cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Noncyclic nonadiabatic holonomic quantum gates via shortcuts to adiabaticity
Creators: name: Li, Sai
name: Shen, Pu
name: Chen, Tao
name: Xue, Zheng-Yuan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: High-fidelity quantum gates are essential for large-scale quantum computation. However, any quantum manipulation will inevitably affected by noises, systematic errors and decoherence effects, which lead to infidelity of a target quantum task. Therefore, implementing high-fidelity, robust and fast quantum gates is highly desired. Here, we propose a fast and robust scheme to construct high-fidelity holonomic quantum gates for universal quantum computation based on resonant interaction of three-level quantum systems via shortcuts to adiabaticity. In our proposal, the target Hamiltonian to induce noncyclic non-Abelian geometric phases can be inversely engineered with less evolution time and demanding experimentally, leading to high-fidelity quantum gates in a simple setup. Besides, our scheme is readily realizable in physical system currently pursued for implementation of quantum computation. Therefore, our proposal represents a promising way towards fault-tolerant geometric quantum computation.
description: 7 pages, 5 figures, accepted by Frontiers of Physics
Almost sure functional central limit theorem for ballistic random walk in random environment
Creators: name: Rassoul-Agha, Firas
name: Seppalainen, Timo
Publisher: name: arXiv
Year: 2007
Subjects: subject: Probability (math.PR)
subject: FOS: Mathematics
subject: 60K37, 60F05, 60F17, 82D30

description: We consider a multidimensional random walk in a product random environment with bounded steps, transience in some spatial direction, and high enough moments on the regeneration time. We prove an invariance principle, or functional central limit theorem, under almost every environment for the diffusively scaled centered walk. The main point behind the invariance principle is that the quenched mean of the walk behaves subdiffusively.
description: Accepted to the Annales de l'Institut Henri Poincare
Cognitive Principles and Preverbal Position in Chinese
Creators: name: Morbiato, Anna
Publisher: name: Università Ca’ Foscari Venezia, Italia
Year: 2014

description:

In Chinese, word order is a powerful linguistic device indicating relations between constituents, on a semantic, syntactic and pragmatic level, and has been the focus of linguistic inquiry over the past decades. Particular attention has been given to the preverbal position, with heated debate on the notion of topic and other pragmatic-related phenomena. This study is a first step towards a better understanding of the order of preverbal NPs and verb modifiers, analyzing them in light of relevant cognition-based word order principles investigated within the cognitive-functional approach. Particular attention is given to the notion of ‘scope’, which pertains both to the discourse and the cognitive level (‘topic scope’ vs. ‘temporal, spatial and semantic scope’), and which seems to better explain the order and the pragmatic role of preverbal NPs. On this basis, this paper suggests a research path towards a deeper cognitive-functional comprehension of the preverbal position that takes into account the interplay of different word order related factors.

description: Annali di Ca’ Foscari. Serie orientale
‘Coalition Politics’ and Regional Steadfastness
Creators: name: Leopardi, Francesco Saverio
Publisher: name: Università Ca’ Foscari Venezia, Italia
Year: 2014

description:

After the evacuation from Beirut in late 1982, the PFLP tries to formulate new policy patterns, both at the Palestinian and the regional level, in order to present its own alternative, opposing Arafat’s attempts to start direct negotiations with Israel under US sponsorship. Despite all the efforts made, the PFLP fails to effectively implement its agenda and results weakened at the end of this phase vis-à-vis Fatah-PLO leadership. From this, stems the necessity to report and assess PFLP’s line and narrative during such a critical phase. The systematic study of PFLP’s official publications (communiqués, congress resolutions, interviews released by the leaders, etc.), in the framework of the broader historiography on the Arab-Israeli conflict, is the methodology employed to achieve these goals.

