cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Severe Insect Pest Impacts on New Zealand Pasture: The Plight of an Ecological Outlier
Creators: name: Goldson, Stephen
name: Barker, Gary M.
name: Chapman, Hazel
name: Popay, Alison
name: Stewart, Alan V.
name: Caradus, John
name: Barratt, Barbara
Publisher: name: AgResearch
Year: 2025
Subjects: classificationCode: 300409
subject: Crop and pasture protection (incl. pests, diseases and weeds)

description: New Zealand’s intensive pastures, comprised almost entirely introduced Lolium L. and Trifolium L. species, are arguably the most productive grazing-lands in the world. However, these areas are vulnerable to destructive invasive pest species. Of these, three of the most damaging pests are weevils (Coleoptera: Curculionidae) that have relatively recently been controlled by three different introduced parasitoids, all belonging to the genus Microctonus Wesmael (Hymenoptera: Braconidae). Arguably that these introduced parasitoids have been highly effective is probably because they, like many of the exotic pest species, have benefited from enemy release. Parasitism has been so intense that, very unusually, one of the weevils has now evolved resistance to its parthenogenetic parasitoid. This review argues that New Zealand’s high exotic pasture pest burden is attributable to a lack of pasture plant and natural enemy diversity that presents little biotic resistance to invasive species. There is a native natural enemy fauna in New Zealand that has evolved over millions of years of geographical isolation. However, these species remain in their indigenous ecosystems and, therefore, play a minimal role in creating biotic resistance in the country’s exotic ecosystems. For clear ecological reasons relating to the nature of New Zealand pastures, importation biological control can work extremely well. Conversely, conservation biological control is less likely to be effective than elsewhere.
Effect of maternal bovine appeasing substance on health and performance of preweaned dairy calves
Creators: name: Bringhenti, Leonardi
name: Colombo, Eduardo
name: Rodrigues, Marjory X.
name: Cooke, Reinaldo F.
Publisher: name: The Bovine Practitioner
Year: 2023
Subjects: appeasing pheromone
stress
calves
Holstein
diarrhea
weight gain

description: This study aimed to evaluate the impacts of a maternal bo­vine appeasing substance (MBAS) administered to preweaned Holstein calves on their health and performance. In total, 410 calves individually allocated were enrolled (Treatment, n = 205; Control, n = 205). Treated calves received a topical application of MBAS to the nuchal skin (2.5 ml) and the skin above the muzzle (2.5 ml) at one day of age and then every 14 days until weaning at 60 days of life. An extra dose was ap­plied when calves were moved from hutches to collective pens at approximately 100 days of age. Calves allocated to the control group did not receive any kind of treatment. MBAS re­duced the incidence of diarrhea (treatment = 58.6% vs control = 70.8%; P = 0.01) as well as mortality risk (treatment = 2.4% vs control = 7.8%; P = 0.02). Furthermore, calves treated with MBAS had greater (P = 0.002) body weight 7 days after calves were moved from the hutches to the collective pens. There­fore, the use of MBAS during the preweaning period appears to be an effective strategy to improve health and growth of dairy calves.
description: The Bovine Practitioner, Vol. 57 No. 2 (2023)
Fractal and Multifractal Properties of Electrographic Recordings of Human Brain Activity: Toward Its Use as a Signal Feature for Machine Learning in Clinical Applications
Creators: name: França, Lucas G. S.
name: Miranda, José G. V.
name: Leite, Marco
name: Sharma, Niraj K.
name: Walker, Matthew C.
name: Lemieux, Louis
name: Wang, Yujiang
Publisher: name: arXiv
Year: 2018
Subjects: subject: Neurons and Cognition (q-bio.NC)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Information Theory (cs.IT)
subject: Adaptation and Self-Organizing Systems (nlin.AO)
subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Biological sciences
subject: FOS: Physical sciences
subject: FOS: Computer and information sciences

