117 research outputs found
Malta : language, literacy and identity in a Mediterranean island society
Available documentation for the early modern period indicates that the Malta harbor towns achieved literacy earlier than the countryside. The Maltese townsmen lived on a trading route, and it was necessary for them to learn the lingua franca, as the language of
trade in the Mediterranean. The educated elite were able to acquire fluent speaking knowledge, as well as the ability to write, Tuscan (a dialect then in the process of becoming standard Italian), while continuing to employ their local Maltese ‘dialect’ on numerous occasions. By and large, the erosion of the position of Maltese as the subordinate language was an inevitable by-product of this development. The Maltese language was able to attain the function of a literary language in the nineteenth century but it had no standard orthography until 1931 and was only adopted as Malta’s official language in 1964.peer-reviewe
Combined strong and weak lensing analysis of 28 clusters from the Sloan Giant Arcs Survey
We study the mass distribution of a sample of 28 galaxy clusters using strong
and weak lensing observations. The clusters are selected via their strong
lensing properties as part of the Sloan Giant Arcs Survey (SGAS) from the Sloan
Digital Sky Survey (SDSS). Mass modelling of the strong lensing information
from the giant arcs is combined with weak lensing measurements from deep
Subaru/Suprime-cam images to primarily obtain robust constraints on the
concentration parameter and the shape of the mass distribution. We find that
the concentration c_vir is a steep function of the mass, c_vir \propto
M_vir^-0.59\pm0.12, with the value roughly consistent with the
lensing-bias-corrected theoretical expectation for high mass (10^15 h^-1 M_sun)
clusters. However, the observationally inferred concentration parameters appear
to be much higher at lower masses (10^14 h^-1 M_sun), possibly a consequence of
the modification to the inner density profiles provided by baryon cooling. The
steep mass-concentration relation is also supported from direct stacking
analysis of the tangential shear profiles. In addition, we explore the
two-dimensional shape of the projected mass distribution by stacking weak
lensing shear maps of individual clusters with prior information on the
position angle from strong lens modelling, and find significant evidence for a
large mean ellipticity with the best-fit value of e = 0.47 \pm 0.06 for the
mass distribution of the stacked sample. We find that the luminous cluster
member galaxy distribution traces the overall mass distribution very well,
although the distribution of fainter cluster galaxies appears to be more
extended than the total mass.Comment: 29 pages, 15+9 figures, 7 tables, accepted for publication in MNRA
A Radio Relic And A Search For The Central Black Hole In The Abell 2261 Brightest Cluster Galaxy
We present VLA images and HST/STIS spectra of sources within the center of the brightest cluster galaxy (BCG) in Abell 2261. These observations were obtained to test the hypothesis that its extremely large, flat core reflects the ejection of its supermassive black hole. Spectra of three of the four most luminous knots embedded in the core were taken to test whether one may represent stars bound to a displaced massive black hole. The three knots have radial velocity offsets dV \u3c ~150 km/s from the BCG. Knots 2 and 3 show kinematics, colors, and stellar masses consistent with infalling low-mass galaxies or larger stripped cluster members. Large errors in the stellar velocity dispersion of Knot 1, however, mean that we cannot rule out the hypothesis that it hosts a high-mass black hole. A2261-BCG has a compact, relic radio-source offset by 6.5 kpc (projected) from the optical core\u27s center, but no active radio core that would pinpoint the galaxy\u27s central black hole to a tight 10 GHz flux limit 48 Myr ago, with an equipartition condition magnetic field of 15 uG. These observations are still consistent with the hypothesis that the nuclear black hole has been ejected from its core, but the critical task of locating the supermassive black hole or demonstrating that A2261-BCG lacks one remains to be done
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Nuclear and chloroplast microsatellite markers to assess genetic diversity and evolution in hazelnut species, hybrids and cultivars
