cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Measurement of the liquid argon energy response to nuclear and electronic recoils
Creators: name: (:Unkn) Unknown
Publisher: name: My University
Year: 2018
Subjects: physics.ins-det
hep-ex

description: © 2018 American Physical Society. A liquid argon time projection chamber, constructed for the Argon Response to Ionization and Scintillation (ARIS) experiment, is exposed to the highly collimated and quasimonoenergetic LICORNE neutron beam at the Institut de Physique Nucléaire d’Orsay (IPNO) in order to study the scintillation response to nuclear and electronic recoils. An array of liquid scintillator detectors, arranged around the apparatus, tag scattered neutrons and select nuclear recoil energies in the [7, 120] keV energy range. The relative scintillation efficiency of nuclear recoils is measured to high precision at null field, and the ion-electron recombination probability is extracted for a range of applied electric fields. Single-scattered Compton electrons, produced by gammas emitted from the deexcitation of 7Li in coincidence with the beam pulse, along with calibration gamma sources, are used to extract the recombination probability as a function of energy and electron drift field. The ARIS results are compared with three recombination probability parametrizations (Thomas-Imel, Doke-Birks, and Paris), allowing for the definition of a fully comprehensive model of the liquid argon response to nuclear and electronic recoils down to the few-keV range. The constraints provided by ARIS to the liquid argon response at low energy allow the reduction of systematics affecting the sensitivity of dark matter search experiments based on liquid argon.
On mass spectrum in 't Hooft's 2D model of mesons
Creators: name: Fateev, V. A.
name: Lukyanov, S. L.
name: Zamolodchikov, A. B.
Publisher: name: arXiv
Year: 2009
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We study 't Hooft's integral equation determining the meson masses M_n in multicolor QCD_2. In this note we concentrate on developing an analytic method, and restrict our attention to the special case of quark masses m_1=m_2=g/\sqrtπ. Among our results is systematic large-n expansion, and exact sum rules for M_n. Although we explicitly discuss only the special case, the method applies to the general case of the quark masses, and we announce some preliminary results for m_1=m_2.
description: 26 pages, 4 figures; v2: refs added, typos corrected
Eleotris perniger
Creators: name: Walsh, Stephen J.
name: Prosanta Chakrabarty
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Actinopterygii
Perciformes
Eleotridae
Eleotris
Eleotris perniger

description: Eleotris perniger: LSUMZ 14540, 8, Honduras, Departamento de Atla'ntida, Cureo River mouth, Refugio de Vida Silvestre, 9 January 2011; UF 27603, 34 (2 CS), Panama, Kuna Yala Province, creek 0.5 mi N of Puerto Obaldia, 4 May 1965.
description: Published as part of Stephen J. Walsh & Prosanta Chakrabarty, 2016, A New Genus and Species of Blind Sleeper (Teleostei: Eleotridae) from Oaxaca, Mexico: First Obligate Cave Gobiiform in the Western Hemisphere, pp. 506-517 in Copeia 104 (2) on page 515, DOI: 10.1643/CI-15-275, http://zenodo.org/record/269586
Korn inequalities for shells with zero Gaussian curvature
Creators: name: (:Unkn) Unknown
Publisher: name: My University
Year: 2018
Subjects: Korn's inequality
Shells
Nonlinear elasticity
Cones
Cylinders

description: © 2017 Elsevier Masson SAS We consider shells with zero Gaussian curvature, namely shells with one principal curvature zero and the other one having a constant sign. Our particular interests are shells that are diffeomorphic to a circular cylindrical shell with zero principal longitudinal curvature and positive circumferential curvature, including, for example, cylindrical and conical shells with arbitrary convex cross sections. We prove that the best constant in the first Korn inequality scales like thickness to the power 3/2 for a wide range of boundary conditions at the thin edges of the shell. Our methodology is to prove, for each of the three mutually orthogonal two-dimensional cross-sections of the shell, a “first-and-a-half Korn inequality”—a hybrid between the classical first and second Korn inequalities. These three two-dimensional inequalities assemble into a three-dimensional one, which, in turn, implies the asymptotically sharp first Korn inequality for the shell. This work is a part of mathematically rigorous analysis of extreme sensitivity of the buckling load of axially compressed cylindrical shells to shape imperfections.
A Spectral Graph Approach to Discovering Genetic Ancestry
Creators: name: Lee, Ann B.
name: Luca, Diana
name: Roeder, Kathryn
Publisher: name: arXiv
Year: 2009
Subjects: subject: Applications (stat.AP)
subject: FOS: Computer and information sciences

description: Mapping human genetic variation is fundamentally interesting in fields such as anthropology and forensic inference. At the same time patterns of genetic diversity confound efforts to determine the genetic basis of complex disease. Due to technological advances it is now possible to measure hundreds of thousands of genetic variants per individual across the genome. Principal component analysis (PCA) is routinely used to summarize the genetic similarity between subjects. The eigenvectors are interpreted as dimensions of ancestry. We build on this idea using a spectral graph approach. In the process we draw on connections between multidimensional scaling and spectral kernel methods. Our approach, based on a spectral embedding derived from the normalized Laplacian of a graph, can produce more meaningful delineation of ancestry than by using PCA. The method is stable to outliers and can more easily incorporate different similarity measures of genetic data than PCA. We illustrate a new algorithm for genetic clustering and association analysis on a large, genetically heterogeneous sample.
description: 6 figures
Hyperbolic extensions of free groups
Creators: name: (:Unkn) Unknown
Publisher: name: My University
Year: 2018
Subjects: math.GT
math.GR