description: The brain is a system operating on multiple time scales, and characterisation of dynamics across time scales remains a challenge. One framework to study such dynamics is that of fractal geometry. However, currently there exists no established method for the study of brain dynamics using fractal geometry, due to the many challenges in the conceptual and technical understanding of the methods. We aim to highlight some of the practical challenges of applying fractal geometry to brain dynamics and propose solutions to enable its wider use in neuroscience. Using intracranially recorded EEG and simulated data, we compared monofractal and multifractal methods with regards to their sensitivity to signal variance. We found that both correlate closely with signal variance, thus not offering new information about the signal. However, after applying an epoch-wise standardisation procedure to the signal, we found that multifractal measures could offer non-redundant information compared to signal variance, power and other established EEG signal measures. We also compared different multifractal estimation methods and found that the Chhabra-Jensen algorithm performed best. Finally, we investigated the impact of sampling frequency and epoch length on multifractal properties. Using epileptic seizures as an example event in the EEG, we show that there may be an optimal time scale for detecting temporal changes in multifractal properties around seizures. The practical issues we highlighted and our suggested solutions should help in developing a robust method for the application of fractal geometry in EEG signals. Our analyses and observations also aid the theoretical understanding of the multifractal properties of the brain and might provide grounds for new discoveries in the study of brain signals. These could be crucial for understanding of neurological function and for the developments of new treatments.
description: Final version published at Frontiers in Physiology. https://doi.org/10.3389/fphys.2018.01767
Probing relic neutrino decays with 21 cm cosmology
Creators: name: Chianese, Marco
name: Di Bari, Pasquale
name: Farrag, Kareem
name: Samanta, Rome
Publisher: name: arXiv
Year: 2018
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We show how 21 cm cosmology can test relic neutrino radiative decays into sterile neutrinos. Using recent EDGES results, we derive constraints on the lifetime of the decaying neutrinos. If the EDGES anomaly will be confirmed, then there are two solutions, one for much longer and one for much shorter lifetimes than the age of the universe, showing how relic neutrino radiative decays can explain the anomaly in a simple way. We also show how to combine EDGES results with those from radio background observations, showing that potentially the ARCADE 2 excess can be also reproduced together with the EDGES anomaly within the proposed non-standard cosmological scenario. Our calculation of the specific intensity at the redshifts probed by EDGES can be also applied to the case of decaying dark matter and it also corrects a flawed expression appeared in previous literature.
description: 18 pages. 2 figures; v2: It matches PLB version
Charge generation and recombination in organic photovoltaics
Creators: name: Vezie, Michelle Southgate
Publisher: name: Imperial College London
Year: 2017

description: At the most basic level, a photovoltaic needs to convert solar power to electrical power. Therefore, the processes which result in electrons reaching the external circuit must out-compete the losses. I address this balance in organic photovoltaics, using a range of experimental techniques and test systems. In Chapter 4, I consider the fundamental limits to solar cell efficiency using detailed balance. I use the voltage loss due to non-radiative recombination as a metric to quantify how close a set of polymer:fullerene blend devices approach the radiative limit, using an indacenodithiophene-co-benzothiadiazole (C2C6-IDTBT) polymer. In particular, I examine the effect of C2C6-IDTBT fractionation on the non-radiative recombination, and find that devices made from high molecular weight polymer exhibit reduced non-radiative recombination losses relative to the non-fractionated polymer. I also probe the effect of polymer molecular weight in Chapters 5 and 6, using a different polymer, a thienothiophene-diketopyrrolopyrrole (DPP-TT-T). In Chapter 5, I find that devices made from high molecular weight DPP-TT-T out-perform devices made from low molecular weight DPP-TT-T, particularly the short-circuit current. While I find some differences in electronic quality, the most striking difference between the polymer fractions is the light absorption: high molecular weight DPP-TT-T absorbs light more strongly than low molecular weight DPP-TT-T. Furthermore, the extinction coefficient maximum of high molecular weight DPP-TT-T is about 50% greater than any conjugated polymer we had measured previously. In Chapter 6, I explore the causes of this high optical absorption. We find that calculated persistence length can be a good predictor of optical absorption strength: polymers with high calculated persistence length, or high linearity, exhibit stronger absorption. We also find that high molecular weigh DPP-TT-T has a greater proportion of linear chain segments than low molecular weight DPP-TT-T, and that this is the likely cause of the greater extinction coefficient. Chapter 7 treats the mechanism of charge separation by using two modified fullerenes with different electron affinities to probe the energetic offset required between the polymer and the acceptor for efficient free charge generation from polymer excitons. We find that, when there is very little energetic offset, the polymer excitons are unable to dissociate, and subsequent charge generation is inefficient. However, when the energetic offset between the polymer and acceptor LUMO levels is increased, the efficiency of polymer exciton dissociation is increased and there is significant charge generation. Overall therefore, I have examined how charge generation, from light absorption to subsequent free charge generation, and recombination, particularly non-geminate recombination in the bulk, affect solar cell performance.
Additional file 3 of GetOrganelle: a fast and versatile toolkit for accurate de novo assembly of organelle genomes
Creators: name: Jin, Jian-Jun
name: Yu, Wen-Bin
name: Yang, Jun-Bo
name: Song, Yu
name: dePamphilis, Claude W.
name: Yi, Ting-Shuang
name: Li, De-Zhu
Publisher: name: figshare
Year: 2020
Subjects: subject: Genetics
subject: FOS: Biological sciences

description: Additional file 3. Review history.
Peptide profiling to predict bitterness in fermented milk from different bacterial cultures and relationship with human bitter taste receptor activation
Creators: name: Maes, Evelyne
name: Ahmad, Raise
name: Hefer, Charles
name: Haines, Stephen
name: Thomas, Ancy
name: Lee, Erin
name: Nguyen, Hanh Thi Hong
name: Day, Li
name: Dalziel, Julie
Publisher: name: AgResearch
Year: 2025
Subjects: classificationCode: 3006
subject: Food sciences

