Electron microscopic and biochemical characterization of Fraction 1 protein

High resolution electron microscopy of Fraction I protein from plant leave

Supporting resource-based analysis of task information needs

We investigate here an approach to modelling the dynamic information requirements of a user performing a number of tasks, addressing both the provision and representation of information, viewing the information as being distributed across a set of resources. From knowledge of available resources at the user interface, and task information needs we can identify whether the system provides the user with adequate support for task execution. We look at how we can use tools to help reason about these issues, and illustrate their use through an example.We also consider a full range of analyses suggested using this approach which could potentially be supported by automated reasoning systems.(undefined

Observations of Toroidal Coupling for Low-N Alfven Modes in the Tca Tokamak

The antenna structure in the TCA tokamak is phased to excite preferentially Alfven waves with known toroidal and poloidal wave numbers. Surprisingly, the loading spectrum includes both discrete and continuum modes with poloidal wave numbers incompatible with the antenna phasing. These additional modes, which are important for our heating experiments, can be attributed to linear mode coupling induced by the toroidicity of the plasma column, when we take into account ion-cyclotron effects

Towards a framework for attention cueing in instructional animations: Guidelines for research and design

This paper examines the transferability of successful cueing approaches from text and static visualization research to animations. Theories of visual attention and learning as well as empirical evidence for the instructional effectiveness of attention cueing are reviewed and, based on Mayer’s theory of multimedia learning, a framework was developed for classifying three functions for cueing: (1) selection—cues guide attention to specific locations, (2) organization—cues emphasize structure, and (3) integration—cues explicate relations between and within elements. The framework was used to structure the discussion of studies on cueing in animations. It is concluded that attentional cues may facilitate the selection of information in animations and sometimes improve learning, whereas organizational and relational cueing requires more consideration on how to enhance understanding. Consequently, it is suggested to develop cues that work in animations rather than borrowing effective cues from static representations. Guidelines for future research on attention cueing in animations are presented

High-Q plasmas in the TFTR tokamak

In the Tokamak Fusion Test Reactor, the highest neutron source strength S{sub n} and D-D fusion power gain Q{sub DD} are realized in the neutral-beam fueled and heated supershot'' regime that occurs after extensive wall conditioning to minimize recycling. For the best supershots, S{sub n} increases approximately as P{sub b}{sup 1.8}. The highest-Q shots are characterized by high T{sub e}, T{sub i}, and stored energy highly peaked density profiles, broad T{sub e} profiles, and lower Z{sub eff}. Replacement of critical areas of the graphite limiter tiles with carbon-fiber composite tiles, and improved alignment with the plasma, have mitigated the carbon bloom.'' Wall conditioning by lithium pellet injection prior to the beam pulse reduces carbon influx and particle recycling. Empirically, Q{sub DD} increases with decreasing pre-injection carbon radiation, and increases strongly with density peakedness during the beam pulse. To date the best fusion results are S{sub n} = 5 {times} 10{sup 16} n/s, Q{sub DD} = 1.85 {times} 10{sup {minus}3}, and neutron yield = 4.0 {times} 10{sup 16} n/pulse, obtained at I{sub p} = 1.6 to 1.9 MA and beam energy E{sub b} = 95 to 103 keV, with nearly balanced co- and counter-injected beam power. Computer simulations of supershot plasmas show that typically 50--60% of S{sub n} arises from beam-target reactions, with the remainder divided between beam-beam and thermonuclear reactions, the thermonuclear fraction increasing with P{sub b}. The simulations predict that Q{sub DT} = 0.3 to 0.4 would be obtained for the best present plasma conditions, if half the deuterium neutral beams were to be replaced by tritium beams. Somewhat higher values are calculated if D beams are injected into a predominantly tritium target plasma. The projected central beta of fusion alphas is 0.4--0.6%, a level sufficient for the study of alpha-induced collective effects. 16 refs., 8 figs., 3 tabs

Conceivability and possibility : some dilemmas for Humeans

This research is published within the Project ‘The Logic of Conceivability’, funded by the European Research Council (ERC CoG), Grant Number 681404.The Humean view that conceivability entails possibility can be criticized via input from cognitive psychology. A mainstream view here has it that there are two candidate codings for mental representations (one of them being, according to some, reducible to the other): the linguistic and the pictorial, the difference between the two consisting in the degree of arbitrariness of the representation relation. If the conceivability of P at issue for Humeans involves the having of a linguistic mental representation, then it is easy to show that we can conceive the impossible, for impossibilities can be represented by meaningful bits of language. If the conceivability of P amounts to the pictorial imaginability of a situation verifying P, then the question is whether the imagination at issue works purely qualitatively, that is, only by phenomenological resemblance with the imagined scenario. If so, the range of situations imaginable in this way is too limited to have a significant role in modal epistemology. If not, imagination will involve some arbitrary labeling component, which turns out to be sufficient for imagining the impossible. And if the relevant imagination is neither linguistic nor pictorial, Humeans will appear to resort to some representational magic, until they come up with a theory of a ‘third code’ for mental representations.Publisher PDFPeer reviewe