The US Department of Agriculture, Agricultural Research Service, National Clonal Germplasm Repository in Corvallis, Oregon, preserves more than 800 accessions of hazelnut (Corylus), including C. avellana cultivars and representatives of 10 other recognized shrub and tree species. Characterization and study of genetic diversity in this collection require cross-transferable markers, such as trinucleotide microsatellite or simple sequence repeat (SSR) markers and universal chloroplast SSR markers. We developed new SSR markers and evaluated 114 Corylus accessions representing 11 species and 44 interspecific hybrids. Eight of 23 SSRs generated easy-to-score alleles in all species and seven were highly polymorphic. For those seven, the average heterozygosity was moderate at 0.49, and mean allele number, genetic diversity and polymorphism information index were high at 11.71, 0.79 and 0.76, respectively. The three most polymorphic SSRs were CaC-C008, CaC-C040 and CaC-C118. Neighbor-joining (NJ) clustering and structure analysis agreed with classical taxonomic analysis and supported inclusion of C. maxima within the large polymorphic species, C. avellana. Analysis also indicated that C. californica is a distinct species rather than a botanical variety of C. cornuta. Six universal cpSSRs were polymorphic in Corylus and generated 21 distinct chlorotypes with an average of 3 alleles per locus. Diversity at these cpSSRs was high and ranged from 0.33 to 0.64, with an average of 0.54. Incongruence in NJ topologies between the nuclear and chloroplast markers could be attributed to chloroplast capture related to hybridization during the ancestral diversification of the genus, or to homoplasy. The phylogeographical relationships among the 21 chlorotypes in the 11 Corylus species support Asia as a refugium where several hazelnut lineages survived during glaciation and from which they continued to evolve after dispersal from Asia through the Mediterranean to Europe, and across the Atlantic and/or the Bering land bridge to North America.Keywords: Simple sequence repeat (SSR) markers, Filbert, Universal chloroplast SSRs, CorylusKeywords: Simple sequence repeat (SSR) markers, Filbert, Universal chloroplast SSRs, Corylu
Collaborative Exploration between NIAS Genebank and USDA ARS (U.S. Department of Agriculture, Agricultural Research Service) for the Collection of Genetic Resources of Fruit and Nut Species in Hokkaidō and the Northern Tōhoku Region
From 7 to 25 September 2009, a collaborative exploration between NIAS Genebank and USDA ARS to collect genetic resources in Hokkaidō and the Northern Tōhoku region was performed. The investigated areas were mainly upper deciduous forest and subalpine conifer forest zones. The vegetation was mainly forests, but we also visited upland bogs and coastal vegetation to collect some particular plants. The expedition obtained 147 seed and plant samples representing 20 genera and 53 species. Collected genera were Actinidia, Chaenomeles, Corylus, Crataegus, Empetrum, Gaultheria, Humulus, Fragaria, Lonicera, Lycium, Malus, Mentha, Prunella, Potentilla, Pyrus, Ribes, Rubus, Sorbu, Vaccinium and Vitis.農業生物資源研究所ジーンバンクと米国農務省研究局との共同事業として,2009年9月7日から25日まで,北海道及び北東北地域の果樹遺伝資源の探索を行った.調査地域の植生は,上部温帯から亜寒帯針葉樹林帯にあたる.主として森林地帯で調査を行ったが,立地条件の特殊な種の探索のため,高山湿原や海岸周辺部も巡った.この結果,以下の20属53種について計147点を収集した:マタタビ属,ボケ属,ハシバミ属,サンザシ属,ガンコウラン属,アカモノ属,カラハナソウ属,イチゴ属,ウグイスカグラ属,クコ属,リンゴ属,ハッカ属,ウツボグサ属,キジムシロ属,ナシ属,スグリ属,キイチゴ属,ナナカマド属,スノキ属,ブドウ属である
Curvature in the scaling relations of early-type galaxies
We select a sample of about 50,000 early-type galaxies from the Sloan Digital
Sky Survey (SDSS), calibrate fitting formulae which correct for known problems
with photometric reductions of extended objects, apply these corrections, and
then measure a number of pairwise scaling relations in the corrected sample. We
show that, because they are not seeing corrected, the use of Petrosian-based
quantities in magnitude limited surveys leads to biases, and suggest that this
is one reason why Petrosian-based analyses of BCGs have failed to find
significant differences from the bulk of the early-type population. These
biases are not present when seeing-corrected parameters derived from
deVaucouleur fits are used. Most of the scaling relations we study show
