cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
X-ray polarimetry in Astrophysics with the Gas Pixel Detector
Creators: name: Muleri, F.
name: Bellazzini, R.
name: Brez, A.
name: Costa, E.
name: Lazzarotto, F.
name: Minuti, M.
name: Pinchera, M.
name: Rubini, A.
name: Soffitta, P.
name: Spandre, G.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The Gas Pixel Detector, recently developed and continuously improved by Pisa INFN in collaboration with IASF-Roma of INAF, can visualize the tracks produced within a low Z gas by photoelectrons of few keV. By reconstructing the impact point and the original direction of the photoelectrons, the GPD can measure the linear polarization of X-rays, while preserving the information on the absorption point, the energy and the time of individual photons. Applied to X-ray Astrophysics, in the focus of grazing incidence telescopes, it can perform angular resolved polarimetry with a huge improvement of sensitivity, when compared with the conventional techniques of Bragg diffraction at 45 degrees and Compton scattering around 90 degrees. This configuration is the basis of POLARIX and HXMT, two pathfinder missions, and is included in the baseline design of IXO, the very large X-ray telescope under study by NASA, ESA and JAXA.
description: Proceeding of MPGD2009 Conference, June 12-15, 2009 Kolympari, Crete, Greece; 10 pages, 6 figures and 1 table
Topological Interpretation of Barbero-Immirzi Parameter
Creators: name: Date, Ghanashyam
name: Kaul, Romesh K.
name: Sengupta, Sandipan
Publisher: name: arXiv
Year: 2008
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We set up a canonical Hamiltonian formulation for a theory of gravity based on a Lagrangian density made up of the Hilbert-Palatini term and, instead of the Holst term, the Nieh-Yan topological density. The resulting set of constraints in the time gauge are shown to lead to a theory in terms of a real SU(2) connection which is exactly the same as that of Barbero and Immirzi with the coefficient of the Nieh-Yan term identified as the inverse of Barbero-Immirzi parameter. This provides a topological interpretation for this parameter. Matter coupling can then be introduced in the usual manner, {\em without} changing the universal topological Nieh-Yan term.
description: 14 pages, revtex4, no figures. Minor modifications with additional remarks. References rearranged
The Importance of the Representation of DMS Oxidation in Global Chemistry‐Climate Simulations
Creators: name: Hoffmann, Erik Hans
name: Heinold, Bernd
name: Kubin, Anne
name: Tegen, Ina
name: Herrmann, Hartmut
Publisher: name: FID GEO
Year: 2021

description: The oxidation of dimethyl sulfide (DMS) is key for the natural sulfate aerosol formation and its climate impact. Multiphase chemistry is an important oxidation pathway but neglected in current chemistry‐climate models. Here, the DMS chemistry in the aerosol‐chemistry‐climate model ECHAM‐HAMMOZ is extended to include multiphase methane sulfonic acid (MSA) formation in deliquesced aerosol particles, parameterized by reactive uptake. First simulations agree well with observed gas‐phase MSA concentrations. The implemented formation pathways are quantified to contribute up to 60% to the sulfate aerosol burden over the Southern Ocean and Arctic/Antarctic regions. While globally the impact on the aerosol radiative forcing almost levels off, a significantly more positive solar radiative forcing of up to +0.1 W m−2 is computed in the Arctic (>60°N). The findings imply the need of both further laboratory and model studies on the atmospheric multiphase oxidation of DMS.
description: Plain Language Summary: The emission of dimethyl sulfide (DMS) represents the largest natural reduced sulfur source into the atmosphere. There, DMS can be oxidized to sulfur dioxide, sulfuric acid, or methane sulfonic acid modifying the radiative properties of aerosol particles and clouds. DMS oxidation is represented in chemistry‐climate models by a limited number of very simplified reactions. Small changes in the parameter settings can have large effects, that's why these should be as accurate as possible. In this study, the DMS chemistry in ECHAM‐HAMMOZ was upgraded. Sensitivity simulations show variations in the natural aerosol radiative forcing due to the different schemes tested in this study. Further laboratory and process studies with models are therefore essential.
description: Key Points: Dimethyl sulfide (DMS) chemistry in chemistry‐climate simulations extended by multiphase methane sulfonic acid (MSA) formation provides more realistic MSA gas‐phase concentrations. Formation of MSA is very sensitive toward reactive uptake on deliquesced aerosol particles. In the Arctic, the extended DMS chemistry leads to a significantly less negative effective radiative forcing of sulfate aerosol.
description: Deutsche Forschungsgemeinschaft (DFG) http://dx.doi.org/10.13039/501100001659
MIGHTEE-HI: deep spectral line observations of the COSMOS field
Creators: name: Heywood, I.
name: Ponomareva, A. A.
name: Maddox, N.
name: Jarvis, M. J.
name: Frank, B. S.
name: Adams, E. A. K.
name: Baes, M.
name: Bianchetti, A.
name: Collier, J. D.
name: Deane, R. P.
name: Glowacki, M.
name: Jung, S. L.
name: Pan, H.
name: Rajohnson, S. H. A.
name: Rodighiero, G.
name: Ruffa, I.
name: Santos, M. G.
name: Sinigaglia, F.
name: Vaccari, M.
Publisher: name: arXiv
Year: 2024
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences

description: The MIGHTEE survey utilises the South African MeerKAT radio telescope to observe four extragalactic deep fields, with the aim of advancing our understanding of the formation and evolution of galaxies across cosmic time. MIGHTEE's frequency coverage encompasses the $\textrm{H}\scriptstyle\mathrm{I}$ line to a redshift of z $\simeq$ 0.58, and OH megamasers to z $\simeq$ 0.9. We present the MIGHTEE-$\textrm{H}\scriptstyle\mathrm{I}$ imaging products for the COSMOS field, using a total of 94.2 h on-target and a close-packed mosaic of 15 individual pointings. The spectral imaging covers two broad, relatively interference-free regions (960-1150 and 1290-1520~MHz) within MeerKAT's L-band, with up to 26 kHz spectral resolution (5.5 km s$^{-1}$ at $z$ = 0). The median noise in the highest spectral resolution data is 74 $μ$Jy beam$^{-1}$, corresponding to a 5$σ$ $\textrm{H}\scriptstyle\mathrm{I}$ mass limit of 10$^{8.5}$ M$_{\odot}$ for a 300 km s$^{-1}$ line at $z$ = 0.07. The mosaics cover $>$4 deg$^{2}$, provided at multiple angular resolution / sensitivity pairings, with an angular resolution for $\textrm{H}\scriptstyle\mathrm{I}$ at $z$ = 0 of 12$''$. We describe the spectral line processing workflow that will be the basis for future MIGHTEE-$\textrm{H}\scriptstyle\mathrm{I}$ products, and validation of, and some early results from, the spectral imaging of the COSMOS field. We find no evidence for line emission at the position of the $z$ = 0.376 \HI~line reported from the CHILES survey at a $>$94 per cent confidence level, placing a 3$σ$ upper limit of 8.1 $\times$ 10$^{9}$ M$_{\odot}$ on $M_{\mathrm{HI}}$ for this galaxy. A public data release accompanies this article.
description: 22 pages, 19 figures
Ocean fertilisation : science and regulation
Creators: name: Mayo-Ramsay, JP
Publisher: name: University Of Tasmania
Year: 2023

description: The threat of climate change may be the greatest social and environmental challenge of our time. Yet if the increase in warming is to be stabilised, then a reduction in atmospheric carbon dioxide (CO\\(_2\\)) is needed. Sink technologies such as ocean fertilisation claim to do this by stimulating phytoplankton to grow into massive blooms, thereby drawing down large amounts of CO\\(_2\\) from the atmosphere into the deep ocean. But the science is unproven and concerns have been raised, not only about its feasibility, but also the environmental and legal implications. This thesis examines the process of ocean fertilisation and the capacity and effectiveness of current international and domestic legal regimes to regulate it. The science and feasibility of ocean fertilisation, primarily as a carbon mitigation measure, but also for carbon trading and seafood production, were considered. Three case studies were used as models to test how each legal instrument could be applied to the selected criteria to measure either capacity or effectiveness. Criteria were drawn from two critical areas of concern ‚ÄövÑvÆ the protection of the environment and enforcement. The research established that current Australian domestic law would most likely have adequate checks and balances to regulate ocean fertilisation activities within Australia's exclusive economic zone and territorial waters, with the exception of some external territories where compliance and enforcement may be problematic. The international law was found to be less effective; the main concern was the use of flags of convenience to bypass regulation on the high seas. Areas of conflict were found, particularly between ocean fertilisation for scientific research and commercial purposes. While there are no existing international legal instruments for ocean fertilisation generally, there is a framework for the assessment of ocean fertilisation for scientific research, leaving the future of commercial ocean fertilisation operations still undetermined. A model for the development of a new legal instrument to regulate ocean fertilisation activities, incorporating both research and commercial applications, was suggested.
'LearnR' & 'shiny' to support the teaching of meta-analysis of data from systematic review of animal studies.
Creators: name: Hobby, David
Publisher: name: Zenodo
Year: 2022
Subjects: ESMARConf2022
evidence synthesis
meta-analysis
RStats

description: Teaching meta-analysis involves combining theoretical statistical knowledge and applying theoretical aspects in practice. Teaching sessions for non-technical students involving R are often beset with technical problems such as outdated software versions, missing and conflicting dependencies, and a tendency for students to arrive on the session day without having installed required software. This causes the first hour(s) of practical sessions to turn into technical troubleshooting sessions. To circumvent these problems, we have created a self-contained web app using the ‘shiny’ and ‘LearnR’ R packages to demonstrate the capabilities of R in meta-analysis. This app runs on a web browser, without the need for students to run R or install packages on their own devices, thus allowing instructors to focus on teaching rather than technical troubleshooting. Using a dataset and code from a previously published systematic review and meta-analysis of animal studies, students are walked-through steps demonstrating theoretical and mathematical foundations of meta-analysis and ultimately replicate the analysis and results. This app supports our live educational workshops but is also designed to be a stand-alone learning resource. At each step, there are multiple choice questions for students to check their understanding of the material. We have demonstrated the use of existing R packages to generate a user-interface for students to learn meta-analysis in practice.
Mini-Workshop: Kronecker, Plethysm, and Sylow Branching Coefficients and their Applications to Complexity Theory
Creators: name: (:Unkn) Unknown
Publisher: name: Zürich : EMS Publ. House
Year: 2020
Subjects: subject: Konferenzschrift
subject: 510