description: Microbial fermentation is frequently used in the food industry to enhance organoleptic experience. In fermented milk and yogurt, peptides released from milk protein upon fermentation can contribute to a bitter taste in the final dairy product, depending on the lactic acid bacterial cultures used. This work used five lactic acid bacteria (LAB) strains: Lactobacillus helveticus (LH), Leuconostoc mesenteroides (CL3), Leuconostoc pseudomesenteroides (CL3ST), Lactococcus lactis (BL1), Streptococcus thermophilus (ST), to investigate the relationship between peptides produced from fermented milks and their ability to activate human bitter taste receptors (TAS2R) in vitro. Label-free peptidomics was performed and relative abundances of bitter peptides compared, based on predicted in silico sequence analysis (in-house database search and Q-values). Milk fermented by LH had the highest number of bitter peptides and was also more efficacious at activating the bitter receptor in vitro, while milk fermented by ST had the least. This work demonstrates that the potential bitter taste of fermented milk can be estimated from the profile of the peptides generated by the lactic acid bacteria fermentation. This approach may be applied to evaluating bitter taste in development of novel dairy products.
Oblivious DNS: Practical Privacy for DNS Queries
Creators: name: Schmitt, Paul
name: Edmundson, Anne
name: Feamster, Nick
Publisher: name: arXiv
Year: 2018
Subjects: subject: Networking and Internet Architecture (cs.NI)
subject: FOS: Computer and information sciences

description: Virtually every Internet communication typically involves a Domain Name System (DNS) lookup for the destination server that the client wants to communicate with. Operators of DNS recursive resolvers---the machines that receive a client's query for a domain name and resolve it to a corresponding IP address---can learn significant information about client activity. Past work, for example, indicates that DNS queries reveal information ranging from web browsing activity to the types of devices that a user has in their home. Recognizing the privacy vulnerabilities associated with DNS queries, various third parties have created alternate DNS services that obscure a user's DNS queries from his or her Internet service provider. Yet, these systems merely transfer trust to a different third party. We argue that no single party ought to be able to associate DNS queries with a client IP address that issues those queries. To this end, we present Oblivious DNS (ODNS), which introduces an additional layer of obfuscation between clients and their queries. To do so, ODNS uses its own authoritative namespace; the authoritative servers for the ODNS namespace act as recursive resolvers for the DNS queries that they receive, but they never see the IP addresses for the clients that initiated these queries. We present an initial deployment of ODNS; our experiments show that ODNS introduces minimal performance overhead, both for individual queries and for web page loads. We design ODNS to be compatible with existing DNS protocols and infrastructure, and we are actively working on an open standard with the IETF.
Analyzing Physics-Dynamics Coupling in an Ensemble of Simplified GCMs
Creators: name: Jablonowski, Christiane
Publisher: name: figshare
Year: 2018
Subjects: subject: Atmospheric Sciences
subject: FOS: Earth and related environmental sciences

description: Analyzing Physics-Dynamics Coupling in an Ensemble of Simplified GCMs
Detection of dust in the most distant known radiogalaxy
Creators: name: Ivison, R. J.
Publisher: name: arXiv
Year: 1995
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: A search for millimetric continuum emission from eight optically-selected, radio-quiet quasars and a radiogalaxy with 3.7 < z < 4.3, has been undertaken using a highly sensitive 7-channel bolometer on the IRAM 30-m Millimetre Radio Telescope. Detections of a potentially dust-rich quasar, and of 8C1435+635, the most distant known radiogalaxy, are reported. An extrapolation of the steepening centimetric radio spectrum of 8C1435+635 accounts for less than one per cent of the observed 1.25-mm flux density, indicating that the emission is most likely from warm dust, although the present data cannot discriminate against synchrotron emission. If the emission is thermal, then the derived dust mass lies in the range, 2E9 < M(dust) < 8E7 Solar for 20 < T(dust) < 100K, or M(dust) ~ 1.6E8 Solar for T(dust) = 60K, similar to that derived for 4C41.17, suggesting a molecular gas mass of between 4E10 and 9E11 Solar. The quasar, PC2047+0123 at z=3.80, has no detectable centimetric emission and the 1.25-mm continuum detected here probably also originates from ~ 1.5E8 Solar masses of dust (again for T(dust) = 60K). Upper limits have been obtained for four quasars, corresponding to dust mass limits of around 3 sigma < 2E8 Solar; less useful limits have been set for a further three quasars.
description: 4 pages; 1 figure; text as compressed ps file at http://www.roe.ac.uk/research/dust.ps.Z; figure as compressed ps file at http://www.roe.ac.uk/research/8c.ps.Z
Luminoso at SemEval-2018 Task 10: Distinguishing Attributes Using Text Corpora and Relational Knowledge
Creators: name: Speer, Robyn
name: Lowry-Duda, Joanna
Publisher: name: arXiv
Year: 2018
Subjects: subject: Computation and Language (cs.CL)
subject: FOS: Computer and information sciences

