Evaluation of Faraday-shielded Stix coils for ion cyclotron resonance heating of a plasma Technical report no. 3

Faraday-shielded Stix coil evaluation including electric field waveform for ion cyclotron resonance heating of plasm

Does Information Lead to Household Electricity Conservation?

This paper estimates the effect of information on residential electricity consumption. Household reading expenditure, education level of the household head, and state “green” electricity pricing program participation rate represent the probability that a household has encountered information relating the carbon emission externalities of energy consumption and human-driven climate change. Reading expenditure has a significant negative effect on household electricity consumption. Initial increases in educational attainment increase electricity consumption, but education beyond high school reduces it. The predicted social norm effect of green pricing participation is insignificant

Programmed cell death during neuronal development: the sympathetic neuron model.

Developing sympathetic neurons of the superior cervical ganglion are one of the best studied models of neuronal apoptosis. These cells require nerve growth factor (NGF) for survival at the time that they innervate their final target tissues during late embryonic and early postnatal development. In the absence of NGF, developing sympathetic neurons die by apoptosis in a transcription-dependent manner. Molecular studies of sympathetic neuron apoptosis began in the 1980s. We now know that NGF withdrawal activates the mitochondrial (intrinsic) pathway of apoptosis in sympathetic neurons cultured in vitro, and the roles of caspases, Bcl-2 (B-cell CLL/lymphoma 2) family proteins and XIAP (X-linked inhibitor of apoptosis protein) have been extensively studied. Importantly, a considerable amount has also been learned about the intracellular signalling pathways and transcription factors that regulate programmed cell death in sympathetic neurons. In this article, we review the key papers published in the past few years, covering all aspects of apoptosis regulation in sympathetic neurons and focusing, in particular, on how signalling pathways and transcription factors regulate the cell death programme. We make some comparisons with other models of neuronal apoptosis and describe possible future directions for the field.Cell Death and Differentiation advance online publication, 25 April 2014; doi:10.1038/cdd.2014.47

Focus Groups as Social Arenas for the Negotiation of Normativity

Aim: This article aims to demonstrate how focus group discussions act as a social arena for the negotiation of social norms and normativity and to discuss the implications for the analysis of focus group discussions. Participants and methods: We have used sequences of group interactions from a focus group study on everyday life and chronic illness to demonstrate how methodological tools from conversation analysis and discursive psychology can be used to facilitate a systematic analysis of the negotiation and legitimization of social norms and normativity in focus groups. The empirical data consisted of six focus groups with a total of 32 participants. Results: The analysis demonstrated negotiations on normativity concerning four central aspects related to living with chronic illness: negotiating normativity about adjustment to the disease, negotiating normativity about being a dutiful employee, negotiating normativity about responsibility for the illness, and negotiating normativity about carrying on. Conclusion: Although the role of interaction in focus group data analysis and its impact on the content of the data should always be viewed in relation to the specific study and study focus, based on the analyses, we argue that adding different epistemological and analytical lenses to a data set may produce different, additional, and more complex insights into the research field

A Unification of Models of Tethered Satellites

In this paper, different conservative models of tethered satellites are related mathematically, and it is established in what limit they may provide useful insight into the underlying dynamics. An infinite dimensional model is linked to a finite dimensional model, the slack-spring model, through a conjecture on the singular perturbation of tether thickness. The slack-spring model is then naturally related to a billiard model in the limit of an inextensible spring. Next, the motion of a dumbbell model, which is lowest in the hierarchy of models, is identified within the motion of the billiard model through a theorem on the existence of invariant curves by exploiting Moser's twist map theorem. Finally, numerical computations provide insight into the dynamics of the billiard model