description: Annali di Ca’ Foscari. Serie orientale
Nematic cells with defect-patterned alignment layers
Creators: name: Backer, Adam S.
name: Callan-Jones, A. C.
name: Pelcovits, Robert A.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Using Monte Carlo simulations of the Lebwohl--Lasher model we study the director ordering in a nematic cell where the top and bottom surfaces are patterned with a lattice of $\pm 1$ point topological defects of lattice spacing $a$. We find that the nematic order depends crucially on the ratio of the height of the cell $H$ to $a$. When $H/a \gtrsim 0.9$ the system is very well--ordered and the frustration induced by the lattice of defects is relieved by a network of half--integer defect lines which emerge from the point defects and hug the top and bottom surfaces of the cell. When $H/a \lesssim 0.9$ the system is disordered and the half--integer defect lines thread through the cell joining point defects on the top and bottom surfaces. We present a simple physical argument in terms of the length of the defect lines to explain these results. To facilitate eventual comparison with experimental systems we also simulate optical textures and study the switching behavior in the presence of an electric field.
Optical vortex dichroism in chiral particles
Creators: name: Forbes, Kayn A.
name: Jones, Garth A.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Optics (physics.optics)
subject: Atomic Physics (physics.atom-ph)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: Circular dichroism is the differential rate of absorption of right- and left-handed circularly polarized light by chiral particles. Optical vortices which convey orbital angular momentum (OAM) possess a chirality associated with the clockwise or anti-clockwise twisting of their wavefront. Here it is highlighted that both oriented and randomly oriented chiral particles absorb photons from twisted beams at different rates depending on whether the vortex twists to the right or the left through a dipole coupling scheme. This is in contrast to previous studies that investigated dipole couplings with vortex modes in the paraxial approximation and showed no such chiral sensitivity to the vortex handedness: only in oriented media where electric quadrupole coupling contributes to optical activity effects due to absorption does such a mechanism exist for paraxial vortices. The distinct difference in the scheme highlighted in this work is that longitudinal fields are taken account of and these allow for OAM transfer even during dipole interactions. Due to the vortex dichroism persisting in randomly oriented collections of chiral particles, the mechanism has a distinct advantage in its potential applicability in chemical and biochemical applications where the systems under study are invariably in the liquid phase. Additionally, the result is put into context in terms of the quantifiable optical chirality, highlighting that optical OAM can in fact increase the optical chirality density of an electromagnetic field.
Like-sign dilepton signals from a leptophobic Z' boson
Creators: name: del Aguila, F.
name: Aguilar-Saavedra, J. A.
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: A new leptophobic neutral gauge boson Z' with small mixing to the Z can have a mass as light as M_Z' ~ 350 GeV, and still have escaped detection at LEP and Tevatron. Such a Z' boson can be derived from E6 and, if the new heavy neutrino singlets in the 27 representation are lighter than M_Z'/2, the process p p(pbar) -> Z' -> NN -> l+- l+- X is observable. Indeed, this new signal could explain the small excess of like-sign dileptons found at Tevatron. Implications for LHC are also discussed. In particular, the Tevatron excess could be confirmed with less than 1 fb-1, and leptophobic Z' masses up to 2.5 TeV can be probed with 30 fb-1.
description: 19 pages, 11 PS figures. Paper significantly enlarged to include analysis for LHC
title: Trophic Ecology Of Deepwater Fishes Associated With The Continental Slope Of The Eastern Norwegian Sea
Creators: name: Bjelland, O.
name: Bergstad, O.A.
Publisher: name: ASC 1998 - O
Year: 2024
Subjects: Fisheries and aquaculture
Ecosystem observation, processes and dynamics

description: No abstracts are to be cited without prior reference to the author.In June 1995 and 1996 demersal fishes on the continental slope of the eastern Norwegian Sea were sampled to study distribution patterns and community structure. The diets of the more abundant slope species were characterised and linkages within the upper slope food-web identified. Few cases of predator-prey relationships between the typical slope fishes were found. Most of the smaller fishes fed on epibenthic crustaceans such as amphipods and mysids, while pelagic crustaceans and fish dominated the diets of larger fishes. Herring ( Clupea harengus) and blue whiting (Micromesistius poutassou) were important prey items of Greenland halibut (Reinhardtius hippoglossoides), and were also eaten by Lycodesfrigidus, Raja hyperborea and roughhead grenadier (Macrourus berg/ax). At least for the latter three species this probably reflected scavenging.
Pauli crystals in harmonic trap and on a sphere
Creators: name: Gampel, Filip
name: Gajda, Mariusz
name: Załuska-Kotur, Magdalena
name: Mostowski, Jan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Quantum Physics (quant-ph)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: Recently predicted and observed Pauli crystals are structures formed by trapped ultracold non-interacting particles obeying Fermi statistics. The relative positions of the particles are determined by the trapping potential and the Pauli exclusion principle. Measuring all particles at once, their positions tend to be close to vertices of non-trivial polyhedrons. Similar shapes are found for systems of particles bound to the surface of a sphere.
A review on function and side effects of systemic corticosteroids used in high-grade COVID-19 to prevent cytokine storms
Creators: name: Langarizadeh, Mohammad Amin
name: Ranjbar Tavakoli, Marziye
name: Abiri, Ardavan
name: Ghasempour, Ali
name: Rezaei, Masoud
name: Ameri, Alieh
Publisher: name: IfADo - Leibniz Research Centre for Working Environment and Human Factors, Dortmund
Year: 2021
Subjects: COVID-19
cytokine storm
corticosteroid therapy
SARS-CoV-2
adverse effects

