203 research outputs found

    Hierarchical Bayes Estimation of Reliability Indexes of Cold Standby Series System under General Progressive Type II Censoring Scheme

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    In this paper, hierarchical Bayes approach is presented for estimation and prediction of reliability indexes and remaining lifetimes of a cold standby series system under general progressive Type II censoring scheme. A simulation study has been carried out for comparison purpose. The study will help reliability engineers in various industrial series system setups

    Preference of Estimation Approach for Rayleigh Progressive Type II Data

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    This paper compare the performance of the empirical Bayes and generalized maximum likelihood estimation approaches in context of progressively Type II censored data from one parameter Rayleigh distribution. The generalized maximum likelihood and empirical Bayes estimates of scale parameter, reliability function, and failure rate function are compared using risk efficiency criterion. The empirical Bayes estimates are considered with respect to squared error loss function. The wind speed data is presented to illustrate the proposed estimation approaches, and an extensive Monte Carlo simulated study is done to compare the empirical Bayes and Generalized maximum likelihood estimates. The study indicates that the empirical Bayesian approach using squared error loss function is preferable than the generalized maximum likelihood approach for the estimation of reliability performances. Keywords: Progressively Type II censored samples, generalized maximum likelihood estimation, squared error loss function, empirical Bayes estimation, Risk efficiency, Monte Carlo simulation.

    Games in Higher Education

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    International audienceThis entry presents an overview of how and why Learning Games are used in higher education.Learning Games can be defined as games that are designed to captivate the learners’ attention and facilitate their learning process. They have explicit educational purposes and can be used for teaching at all levels of education. All types of games can be used for learning: board games, card games, role-playing games, First Person Shooter games, simulation games, management games, puzzle games, treasure huntsâ€ĶThe main characteristic of Learning Games for higher education is the fact that they are designed to teach specific complex skills taught at university or during professional training programs. Unfortunately, it is not infrequent to observe strong opposition on the part of this target audience to this mode of learning, that these adult students associate with children.The use of Learning Games in primary school seems natural to teachers and is encouraged by specialists in didactics and neuroscience. This learning technique is much less frequently used in middle school and is almost completely absent from higher education. Yet teachers at all these levels are faced with the same problems, such as lack of motivation and investment, for which games are known to be an effective solution. This entry presents an overview of the games that can be used for higher education and the reasons why some teachers and students still show resistance to this type of learning. The numerous advantages of games for higher education will then be presented, citing games presently used in universities, in graduate schools and for professional training. Finally, thisDraft : Marfisi-Schottman I. (2019) Games in Higher Education. In: Tatnall A. (eds) Encyclopedia of Education and Information Technologies. Springer, Chamentry presents the current research questions that need to be addressed concerning the design of games for higher education and the acceptance of these games by teachers

    Ability of Group IVB metallocene polyethers containing dienestrol to arrest the growth of selected cancer cell lines

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    <p>Abstract</p> <p>Background</p> <p>Monomeric Group IVB (Ti, Zr and Hf) metallocenes represent a new class of antitumor compounds. There is literature on the general biological activities of some organotin compounds. Unfortunately, there is little information with respect to the molecular level activity of these organotin compounds. We recently started focusing on the anti-cancer activity of organotin polymers that we had made for other purposes and as part of our platinum anti-cancer effort.</p> <p>Methods</p> <p>For this study, we synthesized a new series of metallocene-containing compounds coupling the metallocene unit with dienestrol, a synthetic, nonsteroidal estrogen. This is part of our effort to couple known moieties that offer antitumor activity with biologically active units hoping to increase the biological activity of the combination. The materials were confirmed to be polymeric using light scattering photometry and the structural repeat unit was verified employing matrix assisted laser desorption ionization mass spectrometry and infrared spectroscopy results.</p> <p>Results</p> <p>The polymers demonstrated the ability to suppress the growth of a series of tumor cell lines originating from breast, colon, prostrate, and lung cancers at concentrations generally lower than those required for inhibition of cell growth by the commonly used antitumor drug cisplatin.</p> <p>Conclusion</p> <p>These drugs show great promise in vitro against a number of cancer cell lines and due to their polymeric nature will most likely be less toxic than currently used metal-containing drugs such as cisplatin. These drugs also offer several addition positive aspects. First, the reactants are commercially available so that additional synthetic steps are not needed. Second, synthesis of the polymer is rapid, occurring within about 15 seconds. Third, the interfacial synthetic system is already industrially employed in the synthesis of aromatic nylons and polycarbonates. Thus, the ability to synthesize large amounts of the drugs is straight forward.</p

    The ties that bind: How the dominance of WeChat combines with guanxi to inhibit and constrain China’s contentious politics

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    Despite the market dominance of the 'WeChat' app in today's China, we currently know little about its significance for contentious politics. This paper argues that MIMAs facilitate communication within relatively strong tie networks (compared to conventional Social Network Sites) which prior research indicates is potentially consequential for patterns of contentious political engagement. Drawing on evidence from a series of Chinese WeChat-user focus groups, we reveal that these ‘chat apps’ create spaces where, although users are often connected through strong ties offline, contentious politics rarely manifests. This trend is driven by a range of dynamics, which we elaborate in a theoretically-informed thematic analysis. When contentious politics does emerge, it is reported by our focus group participants to be largely confined to matters of ‘pragmatic’ and/or ‘safe’ politics that concern defending the interests of individuals or discrete groups, but do not challenge the wider political system

    Pch2 Links Chromosome Axis Remodeling at Future Crossover Sites and Crossover Distribution during Yeast Meiosis

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    Segregation of homologous chromosomes during meiosis I depends on appropriately positioned crossovers/chiasmata. Crossover assurance ensures at least one crossover per homolog pair, while interference reduces double crossovers. Here, we have investigated the interplay between chromosome axis morphogenesis and non-random crossover placement. We demonstrate that chromosome axes are structurally modified at future crossover sites as indicated by correspondence between crossover designation marker Zip3 and domains enriched for axis ensemble Hop1/Red1. This association is first detected at the zygotene stage, persists until double Holliday junction resolution, and is controlled by the conserved AAA+ ATPase Pch2. Pch2 further mediates crossover interference, although it is dispensable for crossover formation at normal levels. Thus, interference appears to be superimposed on underlying mechanisms of crossover formation. When recombination-initiating DSBs are reduced, Pch2 is also required for viable spore formation, consistent with further functions in chiasma formation. pch2Δ mutant defects in crossover interference and spore viability at reduced DSB levels are oppositely modulated by temperature, suggesting contributions of two separable pathways to crossover control. Roles of Pch2 in controlling both chromosome axis morphogenesis and crossover placement suggest linkage between these processes. Pch2 is proposed to reorganize chromosome axes into a tiling array of long-range crossover control modules, resulting in chiasma formation at minimum levels and with maximum spacing
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