91 research outputs found
...Meech Lake to the Contrary Notwithstanding (Part I)
No full textIn this essay, which will be published in two parts, the author argues that the Meech Lake Accord was more than a hastily cobbled together political deal between the Prime Minister and ten provincial premiers. Despite the unattractive process by which the Meech Lake Accord was struck, and especially defended, despite the disingenuous character of the arguments most often advanced for its adoption, and despite its close connection with other aspects of the federal government\u27s political agenda which many Canadians found suspicious, the Meech Lake Accord did respond to an important issue in post-patriation constitutionalism. A review of Canadian constitutional history, the evolution of French and English linguistic minorities in Canada, and the complementary motifs of French-Canadian and English-Canadian survivance leads the author to conclude that the forces which generated the Meech Lake Accord have been perennial features of British North American political life since 1759. The symbolic purpose of the Meech Lake Accord was to illustrate that, notwithstanding significant demographic and economic changes in Canada, and notwithstanding that the patriation exercise operated a profound transformation of the complex underpinnings of Canadian federalism, these traditional forces would still play a significant role in defining the values of the country. The failure of the Meech Lake Accord does not mean that these forces are now spent. Rather, it means only that the present federal structure within which they have been accommodated since 1867 probably is no longer appropriate for the task. The author concludes with a prognosis for what the institutional redesign likely to emerge over the next few years will be - a framework he characterizes as heteronomy
The Homeobox Transcription Factor Barx2 Regulates Plasticity of Young Primary Myofibers
No full textCopyright: © 2010 Meech et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Adult mammalian muscle retains incredible plasticity. Muscle growth and repair involves the activation of undifferentiated myogenic precursors called satellite cells. In some circumstances, it has been proposed that existing myofibers may also cleave and produce a pool of proliferative cells that can re-differentiate into new fibers. Such myofiber dedifferentiation has been observed in the salamander blastema where it may occur in parallel with satellite cell activation. Moreover, ectopic expression of the homeodomain transcription factor Msx1 in differentiated C2C12 myotubes has been shown to induce their dedifferentiation. While it remains unclear whether dedifferentiation and redifferentiaton occurs endogenously in mammalian muscle, there is considerable interest in induced dedifferentiation as a possible regenerative tool
Color gradients in the coma of P/Halley
No full textSome important information relevant to the understanding of the gas/dust dynamics near the surface of a comet nucleus concerns knowledge of the grain composition and scattering properties as well as the particle size distribution of dust in the coma. Ground based measurements of light scattered from the dust comae can provide some information about the physical grain properties, in particular about the mean optically dominant grain size. Optical spectra of continua of nine comets presented by Jewitt and Meech, 1986, show that all of the scattered light is reddened with respect to the Sun. There is significant scatter in the amount of reddening seen for different comets. In the near IF regions, the reddening decreases until near 2 to 3 micrometers where the reflectivity is nearly neutral. It is of particular interest to see if there are any observable changes in the grain size distribution during outburst. Although no coma colar changes were observed during the Nov. 1985 outbursts, a color gradient within the coma has been observed in Halley. Radial color gradients in J, H, and K images of Halley as reported by Campins have not been observed by the author
Identification of residues that confer sugar selectivity to UDP-glycosyltransferase 3A (UGT3A) enzymes