description: In December 2019, a cluster of pneumonia caused by a novel coronavirus (2019-nCoV), officially known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged in Wuhan, Hubei province, China. Cytokine storm is an uncontrolled systemic inﬂammatory response resulting from the release of large amounts of pro-inﬂammatory cytokines and chemokines that occurs at phase 3 of viral infection. Such emergence led to the development of many clinical trials to discover efficient drugs and therapeutic protocols to fight with this single-stranded RNA virus. Corticosteroids suppress inflammation of the lungs during the cytokine storm, weaken immune responses, and inhibit the elimination of pathogen. For this reason, in COVID-19 corticosteroid therapy, systemic inhibition of inflammation is observed with a wide range of side effects. The present review discusses the effectiveness of the corticosteroid application in COVID-19 infection and the related side effects of these agents. In summary, a number of corticosteroids, including and especially methylprednisolone and dexamethasone, have demonstrated remarkable efficacy, particularly for COVID-19 patients who underwent mechanical ventilation.
description: EXCLI Journal; 20:Doc339; ISSN 1611-2156
Extraction of Energetic $N_2$ Neutrals for Efficient Plasma Food Processing
Creators: name: Perumal, M.
name: Saravanan, A.
name: Alex, Prince
name: Sunooj, K. V.
name: Mani, Maheswaran
name: Krishnan, G. Gopi
name: Shukla, Lata
name: Bharathi, P.
name: Sinha, Suraj Kumar
Publisher: name: arXiv
Year: 2021
Subjects: subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: Low-temperature plasma (LTP) processing is a green and flexible food processing technology with only known limitation of low energy efficiency. Three established fundamental mechanisms of plasma food processing includes: i) physical damage to membranes and internal cellular components due to bombardment of energetic ions: ii) radicals and charged species led chemical reactions: iii) and radiation-induced modifications. In this investigation, we present a new mechanism of generation and extraction of energetic $N_2$ neutrals from glow discharge plasmas for efficient food processing. For nitrogen dc glow discharge plasma we demonstrate by experiment selective generation and extraction of energetic $N_2$ neutrals and $N_2^+$ ions for treatment of different food samples. Using numerical simulations, the plasma processing parameters are defined for selective extraction of $N_2$ or $N_2^+$ species with specific energies. Treatment of native finger millet flour or ragi flour (Eleusine coracana) with selectively extracted energetic $N_2$ neutrals, with an estimated average energy of 34.20 eV, resulted in improvement of shelf-life and functional properties. Additionally, this processing technique achieved high energy efficiency of ~ 46%. This method of food engineering has advantages of control over active species generation, high power efficiency, reduced processing cost, and chemical-free. Therefore, it opens up wide possibilities in plasma food processing for global food security and food safety.
description: 9 pages, 3 figures
title: Deepwater Fisheries In Vanuatu (Oceania): Are Usual Tools Adequate For The Management Of Small Insular Artisanal Fisheries?
Creators: name: Cillaurren, E.
name: Simier, M.
Publisher: name: ASC 1998 - O
Year: 2024
Subjects: Fisheries and aquaculture
Ecosystem observation, processes and dynamics

description: No abstracts are to be cited without prior reference to the author.The analysis of ten years of fishing effort and deepwaterfish catch in Vanuatu with statistic exploratory methods show specific reaction to the fishing pressure related to the fish habitats. For the Ete!is spp. and the Pristipomoides spp. which habitats are well structured according to the depth, a yearly decreasing of the average length of the catches shows that these fish are the most harvested of the. deep demersal stock. The intern1ediate depth species, like Epinephelus spp. or Aplwreus rutilans appear less harvested. These species are concentrated in few fishing areas and therefore they are supposed to be more affected by local over-fishing. The management of the deep demersa! fishery includes two approaches. The first one is focused on an evaluation of the quotas per species with a recommendation about the maintenance of a species diversity. The second ones identifies the fishing areas which need to be preserved from intensive fishing effort. These areas are situated in the southern island isolated by the 1000 m isobath which limits the extension of the resource and in the eastern islands of the archipelago where the sharp bottom-slope increases the vulnerability of the resource to the fishing effort.
Full Spectroscopic Model and Trihybrid Experimental-Perturbative-Variational Line List for CN
Creators: name: Syme, Anna-Maree
name: McKemmish, Laura K.
Publisher: name: arXiv
Year: 2021
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Accurate line lists are important for the description of the spectroscopic nature of small molecules. While a line list for CN (an important molecule for chemistry and astrophysics) exists, no underlying energy spectroscopic model has been published, which is required to consider the sensitivity of transitions to a variation of the proton-to-electron mass ratio. Here we have developed a Duo energy spectroscopic model as well as a novel hybrid style line list for CN and its isotopologues, combining energy levels that are derived experimentally (Marvel), using the traditional/perturbative approach (Mollist), and the variational approach (from a Duo spectroscopic model using standard ExoMol methodology). The final Trihybrid ExoMol-style line list for 12C14N consists of 28,004 energy levels (6,864 experimental, 1,574 perturbative, the rest variational) and 2,285,103 transitions up to 60,000 cm-1 between the three lowest electronic states (X2Sigma+, A2Pi and B2Sigma+). The spectroscopic model created is used to evaluate CN as a molecular probe to constrain the variation of the proton-to-electron mass ratio; no overly promising sensitive transitions for extragalactic study were identified.
description: Accepted in Monthly Notices of the Royal Astronomical Society. 13 pages, 11 figures
title: Trace Elements In Deep-Water Fish Species From The Rockall Trough
Creators: name: Mormede, S.
name: Davies, I. M.
Publisher: name: ASC 1998 - O
Year: 2024
Subjects: Fisheries and aquaculture
Ecosystem observation, processes and dynamics