description: Luminoso participated in the SemEval 2018 task on "Capturing Discriminative Attributes" with a system based on ConceptNet, an open knowledge graph focused on general knowledge. In this paper, we describe how we trained a linear classifier on a small number of semantically-informed features to achieve an $F_1$ score of 0.7368 on the task, close to the task's high score of 0.75.
description: SemEval 2018, 5 pages
Response of an oscillatory delay differential equation to a periodic stimulus
Creators: name: De Souza, Daniel C.
name: Mackey, Michael C.
Publisher: name: arXiv
Year: 2018
Subjects: subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics
subject: 92B25, 92C45, 34K27, 34K13

description: Periodic hematological diseases such as cyclical neutropenia or cyclical thrombocytopenia, with their characteristic oscillations of circulating neutrophils or platelets, may pose grave problems for patients. Likewise, periodically administered chemotherapy has the unintended side effect of establishing periodic fluctuations in circulating white cells, red cell precursors and/or platelets. These fluctuations, either spontaneous or induced, often have serious consequences for the patient (e.g. neutropenia, anemia, or thrombocytopenia respectively) which exogenously administered cytokines can partially correct. The question of when and how to administer these drugs is a difficult one for clinicians and not easily answered. In this paper we use a simple model consisting of a delay differential equation with a piecewise linear nonlinearity, that has a periodic solution, to model the effect of a periodic disease or periodic chemotherapy. We then examine the response of this toy model to both single and periodic perturbations, meant to mimic the drug administration, as a function of the drug dose and the duration and frequency of its administration to best determine how to avoid side effects.
description: 28 pages
A Well-Posed and Stable Coupling Procedure for the Compressible and Incompressible Navier-Stokes Equations
Creators: name: Ghasemi, Fatemeh
name: Nordstrom, Jan
Publisher: name: figshare
Year: 2018
Subjects: subject: Atmospheric Sciences
subject: FOS: Earth and related environmental sciences

description: A Well-Posed and Stable Coupling Procedure for the Compressible and Incompressible Navier-Stokes Equations
Implications for the Cosmic Ray Spectrum of a Negative Electron Neutrino (Mass)^2
Creators: name: Ehrlich, R.
Publisher: name: arXiv
Year: 1998
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The hypothesis that the electron neutrino is a tachyon with |m|=sqrt(-m^2) = 0.5 eV/c^2 is consistent with certain properties of the cosmic ray spectrum, including: the existence of a change in power law (the "knee") at E = 10^15 eV, the E^-3 power law after the knee, another change in power law (the "ankle") at E = 10^19 eV, the changes in composition above the knee, the change in anisotropy at the knee, and the absence of a GZK cutoff above E = 4 x 10^19 eV. The hypothesis predicts a substantial flux of cosmic ray neutrons in a narrow energy region just above the knee of the spectrum.
description: 28 pages, 4 figures, submitted to Phys. Rev. D
DIFFERENTIATED PRODUCTS, MONOPOLISTIC COMPETITION AND THE INFERIORITY OF FREE TRADE
Creators: name: Mahbob, Abdelhamid
name: Mahbob, Abdelhamid
Publisher: name: Unknown
Year: 1985
Subjects: Industrial Organization

description: In a world of two regions trading differentiated products, free trade may appear to be Pareto inferior to restricted trade. When one region imposes tariffs on its imported varieties of the differentiated good, the world price of all varieties may rise. The likelihood of this result is greater the higher is the degree of product differentiation. With free entry to the industry, the tariff-induced higher price induces more firms producing more varieties in both regions. Consumers with convex preference sets will benefit from such a move. Under some conditions, including a high degree of product differentiation, this utility gain may dominate and restricting trade may yield a greater welfare level for the world.
Nanophotonic engineering of far-field thermal emitters
Creators: name: Baranov, Denis G.
name: Xiao, Yuzhe
name: Nechepurenko, Igor A.
name: Krasnok, Alex
name: Alù, Andrea
name: Kats, Mikhail A.
Publisher: name: arXiv
Year: 2018
Subjects: subject: Optics (physics.optics)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: Thermal emission is a ubiquitous and fundamental process by which all objects at non-zero temperatures radiate electromagnetic energy. This process is often presented to be incoherent in both space and time, resulting in broadband, omnidirectional light emission toward the far field, with a spectral density related to the emitter temperature by Planck's law. Over the past two decades, there has been considerable progress in engineering the spectrum, directionality, polarization, and temporal response of thermally emitted light using nanostructured materials. This review summarizes the basic physics of thermal emission, lays out various nanophotonic approaches to engineer thermal-emission in the far field, and highlights several relevant applications, including energy harvesting, lighting, and radiative cooling.
description: Review article
Where is the Dark Matter?
Creators: name: Bahcall, Neta A.
name: Lubin, Lori M.
name: Dorman, Victoria
Publisher: name: arXiv
Year: 1995
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: How much dark matter is there in the universe and where is it located? These are two of the most fundamental questions in cosmology. We use in this paper optical and x-ray mass determinations of galaxies, groups, and clusters of galaxies to suggest that most of the dark matter may reside in very large halos around galaxies, typically extending to ~200 kpc for bright galaxies. We show that the mass-to-light ratio of galaxy systems does not increase significantly with linear scale beyond the very large halos suggested for individual galaxies. Rather, the total mass of large scale systems such as groups and rich clusters of galaxies, even superclusters, can on average be accounted for by the total mass of their member galaxies, including their large halos (which may be stripped-off in the dense cluster environment but still remain in the clusters) plus the mass of the hot intracluster gas. This conclusion also suggests that we may live in a low-density universe with Omega ~ 0.2 - 0.3.
description: PostScript, to appear in July 10 ApJ Letters; same as previous text minus an extraneous page, 3 figures available on anonymous ftp at ftp://astro.princeton.edu/lml/
Variational-metriplectic formulations of compressible, multiphase, multicomponent geophysical fluids
Creators: name: Eldred, Chris
name: Francois Gay-Balmaz
Publisher: name: figshare
Year: 2018
Subjects: subject: Atmospheric Sciences
subject: FOS: Earth and related environmental sciences