description: © 2018, Mathematical Sciences Publishers. All rights reserved. Given a finitely generated subgroup Γ≤Out(F) of the outer automorphism group of the rank-r free group F = Fr, there is a corresponding free group extension 1→F→EΓ→Γ→1. We give sufficient conditions for when the extension EΓ is hyperbolic. In particular, we show that if all infinite-order elements of Γ are atoroidal and the action of Γ on the free factor complex of F has a quasi-isometric orbit map, then EΓ is hyperbolic. As an application, we produce examples of hyperbolic F-extensions EΓ for which Γ has torsion and is not virtually cyclic. The proof of our main theorem involves a detailed study of quasigeodesics in Outer space that make progress in the free factor complex. This may be of independent interest.
The Cepheid Period-Luminosity Relation at Mid-Infrared Wavelengths: II. Second-Epoch LMC Data
Creators: name: Madore, Barry F.
name: Freedman, Wendy L.
name: Rigby, Jane
name: Persson, S. E.
name: Sturch, Laura
name: Major, Violet
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We present revised and improved mid-infrared Period-Luminosity (PL) relations for Large Magellanic Cloud (LMC) Cepheids based on double-epoch data of 70 Cepheids observed by Spitzer at 3.6, 4.5, 5.8 and 8.0um. The observed scatter at all wavelengths is found to decrease from +/-0.17 mag to +/-0.14 mag, which is fully consistent with the prediction that the total scatter is made up of roughly equal contributions from random sampling of the light curve and nearly-uniform samplings of stars across the instability strip. It is calculated that the Cepheids in this sample have a full amplitude of about 0.4 mag and that their fully-sampled, time-averaged magnitudes should eventually reveal mid-infrared PL relations that each have intrinsic scatter at most at the +/-0.12 mag level, and as low as +/-0.08 mag after correcting for the tilt of the LMC.
description: 7 pages, 6 figures, 1 data table
Normal-state electrical resistivity and superconducting magnetic penetration depth in Eu0.5K0.5Fe2As2
Creators: name: Gasparov, V. A.
name: Jeevan, H. S.
name: Gegenwart, P.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We report measurements of the temperature dependence of the electrical resistivity, ρ(T), and magnetic penetration depth, λ(T), for polycrystalline samples of Eu_0.5K_0.5Fe_2As_2 with Tc=31 K. $ρ(T)$ follows a linear temperature dependence above T_c and bends over to a weaker temperature dependence around 150 K. The magnetic penetration depth, determined by radio frequency technique displays an unusual minimum around 4 K which is associated with short-range ordering of localized Eu3+ moments.
description: 7 pages 4 figures
Public Transport Networks under Random Failure and Directed Attack
Creators: name: Berche, Bertrand
name: von Ferber, Christian
name: Holovatch, Taras
name: Holovatch, Yurij
Publisher: name: arXiv
Year: 2010
Subjects: subject: Physics and Society (physics.soc-ph)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: FOS: Physical sciences

description: The behaviour of complex networks under failure or attack depends strongly on the specific scenario. Of special interest are scale-free networks, which are usually seen as robust under random failure but appear to be especially vulnerable to targeted attacks. In a recent study of public transport networks of 14 major cities of the world we have shown that these systems when represented by appropriate graphs may exhibit scale-free behaviour. In this paper we briefly review some of the recent results about the effects that defunct or removed nodes have on the properties of public transport networks. Simulating different directed attack strategies, we derive vulnerability criteria that result in minimal strategies with high impact on these systems.
description: An invited lecture given at the Workshop 'NET 2009: evolution and complexity' (Rome, May 28th-30th, 2009)
Erotelis smaragdus subsp. civitatum
Creators: name: Walsh, Stephen J.
name: Prosanta Chakrabarty
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Actinopterygii
Perciformes
Eleotridae
Erotelis
Erotelis smaragdus
Erotelis smaragdus civitatum

description: Erotelis smaragdus civitatum: LSUMZ 4475, 2, Louisiana, Jefferson Parish, Bay Macoin, 9 July 1973.
description: Published as part of Stephen J. Walsh & Prosanta Chakrabarty, 2016, A New Genus and Species of Blind Sleeper (Teleostei: Eleotridae) from Oaxaca, Mexico: First Obligate Cave Gobiiform in the Western Hemisphere, pp. 506-517 in Copeia 104 (2) on page 515, DOI: 10.1643/CI-15-275, http://zenodo.org/record/269586
Modified Chaplygin Gas and Constraints on its B parameter from CDM and UDME Cosmological models
Creators: name: Thakur, P.
name: Ghose, S.
name: Paul, B. C.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We study Modified Chaplygin Gas (MCG) as a candidate for dark energy and predict the values of parameters of the gas for a physically viable cosmological model. The equation of state of MCG ($p=B ρ- \frac {A}{ρ^α} $) involves three parameters: $B$, $A$ and $α$. The permitted values of these parameters are determined with the help of dimensionless age parameter ($H_{o}t_{o}$) and $H(z)-z$ Data. Specifically we study the allowed ranges of values of B parameter in terms of $α$ and $A_{s}$ ($A_{s}$ is defined in terms of the constants in the theory). We explore the constraints of the parameters in Cold Dark Matter(CDM) model and UDME(Unified Dark Matter Energy) model respectively.
description: 5 pages, 10 figs
Gobiomorus dormitor
Creators: name: Walsh, Stephen J.
name: Prosanta Chakrabarty
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy

description: Gobiomorus dormitor: LSUMZ 15003, 1, Honduras, Departamento de Colon, Barra Sico, Laguna Bacalar, 28 November 2010; UF 27515, 20 (1 CS), Panama, Canal Zone, Gatun Lake, Frijoles Landing, 26 April 1965.
description: Published as part of Stephen J. Walsh & Prosanta Chakrabarty, 2016, A New Genus and Species of Blind Sleeper (Teleostei: Eleotridae) from Oaxaca, Mexico: First Obligate Cave Gobiiform in the Western Hemisphere, pp. 506-517 in Copeia 104 (2) on page 515, DOI: 10.1643/CI-15-275, http://zenodo.org/record/269586
Fiji's New Parliament and Democracy
Creators: name: Kumar, Avinash
Publisher: name: Canberra, ACT : Coral Bell School of Asia Pacific Affairs, College of Asia and the Pacific, The Australian National University
Year: 2016

description: Parliaments play a crucial role in enhancing democracy, especially in countries that are transitioning from an authoritarian regime to a democratic system. Parliaments are perhaps more important for these countries because they have the potential to pioneer and embrace political change towards democracy (Ziegenhain 2008). In Fiji, the 2014 election and the subsequent return of the parliament were hailed as a positive step towards the restoration of democracy. More importantly, simply by returning, Fiji’s parliament vindicated itself as a resilient institution that has the potential to survive against the odds (Kumar 2012). However, the re-emergence of the parliament has provided evidence both for and against the view that Fiji is on the road back to democracy. This In Brief explicates the two positions by assessing a few key developments in Fiji’s new parliament.
Growth and feeding of deep-sea coral Lophelia pertusa from the California margin under simulated ocean acidification conditions
Creators: name: (:Unkn) Unknown
Publisher: name: My University
Year: 2018
Subjects: Deep-sea
Carbonate saturation
Climate change
Ocean acidification

description: Copyright 2018 Gómez et al. The global decrease in seawater pH known as ocean acidification has important ecological consequences and is an imminent threat for numerous marine organisms. Even though the deep sea is generally considered to be a stable environment, it can be dynamic and vulnerable to anthropogenic disturbances including increasing temperature, deoxygenation, ocean acidification and pollution. Lophelia pertusa is among the better-studied cold-water corals but was only recently documented along the US West Coast, growing in acidified conditions. In the present study, coral fragments were collected at ∼300 m depth along the southern California margin and kept in recirculating tanks simulating conditions normally found in the natural environment for this species. At the collection site, waters exhibited persistently low pH and aragonite saturation states (Ωarag) with average values for pH of 7.66 ± 0.01 and Ωarag of 0.81 ± 0.07. In the laboratory, fragments were grown for three weeks in "favorable" pH/Ωarag of 7.9/1.47 (aragonite saturated) and ‘‘unfavorable’’ pH/Ωarag of 7.6/0.84 (aragonite undersaturated) conditions. There was a highly significant treatment effect (P < 0.001) with an average% net calcification for favorable conditions of 0.023 ± 0.009% d−1 and net dissolution of −0.010 ± 0.014% d-1 for unfavorable conditions. We did not find any treatment effect on feeding rates, which suggests that corals did not depress feeding in low pH/Ωarag in an attempt to conserve energy. However, these results suggest that the suboptimal conditions for L. pertusa from the California margin could potentially threaten the persistence of this cold-water coral with negative consequences for the future stability of this already fragile ecosystem.
A study on a dielectric loaded resonant linear electron accelerator
Creators: name: Creelman, Allan
Publisher: name: University of British Columbia
Year: 2011

description: The pre-accelerator and the dielectric loaded slow-wave structure are examined in detail. The fields in the pre-accelerator are expressed as an infinite series which converges rapidly. It was found that by considering only the first term of the series, good results were obtained for the stored energy, the power dissipated and the cavity Q. Low power tests on the pre-accelerator gave confirmation of theoretical calculations. The fields in the dielectric loaded slow-wave structure were determined experimentally by means of a perturbation method. The results compare favourably with previous theoretical work. An electron beam was introduced into the pre-accelerator cavity using a 2 KV electron gun and measurements were made of the gain in electron energy. Peak microwave power levels of up to 0.19 MW were used and electron energies up to 340 KEV were obtained. It was concluded that the pre-accelerator can provide adequate initial conditions for the capture of electrons in the main accelerator.
Feasibility of muscle synergy outcomes in clinics, robotics, and sports: A systematic review
Creators: name: (:Unkn) Unknown
Publisher: name: My University
Year: 2018
Subjects: subject: 1109 Neurosciences
subject: Brain Disorders
subject: Neurosciences
subject: FOS: Clinical medicine