description: No abstracts are to be cited without prior reference to the author.Samples of three species of deep water fish (Nezumia aequalis, the smooth grenadier, Lepidion eques, the largeye lepidion, and Raja fyllae, the round ray) were obtained from 850-950 m depth on the continental slope of the Rockall Trough wesl of Scotland. (58-59'30'N) in March 1998. Muscle, liver and gill tissues were analysed for cadmium, copper, lead, zinc, mercury, nickel and chromium by various atomic absorption techniques. Median concentrations in muscle tissue were 0.004, 0.21, 0.005, 0.150, and 3,91 mg/kg respectively for the grenadier; 0.005, 0.17, 0.002, 0.077 and 2.62 mg/kg respectively for the lepidion and 0.012, 0.33, 0.027, 0.129 and 5.53 mg/kg respectively for the ray (nickel and chromium were not detectable). In general, the concentrations are similar to those previously reported in other species from this area. Differences in accumulation patterns between species and elements are described using univariate and multivariate statistics (discriminant analysis).
Ultrashort intense-field optical vortices produced with laser-etched mirrors
Creators: name: Strohaber, J.
name: Scarborough, T.
name: Uiterwaal, C. J. G. J.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Optics (physics.optics)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: We introduce a simple and practical method to create ultrashort intense optical vortices for applications involving high-intensity lasers. Our method utilizes femtosecond laser pulses to laser-etch grating lines into laser-quality gold mirrors. These grating lines holographically encode an optical vortex. We derive mathematical equations for each individual grating line to be etched, for any desired (integer) topological charge. We investigate the smoothness of the etched grooves. We show that they are smooth enough to produce optical vortices with an intensity that is only a few percent lower than in the ideal case. We demonstrate that the etched gratings can be used in a folded version of our 2f-2f setup [Mariyenko et al., Opt. Express 19, 7599 (2005)] to compensate angular dispersion. Lastly, we show that the etched gratings withstand intensities of up to 10^12 W/cm2.
description: 14 pages, 12 figures, submitted to Optics Express
Magnetic fields above the surface of a superconductor with internal magnetism
Creators: name: Bluhm, Hendrik
Publisher: name: arXiv
Year: 2007
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: The author presents a method for calculating the magnetic fields near a planar surface of a superconductor with a given intrinsic magnetization in the London limit. He computes solutions for various magnetic domain boundary configurations and derives relations between the spectral densities of the magnetization and the resulting field in the vacuum half space, which are useful if the magnetization can be considered as a statistical quantity and its features are too small to be resolved individually. The results are useful for analyzing and designing magnetic scanning experiments. Application to existing data from such experiments on Sr$_2$RuO$_4$ show that a domain wall would have been detectable, but the magnetic field of randomly oriented small domains and small defects may have been smaller than the experimental noise level.
description: 8 pages, 2 figures. Journal version. Added one figure, some discussion. A few typos corrected
Evidence of orbital reconstruction at interfaces in La0.67Sr0.33MnO3 films
Creators: name: Tebano, A
name: Aruta, C.
name: Sanna, S.
name: Medaglia, P. G.
name: Balestrino, G.
name: Sidorenko, A. A.
name: De Renzi, R.
name: Ghiringhelli, G.
name: Braicovich, L.
name: Bisogni, V.
name: Brookes, N. B.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Electronic properties of transition metal oxides at interfaces are influenced by strain, electric polarization and oxygen diffusion. Linear dichroism (LD) x-ray absorption, diffraction, transport and magnetization on thin La0.7Sr0.3MnO3 films, allow identification of a peculiar universal interface effect. We report the LD signature of preferential 3d-eg(3z2-r2) occupation at the interface, suppressing the double exchange mechanism. This surface orbital reconstruction is opposite of that favored by residual strain and independent of dipolar fields, chemical nature of the substrate and capping.
description: 13 pages, 5 figures
Fidelity enhancement by logical qubit encoding
Creators: name: Henry, Michael K.
name: Ramanathan, Chandrasekhar
name: Hodges, Jonathan S.
name: Ryan, Colm A.
name: Ditty, Michael J.
name: Laflamme, Raymond
name: Cory, David G.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We demonstrate coherent control of two logical qubits encoded in a decoherence free subspace (DFS) of four dipolar-coupled protons in an NMR quantum information processor. A pseudo-pure fiducial state is created in the DFS, and a unitary logical qubit entangling operator evolves the system to a logical Bell state. The four-spin molecule is partially aligned by a liquid crystal solvent, which introduces strong dipolar couplings among the spins. Although the system Hamiltonian is never fully specified, we demonstrate high fidelity control over the logical degrees of freedom. In fact, the DFS encoding leads to higher fidelity control than is available in the full four-spin Hilbert space.
description: 10 pages, 2 figures
Toolkit of Good Practices for Gender Balance in MOOCs
Creators: name: Conchado, Andrea
name: Corti, Paola
name: Baudo, Valeria
name: Santos, Ana Moura
name: Nilsson, Charlotta
name: Villla, Fulgencia
name: Vallada, Eva
name: Rosso, Astrid
name: Svensson Rössner, Erika
name: Ernesto, Teresa
name: Alberti, Virginia
name: Turró, Carlos
Publisher: name: Zenodo
Year: 2020
Subjects: MOOC
gender studies
e-learning

