oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2020 ( 1 )

2019 ( 215 )

2018 ( 265 )

2017 ( 271 )

Custom range...

Search Results: 1 - 10 of 155272 matches for " Stephen B Dunnett "
All listed articles are free for downloading (OA Articles)
Page 1 /155272
Display every page Item
Potential cellular and regenerative approaches for the treatment of Parkinson’s disease
Emma L Lane,Olivia J Handley,Anne E Rosser,Stephen B Dunnett
Neuropsychiatric Disease and Treatment , 2008,
Abstract: Emma L Lane, Olivia J Handley, Anne E Rosser, Stephen B DunnettBrain Repair Group, School of Biosciences, Cardiff University, CF10 3US, UKAbstract: Parkinson’s disease is most commonly treated with a range of pharmacotherapeutics, with the more recent introduction of surgical techniques including deep-brain stimulation. These have limited capabilities to improve symptoms of the disease in more advanced stages, thus new therapeutic strategies including the use of viral vectors and stem cells are in development. Providing a continuous supply of dopamine to the striatum in an attempt to improve the treatment of motor symptoms using enzymes in the dopamine synthesis and machinery is one approach. Alternatively, there are tools which may serve to both protect and encourage outgrowth of surviving neurons using growth factors or to directly replace lost innervation by transplantation of primary tissue or stem cell-derived dopaminergic neurons. We summarize some of the potential therapeutic approaches and also consider the recent EU directives on practical aspects of handling viral vectors, cells and tissues, and in the running of clinical trials in Europe which impact on their development.Keywords: transplantation, viral vector, stem cells, ethics, European Union directive
Assessment of the relationship between pre-chip and post-chip quality measures for Affymetrix GeneChip expression data
Lesley Jones, Darlene R Goldstein, Gareth Hughes, Andrew D Strand, Francois Collin, Stephen B Dunnett, Charles Kooperberg, Aaron Aragaki, James M Olson, Sarah J Augood, Richard LM Faull, Ruth Luthi-Carter, Valentina Moskvina, Angela K Hodges
BMC Bioinformatics , 2006, DOI: 10.1186/1471-2105-7-211
Abstract: We found that the pre-chip variables were significantly correlated with each other but that this correlation was strongest between measures of RNA quality and cRNA yield. Post-mortem interval was negatively correlated with these variables. Four principal components, reflecting array outliers, array adjustment, hybridisation noise and RNA integrity, explain about 75% of the total post-chip measure variability. Two significant canonical correlations existed between the pre-chip and post-chip variables, derived from MAS 5.0, dChip and the Bioconductor packages affy and affyPLM. The strongest (CANCOR 0.838, p < 0.0001) correlated RNA integrity and yield with post chip quality control (QC) measures indexing 3'/5' RNA ratios, bias or scaling of the chip and scaling of the variability of the signal across the chip. Post-mortem interval was relatively unimportant. We also found that the RNA integrity number (RIN) could be moderately well predicted by post-chip measures B_ACTIN35, GAPDH35 and SF.We have found that the post-chip variables having the strongest association with quantities measurable before hybridisation are those reflecting RNA integrity. Other aspects of quality, such as noise measures (reflecting the execution of the assay) or measures reflecting data quality (outlier status and array adjustment variables) are not well predicted by the variables we were able to determine ahead of time. There could be other variables measurable pre-hybridisation which may be better associated with expression data quality measures. Uncovering such connections could create savings on costly microarray experiments by eliminating poor samples before hybridisation.Conducting microarray experiments using Affymetrix arrays is expensive. The quality of the starting material, for instance human post-mortem tissues, is often predetermined and samples may be scarce, leading to variable quality of the extracted RNA. We set out to explore the relationship between quality control (QC) varia
Non-Cooperative Collusion in Static and Dynamic Oligopolies  [PDF]
Stephen B. Wolf
Theoretical Economics Letters (TEL) , 2013, DOI: 10.4236/tel.2013.36053
Abstract:

This paper provides an analysis of collusion in oligopolies from a game-theoretic perspective. It first provides a basic survey of oligopoly models and then uses game theory to analyze non-cooperative or tacit collusion in these models, in a way that should be accessible to undergraduate economics students. In this way, the author characterizes the conditions under which collusive behavior might occur. Importantly, this paper draws its conclusions by using relatively basic methods with which those foreign to the subject should be able to understand.