evidence for curvature: the most luminous galaxies have smaller velocity
dispersions, larger sizes, and fainter surface brightnesses than expected if
there were no curva-ture. These statements remain true if we replace
luminosities with stellar masses; they suggest that dissipation is less
important at the massive end. There is curvature in the dynamical to stellar
mass relation as well: the ratio of dynamical to stellar mass increases as
stellar mass increases, but it curves upwards from this scaling both at small
and large stellar masses. In all cases, the curvature at low masses becomes
apparent when the sample becomes dominated by objects with stellar masses
smaller than 3 x 10^10 M_Sun. We quantify all these trends using second order
polynomials; these generally provide significantly better description of the
data than linear fits, except at the least luminous end.Comment: 15 pages, 17 figures, Accepted by MNRA
OpTIIX: An ISS-Based Testbed Paving the Roadmap Toward a Next Generation Large Aperture UV/Optical Space Telescope
The next generation large aperture UV/Optical space telescope will need a diameter substantially larger than even that of JWST in order to address some of the most compelling unanswered scientific quests. These quests include understanding the earliest phases of the Universe and detecting life on exo-planets by studying spectra of their atmospheres. Such 8-16 meter telescopes face severe challenges in terms of cost and complexity and are unlikely to be affordable unless a new paradigm is adopted for their design and construction. The conventional approach is to use monolithic or preassembled segmented mirrors requiring complicated and risky deployments and relying on future heavy-lift vehicles, large fairings and complex geometry. The new paradigm is to launch component modules on relatively small vehicles and then perform in-orbit robotic assembly of those modules. The Optical Testbed and Integration on ISS eXperiment (OpTIIX) is designed to demonstrate, at low cost by leveraging the infrastructure provided by ISS, telescope assembly technologies and end-to-end optical system technologies. The use of ISS as a testbed permits the concentration of resources on reducing the technical risks associated with robotically integrating the components. These include laser metrology and wavefront sensing and control (WFS&C) systems, an imaging instrument, lightweight, low-cost deformable primary mirror segments and the secondary mirror. These elements are then aligned to a diffraction-limited optical system in space. The capability to assemble the optical system and remove and replace components via the existing ISS robotic systems like the Special Purpose Dexterous Manipulator (SPDM), or by the ISS flight crew, allows for future experimentation, as well as repair
Understanding the circumgalactic medium is critical for understanding galaxy evolution
Galaxies evolve under the influence of gas flows between their interstellar
medium and their surrounding gaseous halos known as the circumgalactic medium
(CGM). The CGM is a major reservoir of galactic baryons and metals, and plays a
key role in the long cycles of accretion, feedback, and recycling of gas that
drive star formation. In order to fully understand the physical processes at
work within galaxies, it is therefore essential to have a firm understanding of
the composition, structure, kinematics, thermodynamics, and evolution of the
CGM. In this white paper we outline connections between the CGM and galactic
star formation histories, internal kinematics, chemical evolution, quenching,
satellite evolution, dark matter halo occupation, and the reionization of the
larger-scale intergalactic medium in light of the advances that will be made on
these topics in the 2020s. We argue that, in the next decade, fundamental
progress on all of these major issues depends critically on improved empirical
characterization and theoretical understanding of the CGM. In particular, we
discuss how future advances in spatially-resolved CGM observations at high
spectral resolution, broader characterization of the CGM across galaxy mass and
redshift, and expected breakthroughs in cosmological hydrodynamic simulations
will help resolve these major problems in galaxy evolution.Comment: Astro2020 Decadal Science White Pape
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