2,086 research outputs found
SocialPosition : Social Position Indicators Construction Toolbox
This R package provides to sociologists (and related scientists) a toolbox to facilitate the construction of social position indicators from survey data. Social position indicators refer to what is commonly known as social class and social status. There exists in the sociological literature many theoretical conceptualisation and empirical operationalization of social class and social status. This first version of the package offers tools to construct the International Socio-Economic Index of Occupational Status (ISEI) and the Oesch social class schema. It also provides tools to convert several occupational classifications (PCS82, PCS03, and ISCO08) into a common one (ISCO88) to facilitate data harmonisation work, and tools to collapse (i.e. group) modalities of social position indicators
Effects of electromagnetic waves on the electrical properties of contacts between grains
A DC electrical current is injected through a chain of metallic beads. The
electrical resistances of each bead-bead contacts are measured. At low current,
the distribution of these resistances is large and log-normal. At high enough
current, the resistance distribution becomes sharp and Gaussian due to the
creation of microweldings between some beads. The action of nearby
electromagnetic waves (sparks) on the electrical conductivity of the chain is
also studied. The spark effect is to lower the resistance values of the more
resistive contacts, the best conductive ones remaining unaffected by the spark
production. The spark is able to induce through the chain a current enough to
create microweldings between some beads. This explains why the electrical
resistance of a granular medium is so sensitive to the electromagnetic waves
produced in its vicinity.Comment: 4 pages, 5 figure
Earliest history of coal mining and grindstone quarrying at Joggins, Nova Scotia, and its implications for the meaning of the place name âJogginsâ
The rich history of coal mining and grindstone quarrying at Joggins, Nova Scotia, prior to Lyellâs visit in 1842 is less well known than its subsequent history. Franquelin first observed coal there in 1686, and within little more than a decade Acadian coal mines had sprung up at the Coal Cliffs. Following the British acquisition of Nova Scotia in 1713, the coal mines attracted Captain Belcher and other New England traders, who loaded their ships with coal for sale in Boston. In 1731, eager to impose duty on this unregulated trade, the Nova Scotia Council sponsored a British coal mine at Joggins operated by Major Cope. Unable to safely load ships at the Coal Cliffs, Cope constructed a wharf and coal depot at Granâchoggin (present-day Downing Cove), seven miles to the north of the mine. It was by association with this depot that the Coal Cliffs later became known as Joggins. Copeâs coal mine survived less than eighteen months before the Miâkmaq, aided and abetted by Acadians, destroyed the site in 1732. Following this episode, Acadians worked the Joggins coal mines until they fell under the control of British forces engaged in the Seven Years War in 1756. Subsequently, the Lords of Trade suppressed coal mining at Joggins, fearing it would harm British imports, and full-scale operations did not recommence until 1847. During this lull, the grindstone industry boomed. Beginning sometime before 1764, the principal stone quarries operated at Lower Cove, where the famous Blue-Grit was cut. Grindstone quarries were also worked on the Maringouin Peninsula and the two opposing sides of Chignecto Bay became known as the North and South Joggins.