description: A MOOC is an online course aimed at unlimited participation and open access via the web and nowadays it often includes validated academic content designed and produced by faculty members and MOOC teams located at Universities. Within the FOSTWOM consortium, almost all HEI partners are MOOC producers with online courses designed in a multidisciplinary collaboration between teaching staff and the development team. Tutors, instructional designers, graphic designers and video editors, ideate and design the STEM content according to the pedagogical-scientific model of each online course (Moura Santos & Fleming, 2020). It is our responsibility as MOOC developers and designers to promote gender equality and provide better opportunities for MOOC participants to access high quality content in a gender-balanced environment. In addition, the virtual classroom offered by MOOCs may provide a more comfortable learning space for many female students (Lee et al., 2017). The free and easy access to the online courses provided by universities may be providing opportunities for female participants to take STEM courses, especially females from less gender-egalitarian and less economically developed countries. Therefore, we have developed a toolkit to support MOOC stakeholders (content experts, MOOCs’ team development members, participants/students) not only in analysing existing STEM MOOCs so that they can raise their awareness on biases, but also in helping them to contribute to future STEM MOOCs free of gender stereotypes. More specifically, the FOSTWOM toolkit provide tools to: ● Make women working in the STEM subjects, researchers and other role models more visible; ● Make women involved in STEM MOOCs, female teachers, professors and lecturers more visible; ● Avoid gender stereotypes in STEM content and activities; ● Use inclusive graphic design: images, colors, avatars and videos, that break gender norms and do not aimed solely at male participants; ● Use real-life applications of relevant content for STEM careers, which include both women and men; ● Design assessment and learning activities in a gender-conscious way; ● Make visible the diversity and variety of competencies (both soft and hard skills) and representations needed among practitioners in the STEM area; ● Promote a gender equality discourse that highlights and problematizes women's under-representation in STEM, and points to the consequences it may have for problem formulation (eg risk of lack of a broad user perspective), product design, research, innovation, etc.
A Conversation with Robert V. Hogg
Creators: name: Randles, Ronald Herman
Publisher: name: arXiv
Year: 2007
Subjects: subject: Methodology (stat.ME)
subject: FOS: Computer and information sciences

description: Robert Vincent Hogg was born on November 8, 1924 in Hannibal, Missouri. He earned a Ph.D. in statistics at the University of Iowa in 1950, where his advisor was Allen Craig. Following graduation, he joined the mathematics faculty at the University of Iowa. He was the founding Chair when the Department of Statistics was created at Iowa in 1965 and he served in that capacity for 19 years. At Iowa he also served as Chair of the Quality Management and Productivity Program and the Hanson Chair of Manufacturing Productivity. He became Professor Emeritus in 2001 after 51 years on the Iowa faculty. He is a Fellow of the Institute of Mathematical Statistics and the American Statistical Association plus an Elected Member of the International Statistical Institute. He was President of the American Statistical Association (1988) and chaired two of its winter conferences (1992, 1994). He received the ASA's Founder's Award (1991) and the Gottfried Noether Award (2001) for contributions to nonparametric statistics. His publications through 1996 are described in Communications in Statistics--Theory and Methods (1996), 2467--2481. This interview was conducted on April 14, 2004 at the Department of Statistics, University of Florida, Gainesville, Florida, and revised in the summer of 2006.
description: Published at http://dx.doi.org/10.1214/088342306000000637 in the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org)
Chemomechanical simulation of microtubule dynamics with explicit lateral bond dynamics
Creators: name: Schmidt, Matthias
name: Kierfeld, Jan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Subcellular Processes (q-bio.SC)
subject: Biomolecules (q-bio.BM)
subject: FOS: Biological sciences