description: Variational-metriplectic formulations of
compressible, multiphase, multicomponent
geophysical fluids
Electrostatic effects, band distortions and superconductivity in twisted graphene bilayers
Creators: name: Guinea, Francisco
name: Walet, Niels R.
Publisher: name: arXiv
Year: 2018
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Bilayer graphene twisted by a small angle shows a significant charge modulation away from neutrality, as the charge in the narrow bands near the Dirac point is mostly localized in the regions of the Moiré pattern with $AA$ stacking. The resulting electrostatic potential gives rise to the dominant contribution to the electron-electron interaction within this low energy band, which becomes significantly distorted. The changes in the band structure are described by new local interactions, and lead to an assisted electron-hopping process. These couplings favor superconductivity at certain fillings.
description: 8 pages and lots of figures
On the entropy of a spherical plasma shell
Creators: name: Bordag, M.
name: Kirsten, K.
Publisher: name: arXiv
Year: 2018
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Negative entropy was repeatedly observed in the Casimir effect caused by dissipation or geometry. However, it was restricted to subsystems. Recently the question about the entropy for a complete Casimir effect like configuration was raised. In the present paper we consider a spherical plasma shell which can be considered as a (crude) model for a giant carbon molecule (e.g., $C_{60}$). The entropy is free of ultraviolet divergences and its calculation does not need any regularization. We calculate the entropy numerically and demonstrate unambiguously the existence of a region where it takes negative values. This region is at small values of temperature and plasma frequency (in units of the radius).
description: 13 pages, 2 figures, some misprints corrected, several improvements
The Temperature Scale of Metal-Rich M Giants Based on TiO Bands: Population Synthesis in the Near Infrared
Creators: name: Schiavon, Ricardo P.
name: Barbuy, Beatriz
Publisher: name: arXiv
Year: 1998
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We have computed a grid of high resolution synthetic spectra for cool stars (2500
description: ApJ accepted, 27 pages + 11 figures, AASLatex v4.0
Classical phase diagram of the stuffed honeycomb lattice
Creators: name: Sahoo, Jyotisman
name: Kochkov, Dmitrii
name: Clark, Bryan K.
name: Flint, Rebecca
Publisher: name: arXiv
Year: 2018
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We investigate the classical phase diagram of the stuffed honeycomb Heisenberg lattice, which consists of a honeycomb lattice with a superimposed triangular lattice formed by sites at the center of each hexagon. This lattice encompasses and interpolates between the honeycomb, triangular and dice lattices, preserving the hexagonal symmetry while expanding the phase space for potential spin liquids. We use a combination of iterative minimization, classical Monte Carlo and analytical techniques to determine the complete ground state phase diagram. It is quite rich, with a variety of non-coplanar and non-collinear phases not found in the previously studied limits. In particular, our analysis reveals the triangular lattice critical point to be a multicritical point with two new phases vanishing via second order transitions at the critical point. We analyze these phases within linear spin wave theory and discuss consequences for the S = 1/2 spin liquid.
description: 18 pages, 23 figures
A simple model of a balanced boundary layer coupled to a large-scale convective circulation
Creators: name: Cullen, Mike
name: Beare, Bob
Publisher: name: figshare
Year: 2018
Subjects: subject: Atmospheric Sciences
subject: FOS: Earth and related environmental sciences

description: A simple model of a balanced boundary layer
coupled to a large-scale convective circulation
Study of RF breakdown in muon cooling cavities
Creators: name: Zarrebini-Esfahani, Arash
Publisher: name: Imperial College London
Year: 2015

