Synthetic approaches to prostaglandins

Imperial Users onl

Management education within a cultural confluence : Twinning programmes in Malaysia

In its steady advance toward Vision 2020, Malaysia has been working hard to balance the skills and competencies of its people commensurate with its economic growth. To this end, educational twinning programmes abound in Malaysia. At present, these programmes are inevitably reliant to a considerable degree on Western thought and science. This paper, written from the perspective of two twinning programme directors, examines cross-cultural management issues underlying educational programme design and delivery. Its focus concentrates on the execution of commerce and business programmes

Cholestasis in pregnancy

This issue of eMedRef provides information to clinicians on the pathophysiology, diagnosis, and therapeutics of cholestasis in pregnancy

Heritage Stone 9. Tyndall Stone, Canada’s First Global Heritage Stone Resource: Geology, Paleontology, Ichnology and Architecture

Tyndall Stone is a distinctively mottled and strikingly fossiliferous dolomitic limestone that has been widely used for over a century in Canada, especially in the Prairie Provinces. It comprises 6–8 m within the lower part of the 43 m thick Selkirk Member of the Red River Formation, of Late Ordovician (Katian) age. It has been quarried exclusively at Garson, Manitoba, 37 km northeast of Winnipeg, since about 1895, and for the past half-century extraction has been carried out solely by Gillis Quarries Ltd. The upper beds tend to be more buff-coloured than the grey lower beds, as a result of groundwater weathering. Tyndall Stone, mostly with a smooth or sawn finish, has been put to a wide variety of uses, including exterior and interior cladding with coursed and random ashlar, and window casements and doorways. Split face finish and random ashlar using varicoloured blocks split along stylolites have become popular for commercial and residential buildings, respectively. Tyndall Stone lends itself to carving as well, being used in columns, coats of arms and sculptures. Many prominent buildings have been constructed using Tyndall Stone, including the provincial legislative buildings of Saskatchewan and Manitoba, the interior of the Centre Block of the House of Commons in Ottawa, courthouses, land titles buildings, post offices and other public buildings, along with train stations, banks, churches, department stores, museums, office buildings and university buildings. These exhibit a variety of architectural styles, from Beaux Arts to Art Deco, Châteauesque to Brutalist. The Canadian Museum of History and the Canadian Museum for Human Rights are two notable Expressionist buildings.   The lower Selkirk Member is massive and consists of bioturbated, bioclastic wackestone to packstone, rich in crinoid ossicles. It was deposited in a low-energy marine environment within the photic zone, on the present-day eastern side of the shallow Williston Basin, which was part of the vast equatorial epicontinental sea that covered much of Laurentia at the time. Scattered thin bioclastic grainstone lenses record episodic, higher energy events. Tyndall Stone is spectacularly fossiliferous, and slabs bearing fossils have become increasingly popular. The most common macrofossils are receptaculitids, followed by corals, stromatoporoid sponges, nautiloid cephalopods, and gastropods. The relative abundance of the macrofossils varies stratigraphically, suggesting that subtle environmental changes took place over time.    