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Many Approaches (many + approach)
Selected AbstractsTesting association between disease and multiple SNPs in a candidate geneGENETIC EPIDEMIOLOGY, Issue 5 2007W. James Gauderman Abstract Current technology allows investigators to obtain genotypes at multiple single nucleotide polymorphism (SNPs) within a candidate locus. Many approaches have been developed for using such data in a test of association with disease, ranging from genotype-based to haplotype-based tests. We develop a new approach that involves two basic steps. In the first step, we use principal components (PCs) analysis to compute combinations of SNPs that capture the underlying correlation structure within the locus. The second step uses the PCs directly in a test of disease association. The PC approach captures linkage-disequilibrium information within a candidate region, but does not require the difficult computing implicit in a haplotype analysis. We demonstrate by simulation that the PC approach is typically as or more powerful than both genotype- and haplotype-based approaches. We also analyze association between respiratory symptoms in children and four SNPs in the Glutathione-S-Transferase P1 locus, based on data from the Children's Health Study. We observe stronger evidence of an association using the PC approach (p = 0.044) than using either a genotype-based (p = 0.13) or haplotype-based (p = 0.052) approach. Genet. Epidemiol. 2007. © 2007 Wiley-Liss, Inc. [source] Combined use of nuclear magnetic resonance and infrared spectroscopy for studying recognition processes between amphenicolic antibiotics and albuminMAGNETIC RESONANCE IN CHEMISTRY, Issue 7 2003Silvia Martini Abstract Biological reactions are mostly concerned with selective interactions between small ligands and macromolecular receptors. The same ligands may activate responses of different intensities and/or effects in the presence of different receptors. Many approaches based on spectroscopic and non-spectroscopic methods have been used to study interactions between small ligands and macromolecular receptors, including methods based on NMR and IR spectroscopic analysis of the solution behaviour of the ligand in the presence of receptors. In this work, we investigated the interaction between ovine serum albumin with two amphenicolic antibiotics [chloramphenicol (CAP) and thiamphenicol (TAP)], using a combined approach based on NMR and IR methodologies, furnishing complementary information about the recognition process occurring within the two systems. The two ligands, despite their similar structures, showed different affinities towards albumin. NMR methodology is based on the comparison of selective () and non-selective () spin,lattice relaxation rates of the ligands in the presence and absence of macromolecular receptors and and temperature dependence analysis. From these studies, the ligand,receptor binding strength was evaluated on the basis of the ,affinity index.' The derivation of the affinity index from chemical equilibrium kinetics for both the CAP,albumin and TAP,albumin systems allowed a comparison of the abilities of the two amphenicolic antibiotics to interact with the protein. IR methodology is based on the comparison of the ligand,protein ,complex' spectra with those of the non-interacting systems. On the basis of the differences revealed, a more thorough IR analysis was performed in order to understand the structural changes which occurred on both ligand and protein molecules within the interacting system. Copyright © 2003 John Wiley & Sons, Ltd. [source] Peptide immunotherapy for allergic diseasesALLERGY, Issue 3 2007M. Larché Specific allergen immunotherapy has been widely practised for almost 100 years. Whilst this approach is disease-modifying and efficacious, the use of whole allergen preparations is associated with an unacceptably high prevalence of allergic adverse events during treatment. Many approaches to reduce the allergenicity of immunotherapy preparations whilst maintaining immunogenicity are under development. One such approach is the use of short synthetic peptides which represent major T-cell epitopes of the allergen. Major potential advantages of this approach include markedly reduced capacity to cross-link immunoglobulin-E and activate mast cells and basophils, and ease of manufacture and standardization. Promising results in preclinical studies have led to the translation of this approach to clinical studies in humans. Peptide immunotherapy is currently under development for allergic and autoimmune diseases. [source] Actively regulating bioengineered tissue and organ formationORTHODONTICS & CRANIOFACIAL RESEARCH, Issue 3 2005DJ Mooney Structured Abstract Authors ,, Mooney DJ, Boontheekul T, Chen R, Leach K Objectives ,, Describe current and future approaches to tissue engineering, specifically in the area of bone regeneration. These approaches will allow one to actively regulate the cellular populations participating in this process. Design ,, Many approaches to actively regulate cellular phenotype are under exploration, and these typically exploit known signal transduction pathways via presentation of specific receptor-binding ligands, and may also deliver mechanical information via the physical bridge formed by the receptor-ligand interactions. Cellular gene expression may also be directly modulated utilizing gene therapy approaches to control tissue regeneration. Conclusions ,, Significant progress has been made to date in bone regeneration using inductive molecules and transplanted cells, and FDA approved therapies have resulted. While approaches to date have focused on delivery of single stimuli (e.g. one growth factor), future efforts will likely attempt to more closely mimic developmental processes by the delivery of multiple inputs to the cells in spatially and temporally regulated fashions. [source] Improving outcomes of cord blood transplantation: HLA matching, cell dose and other graft- and transplantation-related factorsBRITISH JOURNAL OF HAEMATOLOGY, Issue 2 2009Vanderson Rocha Summary The use of unrelated umbilical cord blood (UCB) as an alternative source of haematopoietic stem cells transplantation (HSCT) has been widely used for patients lacking a human leucocyte antigen (HLA) matched donor. One of the disadvantages of using UCB is the limited number of haematopoietic stem cells and, consequently, delayed engraftment and increased risk of early mortality. Many approaches have been investigated in the attempt to improve engraftment and survival. Among those, studies analysing prognostic factors related to patients, disease, donor and transplantation have been performed. Variable factors have been identified, such as factors related to donor choice (HLA, cell dose and others) and transplantation (conditioning and graft- versus -host disease prophylaxis regimens). This review will focus on the interactions between HLA, cell dose and other modifiable factors related to the UCB unit selection and transplantation that may improve outcomes after UCB transplantation. [source] Integrating fuzzy topological maps and