description: The Kronecker, plethysm and Sylow branching coefficients describe the decomposition of representations of symmetric groups obtained by tensor products and induction. Understanding these decompositions has been hailed as one of the definitive open problems in algebraic combinatorics and has profound and deep connections with representation theory, symplectic geometry, complexity theory, quantum information theory, and local-global conjectures in representation theory of finite groups. The overarching theme of the Mini-Workshop has been the use of hidden, richer representation theoretic structures to prove and disprove conjectures concerning these coefficients. These structures arise from the modular and local-global representation theory of symmetric groups, graded representation theory of Hecke and Cherednik algebras, and categorical Lie theory.
Revisiting Global Vegetation Controls Using Multi‐Layer Soil Moisture
Creators: name: Li, Wantong
name: Migliavacca, Mirco
name: Forkel, Matthias
name: Walther, Sophia
name: Reichstein, Markus
name: Orth, René
Publisher: name: FID GEO
Year: 2021

description: The productivity of terrestrial vegetation is determined by multiple land surface and atmospheric drivers. Water availability is critical for vegetation productivity, but the role of vertical variability of soil moisture (SM) is largely unknown. Here, we analyze dominant controls of global vegetation productivity represented by sun‐induced fluorescence and spectral vegetation indices at the half‐monthly time scale. We apply random forests to predict vegetation productivity from several hydrometeorological variables including multi‐layer SM and quantify the variable importance. Dominant hydrometeorological controls generally vary with latitudes: temperature in higher latitudes, solar radiation in lower latitudes, and root‐zone SM in between. We find that including vertically resolved SM allows a better understanding of vegetation productivity and reveals extended water‐related control. The deep(er) SM control for semi‐arid grasses and shrubs illustrates the potential of deep(er) rooting systems to adapt to water limitation. This study highlights the potential to infer sub‐surface processes from remote sensing observations.
description: Key Points: Vertically resolved soil moisture (SM) improves the understanding of large‐scale vegetation productivity and yields extended water‐related controls. Data‐driven evidence for the meaningfulness of the long‐standing modeling paradigm of vertical soil layer discretization. Comparatively deep SM is most relevant in semi‐arid areas and for grasses and shrubs.
description: German Research Foundation
description: ESA Living Planet Fellowship
Phase transformations in the silver-aluminum system
Creators: name: Hawbolt, Edward Bruce
Publisher: name: University of British Columbia
Year: 2011

description: The formation of grain boundary precipitates of the high temperature β phase from the supersaturated ɤ phase has been examined in Ag-5.64 wt.% aluminum alloys at 688°C . Large grained samples were used and the boundary misorientations were determined by X-ray diffraction. At low angle boundaries only primary sideplates formed while above a misorientation of 17° lenticular precipitates were dominant. Precipitate growth was studied on individual grain boundaries using a statistical technique. The lengthening and thickening rates were independent of the grain boundary misorientation indicating that grain boundary diffusion was not significant under these conditions. The precipitates grew with constant shape, with both the length and thickness increasing parabolically with time. By approximating the shape of the precipitate to that of an oblate spheroid growing with constant shape, an equivalent diffusion coefficient was calculated. The value obtained was in good agreement with measurements obtained from diffusion couples. The nature of the quenched β phase was also examined using optical and electron microscopy. The βphase transformed rapidly on cooling, forming a massive [symbol omitted] product or an acicular martensite at higher quenching rates. The structures were very similar to those reported for the Cu-Ga and Cu-Al systems. Many grain boundary precipitates showed unequal growth into the two matrix grains. Measurements of the matrix habit plane suggested that a possible orientation relationship existed between the precipitate and that grain into which no development occurred. In this case the precipitate nucleated in one grain but grew into the opposite grain. Precipitates which developed equally into both grains exhibited no apparent habit relationship with either grain.
Limits of Educational Soft "GeoGebra" in a Critical Constructive Review
Creators: name: Antohe, Valerian
Publisher: name: arXiv
Year: 2009
Subjects: subject: Mathematical Software (cs.MS)
subject: FOS: Computer and information sciences

description: Mathematical educational soft explore, investigating in a dynamical way, some algebraically, geometrically problems, the expected results being used to involve a lot of mathematical results. One such software soft is GeoGebra. The software is free and multi-platform dynamic mathematics software for learning and teaching, awards in Europe and the USA. This paper describes some critical but constructive investigation using the platform for graph functions and dynamic geometry.
description: 8 pages, exposed on 5th International Conference "Actualities and Perspectives on Hardware and Software" - APHS2009, Timisoara, Romania
Study of QCD critical point using the canonical ensemble method
Creators: name: Li, Anyi
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: The existence of the QCD critical point at non-zero baryon density is not only of great interest for experimental physics but also a challenge for the theory. Any hint of the existence of the first order phase transition and, particularly, its critical point will be valuable towards a full understanding of the QCD phase diagram. We use lattice simulation based on the canonical ensemble method to explore the finite baryon density and finite temperature region and look for the QCD critical point. As a benchmark, we run simulations for the four degenerate flavor QCD where we observe a clear signal of the expected first order phase transition. In the two flavor case, we do not see any signal for temperatures as low as $0.83 \rm{T_c}$. Although our real world contains two light quarks and one heavier quark, three degenerate flavor case shares a lot of similar phase structures as the QCD. We scan the phase diagram using clover fermions with $m_π\approx 700{MeV}$ on $6^3\times4$ lattices. The baryon chemical potential is measured as we increase the baryon number and we see the characteristic "S-shape" that signals the first order phase transition. We determine the phase boundaries by Maxwell construction and report our preliminary results for the location of critical point for the present lattice.
description: 17 pages, 11 figures. Plenary talk at 27th International Symposium on Lattice Field Theory (Lattice 2009), Beijing, China, 25-31 Jul 2009
Analysis of volcanic facies at the Chatree gold mine and in the Loei-Petchabun Volcanic belt, central Thailand
Creators: name: Cumming, GV
Publisher: name: University Of Tasmania
Year: 2023