No full textRecent studies in this laboratory characterized the UGT3A family enzymes, UGT3A1 and UGT3A2, and showed that neither uses the traditional UGT co-substrate UDP-glucuronic acid. Rather, UGT3A1 uses N-acetylglucosamine as preferred sugar donor and UGT3A2 uses UDP-glucose. The enzymatic characterization of UGT3A mutants, structural modelling, and multispecies gene analysis have now been employed to identify a residue within the active site of these enzymes that confer their unique sugar preferences. An asparagine (N391) residue in the UGT signature sequence of UGT3A1 is necessary for utilization of UDP-N-acetylglucosamine. Conversely, a phenylalanine (F391) residue in UGT3A2 favors UDP-glucose use. Mutation of N391 to F in UGT3A1 enhances its ability to utilize UDP-glucose and completely inhibits its ability to use UDP-N-acetylglucosamine. An analysis of homology models docked with UDP-sugar donors indicates that N391 in UGT3A1 is able to accommodate the N-acetyl group on C2 of UDP N-acetylglucosamine so that the anomeric carbon atom (C1) is optimally situated for catalysis involving H35. Replacement of N by F at 391 disrupts this catalytically-productive orientation of UDP N-acetylglucosamine but allows a more optimal alignment of UDP-glucose for sugar donation. Multispecies sequence analysis reveals that only primates possess UGT3A sequences containing the N391 residue, suggesting that other mammals may not have the capacity to N-acetylglucosaminidate small molecules. In support of this hypothesis, N391-containing UGT3A forms from two non-human primates were found to use UDP-N-acetylglucosamine, while UGT3A isoforms from non-primates could not use this sugar donor. This work gives new insight into the residues that confer sugar specificity to UGT family members and suggests a primate-specific innovation in glycosidation of small molecule
Potential link between the Sphingosine-1-Phosphate (S1P) system and defective alveolar macrophage phagocytic function in Chronic Obstructive Pulmonary Disease (COPD)
No full textWe previously reported that alveolar macrophages from patients with chronic obstructive pulmonary disease (COPD) are defective in their ability to phagocytose apoptotic cells, with a similar defect in response to cigarette smoke. The exact mechanisms for this defect are unknown. Sphingolipids including ceramide, sphingosine and sphingosine-1-phosphate (S1P) are involved in diverse cellular processes and we hypothesised that a comprehensive analysis of this system in alveolar macrophages in COPD may help to delineate the reasons for defective phagocytic function.We compared mRNA expression of sphingosine kinases (SPHK1/2), S1P receptors (S1PR1-5) and S1P-degrading enzymes (SGPP1, SGPP2, SGPL1) in bronchoalveolar lavage-derived alveolar macrophages from 10 healthy controls, 7 healthy smokers and 20 COPD patients (10 current- and 10 ex-smokers) using Real-Time PCR. Phagocytosis of apoptotic cells was investigated using flow cytometry. Functional associations were assessed between sphingosine signalling system components and alveolar macrophage phagocytic ability in COPD. To elucidate functional effects of increased S1PR5 on macrophage phagocytic ability, we performed the phagocytosis assay in the presence of varying concentrations of suramin, an antagonist of S1PR3 and S1PR5. The effects of cigarette smoking on the S1P system were investigated using a THP-1 macrophage cell line model.We found significant increases in SPHK1/2 (3.4- and 2.1-fold increases respectively), S1PR2 and 5 (4.3- and 14.6-fold increases respectively), and SGPL1 (4.5-fold increase) in COPD vs. controls. S1PR5 and SGPL1 expression was unaffected by smoking status, suggesting a COPD "disease effect" rather than smoke effect per se. Significant associations were noted between S1PR5 and both lung function and phagocytosis. Cigarette smoke extract significantly increased mRNA expression of SPHK1, SPHK2, S1PR2 and S1PR5 by THP-1 macrophages, confirming the results in patient-derived macrophages. Antagonising SIPR5 significantly improved phagocytosis.Our results suggest a potential link between the S1P signalling system and defective macrophage phagocytic function in COPD and advise therapeutic targets.Jameel Barnawi, Hai Tran, Hubertus Jersmann, Stuart Pitson, Eugene Roscioli, Greg Hodge, Robyn Meech, Rainer Haberberger, Sandra Hodg
Metatheatre as a political tool in Yugoslav drama in the 1980s and 1990s