fuzzy geometric maps for behavior-based robotsINTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 3 2002Eugenio Aguirre In behavior-based robots, planning is necessary to elaborate abstract plans that resolve complex navigational tasks. Usually maps of the environment are used to plan the robot motion and to resolve the navigational tasks. Two types of maps have been mainly used: metric and topological maps. Both types present advantages and weakness so that several integration approaches have been proposed in literature. However, in many approaches the integration is conducted to build a global representation model, and the planning and navigational techniques have not been fitted to profit from both kinds of information. We propose the integration of topological and metric models into a hybrid deliberative-reactive architecture through a path planning algorithm based on A* and a hierarchical map with two levels of abstraction. The hierarchical map contains the required information to take advantage of both kinds of modeling. On one hand, the topological model is based on a fuzzy perceptual model that allows the robot to classify the environment in distinguished places, and on the other hand, the metric map is built using regions of possibility with the shape of fuzzy segments, which are used later to build fuzzy grid-based maps. The approach allows the robot to decide on the use of the most appropriate model to navigate the world depending on minimum-cost and safety criteria. Experiments in simulation and in a real office-like environment are shown for validating the proposed approach integrated into the navigational architecture. © 2002 Wiley Periodicals, Inc. [source] Lake restoration: successes, failures and long-term effectsJOURNAL OF APPLIED ECOLOGY, Issue 6 2007MARTIN SØNDERGAARD Summary 1Eutrophication constitutes a serious threat to many European lakes and many approaches have been used during the past 20,30 years to improve lake water quality. Results from the various lake restoration initiatives are diverse and the long-term effects are not well described. 2In this study we evaluated data from more than 70 restoration projects conducted mainly in shallow, eutrophic lakes in Denmark and the Netherlands. Special focus was given to the removal of zooplanktivorous and benthivorous fish, by far the most common internal lake measure. 3In more than half of the biomanipulation projects, Secchi depth increased and chlorophyll a decreased to less than 50% within the first few years. In some of the shallow lakes, total phosphorus and total nitrogen levels decreased considerably, indicating an increased retention or loss by denitrification. The strongest effects seemed to be obtained 4,6 years after the start of fish removal. 4The long-term effect of restoration initiatives can only be described for a few lakes, but data from biomanipulated lakes indicate a return to a turbid state within 10 years or less in most cases. One of reasons for the lack of long-term effects may be internal phosphorus loading from a mobile pool accumulated in the sediment. 5Synthesis and applications. Lake restoration, and in particular fish removal in shallow eutrophic lakes, has been widely used in Denmark and the Netherlands, where it has had marked effects on lake water quality in many lakes. Long-term effects (> 8,10 years) are less obvious and a return to turbid conditions is often seen unless fish removal is repeated. Insufficient external loading reduction, internal phosphorus loading and absence of stable submerged macrophyte communities to stabilize the clear-water state are the most probable causes for this relapse to earlier conditions. [source] Uncertainty in Breast, Prostate, and Colorectal Cancer: Implications for Supportive CareJOURNAL OF NURSING SCHOLARSHIP, Issue 1 2008Maya Shaha Purpose:The aim of this paper was to identify and explore the literature for key aspects of uncertainty experienced by patients who have been diagnosed with breast, prostate, or colorectal cancer. Organizing Construct: Throughout the cancer journey important decisions are made about treatments, symptom control, and supportive care and many approaches have been adopted to examine coping and uncertainty associated with a cancer diagnosis. Uncertainty and its associated attributes, such as stress or anxiety, fluctuate across the disease trajectory. To appreciate the changing nature of uncertainty one should consider its effect on specific patient groups by considering the available evidence. Methods: A comprehensive literature search that was focused on reviews and studies about uncertainty in cancer patients was conducted in PubMed and CINAHL. In total, 40 articles were identified that indicated uncertainty in patients with breast, prostate, or colorectal cancer, although the emphasis in each differed according to the nature and treatment of the disease. Findings: Uncertainty was found to comprise three main themes: uncertainty because of limited or lack of information, uncertainty concerning the course and treatment choices related to the disease, and uncertainty related to everyday life and coping with the disease. Conclusions: Uncertainty influences patients' experiences of their cancer and their coping. Whilst it might be impossible to avoid uncertainty entirely, its negative effects might be ameliorated by understanding patients' specific needs along the disease trajectory of breast, prostate, and colorectal cancer. [source] A unified maximum likelihood approach to document retrievalJOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 10 2001David Bodoff Empirical work shows significant benefits from using relevance feedback data to improve information retrieval (IR) performance. Still, one fundamental difficulty has limited the ability to fully exploit this valuable data. The problem is that it is not clear whether the relevance feedback data should be used to train the system about what the users really mean, or about what the documents really mean. In this paper, we resolve the question using a maximum likelihood framework. We show how all the available data can be used to simultaneously estimate both documents and queries in proportions that are optimal in a maximum likelihood sense. The resulting algorithm is directly applicable to many approaches to IR, and the unified framework can help explain previously reported results as well as guide the search for new methods that utilize feedback data in IR. [source] The Blout Laboratory at Harvard Medical School from 1957 to 1972,BIOPOLYMERS, Issue 5 2008Elizabeth R. Simons Abstract Elkan R. Blout's laboratory at the Children's Cancer Research Foundation and Harvard Medical School pioneered many approaches to the synthesis, conformation and structural studies of polypeptides, biopolymers and selected proteins. Here the early days (1957,1972) of his research group are remembered. © 2008 Wiley Periodicals, Inc. Biopolymers 89: 336,337, 2008. This article was originally published online as an accepted preprint. The "Published Online" date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com [source] | |||||||||||||||||||