description: This thesis presents a detailed volcanological study of the Permo-Triassic rocks that host the low-sulphidation epithermal gold deposit at the Chatree mine in the Loei-Petchabun Volcanic belt, central Thailand. Rocks of similar age that lack appreciable mineralisation have also been studied in the surrounding Petchabun region and in the south of the belt (on Koh Chang Island). Using volcanic facies analysis combined with whole-rock geochemistry, this study seeks to better constrain the depositional setting, origin and style of the volcanism, and volcanic facies architecture at the Chatree epithermal deposit. The aims of this project are: 1. to describe the lithologies in and around the Chatree mine, in the Petchabun Province, and Koh Chang Island and to group them into facies using observations made from drillcore, mine exposures, field outcrops and field samples, 2. to use geochemical and petrological data together with volcanic facies analysis to determine the tectonic setting and source characteristics, 3. to constrain the depositional environment and volcanic setting of the volcanic succession at the Chatree mine and to identify the sequence of eruptive events, and 4. to determine the position of hydrothermal alteration and mineralisation within the stratigraphy that host the Chatree deposit. In doing so, the relative timing of deposition of the volcanic units with respect to mineralisation is defined. This study has significant importance to understanding the host volcanic rocks of the Chatree epithermal deposit. and elsewhere in the Loei‚Äö-Petchabun Volcanic belt (LVb). To date, there has been no detailed volcanological investigation in the region.
Periodic travelling waves in convex Klein-Gordon chains
Creators: name: Herrmann, Michael
Publisher: name: arXiv
Year: 2009
Subjects: subject: Mathematical Physics (math-ph)
subject: Dynamical Systems (math.DS)
subject: FOS: Physical sciences
subject: FOS: Mathematics
subject: 37K60, 47J30, 70F45, 74J30

description: We study Klein-Gordon chains with attractive nearest neighbour forces and convex on-site potential, and show that there exists a two-parameter family of periodic travelling waves (wave trains) with unimodal and even profile functions. Our existence proof is based on a saddle-point problem with constraints and exploits the invariance properties of an improvement operator. Finally, we discuss the numerical computation of wave trains.
description: 12 pages, 3 figures
Correlation Based Time Evolution of the Archeomagnetic Field
Creators: name: Schanner, M.
name: Mauerberger, S.
name: Korte, M.
name: Holschneider, M.
Publisher: name: FID GEO
Year: 2021

description: In a previous study, a new snapshot modeling concept for the archeomagnetic field was introduced (Mauerberger et al., 2020, https://doi.org/10.1093/gji/ggaa336). By assuming a Gaussian process for the geomagnetic potential, a correlation‐based algorithm was presented, which incorporates a closed‐form spatial correlation function. This work extends the suggested modeling strategy to the temporal domain. A space‐time correlation kernel is constructed from the tensor product of the closed‐form spatial correlation kernel with a squared exponential kernel in time. Dating uncertainties are incorporated into the modeling concept using a noisy input Gaussian process. All but one modeling hyperparameters are marginalized, to reduce their influence on the outcome and to translate their variability to the posterior variance. The resulting distribution incorporates uncertainties related to dating, measurement and modeling process. Results from application to archeomagnetic data show less variation in the dipole than comparable models, but are in general agreement with previous findings.
description: Plain Language Summary: Global reconstructions of the past geomagnetic field are useful tools to study the geodynamo process that generates the Earth's magnetic field in the outer core. Data‐based field reconstructions are traditionally represented by a fixed number of coefficients in space and time. In a previous study, a new modeling concept for individual epochs of the magnetic field was introduced, which is better adapted to inhomogeneous data distributions as found in archeomagnetic data, and which provides more realistic uncertainty estimates. This new modeling concept effectively has one coefficient per data point. Here, the new method is expanded to also consider the time evolution and build continuous models of the past geomagnetic field. Uncertainties in archeomagnetic input data and in their ages are taken into account and contribute to estimating reasonable uncertainties for the resulting model. The application of the new method to archeomagnetic data over the past 1,200 years gives general agreement with previous findings with less variation in the dipole field contribution than seen in comparable models.
description: Key Points: Extension of a previous study on spatial correlation based archeomagnetic modeling to the temporal domain. Dating uncertainties are incorporated by the noisy input Gaussian process formalism. Results show general agreement with comparable models with less variation in the dipole field contribution.
description: Deutsche Forschungsgemeinschaft (DFG) http://dx.doi.org/10.13039/501100001659
On the present habitats and ecology of Vertigo pseudosubstriata Ložek, 1954 (Mollusca, Gastropoda, Vertiginidea) in Central Asia and its distribution history in Central and Eastern Europe
Creators: name: Meng, Stefan
name: Vasyliev, Pavlo
name: Khoptynets, Ivan
name: Tkach, Vitalii
name: Maier, Andreas
Publisher: name: FID GEO
Year: 2021