description: Particle accelerators are devices that are capable of forcing charged particles to very high energy levels. Modern particle accelerators are required to produce conditions of extremely high electromagnetic fields in the Radio Frequency (RF) range and produce extremely high accelerating gradients. This has led to various practical issues, one of the most significant being the phenomenon of RF breakdown in the accelerating cavities. When exposed to an intense electromagnetic field, a conducting surface can emit electrons. In the case of an accelerating cavity, these electrons are further accelerated by the RF field. Such emissions are capable of inflicting irreversible damage on the cavity surface and need to be avoided. Among the factors responsible for initiating such emission, the quality of the cavity surface in combination with the operating conditions has been identified as the main one. The mechanisms involved in the initiation of RF breakdown need to be better understood and related to the cavity design criteria, such that they can lead to correctly specified and reproducible designs. The cavity surface quality may be characterised in terms of surface finish and its chemical composition, both of which are strongly affected by the manufacturing processes. Unlike previous studies, this research has focused on the analysis of the effects of fabrication procedures on surface quality. The work involved manufacture and surface characterisation of button shaped samples, which were produced using relevant metal forming and polishing techniques, in preparation for future experimentation in a test system at Fermilab, USA. Although RF breakdown may be initiated locally at the metallic surface, its effects propagate globally across the entire cavity. Surface defects and impurities act as emission sites by inducing local field enhancements. Simulation methods were developed in order to simultaneously study electron emission due to local field enhancement and electron propagation across the cavity, with the benefit of being able to perform tracking in 3D and to verify enhancement factors obtained by theoretical measurements using the surface properties observed on the buttons. This research was conducted in close collaboration with Daresbury Laboratory and Lancaster University in UK as well as the MTA group Fermilab USA.
Persistence paths and signature features in topological data analysis
Creators: name: Chevyrev, Ilya
name: Nanda, Vidit
name: Oberhauser, Harald
Publisher: name: arXiv
Year: 2018
Subjects: subject: Machine Learning (stat.ML)
subject: Machine Learning (cs.LG)
subject: Probability (math.PR)
subject: Statistics Theory (math.ST)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: We introduce a new feature map for barcodes that arise in persistent homology computation. The main idea is to first realize each barcode as a path in a convenient vector space, and to then compute its path signature which takes values in the tensor algebra of that vector space. The composition of these two operations - barcode to path, path to tensor series - results in a feature map that has several desirable properties for statistical learning, such as universality and characteristicness, and achieves state-of-the-art results on common classification benchmarks.
description: Additional experiment and further details. To appear in IEEE Transactions on Pattern Analysis and Machine Intelligence
Parameterised verification for multi-agent systems
Creators: name: Kouvaros, Panagiotis
Publisher: name: Imperial College London
Year: 2015

description: In the past ten years several methods have been put forward for the efficient model checking of multiagent systems against agent-based specifications. Yet, since the number of states is exponential in the number of agents in the system, the model checking problem remains intractable for systems of many agents. This is particularly problematic when wishing to reason about unbounded systems where the number of components is not known at design time. Systems ranging from robotic swarms to e-commerce applications constitute typical examples in which the number of participants is independent of the design process. This thesis develops parameterised model checking techniques for the validation of multiagent systems irrespectively of the number of the agents present. To do this, a semantics that captures parameterised, synchronous multiagent systems and one that models parameterised, interleaved multiagent systems are introduced. Both semantics extend interpreted systems in a parameterised setting where the number of agents is the parameter. Parameterised model checking techniques for the semantical classes introduced are developed. A sound and complete cutoff methodology is studied for parameterised interpreted systems. A sound but incomplete cutoff procedure for parameterised interleaved interpreted systems is also studied. While the latter procedure is in exponential space, three notable subclasses are isolated and more effective verification techniques are put forward. The algorithms proposed are shown to be sound. For one class the decidability of the verification problem is shown and a complete cutoff procedure is discussed. Finally, the model checker MCMAS-P is introduced. The tool supports the verification of unbounded multiagent systems against temporal-epistemic specifications. MCMAS-P implements the procedures here developed; the procedure invoked depends on the properties of the system under examination. Experimental results obtained on cache coherence protocols, mutual exclusion protocols, swarm foraging algorithms, and swarm aggregation algorithms are reported.
Representation of air-sea interactions on an idealised coupled atmosphere-ocean model with focus on the Western Baltic Sea
Creators: name: Bauer, Tobias
name: Hallmuth, Olaf
Publisher: name: figshare
Year: 2018
Subjects: subject: Atmospheric Sciences
subject: FOS: Earth and related environmental sciences

description: Representation of air-sea interactions on an idealised coupled
atmosphere-ocean model with focus on the Western Baltic Sea
DYNAMICS OF THE GALACTIC GLOBULAR CLUSTER NGC 3201
Creators: name: Cote, Patrick
name: Welch, Douglas L.
name: Fischer, Philippe
name: Gebhardt, K.
Publisher: name: arXiv
Year: 1995
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: B,V CCD frames have been used to derive surface brightness profiles for NGC 3201 out to ~18 arcmin. A total of 857 radial velocities with median precision ~1 km/s for 399 member giants have been used to trace the velocity dispersion profile out to 32' (the approximate tidal radius from fits of single-mass, isotropic King-Michie models to the cluster surface brightness profiles). The median difference in radial velocity for stars on either side of an imaginary axis moved through the cluster in 1 degree steps shows a significant maximum amplitude of 1.22+/-0.25 km/s. We discuss possible explanations of this result, including: (1) cluster rotation; (2) preferential stripping of stars on prograde orbits near the limiting radius; (3) the projection of the cluster space velocity onto the plane of the sky and (4) a slight drift in the velocity zero point. It is difficult to identify the primary cause of the observed velocity field structure unambiguously, and we suspect that all of the above processes may play a role. The B,V surface brightness profiles and radial velocities have been modeled with single- & multi-mass King-Michie models and nonparametric techniques. The density and M/L profiles show good agreement over 1.5
description: uuencoded compressed Postscript, 59 pages including 10 figures. Also available at http://www.dao.nrc.ca/DAO/SCIENCE/science.html
Analysis of stability and viscous-inviscid interaction in compressible boundary layers
Creators: name: De Cointet, Thomas
Publisher: name: Imperial College London
Year: 2015