description: We introduce and parameterize a chemomechanical model of microtubule dynamics on the dimer level, which is based on the allosteric tubulin model and includes attachment, detachment and hydrolysis of tubulin dimers as well as stretching of lateral bonds, bending at longitudinal junctions, and the possibility of lateral bond rupture and formation. The model is computationally efficient such that we reach sufficiently long simulation times to observe repeated catastrophe and rescue events at realistic tubulin concentrations and hydrolysis rates, which allows us to deduce catastrophe and rescue rates. The chemomechanical model also allows us to gain insight into microscopic features of the GTP-tubulin cap structure and microscopic structural features triggering microtubule catastrophes and rescues. Dilution simulations show qualitative agreement with experiments. We also explore the consequences of a possible feedback of mechanical forces onto the hydrolysis process and the GTP-tubulin cap structure.
description: 37 pages + 14 figures + supplementary material
Absence of local magnetic moments in Ru and Rh impurities and clusters on Ag(100) and Pt(997)
Creators: name: Honolka, J.
name: Kuhnke, K.
name: Vitali, L.
name: Enders, A.
name: Kern, K.
name: Gardonio, S.
name: Carbone, C.
name: Krishnakumar, S. R.
name: Bencok, P.
name: Stepanow, S.
name: Gambardella, P.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: The magnetism of quench-condensed Ru and Rh impurities and metal films on Ag(100) and Pt(997) has been studied using x-ray magnetic circular dichroism. In the coverage range between 0.22 ML and 2.0 ML no dichroic signal was detected at the M3,2 absorption edges of Ru on Ag(100) at a temperature of 5 K in the presence of an applied magnetic field. The same was found for coverages between 0.12 ML and 0.5 ML of Rh on Ag(100) and Pt(997). It is concluded that the magnetic moments of single impurities, small clusters of various shape and monolayers of the 4d metals are below the detection limit of 0.04 muB per atom. These results provide an unambiguous determination of the local magnetic moment of Ru and Rh deposited on nonmagnetic transition-metal surfaces, which are in contrast with theoretical predictions.
Gravitational instability of a dilute fully ionized gas in the presence of the Dufour effect
Creators: name: Sandoval-Villalbazo, A.
name: Garcia-Perciante, A. L.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: The gravitational instability of a fully ionized gas is analyzed within the framework of linear irreversible thermodynamics. In particular, the presence of a heat flux corresponding to generalized thermodynamic forces is shown to affect the properties of the dispersion relation governing the stability of this kind of system in certain problems of interest.
description: 8 pages, 2 figures
The Lie algebra perturbation lemma
Creators: name: Huebschmann, Johannes
Publisher: name: arXiv
Year: 2007
Subjects: subject: Algebraic Geometry (math.AG)
subject: Commutative Algebra (math.AC)
subject: FOS: Mathematics
subject: 16E45, 16W30, 17B55, 17B56, 17B65, 17B70, 18G10, 55P62

description: Let g be a differential graded Lie algebra and suppose given a contraction of chain complexes of g onto a general chain complex M. We show that the data determine an sh-Lie algebra structure on M, that is, a coalgebra perturbation of the coalgebra differential on the cofree coaugmented differential graded cocommutative coalgebra S' on the suspension of M, a Lie algebra twisting cochain from the perturbed coalgebra S" to the given Lie algebra g, and an extension of this Lie algebra twisting cochain to a contraction of chain complexes from the Cartan-Chevalley-Eilenberg coalgebra on g onto S" which is natural in the data. This extends a result established in a joint paper of the author with J. Stashef [Forum math. 14 (2002), 847-868, math.AG/9906036] where only the particular where M is the homology of g has been explored.
description: 20 pages; in view of a number of comments of J. Stasheff, the exposition has been improved
Interaction of Order and Convexity
Creators: name: Kutateladze, S. S.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Functional Analysis (math.FA)
subject: Metric Geometry (math.MG)
subject: FOS: Mathematics
subject: 46B42, 52A39

description: This is an overview of merging the techniques of Riesz space theory and convex geometry.
description: Prepared for the Russian--German geometry meeting dedicated to the 95th anniversary of A. D. Alexandrov (1912--1999), St. Petersburg, June 18--23, 2007
Path-Integral Formulation of Pseudo-Hermitian Quantum Mechanics and the Role of the Metric Operator
Creators: name: Mostafazadeh, Ali
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We provide a careful analysis of the generating functional in the path integral formulation of pseudo-Hermitian and in particular PT-symmetric quantum mechanics and show how the metric operator enters the expression for the generating functional.
description: Published version, 4 pages
Upgrading the Local Ergodic Theorem for planar semi-dispersing billiards
Creators: name: Chernov, N.
name: Simanyi, N.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Dynamical Systems (math.DS)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 37D50, 34D05

description: The Local Ergodic Theorem (also known as the `Fundamental Theorem') gives sufficient conditions under which a phase point has an open neighborhood that belongs (mod 0) to one ergodic component. This theorem is a key ingredient of many proofs of ergodicity for billiards and, more generally, for smooth hyperbolic maps with singularities. However the proof of that theorem relies upon a delicate assumption (Chernov-Sinai Ansatz), which is difficult to check for some physically relevant models, including gases of hard balls. Here we give a proof of the Local Ergodic Theorem for two dimensional billiards without using the Ansatz.
description: 17 pages, 2 figures
Constraining the nature of High Frequency Peakers. I. The spectral variability
Creators: name: Orienti, M.
name: Dallacasa, D.
name: Stanghellini, C.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Astrophysics (astro-ph)
subject: FOS: Physical sciences