description: Copyright © 2018 Juri Taborri et al. In the last years, several studies have been focused on understanding how the central nervous system controls muscles to perform a specific motor task. Although it still remains an open question, muscle synergies have come to be an appealing theory to explain the modular organization of the central nervous system. Even though the neural encoding of muscle synergies remains controversial, a large number of papers demonstrated that muscle synergies are robust across different tested conditions, which are within a day, between days, within a single subject, and between subjects that have similar demographic characteristics. Thus, muscle synergy theory has been largely used in several research fields, such as clinics, robotics, and sports. The present systematical review aims at providing an overview on the applications of muscle synergy theory in clinics, robotics, and sports; in particular, the review is focused on the papers that provide tangible information for (i) diagnosis or pathology assessment in clinics, (ii) robot-control design in robotics, and (iii) athletes' performance assessment or training guidelines in sports.
Tuned Finite-Difference Diffusion Operators
Creators: name: Maron, Jason
name: Mac Low, Mordecai-Mark
Publisher: name: arXiv
Year: 2008
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: Finite-difference simulations of fluid dynamics and magnetohydrodynamics generally require an explicit diffusion operator, either to maintain stability by attenuating grid-scale structure, or to implement physical diffusivities such as viscosity or resistivity. If the goal is stability only, the diffusion must act at the grid scale, but should affect structure at larger scales as little as possible. For physical diffusivities the diffusion scale depends on the problem, and diffusion may act at larger scales as well. Diffusivity undesirably limits the computational timestep in both cases. We construct tuned finite-difference diffusion operators that minimally limit the timestep while acting as desired near the diffusion scale. Such operators reach peak values at the diffusion scale rather than at the grid scale, but behave as standard operators at larger scales. We focus on the specific applications of hyperdiffusivity for numerical stabilization, and high Schmidt and high Prandtl number simulations where the diffusion scale greatly exceeds the grid scale.
description: 13 pages, 3 figures
Stellar populations of Virgo cluster early-type dwarf galaxies with and without discs: a dichotomy in age?
Creators: name: Paudel, S.
name: Lisker, T.
name: Kuntschner, H.
name: Grebel, E.
name: Glatt, K.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: [Abridged] Using VLT/FORS2 spectroscopy, we have studied the properties of the central stellar populations of a sample of 38 nucleated early-type dwarf (dE) galaxies in the Virgo Cluster. We find that these galaxies do not exhibit the same average stellar population characteristics for different morphological subclasses. The nucleated galaxies without discs are older and more metal poor than the dEs with discs . The alpha-element abundance ratio appears consistent with the solar value for both morphological types. Besides a well-defined relation of metallicity and luminosity, we also find a clear anti-correlation between age and luminosity. More specifically, there appears to be a bimodality: brighter galaxies, including the discy ones, exhibit significantly younger ages than fainter dEs. Therefore, it appears less likely that fainter and brighter dEs have experienced the same evolutionary history, as the well-established trend of decreasing average stellar age when going from the most luminous ellipticals towards low-luminosity Es and bright dEs is broken here. The older and more metal-poor dEs could have had an early termination of star formation activity, possibly being "primordial" galaxies in the sense that they have formed along with the protocluster or experienced very early infall. By contrast, the younger and relatively metal-rich brighter dEs, most of which have discs, might have undergone structural transformation of infalling disc galaxies.
description: Accepted by MNRAS; 22 pages, 20 figures
Giornata di studi - Dottorato in Storia, culture e politiche del globale
Creators: name: Alexandropoulos, Alexandros
name: Bassetto, Elisa
name: Bonasera, Jacopo
name: Guerini, Anna
name: Lovotti, Chiara
name: Menditto, Pasquale
name: Pizzirani, Silvia
name: Proserpio, Licia
Publisher: name: Alma Mater Studiorum - Università di Bologna
Year: 2019
Subjects: M-DEA/01 Discipline demoetnoantropologiche
M-STO/04 Storia contemporanea
SPS/01 Filosofia politica
SPS/02 Storia delle dottrine politiche
SPS/14 Storia e istituzioni dell'Asia

description: La Giornata di studi è un incontro organizzato all'interno del Dottorato di ricerca in Storia, culture e politiche del globale, corso di dottorato interdipartimentale del Dipartimento di Storia Culture Civiltà (DiSCi) e del Dipartimento di Scienze Politiche e Sociali (SPS). L'occasione è utile ai/alle dottorandi/e del primo anno di corso per discutere i primi progressi della ricerca dottorale con un/a esperto/a del proprio campo di studi. Giunto alla sue seconda edizione, l'incontro si è tenuto l'8-9 maggio 2019 preso l'aula Gambi del DiSCi.
A transistorized spherical polarcardiograph
Creators: name: Harding, Patrick John Ronald
Publisher: name: University of British Columbia
Year: 2011

description: The design of a two-dimensional polarcardiograph and the use of two such two-dimensional devices to calculate the third polar coordinate together with the circuitry necessary to derive and amplify a set of voltages proportional to the Cartesian coordinates x, y, and z is described. Although the technique used for obtaining the polar coordinates is similar to that used in other instruments, the circuitry is somewhat different. This is dictated in part by the fact that this device is completely transistorized. Both the Frank and RAFE networks are available for the transformation from patient signals to a set of signals proportional to the Cartesian coordinates x, y, and z. Restoration of the base-line at the optimum time during the cardiac cycle is achieved through a system of gated feedback which is activated by a predictor circuit. The predictor is triggered by an automatic trigger selector. A threshold circuit is associated with each angle output in order to set the output to some predetermined value when the input signal level is so small as to make the angle output indeterminate.
Exploring functional pairing between surface glycoconjugates and human galectins using programmable glycodendrimersomes
Creators: name: (:Unkn) Unknown
Publisher: name: My University
Year: 2018
Subjects: glycodendrimers
glycolipids
aggregation

