111,893 research outputs found
Ceramide Glycanase Activities in Human Cancer Cells
No full textCeramide glycanase (CGase) activities have been detected in different human tumor cells (colon, carcinoma Colo-205; neuroblastoma, IMR-32; breast cancer lines, SKBr3 and MCF7). However, the level of enzymatic activity is lower in these cells compared to that present in other mammalian tissues reported before (Basu, M., Kelly, P., Girzadas, M. A., Li, Z., and Basu, S. Methods Enzymol. (in press)). The majority of CGase activity was found in the 100,000g soluble supernatant fraction isolated from all these cell lines and tissues. Using the soluble enzyme, the requirement for optimum CGase activity was found to be consistent with previous observations found for rat and rabbit tissues (Basu, M., Dastgheib, S., Girzadas, M. A., O'Donnell, P. H., Westervelt, C. W., Li, Z., Inokuchi, J. I., and Basu, S. (1998) Acta Pol. Biochim. 42:327). The CGase activities from both Colo-205 and IMR-32 cells are optimum at a protein to detergent ratio of one. All the mammalian CGases, including human cancer cells, show an optimum pH between 5.5 and 5.8 in sodium acetate buffer. The CGase activities from cancer cells are found to be cation-independent; however, mercury, zinc, and copper ions seem to inhibit the enzyme activity substantially in both tumor cells lines. The mercury ion inhibition of CGase activities from ail different sources indicates a possible structural homology in the CGase proteins. Radiolabeled substrates, labeled at the sphingosine double bond or at the 3-position of sphingosine without modifying double bond of sphingosine were used in this investigation. Both were active substrates with all enzyme preparations isolated from different cancer cells (apparent Km, 500 mu M for nLcOse5[H-3-DT]Cer and 350 mu M for GgOse4[sph-3-H-3]Cer with Colo-205 enzyme). Structural analogues of ceramide and sphingosine (L-PPMP, L-PDMP, alkylamines, and Tamoxifen) inhibited cancer cell CGase activities in vitro
Nitrogen fixation in the western English Channel (NE Atlantic Ocean)
No full textIn temperate Atlantic waters (18.8 to 20.1°C), biological nitrogen fixation has beendemonstrated by 2 independent measurements: 15N-N2 incorporation and nifH identification in theDNA and expressed messenger RNA (mRNA). At 2 stations in the western English Channel, bulkwaters were incubated with 15N-N2. At the high levels of particulate nitrogen (?11.5 ?mol N l–1),absolute fixation rates of 18.9 ± 0.01 and 20.0 nmol N l–1d–1 were determined. While a caveat mustaccompany the magnitude of the rates presented due to the limited number of data, the presence andactivity of diazotrophic organisms in these waters is of ecological significance and may affect currentattitudes to nitrogen and carbon budgets. In particular, our estimate of the rate of N fixation(0.35 mmol N m–2 d–1) is comparable to that of denitrification rates in UK shelf seas. Molecular analysisidentified a diversity of expressed nifH genes, and 21 different prokaryotic nifH transcripts wereidentified
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A letter from Kelly Taylor to Dr. Hector P. Garcia.
No full textA letter from Kelly A. Taylor, Administrative Assistant at the Coca Cola American Bottling Company, to Dr. Hector P. Garcia regarding an agenda for the Communities in Schools Luncheon
Sen and the art of educational maintenance: evidencing a capability, as opposed to an effectiveness, approach to schooling
No full textThere are few more widely applied terms in common parlance than ‘capability’. It is used (inaccurately) to represent everything from the aspiration to provide opportunity to notions of innate academic ability, with everything in between claiming apostolic succession to Amartya Sen, who (with apologies to Aristotle) first developed the concept. This paper attempts to warrant an adaptation of Sen’s capability theory to schooling and schooling policy, and to proof his concepts in the new setting using research involving 100 pupils from 5 English secondary schools and a schedule of questions derived from the capability literature. The findings suggest that a capability approach can provide an alternative to the dominant Benthamite school effectiveness paradigm, and can offer a sound theoretical framework for understanding better the assumed relationship between schooling and well-being
Drawing the Line: How African, Caribbean and White British Women Live Out Psychologically Abusive Experiences
No full textThe final, definitive version of this paper has been published in Violence Against Women, 19 (9):1104-32, Sept 2013 by SAGE Publications Ltd, All rights reserved. © The Author(s) 2013.
The online version of this article can be found at: http://vaw.sagepub.com/content/19/9/110
Kelly, Mrs. P. M.
No full textPhotograph from the C.R. Savage Portrait Studio. Name associated with the photograph: Mrs. P. M. Kell
Kelly, Mrs. P. M.
No full textPhotograph from the C.R. Savage Portrait Studio. Name associated with the photograph: Mrs. P. M. Kell
Emmanuel Mounier and the awakening of Black Africa
No full textEmmanuel Mounier, Director of the Catholic review Esprit, was a pioneering participant in criticising French colonial activities. The debates of the 1940s were strongly framed by France’s ‘mission to civilise’ its colonies, which was supported by universal humanist aspirations but was also criticised as masking policies of exploitation and oppression. The resulting tensions are well demonstrated by Emmanuel Mounier’s book L’Éveil de l’Afrique noire, published after a visit to several areas of French West Africa in the spring of 1947, at a crucial moment in France’s relations with its colonies. This article focuses on the components published in Esprit, Combat, and Présence africaine, which outlined the positive roles that France could play in the region, but warned against the dangers if opportunities were missed, and recognised the particular difficulties confronting the rising African elites. A closer examination of the discursive strategies he deployed shows that Mounier’s frame of reference remained within the paternalist paradigm of republican humanism, and that he saw France’s role as a duty to guide the development of Africa. However, in the myths and metaphors he adopted a more radical vision can be identified, which expressed an underlying anti-colonialism
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