description: This work belongs to the theory of fluid flows at high Reynolds number, characterised by low viscosity and, to a lesser extent, high speeds. It is a mathematically intensive field covering most aspects of applied mathematics, from Partial Differential equations to Numerical Analysis and Complex Analysis. Two of the central areas of research within this particular branch of fluid dynamics are the boundary-layer laminar-turbulent transition and the boundary-layer separation. Both of these phenomena have a high impact on the aerodynamic performance of aircraft wings, turbine blades and other fast-moving objects such as rockets. As a consequence, their study is relevant both for industrial applications and to the scientific community as a whole. The mathematical element pertaining to the analysis of these two phenomena is the consistent use of asymptotic methods, such as matched asymptotic expansions and multiple scales analysis. In particular, this work will be based on the viscous-inviscid interaction theory originally discovered by Lin (1955) and further developed by the work of Neiland (1969) and Stewartson & Williams (1969). In the first chapter of this thesis, we will study the initial stages of the laminar-turbulent transition of a compressible boundary layer on a swept wing. The instability of interest will be the stationary crossflow vortex, which is known to be the main instability mode in three-dimensional boundary layers on a swept wing. We will focus on two specific aspects of the transition process, namely the receptivity and linear stability analysis of the flow. The receptivity mechanism introduced in our work is a roughness of size comparable with that of the boundary layer thickness. This justifies our restriction to the study of the inviscid instability of the flow and the use of the impermeability condition on the roughness. The remaining two chapters are concerned with the viscous-inviscid interaction of the boundary layer in the vicinity of a surface discontinuity. We will first study the behaviour of the subsonic flow exposed to the singular pressure gradient dp/dx = κ(x0 − x)−1/3, as x → x0. It forms when the body contour has a point x = x0 near which yw = (x0 − x)5/3. We will show how logarithmic terms need to be included in the solution. We then study a similar problem, this time in the context of an incoming transonic flow near a point of curvature discontinuity. We will show that in both cases the boundary layer experiences an “extreme acceleration”.
A Near-Infrared Search for Line Emission from Protogalaxies Using the W. M. Keck Telescope
Creators: name: Pahre, M. A.
name: Djorgovski, S. G.
Publisher: name: arXiv
Year: 1995
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present the first results from a near-infrared narrow-band search for primeval galaxies (PGs) using the Keck 10~m telescope. We have targeted our fields for three QSOs and one radio galaxy at redshifts $z = 2.28$ to $4.70$. We selected narrow-band filters in the $K$-band centered on strong emision lines at the redshift of the targets. We reach limiting fluxes between $1.6\times 10^{-17}$~erg~s$^{-1}$~cm$^{-2}$ and $1.0\times 10^{-16}$~erg~s$^{-1}$~cm$^{-2}$, and cover a total area of $\sim 4$~arcmin$^2$. At the redshifts of interest, these flux limits correspond to typical restframe line luminosities of $\sim 10^{42} - 10^{43}$~erg~s$^{-1}$, unobscured star formation rates of $\sim 1 - 100$ $M_\odot$~yr$^{-1}$, and a sampled comoving volume of several tens of Mpc$^3$. We have found no candidate PGs at a $2σ$ confidence level. We demonstrate that for moderate dust absorption ($A_V \gsim 2^m$) in a simple dust-screen model, our preliminary survey puts a strong constraint on intrinsic PG luminosities during an intial burst of star formation. In the case of the QSOs, we have used PSF-subtraction to search for the presence of faint, extended line emission surrounding these radio-quiet AGNs. We find no evidence for extended emission down to $3.7 \times 10^{-17}$~erg~s$^{-1}$~cm$^{-2}$. This imposes limits on the reprocessed fraction of the QSO continuum emission ranging between $0.02$\% and $0.29$\%; if beaming effects are not important, then this implies similarly small covering factors for clouds optically thick to the QSO continuum emission.
description: 9 pages (text) plus 4 figures, uuencoded compressed postscript format, to appear in The Astrophysical Journal (Letters); also available in same format from http://astro.caltech.edu/~map/papers/pgapjl/pgpreprint.uu
The Infrared Surface Brightness Fluctuation Distances to the Hydra and Coma Clusters
Creators: name: Jensen, Joseph B.
name: Tonry, John L.
name: Luppino, Gerard A.
Publisher: name: arXiv
Year: 1998
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present IR surface brightness fluctuation (SBF) distance measurements to NGC 4889 in the Coma cluster and to NGC 3309 and NGC 3311 in the Hydra cluster. We explicitly corrected for the contributions to the fluctuations from globular clusters, background galaxies, and residual background variance. We measured a distance of 85 +/- 10 Mpc to NGC 4889 and a distance of 46 +/- 5 Mpc to the Hydra cluster. Adopting recession velocities of 7186 +/- 428 km/s for Coma and 4054 +/- 296 km/s for Hydra gives a mean Hubble constant of H_0 = 87 +/- 11 km/s/Mpc. Corrections for residual variances were a significant fraction of the SBF signal measured, and, if underestimated, would bias our measurement towards smaller distances and larger values of H_0. Both NICMOS on the Hubble Space Telescope and large-aperture ground-based telescopes with new IR detectors will make accurate SBF distance measurements possible to 100 Mpc and beyond.
description: 24 pages, 4 PostScript figures, 2 JPEG images; accepted for publication in ApJ
Stationary Lifshitz Black Hole of New Massive Gravity
Creators: name: Sarıoğlu, Özgür
Publisher: name: arXiv
Year: 2018
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: I present the stationary Lifshitz black hole solution of three-dimensional New Massive Gravity theory and study its elementary geometric and thermodynamical properties.
description: latex, 11 pages, 1 figure, 1 table; ver 2: references added; ver 3: various improvements including a new appendix on the geodesics, 14 pages; ver 4: published version (with 2 new references)
Diversity and structure of bird and mammal communities in the Semiarid Chaco Region: response to agricultural practices and landscape alterations
Creators: name: Decarre, Julieta
Publisher: name: Imperial College London
Year: 2015

