9,274 research outputs found
Embryonic stem cells: modelling effects ofearly embryo environment
No full textThe Developmental Origins of Health and Disease (DOHaD) hypothesis proposes that embryonic environment can induce permanent changes in metabolism during development, increasing the risk of disease in adults. Adverse environments during critical stages of gestation are sufficient to induce adaptations in offspring and disease susceptibility in later life. Rodent models show that maternal diet exclusively during preimplantation development induces cardiovascular and metabolic disease in adult offspring. Changes must therefore occur within the distinct cell populations of the early embryo and be maintained throughout development. Determining adaptive mechanisms has been challenging due to the small size of the early embryo, and genetic variability in outbred strains previously used. We generated mouse embryonic stem (ES) cells from inbred C57BL/6 mice as a model to overcome these problems. These were used to characterise mechanisms associated with the embryo’s adaptive responses to maternal diet. ES cell lines were derived from blastocysts of C57BL/6 mice assigned to either an isocaloric low protein diet (LPD), or a control diet exclusively through preimplantation development. ES cell lines were characterised for karyotype, sex, gene expression, and functional characteristics including proliferation, death, and metabolism at standardised passages. LPD had no impact on blastocyst formation in vivo or blastocyst cell lineage allocation. Experimental conditions did affect blastocyst outgrowth development in vitro. LPDoutgrowths cultured with less feeder fibroblasts showed slower development than controls. Although LPD blastocyst outgrowth was comparable to controls under high feeder growth conditions, there was a significant reduction in the capacity for ES cell derivation. There was a prominent sex bias towards male ES cell lines. These ES cells retained similar levels of gene expression related to pluripotency, housekeeping and developmental functions irrespective of diet. LPD did not affect growth or metabolism. These cells however showed increased basal apoptosis, and reduced levels of phosphorylated Extracellular signal-regulated kinase (ERK). The reduced ES cell isolation efficiency may indicate a reduced number of pluripotent cells present within the early embryo or increased sensitivity of these cells in response to maternal LPD. Increased apoptosis in ES cells derived from LPD-blastocysts reveal that these cells are indeed more sensitive. Reduced activated ERK may suggest that dysregulated ERK-mediated survival signalling causes enhanced apoptosis. Such adaptations in the early embryo may impact on lineage allocation as differentiation occurs. These ES cell lines may provide a model to investigate such mechanistic adaptations in post-implantation tissues providing further insight into foetal responses to poor nutrition and the induction of adult onset disease
Groundwater flows and groundwater - surface water interactions in the Corangamite CMA region
No full textAnnette Barton, Jim Cox, Peter Dahlhaus and Andrew Herczeghttp://crcleme.org.au/Pubs/Monographs/Regolith2006.htm
Concentration in Knowledge Output: A case of Economics Journals
No full textThis paper assesses the degree of author concentration in seven economics journals, which were published in India during 1990-2002. To measure the degree of author concentration, Lotka's Law was used. Moreover, we also make an exploratory analysis of the geographic, economics subfield and institutional concentration in 704 economics journals. An important finding of this paper is that specialized journals in the sample report the highest degree of author concentration. This result is quite similar to the findings by Cox and Chung (1991). Furthermore, there are several instances showing that the journals lean towards certain norms; this may affect the flow of innovative ideas into economics. We conclude that a knowledge activity, involving the high degree of concentration and a biased publication process, may affect the flow of new ideas into the discipline.Concentration, Lotka's Law
Developing a library strategic response to Artificial Intelligence
No full textThe purpose of this working document is to set out considerations relevant for libraries developing a strategic response to Artificial Intelligence.The text is organised around developing a set of questions that prompt reflection and action (section 4). It is hoped that the document can support local decision making about AI.Authorship: This working document for discussion was prepared by Andrew Cox, as convenor of the IFLA Artificial Intelligence SIG. Comments for further iterations of the document are invited.</p
Book review: Balnaves, Edmund, Bultrini, Leda, Cox, Andrew and Uzwyshyn, Raymond (eds). New horizons of artificial intelligence in libraries
No full textBalnaves, Edmund, Bultrini, Leda, Cox, Andrew and Uzwyshyn, Raymond (eds). (2025). New horizons of artificial intelligence in libraries. Berlin: DeGruyter Saur. x, 384 p. e-ISBN 978-3-11-133643-5 (IFLA Publications, vol. 185
Tomographic inversion of focusing operators