The distinctive mottles—‘tapestry’ in the trade—have been regarded as dolomitized burrows assigned to Thalassinoides and long thought to have been networks of galleries likely made by arthropods. In detail, however, the bioclastic muddy sediment underwent a protracted history of bioturbation, and the large burrows were mostly horizontal back-filled features that were never empty. They can be assigned to Planolites. The matrix and the sediment filling them were overprinted by several generations of smaller tubular burrows mostly referrable to Palaeophycus due to their distinctive laminated wall linings. Dolomite replaced the interiors of the larger burrows as well as smaller burrows and surrounding matrix during burial, which is why the mottling is so variable in shape.Tyndall Stone est un calcaire dolomitique distinctement marbré et remarquablement fossilifère qui a été largement utilisé pendant plus d'un siècle au Canada, en particulier dans les provinces des Prairies. Ce calcaire s'étend sur 6 à 8 m dans la partie inférieure du membre de Selkirk de la formation de Red River, d'une épaisseur de 43 m et d'âge Ordovicien supérieur (Katien). Il est exploité exclusivement à Garson (Manitoba), à 37 km au nord-est de Winnipeg, depuis environ 1895 et, depuis un demi-siècle, l'extraction est assurée exclusivement par Gillis Quarries Ltd. En raison de l'altération par les eaux souterraines, les couches supérieures ont tendance à être brun clair alors que les couches inférieures sont grises. Le calcaire Tyndall Stone, dont la finition est le plus souvent adoucie ou sciée, a été utilisé à des fins très diverses, notamment pour le revêtement extérieur et intérieur avec des pierres de taille à assises irrégulières, ainsi que pour les encadrements de fenêtres et les embrasures de portes. Le fini éclaté et la pierre de taille de dimension aléatoire utilisant des blocs polychromes fendus le long de stylolites sont devenus populaires pour les bâtiments commerciaux et résidentiels, respectivement. Tyndall Stone se prête également à la taille de colonnes et à la réalisation d’armoiries et de sculptures. De nombreux bâtiments importants ont été construits en Tyndall Stone, notamment les édifices législatifs provinciaux de la Saskatchewan et du Manitoba, l'intérieur de l'édifice du Centre de la Chambre des communes à Ottawa, des palais de justice, des bureaux de titres fonciers, des bureaux de poste et d'autres édifices publics, ainsi que des gares, des banques, des églises, des grands magasins, des musées, des immeubles de bureaux et des bâtiments universitaires. Ces bâtiments présentent une grande variété de styles architecturaux, des Beaux-Arts à l'Art déco, en passant par le style Château et le Brutalisme. Le Musée canadien de l'histoire et le Musée canadien pour les droits de la personne sont deux bâtiments expressionnistes remarquables.   Le membre inférieur de Selkirk est massif et se compose de roche sédimentaire carbonatée wackestone à packstone bioturbée et bioclastique, riche en ossicules de crinoïdes. Il s'est déposé dans un environnement marin à faible énergie dans la zone photique, sur l'actuel versant oriental du bassin de Williston peu profond, qui faisait partie de la vaste mer épicontinentale équatoriale couvrant la majeure partie de la Laurentia à l'époque. De minces lentilles éparses de grès bioclastique témoignent d'événements épisodiques à haute énergie. Tyndall Stone est spectaculairement fossilifère et les dalles contenant des fossiles sont de plus en plus populaires. Les macrofossiles les plus courants sont les réceptaculitides, suivis des coraux, des éponges stromatoporoïdes, des céphalopodes nautiloïdes et des gastéropodes. L'abondance relative des macrofossiles varie en fonction de la stratigraphie, ce qui suggère que des changements environnementaux subtils ont eu lieu au fil du temps.   Les marbrures distinctives – appelées "tapisserie" dans le commerce – ont été perçues comme des terriers dolomitisés attribués aux Thalassinoides et longtemps considérées comme des réseaux de galeries vraisemblablement creusés par des arthropodes. Dans le détail, cependant, le sédiment vaseux bioclastique a subi une longue histoire de bioturbation, et les grands terriers étaient principalement des éléments horizontaux remblayés qui n'étaient jamais vides. Ils peuvent être attribués à des Planolites. La matrice et les sédiments qui les remplissent sont surchargés par plusieurs générations de terriers tubulaires plus petits, principalement attribuables à des Palaeophycus en raison de leurs revêtements muraux stratifiés distinctifs. La dolomite a remplacé l'intérieur des plus grands terriers ainsi que des plus petits terriers et la matrice environnante pendant l'enfouissement, ce qui explique la forme variable de la marbrure

