In this paper we present an experimental study of edge turbulence in the Large Plasma Device at UCLA. We utilize a scan of discharge power and prefill pressure (neutral density) to show experimentally that turbulent density fluctuations decrease with decreasing density gradient, as predicted for resistive drift-wave turbulence (RDWT). As expected for RDWT, we observe that the cross-phase between the density and potential fluctuations is close to 0. Moreover, the addition of an electron temperature gradient leads to a reduction in the amplitude of the density fluctuations, as expected for RDWT. However, counter to theoretical expectations, we find that the potential fluctuations do not follow the same trends as the density fluctuations for changes either in density gradients or the addition of a temperature gradient. The disconnect between the density and potential fluctuations is connected to changes in the parallel flows as a result of differences in the prefill pressure, i.e. neutral density. Further analysis of the density and potential fluctuation spectra show that the electron temperature gradient reduces the low frequency fluctuations up to $10 \,{\rm kHz}$ and the introduction of a temperature gradient leads to an unexpected ${\sim }{\rm \pi}$ shift of the density–potential cross-phase at ${\sim }10\,{\rm kHz}$, while maintaining the typical resistive drift-wave cross-phase at lower frequencies. These experiments partly confirm existing knowledge on resistive drift-wave turbulence, but also introduce new observations that indicate a need for dedicated nonlinear three-dimensional turbulence simulations that include neutrals.

As part of the project reported on in this special issue, the present study provides an overview of the types of action accomplished by other-repetition in Italian, with particular reference to the variety of the language spoken in the northeastern province of Trento. The analysis surveys actions within the domain of initiating repair, actions that extend beyond initiating repair, and actions that are alternative to initiating repair. Pitch contour emerges as a central design feature of other-repetition in Italian, with six nuclear contours associated with distinct types of action, sequential trajectories, and response patterns. The study also documents the interplay of pitch contour with other prosodic features (pitch span and register) and visible behavior (head nods, eyebrow movements). (Repetition, conversation, prosody, intonation, action, Italian)*

In this article, I introduce the aims and scope of a project examining other-repetition in natural conversation. This introduction provides the conceptual and methodological background for the five language-specific studies contained in this special issue, focussing on other-repetition in English, Finnish, French, Italian, and Swedish. Other-repetition is a recurrent conversational phenomenon in which a speaker repeats all or part of what another speaker has just said, typically in the next turn. Our project focusses particularly on other-repetitions that problematise what is being repeated and typically solicit a response. Previous research has shown that such repetitions can accomplish a range of conversational actions. But how do speakers of different languages distinguish these actions? In addressing this question, we put at centre stage the resources of prosody—the nonlexical acoustic-auditory features of speech—and bring its systematic analysis into the growing field of pragmatic typology—the comparative study of language use and conversational structure. (Repetition, conversation, prosody, pragmatics, typology)*

People often begin stories in conversation by referring to person, time, and place. We study story beginnings in three societies and find place reference is recurrently used to (i) set the stage, foreshadowing the type of story and the kind of response due, and to (ii) make the story cohere, anchoring elements of the developing story. Recipients orient to these interactional affordances of place reference by responding in ways that attend to the relevance of place for the story and by requesting clarification when references are incongruent or noticeably absent. The findings are based on 108 story beginnings in three unrelated languages: Cha'palaa, a Barbacoan language of Ecuador; Northern Italian, a Romance language of Italy; and Siwu, a Kwa language of Ghana. The commonalities suggest we have identified generic affordances of place reference, and that storytelling in conversation offers a robust sequential environment for systematic comparative research. (Storytelling, place, narrative, conversation analysis, interactional linguistics)*

The future space debris environment will be dominated by the production of fragments coming from massive fragmentations. In order to identify the most relevant parameters influencing the long term evolution of the environment and to assess the criticality of selected space objects in different regions of the circumterrestrial space, a large parametric study was performed. In this framework some indicators were produced to quantify and rank the relevance of selected fragmentations on the long term evolution of the space debris population. Based on the results of the fragmentation studies, a novel analytic index, the Criticality of Spacecraft Index, aimed at ranking the environmental criticality of abandoned objects in LEO, has been devised and tested on a sample population of orbiting objects.

We prove a version of Kontsevich’s formality theorem for two subspaces (branes) of a vector space X. The result implies, in particular, that the Kontsevich deformation quantizations of S(X*) and ∧(X) associated with a quadratic Poisson structure are Koszul dual. This answers an open question in Shoikhet’s recent paper on Koszul duality in deformation quantization.

Large-signal radiofrequency performances of surface channel diamond MESFET fabricated on hydrogenated polycrystalline diamond are investigated. The adopted device structure is a typical coplanar two-finger gate layout, characterized in DC by an accumulation-like behavior with threshold voltage Vt ∼ 0-0.5 V and maximum DC drain current of 120 mA/mm. The best radiofrequency performances (in terms of fT and fmax) were obtained close to the threshold voltage. Realized devices are analyzed in standard class A operation, at an operating frequency of 2 GHz. The MESFET devices show a linear power gain of 8 dB and approximately 0.2 Wmm RF output power with 22% power added efficiency. An output power density of about 0.8 W/mm can be then extrapolated at 1 GHz, showing the potential of surface channel MESFET technology on polycrystalline diamond for microwave power devices.

Gliosis is strongly implicated in the development and maintenance of persistent pain states following chronic constriction injury of the sciatic nerve. Here we demonstrate that in the dorsal horn of the spinal cord, gliosis is accompanied by changes in glial amino acid transporters examined by immunoblot, immunohistochemistry and RT-PCR. Cytokines, proinflammatory mediators and microglia increase up to postoperative day (pd) 3 before decreasing on pd 7. Then, spinal glial fibrillary acidic protein increases on pd 7, lasting until pd 14 and later. Simultaneously, the expression of glial amino acid transporters for glycine and glutamate (GlyT1 and GLT1) is reduced on pd 7 and pd 14. Consistent with a reduced expression of GlyT1 and GLT1, high performance liquid chromatography reveals a net increase in the concentration of glutamate and glycine on pd 7 and pd 14 in tissue from the lumbar spinal cord of neuropathic mice. In this study we have confirmed that microglial activation precedes astrogliosis. Such a glial cytoskeletal rearrangement correlates with a marked decrease in glycine and glutamate transporters, which might, in turn, be responsible for the increased concentration of these neurotransmitters in the spinal cord. We speculate that these phenomena might contribute, via over-stimulation of NMDA receptors, to the changes in synaptic functioning that are responsible for the maintenance of persistent pain.

We investigate secular changes in the distribution of personal expenditure in Italy. To this end we present a new data set, consisting of 4,370 family-level budgets scattered over the years 1881–1961. Our methodology is innovative for this kind of study. Italy's secular trend proves to have been egalitarian, and to have accelerated in periods of fast output growth. Sectoral, residential, and demographic changes associated with “modern economic growth” account for a minor part of the observed changes in expenditure distribution, suggesting that other factors, such as wage differentials, play a dominant role in explaining the dynamics of inequality.