description: The small terrestrial gastropod Vertigo pseudosubstriata Ložek, 1954 is one of the rarest glacial indicator species in the Pleistocene of Central and Eastern Europe. In all, this species has been found at only about 15 sites in Europe. V. pseudosubstriata was initially described as a fossil in Central Europe and was discovered only later alive in Central Asia. With regard to its modern distribution, 25 habitats with V. pseudosubstriata have been examined in Tien Shan and in the central and southern Altai. These findings seem to capture the contemporary distribution of the species and provide information on the boundaries of its ecological requirements. These data are of great significance for the interpretation of the fossil assemblages. Since the few fossil specimens in Europe date from very different glacial periods in the Elsterian, Saalian Complex and Weichselian, it can be concluded that V. pseudosubstriata apparently immigrated in at least three distinct waves. Most of the Pleistocene specimens in eastern Central Europe and Eastern Europe are reported from archaeological sites of the Upper Middle Weichselian (Gravettian), roughly between 33 and 29 ka cal bp. In this paper, we review all reported modern and fossil occurrences and discuss the species' ecological range.
VLT Spectropolarimetry of the optical transient in NGC300. Evidence for asymmetry in the circumstellar dust
Creators: name: Patat, F.
name: Maund, J. R.
name: Benetti, S.
name: Botticella, M. -T.
name: Cappellaro, E.
name: Harutyunyan, A.
name: Turatto, M.
Publisher: name: arXiv
Year: 2009
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: AIMS: The main goal of this work is to study possible signs of asymmetry in the bright optical transient in NGC300, with the aim of getting independent information on the explosion mechanism, the progenitor star and its circumstellar environment. METHODS: Using VLT-FORS1 we have obtained low-resolution optical linear spectropolarimetry of NGC300 OT2008-1 on two epochs, 48 and 55 days after the discovery, covering the spectral range 3600--9330A. RESULTS: The data show a continuum polarization at a very significant level. At least two separate components are identified. The first is characterized by a strong wavelength dependency and a constant position angle (68.6+/-0.3 degrees), which is parallel to the local spiral arm of the host galaxy. The second shows a completely different position angle (151.3+/-0.4) and displays a mild but statistically significant evolution between the two epochs. While the former is identified as arising in the interstellar dust associated with NGC300, the latter is most likely due to continuum polarization by dust scattering in the circumstellar environment. No line depolarization is detected in correspondence of the most intense emission lines, disfavoring electron scattering as the source of intrinsic polarization. This implies a very small deviation from symmetry in the continuum-forming region. Given the observed level of intrinsic polarization, the transient must be surrounded by a significant amount of dust (>4x10^-5 Msun), asymmetrically distributed within a few thousand AU. This most likely implies that one or more asymmetric outflow episodes took place during the past history of the progenitor.
description: Accepted for publication in Astronomy and Astrophysics. 16 pages, 16 figures
Geology of the Granville Harbour area and mineralization in the Gourlays Creek prospect
Creators: name: Norris, RG
Publisher: name: University Of Tasmania
Year: 2023