No full textSeismic images of the structure of the earth are a prerequisite for finding new hydrocarbon reservoirs. The quality of a seismic images is highly dependent on the accuracy of the velocity model of the subsurface. Conventional imaging consists of an iterative process between obtaining the image using a velocity model, and updating this model by investigating the properties of the image. The Common Focal Point (CFP) method makes it possible to analyze and treat seismic data in a fundamentally different way as it uses a two-step approach: 1) two-way reflection data are transformed into one-way data by estimating focusing operators, and 2) these focusing operators are used to estimate the velocity model by tomographic inversion. This second step, the tomographic inversion of focusing operators, is the subject of this thesis. This research contains two important new aspects. First, the use of focusing operators in (3D) velocity model estimation. Second the data-driven approach of the method. Some additional concepts like the inclusion of a priori information, the joint inversion of P and S-wave operators, and the new concept of the focal point clouds, by which the adequacy of the velocity model can be analyzed, are also addressed. After evaluation of the method of tomographic inversion of focusing operators on both synthetic and real data it can be concluded that the method results in accurate velocity models and is capable of dealing with complex subsurface models.Applied Science
Printing Polemic: An Examination Of The Prose Polemic Of Andrew Marvell And His Relationship With His Readership
No full textPrinting Polemic aims to deepen critical understanding of Andrew Marvell's printed prose by fully re-politicising these works. These texts are polemic, the aim of publishing to incense and incite the reader, convincing them of the urgent need for reform. Critical attention has largely focused on The Rehearsal Transpros'd and An Account of the Growth of Popery; this thesis will correct this imbalance by interrogating his prose as an oeuvre, in order to reveal the anti-establishment themes prevalent across these works, which run the gamut from satire to secret history. Across these works, Marvell insists on the need for adequate political representation, freedom of conscience, and an end to institutional corruption - appealing to the public sphere his primary means of effecting change. This thesis centres the reader, reconstructing the cultural and political apparatus shaping the lives and attitudes of Marvell's Restoration audience. These texts are rich in allusion, and considering Marvell's prose in relation to contemporary literature and ephemera - from rhetorical manuals, polemical tracts, theatre, newspapers and even his own poetry - reveals the subtext available to an active reader. This thesis will also contribute to the field by analysing Marvell's relationship to means of political expression, namely petitions and political parties, to retrace the implicit means by which Marvell encourages political participation (whilst skirting accusations of sedition in an increasingly hostile political climate). Contextualising these pamphlets with the reader in mind reveals both the effectiveness of Marvell's rhetorical strategy and the depth of his subversion. The intricacy of his subtext is crucial to his polemical agenda - in Marvell's rhetoric, shaping active readers is a means of creating active citizens
Thrombosis Is Reduced by Inhibition of COX-1, but Unaffected by Inhibition of COX-2, in an Acute Model of Platelet Activation in the Mouse
No full textThis 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
LC-MS/MS Confirms That COX-1 Drives Vascular Prostacyclin Whilst Gene Expression Pattern Reveals Non-Vascular Sites of COX-2 Expression
No full textPMCID: PMC3711559This 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
High-Level Approaches to Confidence Estimation in Speech Recognition
No full textWe describe some high-level approaches to estimating confidence scores for the words output by a speech recognizer. By "high-level" we mean that the proposed measures do not rely on decoder specific "side information" and so should find more general applicability than measures that have been developed for specific recognizers. Our main approach is to attempt to decouple the language modeling and acoustic modeling in the recognizer in order to generate independent information from these two sources that can then be used for estimation of confidence. We isolate these two information sources by using a phone recognizer working in parallel with the word recognizer. A set of techniques for estimating confidence measures using the phone recognizer output in conjunction with the word recognizer output is described. The most effective of these techniques is based on the construction of "metamodels," which generate alternative word hypotheses for an utterance. An alternative approach requires no other recognizers or extra information for confidence estimation and is based on the notion that a word that is semantically "distant" from the other decoded words in the utterance is likely to be incorrect. We describe a method for constructing "semantic similarities" between words and hence estimating a confidence. Results using the U.K. version of the Wall Street Journal are given for each technique
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