description: We investigate the spectral characteristics of 51 candidate High Frequency Peakers (HFPs), from the ``bright'' HFP sample, in order to determine the nature of each object, and to obtain a smaller sample of genuine young radio sources. Simultaneous multi-frequency VLA observations carried out at various epochs have been used to detect flux density and spectral shape variability in order to pinpoint contaminant objects, since young radio sources are not expected to be significantly variable on such a short time-scale. From the analysis of the spectral variability we find 13 contaminant objects, 11 quasars, 1 BL Lac, and 1 unidentified object, which we have rejected from the sample of candidate young radio sources. The 6 years elapsed between the first and latest observing run are not enough to detect any substantial evolution of the overall spectrum of genuine, non variable, young radio sources. If we also consider the pc-scale information, we find that the total radio spectrum we observe is the result of the superposition of the spectra of different regions (lobes, hot-spots, core, jets), instead of a single homogeneous radio component. This indicates that the radio source structure plays a relevant role in determining the spectral shape also in the rather common case in which the morphology appears unresolved even on high-resolution scales.
description: 14 pages, 3 figures; accepted for pubblication in A&A
Quantum indirect estimation theory and joint estimate of all moments of two incompatible observables
Creators: name: D'Ariano, Giacomo Mauro
name: Perinotti, Paolo
name: Sacchi, Massimiliano Federico
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We introduce the quantum indirect estimation theory, which provides a general framework to address the problem of which ensemble averages can be estimated by means of an available set of measuring apparatuses, e. g. estimate the ensemble average of an observable by measuring other observable. A main ingredient in this approach is that of informationally complete (infocomplete in short) measurements, which allow to estimate the ensemble average of any arbitrary system operator, as for quantum tomography. This naturally leads to the more stringent concept of AB-informationally complete measurements, by which one can estimate jointly all the moments of two incompatible observables A and B. After analyzing all general properties of such measurements, we address the problem of their optimality, and we completely solve the case of qubits, showing that a sigma_x sigma_y-infocomplete measurement is less noisy than any infocomplete one. We will also discuss the relation between the concept of AB-infocompleteness and the notion of joint measurement of observables A and B.
System Design for a Long-Line Quantum Repeater
Creators: name: Van Meter, Rodney
name: Ladd, Thaddeus D.
name: Munro, W. J.
name: Nemoto, Kae
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We present a new control algorithm and system design for a network of quantum repeaters, and outline the end-to-end protocol architecture. Such a network will create long-distance quantum states, supporting quantum key distribution as well as distributed quantum computation. Quantum repeaters improve the reduction of quantum-communication throughput with distance from exponential to polynomial. Because a quantum state cannot be copied, a quantum repeater is not a signal amplifier, but rather executes algorithms for quantum teleportation in conjunction with a specialized type of quantum error correction called purification to raise the fidelity of the quantum states. We introduce our banded purification scheme, which is especially effective when the fidelity of coupled qubits is low, improving the prospects for experimental realization of such systems. The resulting throughput is calculated via detailed simulations of a long line composed of shorter hops. Our algorithmic improvements increase throughput by a factor of up to fifty compared to earlier approaches, for a broad range of physical characteristics.
description: 12 pages, 13 figures. v2 includes one new graph, modest corrections to some others, and significantly improved presentation. to appear in IEEE/ACM Transactions on Networking
Giant Molecular Cloud Formation at the Interface of Colliding Supershells in the Large Magellanic Cloud
Creators: name: Fujii, Kosuke
name: Mizuno, Norikazu
name: Dawson, J. R.
name: Inoue, Tsuyoshi
name: Torii, Kazufumi
name: Onishi, Toshikazu
name: Kawamura, Akiko
name: Muller, Erik
name: Minamidani, Tetsuhiro
name: Tsuge, Kisetsu
name: Fukui, Yasuo
Publisher: name: arXiv
Year: 2021
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: We investigate the Hi envelope of the young, massive GMCs in the star-forming regions N48 and N49, which are located within the high column density Hi ridge between two kpc-scale supergiant shells, LMC 4 and LMC 5. New long-baseline Hi 21 cm line observations with the Australia Telescope Compact Array (ATCA) were combined with archival shorter baseline data and single dish data from the Parkes telescope, for a final synthesized beam size of 24.75" by 20.48", which corresponds to a spatial resolution of ~ 6 pc in the LMC. It is newly revealed that the Hi gas is highly filamentary, and that the molecular clumps are distributed along filamentary Hi features. In total 39 filamentary features are identified and their typical width is ~ 21 (8-49) [pc]. We propose a scenario in which the GMCs were formed via gravitational instabilities in atomic gas which was initially accumulated by the two shells and then further compressed by their collision. This suggests that GMC formation involves the filamentary nature of the atomic medium.
description: 22 pages, 4 tables, 16 figures
Unquenching effects in the quark and gluon propagator
Creators: name: Kamleh, Waseem
name: Bowman, Patrick O.
name: Leinweber, Derek B.
name: Williams, Anthony G.
name: Zhang, Jianbo
Publisher: name: arXiv
Year: 2007
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: In this work we examine the Fat-Link Irrelevant Clover (FLIC) overlap quark propagator and the gluon propagator on both dynamical and quenched lattices. The tadpole-improved Luscher-Weisz gauge action is used in both cases. The dynamical gauge fields use the FLIC fermion action for the sea quark contribution. We observe that the presence of sea quarks causes a suppression of the mass function, quark renormalization function and gluon dressing function in the infrared. The ultraviolet physics is unaffected.
description: 10 pages, 7 figures
title: A New Method For Estimating The Abundance Of Patagonian Toothfish (Dissostichus Eleginoides)
Creators: name: Yau, C.
name: Collins, M. A.
name: Everson, I.
name: Nolan, C. P.
Publisher: name: ASC 1998 - O
Year: 2024
Subjects: Fisheries and aquaculture
Ecosystem observation, processes and dynamics