description: The conversion of land from natural environments to human-managed areas has been particularly pronounced in the semiarid Chaco Region. In this context, it is critical to understand the impacts that these major changes have on species diversity. The specific aims of this thesis were to understand: i) how the different human-modified environments influenced the distribution of the bird assemblages in the current agricultural matrix; ii) which local and landscape scale characteristics best explained species richness and relative abundance of mammals; and iii) what is the relationship between biodiversity and profit for both taxa, and given this relationship, to what extent can conservation and production objectives be simultaneously achieved. Bird and mammal community data was gathered in seven different habitats of an agricultural matrix and inside a National Park. Bird species richness and abundance were extremely low in highly modified environments (agriculture plots), but increased significantly in intermediate, or low modified habitats (silvopasture plots, forest outside and inside the National Park, respectively). Richness and capture frequency of mammals increased gradually across the gradient of habitat modification, from low numbers in agricultural habitats to a maximum in National Park forests. Changes in species composition with production intensification differed between birds and mammals. The bird communities were similar for low- and intermediate-intensity farming, with constant number of species, abundance and community integrity. However, further intensification led to an abrupt decline, defining a clear threshold. Mammal species richness was maintained in low-yield farming, relative abundance declined with increasing production, favoured by a wildlife-friendly farming approach. In contrast to birds, mammal community integrity decreased exponentially with increased levels of intensification, showing that only protected or well-preserved forests can support some habitat-restricted species. The results suggest that a combined strategy is the best option to achieve conservation and production targets that include both taxa.
Forbidden Fe+ Emission from Supernovae Remnants in M33
Creators: name: Lumsden, S. L.
name: Puxley, P. J.
Publisher: name: arXiv
Year: 1995
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Supernovae remnants are known to be luminous sources of infrared [FeII] emission. By studying how the luminosity scales with age, environment and other relevant factors, we can construct an [FeII] luminosity function for supernovae remnants. This will enable us to predict supernovae rates in starburst galaxies that are too distant for individual remnants to be resolved. First, however, we require accurate luminosities for a sample of remnants of varying ages, and in varying physical environments. As part of this project we have carried out an initial study of a small sample of evolved (ages greater than a few thousand years) remnants in M33. From these data we tentatively conclude that there is evidence for the peak luminosity in the [FeII] lines of these sources to arise in a narrow range of ages. In other respects, the M33 remnants are similar to their galactic and Magellanic Cloud counterparts in the observed peak luminosity. From this, and internal evidence as to the environment present in these regions, we conclude that the luminosity of evolved remnants is only marginally dependent on density and metallicity.
description: 12 pages, uuencoded compressed postscript. Also available as postscript file from ftp://aaoepp.aao.gov.au/local/sll/snr.ps Accepted for publication in Monthly Notices of the Royal Astronomical Society
title: Frontonasal meningoencephalocele
Creators: name: Argeta Shegiro, Mamo
Publisher: name: EURORAD
Year: 2024
Subjects: subject: Head & neck imaging
subject: CNS
subject: Head and neck
subject: Neuroradiology brain
subject: CT
subject: CT-High Resolution
subject: Computer Applications-3D
subject: Education
subject: Surgery
subject: Congenital
subject: Clinical Case

description: Clinical History: A 15-day-old male neonate with clinical data of facial swelling since birth. The mother was from the countryside, and she had no antenatal follow-up or ultrasound scan during pregnancy. The parents noticed the facial swelling only after birth.

description: 15 days, male