description: © 2018 National Academy of Sciences. All Rights Reserved. Precise translation of glycan-encoded information into cellular activity depends critically on highly specific functional pairing between glycans and their human lectin counter receptors. Sulfo-glycolipids, such as sulfatides, are important glycolipid components of the biological membranes found in the nervous and immune systems. The optimal molecular and spatial design aspects of sulfated and nonsulfated glycans with high specificity for lectin-mediated bridging are unknown. To elucidate how different molecular and spatial aspects combine to ensure the high specificity of lectin-mediated bridging, a bottom-up toolbox is devised. To this end, negatively surface-charged glycodendrimersomes (GDSs), of different nanoscale dimensions, containing sulfo-lactose groups are self-assembled in buffer from a synthetic sulfatide mimic: Janus glycodendrimer (JGD) containing a 3′-O-sulfo-lactose headgroup. Also prepared for comparative analysis are GDSs with nonsulfated lactose, a common epitope of human membranes. These self-assembled GDSs are employed in aggregation assays with 15 galectins, comprising disease-related human galectins, and other natural and engineered variants from four families, having homodimeric, heterodimeric, and chimera architectures. There are pronounced differences in aggregation capacity between human homodimeric and heterodimeric galectins, and also with respect to their responsiveness to the charge of carbohydrate-derived ligand. Assays reveal strong differential impact of ligand surface charge and density, as well as lectin concentration and structure, on the extent of surface cross-linking. These findings demonstrate how synthetic JGD-headgroup tailoring teamed with protein engineering and network assays can help explain how molecular matchmaking operates in the cellular context of glycan and lectin complexity.
Gobiomorus maculatus
Creators: name: Walsh, Stephen J.
name: Prosanta Chakrabarty
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Actinopterygii
Perciformes
Eleotridae
Gobiomorus
Gobiomorus maculatus

description: Gobiomorus maculatus: UF 19619, 1 CS, Costa Rica, Puntarenas Province, tidal stream of estuary at Quepos, 2 July 1973.
description: Published as part of Stephen J. Walsh & Prosanta Chakrabarty, 2016, A New Genus and Species of Blind Sleeper (Teleostei: Eleotridae) from Oaxaca, Mexico: First Obligate Cave Gobiiform in the Western Hemisphere, pp. 506-517 in Copeia 104 (2) on page 515, DOI: 10.1643/CI-15-275, http://zenodo.org/record/269586
PIC simulations of the Thermal Anisotropy-Driven Weibel Instability: Field growth and phase space evolution upon saturation
Creators: name: Stockem, A
name: Dieckmann, M E
name: Schlickeiser, R
Publisher: name: arXiv
Year: 2009
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The Weibel instability is investigated with PIC simulations of an initially unmagnetized and spatially uniform electron plasma. This instability, which is driven by the thermally anisotropic electron distribution, generates electromagnetic waves with wave vectors perpendicular to the direction of the higher temperature. Two simulations are performed: A 2D simulation, with a simulation plane that includes the direction of higher temperature, demonstrates that the wave spectrum is initially confined to one dimension. The electric field components in the simulation plane generated by the instability equalize at the end of the simulation through a secondary instability. A 1D PIC simulation with a high resolution, where the simulation box is aligned with the wave vectors of the growing waves, reveals details of the electron phase space distribution and permits a comparison of the magnetic and electric fields when the instability saturates. It is shown that the electrostatic field is driven by the magnetic pressure gradient and that it and the magnetic field redistribute the electrons in space.
description: Plasma Phys Controll Fusion, in press (to appear in june 2009)
Revolution in the theater of war: drones, consumer technology and open source intelligence as forces of change in modern warfare
Creators: name: Schmidt, Christian Thorge
Publisher: name: Zenodo
Year: 2023

description: In today's era of warfare, we are witnessing a profound transformation driven by the influence of modern technologies. This paper examines how drones, consumer technology and open source intelligence have revolutionized and in many cases rendered traditional warfare strategies obsolete. Rather than relying solely on specialized military technology, modern armed forces are increasingly turning to more cost-effective, accessible and technologically advanced consumer technologies. This development has not only fundamentally changed the way wars are fought, but has also led to a massive shift in cost structures. Mass and availability have become more important, with flimsy, off-the-shelf technologies being used alongside traditional military technology.
Evaluation of global HIV/SIV envelope gp120 RNA structure and evolution within and among infected hosts
Creators: name: (:Unkn) Unknown
Publisher: name: My University
Year: 2018
Subjects: HIV
SIV
RNA structure
evolution
SHAPE
phylogenetics