description: No abstracts are to be cited without prior reference to the author.The Patagonian toothfish Dissostichus eleginoides has been the subject of a rapidly expanding longline fishery in the Southern Ocean. Traditional methods of estimating stock size have proved difficult to apply because the fish are found on the continental slope at depths of 1000 m. During September 1997, the Aberdeen .University Deep Ocean Submersible (AUDOS) was used to estimate numerical density and size of toothfish in waters around South Georgia and the Falkland Islands. These are the first estimates that are independent of the commercial fishery.
The brachistochrone problem in open quantum systems
Creators: name: Rotter, Ingrid
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Recently, the quantum brachistochrone problem is discussed in the literature by using non-Hermitian Hamilton operators of different type. Here, it is demonstrated that the passage time is tunable in realistic open quantum systems due to the biorthogonality of the eigenfunctions of the non-Hermitian Hamilton operator. As an example, the numerical results obtained by Bulgakov et al. for the transmission through microwave cavities of different shape are analyzed from the point of view of the brachistochrone problem. The passage time is shortened in the crossover from the weak-coupling to the strong-coupling regime where the resonance states overlap and many branch points (exceptional points) in the complex plane exist. The effect can {\it not} be described in the framework of standard quantum mechanics with Hermitian Hamilton operator and consideration of $S$ matrix poles.
description: 18 pages
Scattering polarization of hydrogen lines from electric-induced atomic alignment
Creators: name: Casini, R.
name: Sainz, R. Manso
Publisher: name: arXiv
Year: 2007
Subjects: subject: Quantum Physics (quant-ph)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: We consider a gas of hydrogen atoms illuminated by a broadband, unpolarized radiation with zero anisotropy. In the absence of external fields, the atomic J-levels are thus isotropically populated. While this condition persists in the presence of a magnetic field, we show instead that electric fields can induce the alignment of those levels. We also show that this electric alignment cannot occur in a two-term model of hydrogen (e.g., if only the Ly-alpha transition is excited), or if the level populations are distributed according to Boltzmann's law.
description: 10 pages, 4 figures. Accepted by J.Phys.B: At.Mol.Opt.Phys
Atomic-charge distribution in glasses by terahertz spectroscopy
Creators: name: Taraskin, S. N.
name: Simdyankin, S. I.
name: Elliott, S. R.
Publisher: name: arXiv
Year: 2007
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: FOS: Physical sciences

description: It is demonstrated that the width of the uncorrelated atomic-charge distribution in glasses can be extracted from the frequency dependence of the coupling coefficient for the far-infrared absorption measured experimentally by the time-domain terahertz spectroscopy technique. This value for As2S3 glass is found to be 0.12 (e). A density functional theory-based tight-binding molecular dynamics model of As2S3 glass qualitatively supports these findings.
title: Assessment Of The Roundnose Grenadier (Coryphaenoides Rupestris) Stock In The Rockall Trough And Neighbouring Areas (ICES Sub-Areas V, Vi And Vii)
Creators: name: Lorance, Pascal
name: Dupouy, Hervé
name: Allain, Valérie
Publisher: name: ASC 1998 - O
Year: 2024
Subjects: Fisheries and aquaculture
Ecosystem observation, processes and dynamics

description: No abstracts are to be cited without prior reference to the author.The catch (landings and discards) at age of roundnose grenadier (Coryphaenoides rupestris) are used to assess the stock in the areas exploited by French trawlers. A pseudo cohort analysis corrected for changes in fishing effort in the period before the year which catch at age are analysed was carried out for the years 1996 and 1997. To get the input parameters, an age length key was estimated from unvalidated otoliths readings from sampling in the same years. This age length key was combined with length distribution data from surveys prior to exploitation and from landings in 1990 (early in the history of the fishery) to estimate the total mortality then equivalent to the natural mortality. This pseudo cohort poorly converged suggesting a low annual fishing mortality. The behaviour of the stock was further investigated from yield per recruit analysis. Because of a series of lacks in the knowledge of the species (stock (s) distribution, unvalidated ages ... ), the estimates of fishing mortality must be considered with caution. The main interest of the analysis is probably to stress the impact of the discards on the potential yield of roundnose grenadier.
title: Deep Water Fisheries At Iceland
Creators: name: Magnusson, Jakob
Publisher: name: ASC 1998 - O
Year: 2024
Subjects: Fisheries and aquaculture
Ecosystem observation, processes and dynamics

description: No abstracts are to be cited without prior reference to the author.This paper is an extract from the EC FAIR Project CT 95-0655, Sub-Task 1.5. During the first half of this century, the modem fishing technique developed rather rapidly in the Icelandic fishery when it changed from hand- and longline fishery carried out from open and small-decked hand- and wind-powered boats to motorised cutters and steam trawlers. However, the fishery remained in relatively shallow waters, i.e. less than 400 min spite of the modernisation of the fleet and gear. Also, the target species in particular cod ( Gadus morhua) remained the same.