The Power of Non-Determinism in Higher-Order Implicit Complexity

We investigate the power of non-determinism in purely functional programming languages with higher-order types. Specifically, we consider cons-free programs of varying data orders, equipped with explicit non-deterministic choice. Cons-freeness roughly means that data constructors cannot occur in function bodies and all manipulation of storage space thus has to happen indirectly using the call stack. While cons-free programs have previously been used by several authors to characterise complexity classes, the work on non-deterministic programs has almost exclusively considered programs of data order 0. Previous work has shown that adding explicit non-determinism to cons-free programs taking data of order 0 does not increase expressivity; we prove that this - dramatically - is not the case for higher data orders: adding non-determinism to programs with data order at least 1 allows for a characterisation of the entire class of elementary-time decidable sets. Finally we show how, even with non-deterministic choice, the original hierarchy of characterisations is restored by imposing different restrictions.Comment: pre-edition version of a paper accepted for publication at ESOP'1

Relative motion of satellites exploiting the super-integrability of Kepler's problem

This paper builds upon thework of Palmer and Imre exploring the relative motion of satellites on neighbouring Keplerian orbits.We make use of a general geometrical setting from Hamiltonian systems theory to obtain analytical solutions of the variational Kepler equations in an Earth centred inertial coordinate frame in terms of the relevant conserved quantities: relative energy, relative angular momentum and the relative eccentricity vector. The paper extends the work on relative satellite motion by providing solutions about any elliptic, parabolic or hyperbolic reference trajectory, including the zero angular momentum case. The geometrical framework assists the design of complex formation flying trajectories. This is demonstrated by the construction of a tetrahedral formation, described through the relevant conserved quantities, for which the satellites are on highly eccentric orbits around the Sun to visit the Kuiper belt

Glycine and hyperammonemia : potential target for the treatment of hepatic encephalopathy

Hepatic encephalopathy (HE) is a neuropsychiatric disorder caused by hepatic dysfunction. Numerous studies dictate that ammonia plays an important role in the pathogenesis of HE, and hyperammonemia can lead to alterations in amino acid homeostasis. Glutamine and glycine are both ammoniagenic amino acids that are increased in liver failure. Modulating the levels of glutamine and glycine has shown to reduce ammonia concentration in hyperammonemia. Ornithine Phenylacetate (OP) has consistently been shown to reduce arterial ammonia levels in liver failure by modulating glutamine levels. In addition to this, OP has also been found to modulate glycine concentration providing an additional ammonia removing effect. Data support that glycine also serves an important role in N-methyl D-aspartate (NMDA) receptor mediated neurotransmission in HE. This potential important role for glycine in the pathogenesis of HE merits further investigations

The MEK-ERK pathway negatively regulates bim expression through the 3' UTR in sympathetic neurons

Background: Apoptosis plays a critical role during neuronal development and disease. Developing sympathetic neurons depend on nerve growth factor (NGF) for survival during the late embryonic and early postnatal period and die by apoptosis in its absence. The proapoptotic BH3-only protein Bim increases in level after NGF withdrawal and is required for NGF withdrawal-induced death. The regulation of Bim expression in neurons is complex and this study describes a new mechanism by which an NGF-activated signalling pathway regulates bim gene expression in sympathetic neurons.Results: We report that U0126, an inhibitor of the prosurvival MEK-ERK pathway, increases bim mRNA levels in sympathetic neurons in the presence of NGF. We find that this effect is independent of PI3-K-Akt and JNK-c-Jun signalling and is not mediated by the promoter, first exon or first intron of the bim gene. By performing 3' RACE and microinjection experiments with a new bim-LUC+3'UTR reporter construct, we show that U0126 increases bim expression via the bim 3' UTR. We demonstrate that this effect does not involve a change in bim mRNA stability and by using PD184352, a specific MEK1/2-ERK1/2 inhibitor, we show that this mechanism involves the MEK1/2-ERK1/2 pathway. Finally, we demonstrate that inhibition of MEK/ERK signalling independently reduces cell survival in NGF-treated sympathetic neurons.Conclusions: These results suggest that in sympathetic neurons, MEK-ERK signalling negatively regulates bim expression via the 3' UTR and that this regulation is likely to be at the level of transcription. This data provides further insight into the different mechanisms by which survival signalling pathways regulate bim expression in neurons