description: Lentiviral RNA genomes contain structural elements that play critical roles in viral replication. Although structural features of 5'-untranslated regions have been well characterized, attempts to identify important structures in other genomic regions by Selective 2'-Hydroxyl Acylation analyzed by Primer Extension (SHAPE) have led to conflicting structural and mechanistic conclusions. Previous approaches accounted neither for sequence heterogeneity that is ubiquitous in viral populations, nor for selective constraints operating at the protein level. We developed an approach that augments SHAPE with phylogenetic analyses and applied it to investigate structure in coding regions (cRNA) within the HIV and SIV envelope genes. Analysis of single-genome SHAPE data with phylogenetic information from diverse lentiviral sequences argues against the conservation of a putative global gp120 RNA structure but points to the existence of core RNA sub-structures. Our findings establish a framework for considering sequence heterogeneity and protein function in de novo RNA structure inference approaches.
Crystal structures of two 1,3-thiazolidin-4-one derivatives featuring sulfide and sulfone functional groups
Creators: name: (:Unkn) Unknown
Publisher: name: My University
Year: 2018
Subjects: chair conformation
crystal structure
envelope pucker
thia­zolidin-4-one
thia­zolidinone

description: © 2018 International Union of Crystallography. All rights reserved. The crystal structures of two closely related compounds, 1-cyclohexyl-2-(2-nitrophenyl)-1,3-thiazolidin-4-one, C15H18N2O3S, (1) and 1-cyclohexyl-2-(2-nitrophenyl)-1,3-thiazolidin-4-one 1,1-dioxide, C15H18N2O5S, (2), are presented. These compounds are comprised of three types of rings: thiazolidinone, nitrophenyl and cyclohexyl. In both structures, the rings are close to mutually perpendicular, with interplanar dihedral angles greater than 80° in each case. The thiazolidinone rings in both structures exhibit envelope puckering with the S atom as flap and the cyclohexyl rings are in their expected chair conformations. The two structures superpose fairly well, except for the orientation of the nitro groups with respect to their host phenyl ring, with a difference of about 10° between 1 and 2. The extended structure of 1 has two kinds of weak C - H⋯O interactions, giving rise to a closed ring formation involving three symmetry-related molecules. Structure 2 has four C - H⋯O interactions, two of which are exclusively between symmetry-related thiazolidinone dioxide moieties and have a parallel 'give-and-take-fashion' counterpart. In the other two interactions, the nitrophenyl ring and the cyclohexane ring each offer an H atom to the two O atoms on the sulfone group. Additionally, a C - H⋯π interaction between a C - H group of the cyclohexane ring and the nitrophenyl ring of an adjacent molecule helps to consolidate the structure.
Stochastic Quantum Molecular Dynamics
Creators: name: Appel, Heiko
name: Di Ventra, Massimiliano
Publisher: name: arXiv
Year: 2009
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: An approach to correlated dynamics of quantum nuclei and electrons both in dynamical interaction with external environments is presented. This stochastic quantum molecular dynamics rests on a theorem that establishes a one-to-one correspondence between the total ensemble-averaged current density of interacting nuclei and electrons and a given external vector potential. The theory allows for a first-principles description of phenomena previously inaccessible via standard quantum molecular dynamics such as electronic and nuclear relaxation in photochemistry, dissipative correlated electron-ion dynamics in intense laser fields, nuclear dephasing, etc. As a demonstration of the approach, we discuss the rotational relaxation of 4-(N,N-dimethylamino)benzonitrile in a uniform bath in the limit of classical nuclei.
description: 4 pages, 1 figure
Plancton y la fórmula secreta: efectos de los parámetros fisicoquímicos en comunidades planctónicas en el ecosistema de manglar de Las Lisas, Santa Rosa, Guatemala.
Creators: name: Forkel-Borrayo, Franz
name: Juárez, Glenda Sofía Díaz
name: Monterroso-Molina, Adriana Sofía
name: Gatica, Gerardo
Publisher: name: Zenodo
Year: 2023
Subjects: camaronera
copépodos
diatomeas
dinoflagelados
fosfatos
nitratos
turbidez

description: Reporte realizado por estudiantes de la Universidad del Valle sobre los efectos de distintos parámetros fisicoquímicos en las comunidades de plancton en ecosistemas de manglares en Las Lisas, Guatemala. Se incluye material adicional como la base de datos, el código para R Studio y gráficos adicionales.
Non-Equipartition of Energy, Masses of Nova Ejecta, and Type Ia Supernovae
Creators: name: Shara, Michael M.
name: Yaron, Ofer
name: Prialnik, Dina
name: Kovetz, Attay
Publisher: name: arXiv
Year: 2010
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The total masses ejected during classical nova eruptions are needed to answer two questions with broad astrophysical implications: Can accreting white dwarfs be pushed towards the Chandrasekhar mass limit to yield type Ia supernovae? Are Ultra-luminous red variables a new kind of astrophysical phenomenon, or merely extreme classical novae? We review the methods used to determine nova ejecta masses. Except for the unique case of BT Mon (nova 1939), all nova ejecta mass determinations depend on untested assumptions and multi-parameter modeling. The remarkably simple assumption of equipartition between kinetic and radiated energy (E_kin and E_rad, respectively) in nova ejecta has been invoked as a way around this conundrum for the ultra-luminous red variable in M31. The deduced mass is far larger than that produced by any classical nova model. Our nova eruption simulations show that radiation and kinetic energy in nova ejecta are very far from being in energy equipartition, with variations of four orders of magnitude in the ratio E_kin/E_rad being commonplace. The assumption of equipartition must not be used to deduce nova ejecta masses; any such "determinations" can be overestimates by a factor of up to 10,000. We data-mined our extensive series of nova simulations to search for correlations that could yield nova ejecta masses. Remarkably, the mass ejected during a nova eruption is dependent only on (and is directly proportional to) E_rad. If we measure the distance to an erupting nova and its bolometric light curve then E_rad and hence the mass ejected can be directly measured.
description: 9 pages, 4 figures, awaiting publication in ApJL
Crystal structures of sodium-, lithium-, and ammonium 4,5-dihydroxybenzene-1,3-disulfonate (tiron) hydrates
Creators: name: (:Unkn) Unknown
Publisher: name: My University
Year: 2018
Subjects: bioinorganic
catechol
crystal structure
metal organic framework
sodium channel

