57 research outputs found
On the mechanisms governing gas penetration into a tokamak plasma during a massive gas injection
A new 1D radial fluid code, IMAGINE, is used to simulate the penetration of gas into a tokamak plasma during a massive gas injection (MGI). The main result is that the gas is in general strongly braked as it reaches the plasma, due to mechanisms related to charge exchange and (to a smaller extent) recombination. As a result, only a fraction of the gas penetrates into the plasma. Also, a shock wave is created in the gas which propagates away from the plasma, braking and compressing the incoming gas. Simulation results are quantitatively consistent, at least in terms of orders of magnitude, with experimental data for a D 2 MGI into a JET Ohmic plasma. Simulations of MGI into the background plasma surrounding a runaway electron beam show that if the background electron density is too high, the gas may not penetrate, suggesting a possible explanation for the recent results of Reux et al in JET (2015 Nucl. Fusion 55 093013)
The Coupling of Alternative Splicing and Nonsense-Mediated mRNA Decay
Most human genes exhibit alternative splicing, but not all alternatively spliced transcripts produce functional proteins. Computational and experimental results indicate that a substantial fraction of alternative splicing events in humans result in mRNA isoforms that harbor a premature termination codon (PTC). These transcripts are predicted to be degraded by the nonsense-mediated mRNA decay (NMD) pathway. One explanation for the abundance of PTC-containing isoforms is that they represent splicing errors that are identified and degraded by the NMD pathway. Another potential explanation for this startling observation is that cells may link alternative splicing and NMD to regulate the abundance of mRNA transcripts. This mechanism, which we call "Regulated Unproductive Splicing and Translation" (RUST), has been experimentally shown to regulate expression of a wide variety of genes in many organisms from yeast to human. It is frequently employed for autoregulation of proteins that affect the splicing process itself. Thus, alternative splicing and NMD act together to play an important role in regulating gene expression
A Service Member's Self in Transition: A Longitudinal Case Study Analysis
Adopting a narrative approach with a dialogical framework, a longitudinal case study is presented that describes a service member's self in transition from active service into the civilian population. An analysis and interpretation of the case study leads to the hypothesis that if a dominant military I-position appears in the self, a transition may initially create decentering movements of the self that in turn decrease integration and dialogical capacity of the self. New narrative concepts of who one is to become may take time to shape and anchor in corresponding I-position(s) of the self, and self-adaption may only reach a certain level of integration. However, the rise of a third position may unify two conflicting parts, or I-positions, of the self. This may prove to be a promising development for integration and dialogue of the self. Future research is encouraged that examines this hypothesis more broadly
Solicited audio diaries in longitudinal narrative research: a view from inside
The use of solicited audio diaries in longitudinal qualitative enquiry is rare. Moreover, an understanding of the unique insights that these diaries might give the qualitative researcher has largely been absent in our consideration of appropriate methods for data collection. This article aims to address this deficit by providing a critical reflection on the use of solicited audio diaries in longitudinal narrative research from practical, theoretical and analytical perspectives. The data is drawn from a longitudinal study investigating medical students' professional identity formation. In an attempt to reach the broadest audience, both structural aspects and communicative elements of talk within the data are considered alongside ethical issues and emotional work that the longitudinal audio-diary researcher might encounter. In addition to presenting extracts from a variety of diary entries, a single event narrative is presented in full, alongside an analysis, in order to demonstrate the powerful utility of this underused method
Using laboratory experiments to study law and crime
The 19th and 20th centuries produced breakthroughs in physics, chemistry, and the biological sciences. Laboratory research played an important role in the rapid advances made in these fields. Laboratory research can also contribute progress in the social sciences and, in particular, to law and criminology. To make this argument, we begin by discussing what laboratory experiments can and cannot do. We then provide three illustrations of lab experiments that have contributed to understanding of crime and law and discuss how these laboratory data complement those gained through other methods
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