RĂSUMĂ
On connaĂźt moins bien le riche passĂ© de lâextraction du charbon et de la pierre meuliĂšre Ă Joggins, NouvelleâĂcosse, avant la visite de Lyell en 1842, que son passĂ© subsĂ©quent. Franquelin y avait observĂ© du charbon pour la premiĂšre fois en 1686 et en lâespace dâun peu plus dâune dĂ©cennie, plusieurs mines de charbon acadiennes Ă©taient apparues Ă Coal Cliffs. Ă la suite de lâacquisition de la NouvelleâĂcosse par les Britanniques en 1713, les mines de charbon ont attirĂ© le capitaine Belcher et dâautres commerçants de la NouvelleâAngleterre qui chargeaient leurs vaisseaux de charbon pour le vendre Ă Boston. En 1731, impatient dâimposer des droits sur ce commerce non rĂ©glementĂ©, le Conseil de la NouvelleâĂcosse a parrainĂ© lâexploitation Ă Joggins dâune mine de charbon britannique exploitĂ©e par le major Cope. Incapable de charger de façon sĂ©curitaire les navires Ă Coal Cliffs, Cope construisit un quai et un dĂ©pĂŽt de charbon Ă Granâchoggin (anse Downing actuelle), Ă sept milles au nord de la mine. Lâassociation Ă ce dĂ©pĂŽt a plus tard confĂ©rĂ© Ă Coal Cliffs le nom de Joggins. La mine de charbon de Cope a subsistĂ© moins de 18 mois jusquâĂ ce que les Micmacs, aidĂ©s et soutenus par les Acadiens, dĂ©truisirent lâemplacement en 1732. AprĂšs cet Ă©pisode, les Acadiens ont exploitĂ© les mines de charbon de Joggins jusquâĂ ce quâelles tombent sous le contrĂŽle des forces britanniques engagĂ©es dans la guerre de Sept Ans en 1756. Les lords du commerce ont subsĂ©quemment supprimĂ© lâextraction du charbon Ă Joggins, par crainte quâelle fasse tort aux importations britanniques, et lâexploitation Ă grande Ă©chelle nâa pas recommencĂ© avant 1847. Pendant cette pĂ©riode dâaccalmie, lâindustrie de la pierre meuliĂšre a connu un essor notable. Les principales carriĂšres de pierre ont commencĂ© leurs activitĂ©s dans les annĂ©es ayant prĂ©cĂ©dĂ© 1764 Ă Lower Cove, oĂč lâon extrayait le fameux grĂšs dur bleu. Des carriĂšres de pierre meule ont Ă©galement Ă©tĂ© exploitĂ©es sur la pĂ©ninsule Maringouin et les deux rives opposĂ©es de la baie Chignectou devinrent connues sous les noms de North et South Joggins
Anatomically-preserved cordaitalean trees from Lower Pennsylvanian (Langsettian) dryland alluvial-plain deposits at Joggins, Nova Scotia
Recent discoveries at Joggins, Nova Scotia have altered our understanding of the Pennsylvanian tropical biome. Of particular signiïŹcance has been the recognition of seasonal dryland ecosystems, compositionally distinct from the peat-forming wetland rainforests. Here I describe two anatomically-preserved fossil plant specimens from dryland alluvial plain facies. The ïŹrst specimen, Mesoxylon cf. sutclifïŹ i, is previously unknown from Joggins. It is a septate cordaitalean axis with mesarch leaf traces and a non-sympodial vasculature. Where found as isolated blocks, the secondary xylem of this plant has previously been classiïŹed as Dadoxylon recentium. The axis exhibits subtle growth interruptions suggestive of tropical rainfall seasonality, while associated traumatic zones may record ïŹre-damage. The second specimen is a Dadoxylon stump rooted within well-drained ïŹoodbasin soils. It conïŹrms earlier conjecture, based on parautochthonous assemblages, that cordaitalean trees grew in inter-channel areas. Together these new specimens improve our knowledge of the composition and ecology of seasonal dryland vegetation at Joggins.