description: The dominantly (meta-)sedimentary sequence of the Granville Harbour area ranges in age from Late,Proterozoic to Devonian. Five phases of deformation are recognized in these sequences; two are correlated with the Late Proterozoic Penguin Orogeny, one with the Upper Cambrian Jukesian Movement, and two with the Early to late-Middle Devonian (Tabberabberan) Orogeny. Lower greenschist facies metamorphism accompanied the Penguin Orogeny. Faulted against the Oonah Formation and unconformably underlying the Mt Zeehan Conglomerate are 415 m of interlayered schists, phyllites, quartzites and dolomites. This sequence is a probable lithostratigraphic correlate of the Crimson Creek Formation and has been named the Duck Creek Sequence. Minor metavolcanics contained within the Duck Creek Sequence, Oonah Formation and Whyte schist are defined chemically as ocean-floor tholeiite basalts. Within the Gourlays Creek Prospect, the Oonah Formation hosts two distinct styles of mineralization: (i) syngenetic banded iron formation of chemical origin, and (ii) calcic, garnet-pyroxene, metasomatic infiltration exoskarn. The banded iron formation is a stratabound and stratiform horizon consisting of massive and banded magnetite-pyrite-(quartz) and magnetite-barite mineralization. This chemical exhalative, banded iron formation is a probable analogue of the (Recent) Red Sea metalliferous sediments and is the only recognized deposit of its type in Tasmania. Sulphur isotopes from this horizon give 8 34 S values for pyrite in the range of -7.6 to +15.5%a and for barite, 34 +35.8%o. A combination of inorganic reduction of Precambrian seawater, (6 S = +20 to +25% ), with isotope disequtlibrium, and biogenic reduction is required to explain the range in pyrite s34s values. Intrusion of the Devonian Heemskirk Granite was accompanied by the formation of a garnet- pyroxene skarn. The dominantly calcic mineralogy of the skarn is suggestive of a lime-rich protolith. The deposition of magnetitepyrrhotite- chalcopyrite and pyrite occurred during retrograde skarn alteration. Sulphur isotope studies of skarn-associated sulphides indicate a source fluid with a 8 34s value of +7 to +15%0 ‚Äö Such high values indicate an inhomogeneous source consisting of barite from the banded iron formation, primary pyrite and/or magmatic sulphur. From fluid inclusion studies, homogenization temperatures for garnet and late-stage, retrograde quartz are )500¬¨‚àûC and 330-340¬¨‚àûC respectively. Deposition of sulphides during retrograde skarn alteration is inferred to occur at temperatures of 350-360¬¨‚àûC, pressures of 13-35 MPa and from a 20-21 wt% equiv. NaCl solution. Minor tin (<0.35%) mineralization is considered to be associated with retrograde skarn formation.
Fundamental physics on natures of the macroscopic vacuum under high intense electromagnetic fields with accelerators
Creators: name: Homma, Kensuke
Publisher: name: arXiv
Year: 2009
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: High intense electromagnetic fields can be unique probes to study natures of macroscopic vacua by themselves. Combining accelerators with the intense field can provide more fruitful probes which can neither be achieved by only intense fields nor only high energy accelerators. We will overview the natures of vacua which can be accessible via intense laser-laser and intense laser-electron interactions. In the case of the laser-laser interaction, we propose how to observe nonlinear QED effects and effects of new fields like light scalar and pseudo scalar fields which may contribute to a macroscopic nature of our universe such as dark energy. In the case of the laser-electron interaction, in addition to nonlinear QED effects, we can further discuss the nature of accelerating field in the vacuum where we can access physics related with event horizons such as Hawking-Unruh radiations. We will introduce a recent experimental trial to search for this kind of odd radiations.
description: 12 pages, 6 figures
Fast optical variability of Naked-Eye Burst - manifestation of periodic activity of internal engine
Creators: name: Beskin, G.
name: Karpov, S.
name: Bondar, S.
name: Guarnieri, A.
name: Bartolini, C.
name: Greco, G.
name: Piccioni, A.
Publisher: name: arXiv
Year: 2009
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We imaged the position of the Naked-Eye Burst, GRB080319B, before, during and after its gamma-ray activity with sub-second temporal resolution and discovered the fast variability of its prompt optical emission. Its characteristics and similarity with properties of gamma emission temporal structure suggest that it reflects the behaviour of internal engine -- supposedly, a hyperaccreting solar-mass black hole formed in the collapse of a massive stellar core.
description: Submitted to Science; please note that this manuscript is subject to press embargo
Results of the Electron Drift Instrument on Cluster
Creators: name: Paschmann, G.
name: Quinn, J. M.
name: Torbert, R. B.
name: McIlwain, C. E.
name: Vaith, H.
name: Haaland, S.
name: Matsui, H.
name: Kletzing, C. A.
name: Baumjohann, W.
name: Haerendel, G.
Publisher: name: FID GEO
Year: 2021

description: The electron drift instrument (EDI) on Cluster pioneered a new method of measuring electric fields, using a beam of electrons to sample the drift velocity over a km‐scale gyro orbit. The technique is especially well suited to measuring weak, sub‐mV/m, convection fields due to its sensitivity (to both components in the plane perpendicular to B) and because it is unaffected by the anomalous local electric fields that are generated by spacecraft‐plasma interactions. Because EDI requires exquisite beam pointing with active tracking of the firing directions, measurements are less regular, or even impossible, in rapidly varying electric and magnetic fields; however, in the many regimes where tracking is successful the resulting measurements are reliably accurate. We review the EDI technique and instrumentation, and present six areas of investigation using Cluster data: (1) Detailed comparisons of EDI data with the electric field and waves double probe measurements show excellent agreement in many cases but identify large discrepancies where strong ion outflow in the polar regions creates local spacecraft wake effects. (2) The wake effect is exploited to infer quantitative ion outflow rates. Detailed convection patterns in the (3) polar cap, (4) lobe, and (5) inner magnetosphere are derived under various driver conditions using statistical analyses of long term measurements during the Cluster mission. (6) EDI's large geometric‐factor detector is used for extremely high time resolution measurements of electrons at a specified energy and pitch angle.
description: Key Points: Complementarity of electron drift and double‐probe techniques established. Inner magnetosphere, polar cap, and tail‐lobe convection patterns determined. Key contribution to ion outflow velocities made.
O(a^2) corrections to the propagator and bilinears of Wilson / clover fermions
Creators: name: Constantinou, Martha
name: Panagopoulos, Haralambos
name: Stylianou, Fotos
Publisher: name: arXiv
Year: 2008
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: FOS: Physical sciences