No full textThe wars in the Balkans in the 1990s inspired great interest in the historical, socioeconomic and political aspects of the disintegration of the former Yugoslavia. These accounts often referred to the actual events as the ‘Yugoslav tragedy’. Yugoslav theatre, meanwhile, received comparatively negligible attention.An overview of Yugoslav drama in translation points to an interesting trend. The plays which made it to Western Europe, particularly in the 1980s, were plays with a definite metatheatrical dimension. At the same time in Yugoslavia, metatheatre spontaneously became the most effective means of socio-political re-examination. The metatheatrical trend re-occurred with a very different function in the 1990s when the everyday Yugoslav reality was highly theatricalised in the media controlled by the Milosevic regime. In both 1980s and 1990s Yugoslavia, metatheatre essentially sought to examine the collective audience preconceptions.Yugoslavia’s most renowned contemporary playwright, Dušan Kovadevic, is the author of four metaplays studied in this thesis. Other internationally acclaimed Yugoslav metaplays of the period 1980-1999 studied here include Slobodan Snajder’s The Croatian Faust. Ljubomir Simovid’s The Travelling Theatre Sopalovic. Nenad Prokid’s The Metastable Grail. Biljana Srbljanovic’s Family Tales as well as Goran Markovic’s A Tour and Nebojša Romcevic’s Caroline Neuber. Contextually, the thesis also features analyses of older Yugoslav metaplays such as Ivo Brešan’s The Stage Play of Hamlet in the Village of Lower Jerkwater and Dušan Jovanovic’s Act a Brain Tumour or Air Pollution.The thesis is by no means a definitive overview of Yugoslav theatre and its contexts but primarily an exploration of the metatheatrical device, its political significance and its features in Yugoslavia of the 1980s and the rump-state of Yugoslavia in the 1990s
Metatheatre as a political tool in Yugoslav drama in the 1980s and 1990s
No full textThe wars in the Balkans in the 1990s inspired great interest in the historical, socioeconomic and political aspects of the disintegration of the former Yugoslavia. These accounts often referred to the actual events as the ‘Yugoslav tragedy’. Yugoslav theatre, meanwhile, received comparatively negligible attention.An overview of Yugoslav drama in translation points to an interesting trend. The plays which made it to Western Europe, particularly in the 1980s, were plays with a definite metatheatrical dimension. At the same time in Yugoslavia, metatheatre spontaneously became the most effective means of socio-political re-examination. The metatheatrical trend re-occurred with a very different function in the 1990s when the everyday Yugoslav reality was highly theatricalised in the media controlled by the Milosevic regime. In both 1980s and 1990s Yugoslavia, metatheatre essentially sought to examine the collective audience preconceptions.Yugoslavia’s most renowned contemporary playwright, Dušan Kovadevic, is the author of four metaplays studied in this thesis. Other internationally acclaimed Yugoslav metaplays of the period 1980-1999 studied here include Slobodan Snajder’s The Croatian Faust. Ljubomir Simovid’s The Travelling Theatre Sopalovic. Nenad Prokid’s The Metastable Grail. Biljana Srbljanovic’s Family Tales as well as Goran Markovic’s A Tour and Nebojša Romcevic’s Caroline Neuber. Contextually, the thesis also features analyses of older Yugoslav metaplays such as Ivo Brešan’s The Stage Play of Hamlet in the Village of Lower Jerkwater and Dušan Jovanovic’s Act a Brain Tumour or Air Pollution.The thesis is by no means a definitive overview of Yugoslav theatre and its contexts but primarily an exploration of the metatheatrical device, its political significance and its features in Yugoslavia of the 1980s and the rump-state of Yugoslavia in the 1990s
La ayahuasca retratada a traves del cine : Un amilisis de Ia controversia que Ia considera tanto una medicina como un peligro.
No full text50 p.The author reviews the medicinal and spiritual uses of ayahuasca tea in Amazonian culture. Research includes three documentary films: “The Mirror of the Spirit,” by Joao Meirinhos (2014), “Ayahuasca: Vid del alma,” by Richard Meech (2010), and “Metamorphosis,” by Keith Aronowitz (2009). The author also includes her own observation of ceremonies of ayahuasca and san pedro at the Gaia Sagrada retreat center in Ecuador
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