RĂSUMĂ
Des dĂ©couvertes rĂ©centes Ă Joggins (Nouvelle-Ăcosse), ont modiïŹĂ© notre comprĂ©hension du biome tropical pennsylvanien. La reconnaissance d'Ă©cosystĂšmes de milieux arides saisonniers aux compositions distinctes des forĂȘts tropicales humides ayant formĂ© des tourbiĂšres, s'avĂšre particuliĂšrement importante. Je dĂ©cris aux prĂ©sentes deux spĂ©cimens prĂ©servĂ©s de plantes fossiles anatomiquement provenant du faciĂšs d'une plaine alluviale de milieu aride. Le premier spĂ©cimen, un Mesoxylon cf. sutclifïŹ i, Ă©tait auparavant inconnu Ă Joggins. Il s'agit d'un axe cordaitalĂ©en cloisonnĂ© comportant des cicatrices foliaires Ă arc moyen et une vasculature non sympodiale. Lors de sa dĂ©couverte sous forme de blocs isolĂ©s, on avait prĂ©cĂ©demment classiïŹĂ© le xylĂšme secondaire de cette plante en tant que Dadoxylon recentium L'axe prĂ©sente des interruptions de croissance subtiles Ă©voquant des chutes de pluie tropicales saisonniĂšres, tandis que les cernes traumatiques associĂ©s pourraient tĂ©moigner de dommages causĂ©s par le feu. Le second spĂ©cimen est une souche de Dadoxylon qui plongeait ses racines Ă l'intĂ©rieur des sols d'un bassin de crue bien drainĂ©. Il conïŹrme une conjecture antĂ©rieure, basĂ©e sur des assemblages parautochtones, supposant que les arbres cordaitalĂ©ens aient poussĂ© dans des secteurs situĂ©s entre des chenaux. Ces deux nouveaux spĂ©cimens amĂ©liorent notre connaissance de la composition et de l'Ă©cologie de la vĂ©gĂ©tation saisonniĂšre des milieux arides Ă Joggins.
[Traduit par la rédaction.
New Brunswick and Nova Scotia: the First Geological Field Trip by a North American College
The first known geological excursion by a North American college was conducted in 1835. Twenty staff and students belonging to Williams College â a liberal arts college in Massachusetts, USA â explored the geology bordering the Bay of Fundy in northeast Maine, New Brunswick and Nova Scotia. Led by two young professors of natural history, Ebenezer Emmons and Albert Hopkins, the party made extensive observations around Pasammaquoddy Bay, Saint John, Parrsboro, and Windsor, as well as more widely through the Minas and Cumberland basins. Although partly following in the footsteps of two pioneering Bostonians, Charles Jackson and Francis Alger, who had reconnoitred the region in the late 1820s, the Williams College party nevertheless made several original observations. One of most important was a study of the anatomy and paleoclimatic significance of permineralized plants from Joggins and Grindstone Island undertaken by Emmons. This was only the second study of its kind worldwide and later inspired William Dawson to do similar work. Largely overlooked by historians of geology, the Williams College expedition, which comprised a four-week voyage of about 1800 km, illustrates well the challenges and opportunities of geological field work in the early Nineteenth Century.
RĂSUMĂ
La premiĂšre excursion gĂ©ologique connue dâun collĂšge nordâamĂ©ricain a Ă©tĂ© rĂ©alisĂ©e en 1835. Vingt membres du personnel et Ă©tudiants du CollĂšge Williams â collĂšge dâarts libĂ©raux du Massachusetts, Etats-Unis â ont explorĂ© la gĂ©ologie des bords de la baie de Fundy dans le nordâest du Maine, au NouveauâBrunswick et en NouvelleâĂcosse. Le groupe dirigĂ© par deux jeunes professeurs dâhistoire naturelle, Ebenezer Emmons et Albert Hopkins, a effectuĂ© de nombreuses observations dans les environs de la baie de Passamaquoddy, de SaintâJean, de Parrsboro et de Windsor, ainsi que dans des secteurs plus Ă©tendus Ă lâintĂ©rieur des bassins Minas et Cumberland. MĂȘme si le groupe du CollĂšge Williams a en partie suivi les pas de deux pionniers de Boston, Charles Jackson et Francis Alger, qui avaient effectuĂ© une reconnaissance de la rĂ©gion vers la fin des annĂ©es 1820, il a nĂ©anmoins fait plusieurs observations originales. Lâune des plus importantes a Ă©tĂ© lâĂ©tude de lâanatomie et de lâimportance palĂ©oclimatique des vĂ©gĂ©taux minĂ©ralisĂ©s de Joggins et de lâĂźle Grindstone rĂ©alisĂ©e par Emmons. Il sâagissait seulement de la deuxiĂšme Ă©tude du genre Ă lâĂ©chelle mondiale; elle a ultĂ©rieurement inspirĂ© Williams Dawson Ă exĂ©cuter des travaux similaires. Largement nĂ©gligĂ©e par les historiens de gĂ©ologie, lâexpĂ©dition du CollĂšge Williams, qui a comportĂ© un voyage de quatre semaines dâenviron 1 800 kilomĂštres, illustre bien les dĂ©fis et les possibilitĂ©s qui sâoffraient dans le domaine des travaux gĂ©ologiques sur le terrain au dĂ©but du 19e siĂšcle. [Traduit par la redaction
