researchers strive to build devices that are as soft, flexible and comfortable as traditional cloth artifacts.image002CAGR projections from 2016-2026 for key e-textiles markets. Using Sensors provide a nervous system to detect signals, thus in a passive smart material, the existence of sensors is essential and wireless option gives the ultimate availability to measure information or to send data instantly. All over the world there is a large field to work with and characterizes key market sectors including ‘Sports & Fitness’, ‘Medical & Healthcare’, ‘Wellness’, ‘Home & Lifestyle’, ‘Industrial, commercial, military’, ‘Fashion’ and ‘Others’ (including automotive) giving more opportunities
New Observations and a New Interpretation of CO(3--2) in IRAS F10214+4724
Creators: name: Downes, D.
name: Solomon, P. M.
name: Radford, S. R.
Publisher: name: arXiv
Year: 1995
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: New observations with the IRAM interferometer of CO(3--2) from the highly luminous galaxy IRAS F10214+4724 show the source is 1.5'' x <= 0.9'' ; they display no evidence of any velocity gradient. This size, together with optical and IR data that show the galaxy is probably gravitationally lensed, lead to a new model for the CO distribution. In contrast to many lensed objects, we have a good estimate of the intrinsic CO and far IR surface brightnesses, so we can derive the CO and far IR/sub-mm magnifications. The CO is magnified 10 times and has a true radius of 400 pc. and the far IR is magnified 13 times and has a radius of 250 pc. The true far IR luminosity is 4 to 7e12 Lsun and the molecular gas mass is 2e10 Msun . This is nearly an order of magnitude less than previously estimated. Because the far IR magnification is lower than the mid and near IR magnification, the intrinsic spectral energy distribution now peaks in the far infrared. That is, nearly all of the energy of this object is absorbed and re-emitted in the far infrared. In CO luminosity, molecular gas content, CO linewidth, and corrected far IR luminosity, 10214+472 is a typical, warm, IR ultraluminous galaxy.
description: 18 pages, including 3 figures, of gzipped, uuencoded postscript. To be published Ap.J. Letters
Patient-specific instrumentations for complex knee surface preparation
Creators: name: Li, Jianmo
Publisher: name: Imperial College London
Year: 2015

description: Osteoarthritis of the knee is one of the most prevalent diseases. The primary treatment for young patients is regenerative cartilage repair. The best treatment for the middle aged group is cartilage substitution material. Although in the worst case scenario, knee replacement becomes an option, giving proper treatment in advance, most patients can postpone or even avoid the irreversible replacement procedure. Since the surface varies in size and shape among patients, the conventional standard sized instruments are not appropriate for these novel treatments. The existing preparation technique used by surgeons is freehand debridement, which relies on highly skilful and experienced surgeons to yield good results. Although there are some patient-specific instrumentations on the market, the majority of them are designed to assist the conventional knee replacement implants, and are not applicable on curved surfaces. The aim of this study was to develop effective, simple and standardized patient-specific instrumentations for large joint surface preparation. The study started from verifying the accuracy of experimental equipment and proposed patient-specific techniques and instruments. Then, an experiment on plastic bone samples was performed. The outcomes showed that the errors of repairing surface, depth, and position were less than ±0.5 mm, ±0.5 mm and ±1.0 mm respectively. This is regarded as sufficiently accurate to prepare the knee surface. Then, some improvements were made on the surgical jigs and procedures for the later cadaveric experiment. Eight cadaveric samples were tested. The outcomes showed that the 5% and 95% percentiles of errors in repairing surface, position errors and depth errors were -0.22 mm to 0.56 mm, -1.40 mm to 1.04 mm, and -0.58 mm to 0.20 mm respectively. Furthermore, patient-specific instrumentations were designed for arthroscopic procedures, which is the only patient-specific guide that can be used arthroscopically for orthopaedic surgeries. A tibial preparation guide was also designed, but further tests are needed for this device.
X-ray properties of the Parkes sample of flat-spectrum radio sources: dust in radio-loud quasars?
Creators: name: Siebert, J.
name: Brinkmann, W.
name: Drinkwater, M. J.
name: Yuan, W.
name: Francis, P. J.
name: Peterson, B. A.
name: Webster, R. L.
Publisher: name: arXiv
Year: 1998
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We investigate the X-ray properties of the Parkes sample of flat-spectrum radio sources using data from the ROSAT All-Sky Survey and archival pointed PSPC observations. In total, 163 of the 323 sources are detected. For the remaining 160 sources 2 sigma upper limits to the X-ray flux are derived. We present power-law photon indices for 115 sources, which were either determined with a hardness ratio technique or from direct fits to pointed PSPC data. For quasars, the soft X-ray photon index is correlated with redshift and with radio spectral index. Webster et al. (1995) discovered many sources with unusually red optical continua among the quasars of this sample and interpreted this result in terms of extinction by dust. Although the X-ray spectra in general do not show excess absorption, we find that low-redshift optically red quasars have significantly lower soft X-ray luminosities on average than objects with blue optical continua. The difference disappears for higher redshifts, as is expected for intrinsic absorption by cold gas associated with the dust. Alternative explanations are briefly discussed. We conclude, however, that dust does play an important role in some of the radio-loud quasars with red optical continua.
description: 21 pages, 13 figures, to appear in MNRAS
Computer based analysis of diffuse fibrosing lung diseases
Creators: name: Jacob, Joseph
Publisher: name: Imperial College London
Year: 2015