description: We present the corrections to the fermion propagator, to second order in the lattice spacing, O(a^2), in 1-loop perturbation theory. The fermions are described by the clover action and for the gluons we use a 3-parameter family of Symanzik improved actions. Our calculation has been carried out in a general covariant gauge. The results are provided as a polynomial of the clover parameter, and are tabulated for 10 popular sets of the Symanzik coefficients (Plaquette, Tree-level Symanzik, Iwasaki, TILW and DBW2 action). We also study the O(a^2) corrections to matrix elements of fermion bilinear operators that have the form $\barΨΓΨ$, where $Γ$ denotes all possible distinct products of Dirac matrices. These correction terms are essential ingredients for improving, to O(a^2), the matrix elements of the fermion operators. Our results are applicable also to the case of twisted mass fermions. A longer write-up of this work, including non-perturbative results, is in preparation together with V. Gimenez, V. Lubicz and D. Palao.
description: 7 pages, 1 figure. Talk presented at the XXVI International Symposium on Lattice Field Theory, July 14-19, 2008, Williamsburg, VA, USA
Constraining Global Marine Iron Sources and Ligand‐Mediated Scavenging Fluxes With GEOTRACES Dissolved Iron Measurements in an Ocean Biogeochemical Model
Creators: name: Somes, Christopher J.
name: Dale, Andrew W.
name: Wallmann, Klaus
name: Scholz, Florian
name: Yao, Wanxuan
name: Oschlies, Andreas
name: Muglia, Juan
name: Schmittner, Andreas
name: Achterberg, Eric P.
Publisher: name: FID GEO
Year: 2021

description: Iron is a key micronutrient controlling phytoplankton growth in vast regions of the global ocean. Despite its importance, uncertainties remain high regarding external iron source fluxes and internal cycling on a global scale. In this study, we used a global dissolved iron data set, including GEOTRACES measurements, to constrain source and scavenging fluxes in the marine iron component of a global ocean biogeochemical model. Our model simulations tested three key uncertainties: source inputs of atmospheric soluble iron deposition (varying from 1.4 to 3.4 Gmol/yr), reductive sedimentary iron release (14–117 Gmol/yr), and compared a variable ligand parameterization to a constant distribution. In each simulation, scavenging rates were tuned to reproduce the observed global mean iron inventory for consistency. The variable ligand parameterization improved the global model‐data misfit the most, suggesting that heterotrophic bacteria are an important source of ligands to the ocean. Model simulations containing high source fluxes of atmospheric soluble iron deposition (3.4 Gmol/yr) and reductive sedimentary iron release (114 Gmol/yr) further improved the model most notably in the surface ocean. High scavenging rates were then required to maintain the iron inventory resulting in relatively short surface and global ocean residence times of 0.83 and 7.5 years, respectively. The model simulates a tight spatial coupling between source inputs and scavenging rates, which may be too strong due to underrepresented ligands near source inputs, contributing to large uncertainties when constraining individual fluxes with dissolved iron concentrations. Model biases remain high and are discussed to help improve global marine iron cycle models.
description: Key Points: Global marine iron model tests varying levels of atmospheric deposition, sedimentary release, ligand distributions, and scavenging rates. Simulations that best reproduce observations include variable ligands and high rates of atmospheric deposition and sedimentary release. Simulations with high iron sources require high scavenging rates resulting in short residence times.
description: Deutsche Forschungsgemeinschaft (DFG) http://dx.doi.org/10.13039/501100001659
description: European Union Horizon 2020 Program
description: United States National Science Foundation
Utilizing Retirement Planning as Leverage for Age Reduction among Workers
Creators: name: Delali Adjoa Dovie
Publisher: name: figshare
Year: 2021
Subjects: Economics

description: Preparedness inadequacy for the retirement transition is one of the critical reasons for age reduction. This chapter examines retirement planning as a leveraging strategy and vibrant remedy for age reduction using quantitative data obtained from formal and informal sector workers (N=442). The findings show that retirement plans are categorized into short-term, medium, and long-term plans. Collectively, these yield income, health, housing, social networks, leisure, and paid work beyond pensions. Post-retirement income is a significant determinant of the retirement decision. Retirement planning can be used to leverage the lack of preparedness for retirement, which in turn reduces the activity of age reduction. This averts dependency in old age and creates the avenue for successful ageing, which is often heralded by the retirement transition. Further, not planning for retirement and the associated act of age reduction is an indication of the non-acknowledgment of the notion of active ageing. Noteworthy age reduction is a portrayal of old age as a shameful loss of youthfulness. This chapter argues that planning for retirement may be the best alternative strategy for combating age reduction from an economic outcome dimension. Retirement planning is leveraged without which labor cannot achieve old age oriented social protection at the individual level.
Rhizobien in der Pflanzenmikrobiota
Creators: name: Wippel, Kathrin
name: Schulze-Lefert, Paul
name: Garrido-Oter, Ruben
Publisher: name: FID GEO
Year: 2019