description: © Herbst-Gervasoni et al. 2018. The solid-state structures of the Na+, Li+, and NH4+ salts of the 4,5-dihydroxybenzene-1,3-disulfonate (tiron) dianion are reported, namely disodium 4,5-dihydroxybenzene-1,3-disulfonate, 2Na+·C6H4O8S22-, μ-4,5-dihydroxybenzene-1,3-disulfonato-bis[aqualithium(I)] hemihydrate, [Li2(C6H4O8S2)(H2O)2]·0.5H2O, and diammonium 4,5-dihydroxybenzene-1,3-disulfonate monohydrate, 2NH4+·C6H4O8S22-·H2O. Intermolecular interactions vary with the size of the cation, and the asymmetric unit cell, and the macromolecular features are also affected. The sodium in Na2(tiron) is coordinated in a distorted octahedral environment through the sulfonate oxygen and hydroxyl oxygen donors on tiron, as well as an interstitial water molecule. Lithium, with its smaller ionic radius, is coordinated in a distorted tetrahedral environment by sulfonic and phenolic O atoms, as well as water in Li2(tiron). The surrounding tiron anions coordinating to sodium or lithium in Na2(tiron) and Li2(tiron), respectively, result in a three-dimensional network held together by the coordinate bonds to the alkali metal cations. The formation of such a three-dimensional network for tiron salts is relatively rare and has not been observed with monovalent cations. Finally, (NH4)2(tiron) exhibits extensive hydrogen-bonding arrays between NH4+ and the surrounding tiron anions and interstitial water molecules. This series of structures may be valuable for understanding charge transfer in a putative solid-state fuel cell utilizing tiron.
A multi-mode microwave cavity resonator
Creators: name: Fall, Stewart Temple
Publisher: name: University of British Columbia
Year: 2011

description: Most multi-mode microwave cavity filters exhibit insertion-loss characteristics which deviate widely from the theoretical responses on the low frequency side of the passband. This paper describes an X-band three-mode filter which inherently overcomes the primary cause of the response discrepancy. The design includes a method of identification of the field configurations within the cavity and a method of relating the coupling produced between two degenerate modes of resonance by a probe to the relative frequency shift caused by the probe. A simple method of measuring insertion loss is shown, and both theoretical and measured insertion loss characteristics are recorded for three bandwidths, 7.4 mc/s, 10.0 mc/s, and 13.6 mc/s, all of which show no extreme discrepancy between the theoretical and measured responses.
Adaptive landscape of protein variation in human exomes
Creators: name: (:Unkn) Unknown
Publisher: name: My University
Year: 2018
Subjects: adaptation
evolution
missense

description: © The Author(s) 2018. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. The human genome contains hundreds of thousands of missense mutations. However, only a handful of these variants are known to be adaptive, which implies that adaptation through protein sequence change is an extremely rare phenomenon in human evolution. Alternatively, existing methods may lack the power to pinpoint adaptive variation. We have developed and applied an Evolutionary Probability Approach (EPA) to discover candidate adaptive polymorphisms (CAPs) through the discordance between allelic evolutionary probabilities and their observed frequencies in human populations. EPA reveals thousands of missense CAPs, which suggest that a large number of previously optimal alleles experienced a reversal of fortune in the human lineage. We explored nonadaptive mechanisms to explain CAPs, including the effects of demography, mutation rate variability, and negative and positive selective pressures in modern humans. Many nonadaptive hypotheses were tested, but failed to explain the data, which suggests that a large proportion of CAP alleles have increased in frequency due to beneficial selection. This suggestion is supported by the fact that a vast majority of adaptive missense variants discovered previously in humans are CAPs, and hundreds of CAP alleles are protective in genotype-phenotype association data. Our integrated phylogenomic and population genetic EPA approach predicts the existence of thousands of nonneutral candidate variants in the human proteome. We expect this collection to be enriched in beneficial variation. The EPA approach can be applied to discover candidate adaptive variation in any protein, population, or species for which allele frequency data and reliable multispecies alignments are available.
Measurement of the helicity asymmetry e in ω→π+π-π0 photoproduction
Creators: name: (:Unkn) Unknown
Publisher: name: My University
Year: 2017
Subjects: nucl-ex
hep-ex