Use of Host-Plant Trait Space by Phytophagous Insects during Host-Associated Differentiation: The Gape-and-Pinch Model
Stephen B. Heard
International Journal of Ecology , 2012, DOI: 10.1155/2012/192345
Abstract: Ecological speciation via host shifting has contributed to the astonishing diversity of phytophagous insects. The importance for host shifting of trait differences between alternative host plants is well established, but much less is known about trait variation within hosts. I outline a conceptual model, the “gape-and-pinch” (GAP) model, of insect response to host-plant trait variation during host shifting and host-associated differentiation. I offer four hypotheses about insect use of plant trait variation on two alternative hosts, for insects at different stages of host-associated differentiation. Collectively, these hypotheses suggest that insect responses to plant trait variation can favour or oppose critical steps in herbivore diversification. I provide statistical tools for analysing herbivore trait-space use, demonstrate their application for four herbivores of the goldenrods Solidago altissima and S. gigantea, and discuss their broader potential to advance our understanding of diet breadth and ecological speciation in phytophagous insects.
The Geographic Origins of Strategic Culture
Stephen B. Smith
Khazar Journal of Humanities and Social Sciences , 2012,
Abstract: Strategic culture is a concept that characterizes the way a security community thinks about the use of force or the threat of the use of force. It is constantly evolving, but only changes slowly as it is tethered to geography and history. Strategic culture allows the realists to hone his or her skills even more precisely than material variables allow for as beliefs and habits of mind are important variables in decision making at the top levels, but are difficult to quantify. For practitioners of strategy the concept of strategic culture is a helpful tool in understanding what kinds of forces an opponent will deploy and how they will be used in war. Before, however, we can use strategic culture to help us prepare strategies we must first develop a deep understanding of where it comes from then we should be able to understand better our opponents and eventually perhaps even ourselves.
Kaposi′s Sarcoma (KS) In Liberia
Kennedy Stephen B
Indian Journal of Dermatology , 2002,
Abstract:
PROCESS ANALYTICAL TECHNOLOGY FOR BIOTECHNOLOGY PRODUCTS
B. Stephen Rathinaraj
International Journal of Pharmaceutical Research and Development , 2010,
Abstract: Although biotechnology pharmaceutical manufacturers have historically placed a strong emphasis on the manufacturing process as a major contributor to product quality, extensive utilization of process analytical technology (PAT), as a quality systems method, has yet to be fully realized. One impediment is the inherent complexity of the protein- based products that makes it difficult to ascertain the product characteristics that are critical to safety, efficacy, and stability. In spite of this, there are many aspects of biotech manufacturing that are amenable to a PAT system of monitoring and control which can result in improved productivity, manufacturing consistency, and product quality.
On the average value for nonconstant eigenfunctions of the p-Laplacian assuming Neumann boundary data
Stephen B. Robinson
Electronic Journal of Differential Equations , 2003,
Abstract: We show that nonconstant eigenfunctions of the $p$-Laplacian do not necessarily have an average value of 0, as they must when $p=2$. This fact has implications for deriving a sharp variational characterization of the second eigenvalue for a general class of nonlinear eigenvalue problems.
Use of Host-Plant Trait Space by Phytophagous Insects during Host-Associated Differentiation: The Gape-and-Pinch Model
Stephen B. Heard
International Journal of Ecology , 2012, DOI: 10.1155/2012/192345
Abstract: Ecological speciation via host shifting has contributed to the astonishing diversity of phytophagous insects. The importance for host shifting of trait differences between alternative host plants is well established, but much less is known about trait variation within hosts. I outline a conceptual model, the “gape-and-pinch” (GAP) model, of insect response to host-plant trait variation during host shifting and host-associated differentiation. I offer four hypotheses about insect use of plant trait variation on two alternative hosts, for insects at different stages of host-associated differentiation. Collectively, these hypotheses suggest that insect responses to plant trait variation can favour or oppose critical steps in herbivore diversification. I provide statistical tools for analysing herbivore trait-space use, demonstrate their application for four herbivores of the goldenrods Solidago altissima and S. gigantea, and discuss their broader potential to advance our understanding of diet breadth and ecological speciation in phytophagous insects. 1. Introduction The insects have long been held up as providing spectacular examples of rapid diversification and high standing diversity (e.g., [1–3]). Among insects, phytophagous clades often undergo dramatic radiations [4], and phytophagous lineages tend to be more diverse than their nonphytophagous sisters [5, 6]. One likely driver of diversification among phytophagous insects is their tendency to specialize on host-plant species or organs [7–10] and to diversify via host or organ shifts followed by host-associated differentiation (HAD), the evolution of new specialist races or species [9, 11–14]. Because many cases of HAD appear to have proceeded in sympatry [15], a great deal of theoretical and empirical work has focused on understanding ways in which adaptation to different host plants can impose disruptive selection on nascent specialist forms and also reduce gene flow (or permit differentiation in the face of gene flow) between those forms [14–16]. Phytophagous insects, along with parasitoids [17], freshwater fishes [18], seed-eating birds [19], and habitat-specialist plants [20] and lizards [21] have therefore been central to the development of ideas about ecological speciation [22]. A common theme among case studies of ecological speciation is the existence of two alternative niches—microhabitats, resources, reproductive strategies, and so forth—that can be exploited by individuals of a single species, with the potential for disruptive selection to operate between the alternative niches. For
Separation and coupling cutoffs for tuples of independent Markov processes
Stephen B. Connor
Mathematics , 2008,
Abstract: We consider an $n$-tuple of independent ergodic Markov processes, each of which converges (in the sense of separation distance) at an exponential rate, and obtain a necessary and sufficient condition for the $n$-tuple to exhibit a separation cutoff. We also provide general bounds on the (asymmetric) window size of the cutoff, and indicate links to classical extreme value theory.
Page 1 /155272
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.