description: Für das Wachstum und Überleben der Pflanze im Boden ist ihre Mikrobiota von maßgeblicher Bedeutung. Pflanzen-Mikrobiota-Interaktionen können unter Laborbedingungen durch definierte Gemeinschaften von Kommensalen nachgestellt und durch Ko-Kultivierung mit dem keimfreien Pflanzenwirt auf ihre Wirkung auf das Wachstum und die Gesundheit der Pflanzen geprüft werden. Die Ordnung der Rhizobiales gehört zum Kern der Pflanzenmikrobiota und beinhaltet stickstoffbindende Wurzelknöllchenbakterien, die in einer Symbiose mit Leguminosen leben. Nur kompatible Wirt-Symbionten-Paare können Symbiosen etablieren, was durch hochspezialisierte und verknüpfte Signalwege zwischen den beiden Partnern gewährleistet wird. Vergleichende Genomanalysen von Symbionten und Rhizobiales-Wurzelkommensalen aus Nicht-Leguminosen zeigen, dass der jüngste gemeinsame Vorfahre zwar die Fähigkeit zur Wurzelbesiedelung mit breitem Wirtspektrum besaß, symbiontische Interaktionen sich jedoch erst durch Gentransfer, der in der Evolution mehrfach unabhängig in mehreren Familien der Rhizobiales erfolgt ist, entwickelten.
description: Rhizobia in the plant microbiota The plant microbiota is of critical importance for plant growth and survival in soil. To explore mechanisms underlying plant-microbiota interactions, defined commensal communities can be composed from microbiota culture collections and co-cultivated with germ-free plants to determine their impact on plant growth and health. The order Rhizobiales belongs to the core microbiota and includes nitrogen-fixing bacteria that are known to engage in symbiotic interactions with legumes. Compatible host-symbiont pairs are needed for a functional symbiosis, which involves the activation of highly specialized and interdependent signaling pathways between the two partners. Comparative genome analysis of more than 1,300 legume symbionts and rhizobial root commensals from non-leguminous plants revealed that the most recent common ancestor of rhizobia lacked the gene repertoire needed for symbiosis and was able to colonize roots of a wide variety of plants. During evolution, key symbiosis genes were acquired multiple independent times by commensals belonging to different families of the Rhizobiales order.
Engaging the convict legacy : art's role as a means of understanding
Creators: name: Henri, CJ
Publisher: name: University Of Tasmania
Year: 2023

description: Based on the heritage sites that form part of Australia's convict legacy, focusing mainly within Van Diemen's Land (Tasmania), this project explores ways in which the economic, social and cultural context of the transportation experience can be communicated to the 21st century visitors to the various sites. The importance of art in mediating site in the service of history will be demonstrated through the conception and curation of a major installation work inviting international participation. Behind the practice--‚ÄövÑv™led investigation lies research into possible interpretative and art installation strategies for specific sites: some of the strategies have been initiated in the course of this project, while others remain as suggestions for consideration in future contexts. All aspects of the project retain a focus on demonstrating the importance of art as a significant tool to bring attention to history. This is a project by an artist working within a worldwide community that retains links to a convict past, not the work of an historian. With the recent World Heritage nomination of eleven convict sites within Australia this research is pertinent to current concerns within the heritage and tourism industries regarding the communication of these sites to a non--‚ÄövÑv™expert, cross--‚ÄövÑv™cultural, international audience. Sites central to the research include Maria Island, Cascades Female Factory and Woolmers Estate. Attention to conventional history is used to inform the practice component of the project. Producing and presenting past experiences of each site through art in the form of exhibitions, installations and performance art is one possible interpretation strategy. Reference has been made to artists who have worked in similar themes and media including Hossein Valamanesh and Angela Valamanesh, Anne Ferran, Fiona Hall and Julie Gough, and to Susan Best's ideas of affect. Writers who have addressed the question of interpretive modes of history include Ann Curthoys and John Docker. Kate Grenville and Rohan Wilson provide recent examples through the contemporary historical novel of literary evocations of site. The tenets of tourism are derived from Dean McCannell. The project demonstrates that art works can be used by historians and site custodians to evoke story, memory and a sense of place and time that enriches the visitor experience and can elicit poignant and sometime surprising responses from those who choose to participate in the collaborative aspects of the project, from simply attending a site or exhibition having direct input to installations and related site--‚ÄövÑv™specific activities.
In situ S‐isotope compositions of sulfate and sulfide from the 3.2 Ga Moodies Group, South Africa: A record of oxidative sulfur cycling
Creators: name: Nabhan, Sami
name: Marin‐Carbonne, Johanna
name: Mason, Paul R.D.
name: Heubeck, Christoph
Publisher: name: FID GEO
Year: 2020

description: Sulfate minerals are rare in the Archean rock record and largely restricted to the occurrence of barite (BaSO4). The origin of this barite remains controversially debated. The mass‐independent fractionation of sulfur isotopes in these and other Archean sedimentary rocks suggests that photolysis of volcanic aerosols in an oxygen‐poor atmosphere played an important role in their formation. Here, we report on the multiple sulfur isotopic composition of sedimentary anhydrite in the ca. 3.22 Ga Moodies Group of the Barberton Greenstone Belt, southern Africa. Anhydrite occurs, together with barite and pyrite, in regionally traceable beds that formed in fluvial settings. Variable abundances of barite versus anhydrite reflect changes in sulfate enrichment by evaporitic concentration across orders of magnitude in an arid, nearshore terrestrial environment, periodically replenished by influxes of seawater. The multiple S‐isotope compositions of anhydrite and pyrite are consistent with microbial sulfate reduction. S‐isotope signatures in barite suggest an additional oxidative sulfate source probably derived from continental weathering of sulfide possibly enhanced by microbial sulfur oxidation. Although depositional environments of Moodies sulfate minerals differ strongly from marine barite deposits, their sulfur isotopic composition is similar and most likely reflects a primary isotopic signature. The data indicate that a constant input of small portions of oxidized sulfur from the continents into the ocean may have contributed to the observed long‐term increase in Δ33Ssulfate values through the Paleoarchean.
description: Centre National de la Recherche Scientifique
description: Deutsche Forschungsgemeinschaft
description: H2020 European Research Council