9,368 research outputs found

    A parents group and its relation to the problem of mental retardation

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    Thesis (Ed.M.)--Boston Universit

    Generation and Characterization of a Tissue-Specific Centrosome Indicator Mouse Line.

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    Centrosomes are major microtubule organizing centers (MTOCs) that play an important role in chromosome segregation during cell division. Centrosomes provide a stable anchor for microtubules, constituting the centers of the spindle poles in mitotic cells, and determining the orientation of cell division. However, visualization of centrosomes is challenging because of their small size. Especially in mouse tissues, it has been extremely challenging to observe centrosomes belonging to a specific cell type of interest among multiple comingled cell types. To overcome this obstacle, we generated a tissue-specific centrosome indicator. In this mouse line, a construct containing a floxed neomyocin resistance gene with a triplicate polyA sequence followed by an EGFP-Centrin1 fusion cassette was knocked into the Rosa locus. Upon Cre-mediated excision, EGFP-Centrin1 was expressed under the control of the Rosa locus. Experiments utilizing mouse embryo fibroblasts (MEFs) demonstrated the feasibility of real-time imaging, and showed that EGFP-Centrin1 expression mirrored the endogenous centrosome cycle, undergoing precisely one round of duplication through the cell cycle. Moreover, experiments using embryo and adult mouse tissues demonstrated that EGFP-Centrin1 specifically mirrors the localization of endogenous centrosomes. genesis 54:286-296, 2016. © 2016 The Authors. Genesis Published by Wiley Periodicals, Inc

    On a Service-Oriented Approach for an Engineering Knowledge Desktop

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    Increasingly, manufacturing companies are shifting their focus from selling products to providing services. As a result, when designing new products, engineers must increasingly consider the life cycle costs in addition to any design requirements. To identify possible areas of concern, designers are required to consult existing maintenance information from identical products. However, in a large engineering company, the amount of information available is significant and in wide range of formats. This paper presents a prototype knowledge desktop suitable for the design engineer. The Engineering Knowledge Desktop analyses and suggests relevant information from ontologically marked-up heterogeneous web resources. It is designed using a Service-Oriented Architecture, with an ontology to mediate between Web Services. It has been delivered to the user community for evaluation

    Species from different taxonomic groups show similar invasion traits

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    Invasion ecology tends to treat taxonomic groups separately. However, given that all invasive species go through the same stages of the invasion process (transport, escape, establishment, spread), it is likely that – across taxa – comparable traits help to successfully complete this process ("invasion traits"). Perhaps not all invasive species have the same invasion traits, but different combinations of invasion traits can be found among invaders, corresponding to different possibilities to become a successful invader. These combinations of invasion traits might be linked to taxonomic affiliation, but this is not necessarily the case. We created a global dataset with 201 invasive species from seven major taxonomic groups (animals, green plants, fungi, heterokonts, bacteria, red algae, alveolates) and 13 invasion traits that are applicable across all taxa. The dataset was analysed with cluster analysis to search for similarities in combinations of invasion traits. Three of the five clusters, comprising 60% of all species, contain several major taxonomic groups. While some invasion trait frequencies were significantly related to taxonomic affiliation, the results show that invasive species from different taxonomic groups often share similar combinations of invasion traits. A post-hoc analysis suggests that combinations of traits characterizing successful invaders can be associated with invasion stages across taxa. Our findings suggest that there are no universal invasion traits which could explain the invasion success of all invaders, but that invaders are successful for different reasons which are represented by different combinations of invasion traits across taxonomic groups

    Bayesian Gene Set Analysis

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    Gene expression microarray technologies provide the simultaneous measurements of a large number of genes. Typical analyses of such data focus on the individual genes, but recent work has demonstrated that evaluating changes in expression across predefined sets of genes often increases statistical power and produces more robust results. We introduce a new methodology for identifying gene sets that are differentially expressed under varying experimental conditions. Our approach uses a hierarchical Bayesian framework where a hyperparameter measures the significance of each gene set. Using simulated data, we compare our proposed method to alternative approaches, such as Gene Set Enrichment Analysis (GSEA) and Gene Set Analysis (GSA). Our approach provides the best overall performance. We also discuss the application of our method to experimental data based on p53 mutation status

    Materials Development: Pitfalls, Successes, and Lessons

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    The incorporation of new or improved materials in aerospace systems, or indeed any systems, can yield tremendous payoffs in the system performance or cost, and in many cases can be enabling for a mission or concept. However, the availability of new materials requires advance development, and too often this is neglected or postponed, leaving a project or mission with little choice. In too many cases, the immediate reaction is to use what was used before; this usually turns out not to be possible and results in large sums of money, and amounts of time, being expended on reinvention rather than development of a material with extended capabilities. Material innovation and development is time consuming, with some common wisdom claiming that the timeline is at least 20 years. This time expands considerably when development is stopped and restarted, or knowledge is lost. Down selection of materials is necessary, especially as the Technical Readiness Level (TRL) increases. However, the costs must be considered and approaches should be taken to retain knowledge and allow for restarting the development process. Regardless of the exact time required, it is clear that it is necessary to have materials, at all stages of development, in a research and development pipeline and available for maturation as required. This talk will discuss some of theses issues, including some of the elements for a development path for materials. Some history of materials developments will be included. The usefulness of computational materials science, as a route to decreasing material development time, will be an important element of this discussion. Collaboration with outside institutions and nations is also critical for innovation, but raises the issues of intellectual property and protections, and national security (ITAR rules, for example)

    The Effects of ITQ Management on Fishermen’s Welfare When the Processing Sector is Imperfectly Competitive

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    In this paper we use a general model of imperfect competition to predict welfare changes within an open-access fishery transitioning to individual transferable quota (ITQ) management. Although related research has explored the effects of market power in the harvesting sector on ITQ performance, none have considered the implications of an imperfectly competitive processing sector. This study addresses this question specifically in the context of the Atlantic herring fishery, although its implications are relevant to all fisheries with similar industry structure. Our results show that ITQs could have a negative impact on fishermen’s welfare when processors have market power and the cap on aggregate harvest is binding or becomes binding with the implementation of ITQs.ITQ, imperfect competition, welfare analysis, fisheries

    Social, religious, and economic status of women in Colonial days as shown in the writings of that period

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