949 research outputs found
Cytochrome P450 scc and the cholesterol side chain cleavage reaction of adrenal cortex mitochrondria
On ‘common-sense ontology’:A comment on the paper by Frank Hindriks and Francesco Guala
This note comments on Hindriks and Guala’s ‘unified theory of institutions’. One of the components that Hindriks and Guala seek to unify, and which they claim is unsatisfactory on its own, is the analysis of conventions that derives from the work of Lewis. I argue that the Lewisian approach provides simple and powerful explanations of many regularities in the social behaviour of humans and other animals. Those explanations can be seen as good social science even if, as Hindriks and Guala argue, they do not fit with common-sense ontology
Reclaiming Virtue Ethics for Economics
Virtue ethics is an important strand of moral philosophy which normative economists have largely neglected. It underpins influential critiques of the market (as a domain in which instrumental motivation corrodes virtue) and of economics (as justifying such motivation). We explain and respond to this critique. Using the methods of virtue ethics and with reference to the writings of major economists, we propose an understanding of the ‘telos’ (purpose) of markets as cooperation for mutual benefit, and identify traits that thereby count as virtues for market participants. We conclude that the market need not be seen as a virtue-free zone
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Computer mediated communication of discourse: learning together online
Computer mediated communication (CMC) is a new form of communication that is increasingly being used in academic discourse. This research examines such key issues as how literacy is affected by the use of CMC, how computers can be used to teach collaboratively and the role of CMC in developing written argument. A shift from print-based literacy to interactive electronic-based literacy has the potential to transform the nature of both literacy and pedagogy.
This project employs a Socio-cultural and Discourse Analysis perspective and investigates the use of CMC in post-graduate education and its effect on academic literacy. It also examines how computer mediated collaboration can effectively aid the process of induction into communities of discursive practice.
This study will investigate the dialogical nature of academic discourse and the relationship of CMC to collaborative learning
Logan Braes
Awaiting the return of her love, Williehttps://egrove.olemiss.edu/kgbsides_scot/1002/thumbnail.jp
Regulation of the retinoblastoma proteins by the human herpesviruses
Viruses are obligate intracellular parasites that alter the environment of infected cells in order to replicate more efficiently. One way viruses achieve this is by modulating cell cycle progression. The main regulators of progression out of G0, through G1, and into S phase are the members of the retinoblastoma (Rb) family of tumor suppressors. Rb proteins repress the transcription of genes controlled by the E2F transcription factors. Because the expression of E2F-responsive genes is required for cell cycle progression into the S phase, Rb arrests the cell cycle in G0/G1. A number of viral proteins directly target Rb family members for inactivation, presumably to create an environment more hospitable for viral replication. Such viral proteins include the extensively studied oncoproteins E7 (from human papillomavirus), E1A (from adenovirus), and the large T (tumor) antigen (from simian virus 40). Elucidating how these three viral proteins target and inactivate Rb has proven to be an invaluable approach to augment our understanding of both normal cell cycle progression and carcinogenesis. In addition to these proteins, a number of other virally-encoded inactivators of the Rb family have subsequently been identified including a surprising number encoded by human herpesviruses. Here we review how the human herpesviruses modulate Rb function during infection, introduce the individual viral proteins that directly or indirectly target Rb, and speculate about what roles Rb modulation by these proteins may play in viral replication, pathogenesis, and oncogenesis
Coastal oceanography and sedimentology in New Zealand, 1967-91.
This paper reviews research that has taken place on physical oceanography and sedimentology on New Zealand's estuaries and the inner shelf since c. 1967. It includes estuarine sedimentation, tidal inlets, beach morphodynamics, nearshore and inner shelf sedimentation, tides and coastal currents, numerical modelling, short-period waves, tsunamis, and storm surges. An extensive reference list covering both published and unpublished material is included. Formal teaching and research programmes dealing with coastal landforms and the processes that shape them were only introduced to New Zealand universities in 1964; the history of the New Zealand Journal of Marine and Freshwater Research parallels and chronicles the development of physical coastal science in New Zealand, most of which has been accomplished in last 25 years
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Recapitulating mammary gland development and breast cancer cell migration in vitro using 3D engineered scaffolds
The adult mammary gland is comprised of a bi-layered epithelium of luminal and myoepithelial cells surrounded by an adipocyte-rich fat pad, a highly collagenous extra-cellular matrix (ECM) and a number of other stromal and endothelial cell types. Mammary stem cells (MaSCs) reside within the epithelium and these are capable of repopulating a mammary fat pad that is devoid of epithelium, upon transplantation. It was sought to recapitulate this process of MaSCs repopulating a fat pad using a synthetic fat pad, engineered from a collagen scaffold invested with adipocytes, to provide an in vitro 3D model. Fluorescently tagged murine Axin2-expressing cells were obtained from transgenic mice and seeded into these scaffolds and cultured, mimicking the process of fat pad repopulation. Immunohistochemical analysis demonstrated that Axin2+ myoepithelial cells were rarely capable of forming bi-layered structures that expressed correct myoepithelial localisation and resemblance to a luminal morphology.
Breast tumours surrounded by anisotropic (directional) collagen fibres running perpendicular to the tumour boundary are more aggressive and associated with poor patient prognosis. To recapitulate this anisotropic collagen phenotype in vitro, an ice-templating technique was used to modify the structure of the collagen scaffolds producing both non-directional (isotropic) and anisotropic internal architectures. Tumour cells from various breast cancer cell lines were seeded into both isotropic and anisotropic scaffolds to investigate whether this approach could distinguish cell type-specific migratory ability and whether anisotropy affected migration efficiency. Following analysis by confocal microscopy and ImageJ, anisotropic scaffolds were observed to enhance the migratory potential of MDA-MB-231 breast cancer cells. These results highlight the importance of collagen alignment and provide a reproducible method to quantitatively measure cell migration in 3D for cells derived from different breast cancer subtypes.
Building on these data, the protocol was adapted to permit the direct investigation of tumour biopsy material. Given the heterogeneity of breast tumours, it was considered important to maintain tumour architecture and stromal components. Thus, murine mammary tumour fragments from two different established mammary cancer models were utilised and cultured in anisotropic collagen scaffolds in the presence or absence of adipocytes to allow an investigation of their influence on tumour cell migration. Further experiments included addition of various therapeutic drugs followed by immunofluorescence microscopy coupled with an optical clearing technique. These data demonstrated the utility of the model in determining both the rate and capacity of tumour cells to migrate through the engineered stroma while shedding light also on the mode of migration. Moreover, the response of different mammary tumour types to chemotherapeutic drugs could be could be readily quantified.
To humanize the fat pad for subsequent human tissue analysis, human mesenchymal stem cells (MSC) were obtained from reduction mammoplasties and immortalised, before differentiating them into adipocytes within anisotropic collagen scaffolds. Human breast cancer cells were fluorescently tagged for tracking using lentiviral methods and were seeded into scaffolds invested with differentiated MSCs. Both cell types were successfully co-cultured for 7 days and imaged using multiphoton methods.National Centre for the Refinement, Reduction and Replacement of Animals in Research (NC3Rs
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