description: Computer based CT analysis of interstitial lung disease (ILD) may finally have come of age with sophisticated new software algorithms that can analyse CTs of patients with idiopathic pulmonary fibrosis (IPF) with similar, or superior, precision to visual scoring by radiologists. However, the latest iterations of such tools have not been evaluated in large populations or in fibrosing lung diseases (FLD) other than IPF. The investigations in this thesis aimed to identify the role of a computer-based tool CALIPER, compared to visual CT scoring and pulmonary function indices, in predicting prognosis at baseline in a large IPF cohort and across a range of FLDs. A second line of enquiry was exploration of the utility of serial CT as a prognosticator in IPF patients. Visual scores for these investigations were provided by four experienced sub-specialty thoracic radiologists. Baseline CT analysis in IPF demonstrated that CALIPER parameters, particularly the percentage of the lung occupied by vessels (parenchymal vascular percentage - PVP), were strong predictors of pulmonary function indices as well as mortality. CALIPER variables were the strongest predictors of mortality in patients with hypersensitivity pneumonitis and connective tissue disease-related-ILD and were one of the strongest predictors of mortality in an “all-comers” cohort of FLD. Serial evaluation of CT scans demonstrated that change in CALIPER variables, specifically change in PVP, was a stronger and more sensitive predictor of survival than the best available measure of disease worsening in IPF, namely change in forced vital capacity (FVC). It is concluded that CALIPER is a viable complementary tool in the baseline and serial evaluation of IPF and the baseline analysis of the majority of FLDs. Change in PVP, in particular, may represent a new index in the clinical evaluation of disease progression in IPF and could represent a co-endpoint alongside FVC change in clinical trials.
Fredholm operators and essential S-spectrum in the quaternionic setting
Creators: name: Muraleetharan, B.
name: Thirulogasanthar, K.
Publisher: name: arXiv
Year: 2018
Subjects: subject: Functional Analysis (math.FA)
subject: FOS: Mathematics
subject: 81R30, 46E22

description: For bounded right linear operators, in a right quaternionic Hilbert space with a left multiplication defined on it, we study the approximate $S$-point spectrum. In the same Hilbert space, then we study the Fredholm operators and the Fredholm index. In particular, we prove the invariance of the Fredholm index under small norm operator and compact operator perturbations. Finally, in association with Fredholm operators, we develop the theory of essential S-spectrum. We also characterize the $S$-spectrum in terms of the essential S-spectrum and Fredholm operators. In the sequel we study left and right S-spectrums as needed for the development of the theory presented in this note.
description: 29 pages