A Cordaixylon axis from well-drained alluvial plain facies in the Lower Pennsylvanian Joggins Formation of Nova Scotia
Plant remains showing preservation of cellular anatomy are rare in the Lower Pennsylvanian Joggins Formation of Nova Scotia. Here I report an anatomically preserved cordaitalean axis that shows endarch maturation and a sympodial vascular architecture. The specimen belongs to the morphogenus Cordaixylon, but in the absence of extraxylary tissue or attached fertile material, it cannot be assigned to a species. Together with a previously reported Mesoxylon axis with mesarch and non-sympodial vasculature, the new discovery demonstrates the existence of both major organizational types of cordaitalean at this locality. Previous reports have identified Cordaixylon as a plant that preferred peat mire environments. In this paper, the morphogenus is recorded from well-drained alluvial plain facies, thus extending knowledge of its ecological range.
Résumé
Les vestiges de plantes prĂ©sentant une prĂ©servation de lâanatomie cellulaire sont rares Ă lâintĂ©rieur de la Formation du Pennsylvanien infĂ©rieur de Joggins, en Nouvelle-Ăcosse. Je fais part dans les prĂ©sentes dâun axe de cordaitalĂ©en natomiquement prĂ©servĂ© qui affiche une maturation circulaire Ă partir de lâintĂ©rieur et une architecture vasculaire sympodiale. Le spĂ©cimen fait partie du morphogenre Cordaixylon, mais en lâabsence de tissu extraxylaire ou de matiĂšre fertile y Ă©tant fixĂ©e, on ne peut pas le rattacher Ă une espĂšce donnĂ©e. La nouvelle dĂ©couverte, conjuguĂ©e Ă un axe de Mesoxylon prĂ©cĂ©demment signalĂ© qui comportait une vasculature non sympodiale Ă Ă©lĂ©ments en spirale internes, rĂ©vĂšle lâexistence des deux principaux types structuraux de cordaitalĂ©ens Ă cet emplacement. Des rapports antĂ©rieurs avaient dĂ©fini le Cordaixylon en tant que plante prĂ©fĂ©rant les environnements Ă bourbiers de tourbe. Le prĂ©sent document fait Ă©tat de lâobservation du morphogenre dâun faciĂšs de plaine alluviale bien drainĂ©e, ce qui Ă©tend notre connaissance de son aire de distribution Ă©cologique
MILES extended: Stellar population synthesis models from the optical to the infrared
We present the first single-burst stellar population models which covers the
optical and the infrared wavelength range between 3500 and 50000 Angstrom and
which are exclusively based on empirical stellar spectra. To obtain these joint
models, we combined the extended MILES models in the optical with our new
infrared models that are based on the IRTF (Infrared Telescope Facility)
library. The latter are available only for a limited range in terms of both age
and metallicity. Our combined single-burst stellar population models were
calculated for ages larger than 1 Gyr, for metallicities between [Fe/H] = -0.40
and 0.26, for initial mass functions of various types and slopes, and on the
basis of two different sets of isochrones. They are available to the scientific
community on the MILES web page. We checked the internal consistency of our
models and compared their colour predictions to those of other models that are
available in the literature. Optical and near infrared colours that are
measured from our models are found to reproduce the colours well that were
observed for various samples of early-type galaxies. Our models will enable a
detailed analysis of the stellar populations of observed galaxies.Comment: 9 pages, 10 figures, published in A&
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