Universality of the Small-Scale Dynamo Mechanism

We quantify possible differences between turbulent dynamo action in the Sun and the dynamo action studied in idealized simulations. For this purpose we compare Fourier-space shell-to-shell energy transfer rates of three incrementally more complex dynamo simulations: an incompressible, periodic simulation driven by random flow, a simulation of Boussinesq convection, and a simulation of fully compressible convection that includes physics relevant to the near-surface layers of the Sun. For each of the simulations studied, we find that the dynamo mechanism is universal in the kinematic regime because energy is transferred from the turbulent flow to the magnetic field from wavenumbers in the inertial range of the energy spectrum. The addition of physical effects relevant to the solar near-surface layers, including stratification, compressibility, partial ionization, and radiative energy transport, does not appear to affect the nature of the dynamo mechanism. The role of inertial-range shear stresses in magnetic field amplification is independent from outer-scale circumstances, including forcing and stratification. Although the shell-to-shell energy transfer functions have similar properties to those seen in mean-flow driven dynamos in each simulation studied, the saturated states of these simulations are not universal because the flow at the driving wavenumbers is a significant source of energy for the magnetic field.Comment: 16 pages, 9 figures, accepted for publication in Ap

Reconceptualising the relationship between the creative economy and the city: Learning from the financial crisis

This paper uses the financial crisis as an opportunity to examine a number of key questions about the relationship of the creative economy and the city. We argue that weak conceptualisation of the nature of the relationship between the creative economy and the city, as well as a lack of clarity about what the creative economy is, has subverted debates about this important topic. This paper comprises four major sections: the first introduces the field of the creative economy, the second section seeks to clarify what exactly we mean by the term financial crisis; here we highlight the multifaceted character of the financial crisis and is variable impacts across the field of the creative economy. The third part outlines the range and diversity of the actually existing relations between the creative economy and the city. In the fourth section we reflect upon the earlier argument to consider what we can learn about the impacts (actual and expected) of the financial crisis on the creative economy and the city, and additionally to reflect upon what this might indicate about the changing and perhaps transformed relationship between the creative economy and the city in the last quarter century

Linear stochastic dynamics with nonlinear fractal properties

Stochastic processes with multiplicative noise have been studied independently in several different contexts over the past decades. We focus on the regime, found for a generic set of control parameters, in which stochastic processes with multiplicative noise produce intermittency of a special kind, characterized by a power law probability density distribution. We present a review of applications on population dynamics, epidemics, finance and insurance applications with relation to ARCH(1) process, immigration and investment portfolios and the internet. We highlight the common physical mechanism and summarize the main known results. The distribution and statistical properties of the duration of intermittent bursts are also characterized in details.Comment: 26 pages, Physica A (in press

Formation of quasi-free-standing graphene on SiC(0001) through intercalation of erbium

Activation of the carbon buffer layer on 4H- and 6H-SiC substrates using elements with high magnetic moments may lead to novel graphene/SiC-based spintronic devices. In this work, we use a variety of surface analysis techniques to explore the intercalation of Er underneath the buffer layer showing evidence for the associated formation of quasi-free-standing graphene (QFSG). A combined analysis of low energy electron diffraction (LEED), atomic force microscopy (AFM), X-ray and ultraviolet photoemission spectroscopy (XPS and UPS), and metastable de-excitation spectroscopy (MDS) data reveals that annealing at temperatures up to 1073 K leads to deposited Er clustering at the surface. The data suggest that intercalation of Er occurs at 1273 K leading to the breaking of back-bonds between the carbon buffer layer and the underlying SiC substrate and the formation of QFSG. Further annealing at 1473 K does not lead to the desorption of Er atoms but does result in further graphitization of the surface

Mainstreaming domestic and gender-based violence into sociology and the criminology of violence

Sociological and criminological views of domestic and gender-based violencegenerally either dismiss it as not worthy of consideration, or focus on specificgroups of offenders and victims (male youth gangs, partner violence victims). Inthis paper, we take a holistic approach to violence, extending the definition fromthat commonly in use to encompass domestic violence and sexual violence. Weoperationalize that definition by using data from the latest sweep of the CrimeSurvey for England and Wales. By so doing, we identify that violence is currentlyunder-measured and ubiquitous; that it is gendered, and that other forms of violence (family violence, acquaintance violence against women) are equally ofconcern. We argue that violence studies are an important form of activity forsociologists