description: © 2017 American Physical Society. The double-polarization observable E was studied for the reaction γp→pω using the CEBAF Large Acceptance Spectrometer (CLAS) in Hall B at the Thomas Jefferson National Accelerator Facility and the longitudinally polarized frozen-spin target (FROST). The observable was measured from the charged decay mode of the meson, ω→π+π-π0, using a circularly polarized tagged-photon beam with energies ranging from the ω threshold at 1.1 to 2.3 GeV. A partial-wave analysis within the Bonn-Gatchina framework found dominant contributions from the 3/2+ partial wave near threshold, which is identified with the subthreshold N(1720)3/2+ nucleon resonance. To describe the entire data set, which consisted of ω differential cross sections and a large variety of polarization observables, further contributions from other nucleon resonances were found to be necessary. With respect to nonresonant mechanisms, π exchange in the t channel was found to remain small across the analyzed energy range, while Pomeron t-channel exchange gradually grew from the reaction threshold to dominate all other contributions above W≈2 GeV.
Particle emission from a black hole on a tense codimension-2 brane
Creators: name: al-Binni, Usama A.
name: Siopsis, George
Publisher: name: arXiv
Year: 2009
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We calculate analytically grey-body factors of Schwarzschild black-holes localized on a 3-brane of finite tension and codimension 2. We obtain explicit expressions for various types of particles emitted in the bulk as well as on the brane in both the low and high frequency regimes. In the latter case, we obtain expressions which are valid for arbitrary number of extra dimensions if the brane tension vanishes.
description: 35 pages incl. 13 figures, added/corrected references
Guidance and Self-Sorting of Active Swimmers: 3D Periodic Arrays Increase Persistence Length of Human Sperm Selecting for the Fittest
Creators: name: (:Unkn) Unknown
Publisher: name: My University
Year: 2018
Subjects: fertility
multiparticle collision dynamics
multiscale simulations
persistence length
sperm sorting

description: © 2017 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Male infertility is a reproductive disease, and existing clinical solutions for this condition often involve long and cumbersome sperm sorting methods, including preprocessing and centrifugation-based steps. These methods also fall short when sorting for sperm free of reactive oxygen species, DNA damage, and epigenetic aberrations. Although several microfluidic platforms exist, they suffer from structural complexities, i.e., pumps or chemoattractants, setting insurmountable barriers to clinical adoption. Inspired by the natural filter-like capabilities of the female reproductive tract for sperm selection, a model-driven design, featuring pillar arrays that efficiently and noninvasively isolate highly motile and morphologically normal sperm, with lower epigenetic global methylation, from raw semen, is presented. The Simple Periodic ARray for Trapping And isolatioN (SPARTAN) created here modulates the directional persistence of sperm, increasing the spatial separation between progressive and nonprogressive motile sperm populations within an unprecedentedly short 10 min assay time. With over 99% motility of sorted sperm, a 5-fold improvement in morphology, 3-fold increase in nuclear maturity, and 2–4-fold enhancement in DNA integrity, SPARTAN offers to standardize sperm selection while eliminating operator-to-operator variations, centrifugation, and flow. SPARTAN can also be applied in other areas, including conservation ecology, breeding of farm animals, and design of flagellar microrobots for diagnostics.
Probing non-universal gaugino masses via Higgs boson production under SUSY cascades at the LHC: A detailed study
Creators: name: Bandyopadhyay, Priyotosh
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Cascade decays of Supersymmetric (SUSY) particles are likely to be prolific sources of Higgs bosons at the Large Hadron Collider (LHC). In this work, we explore, with the help of detailed simulation, the role of non-universal gaugino masses in the production of the Higgs bosons under SUSY cascades. The analysis is carried out by choosing an appropriate set of benchmark points with non-universal gaugino masses in the relevant SUSY parameter space and then contrasting the resulting observations with the corresponding cases having universal relationship among the same. It is shown that even of data at an early phase of the LHC-run with 10 fb$^{-1}$ one would be able to see, under favourable situations, the imprint of non-universal gaugino masses by reconstructing various Higgs boson resonances and comparing their rates. With increased accumulated luminosities, the indications would naturally become distinct over a larger region of the parameter space.
description: 48 pages
Planar Metamaterials for Antireflection Coating
Creators: name: Chen, H. -T.
name: Zhou, J.
name: O'Hara, J. F.
name: Chen, F.
name: Azad, A. K.
name: Taylor, A. J.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: We present a novel antireflection approach utilizing planar metamaterials on dielectric surfaces. It consists of a split-ring resonator array and a metal mesh separated by a thin dielectric spacer. The coating dramatically reduces the reflectance and greatly enhances the transmittance over a wide range of incidence angles and a narrow bandwidth. Antireflection is achieved by tailoring the magnitude and phase shifts of waves reflected and transmitted at metamaterial boundaries, resulting in a destructive interference in reflection and constructive interference in transmission. The coating can be very thin and there is no requirement for the spacer dielectric constant.
Modeling the flyby anomalies with dark matter scattering
Creators: name: Adler, Stephen L.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: We continue our exploration of whether the flyby anomalies can be explained by scattering of spacecraft nucleons from dark matter gravitationally bound to the earth. We formulate and analyze a simple model in which inelastic and elastic scatterers populate shells generated by the precession of circular orbits with normals tilted with respect to the earth's axis. Good fits to the data published by Anderson et al. are obtained.
description: Latex, 20 pages; revised version has moved derivations to Appendices and gives further numerical results in Sec. III and in added Tables VI and VII