Balancing Error and Dissipation in Computing

Modern digital electronics support remarkably reliable computing, especially given the challenge of controlling nanoscale logical components that interact in fluctuating environments. However, we demonstrate that the high-reliability limit is subject to a fundamental error-energy-efficiency tradeoff that arises from time-symmetric control: Requiring a low probability of error causes energy consumption to diverge as logarithm of the inverse error rate for nonreciprocal logical transitions. The reciprocity (self-invertibility) of a computation is a stricter condition for thermodynamic efficiency than logical reversibility (invertibility), the latter being the root of Landauer's work bound on erasing information. Beyond engineered computation, the results identify a generic error-dissipation tradeoff in steady-state transformations of genetic information carried out by biological organisms. The lesson is that computation under time-symmetric control cannot reach, and is often far above, the Landauer limit. In this way, time-asymmetry becomes a design principle for thermodynamically efficient computing.Comment: 19 pages, 8 figures; Supplementary material 7 pages, 1 figure; http://csc.ucdavis.edu/~cmg/compmech/pubs/tsp.ht

Feelings in Literature

In this article it is argued that feelings are all important to the function of literature. In contradiction to music that is concerned with the inwardness of humankind, literature has, because of language, the capacity to create fictional worlds that in many respects are similar to and related to the life world within which we live. One of the most important reasons for our emotional engagement in literature is our empathy with others and our constant imagining and hypothesizing on possible developments in our interactions with them. Hence, we understand and engage ourselves in fictional worlds. It is further claimed and exemplified, how poetic texts are very good at rhetorically engage and manipulate our feelings. Finally, with reference to the important work of Ellen Dissanayake, it is pointed out that the first kind of communication in which we engage, that between mother and infant, is a kind of speech that positively engages the infant in a dialogue with the mother by means of poetic devices

Ecology and thermal inactivation of microbes in and on interplanetary space vehicle components

Dry heat sterilization of spacecraft was investigated by studying the production of spore crops, and thermal inactivation of the spores, and bacillus subtillus. Spore assays were made by conventional plate count methods, and survival curves for the spores are presented. The results indicate that the inherent resistance of spores from a parent cell can be maintained

Ecology and thermal inactivation of microbes in and on interplanetary space vehicle components

Experiments performed on the heat resistant organism CK 4-6 are described. Its response to dry heat at two temperatures (125 C and 135 C) at eight humidity levels (0.001 percent to 100 percent RH) in a closed can system is studied

Long-Term Potentiation: One Kind or Many?

Do neurobiologists aim to discover natural kinds? I address this question in this chapter via a critical analysis of classification practices operative across the 43-year history of research on long-term potentiation (LTP). I argue that this 43-year history supports the idea that the structure of scientific practice surrounding LTP research has remained an obstacle to the discovery of natural kinds

Mind-modelling with corpus stylistics in David Copperfield

We suggest an innovative approach to literary discourse by using corpus linguistic methods to address research questions from cognitive poetics. In this article, we focus on the way that readers engage in mind-modelling in the process of characterisation. The article sets out our cognitive poetic model of characterisation that emphasises the continuity between literary characterisation and real-life human relationships. The model also aims to deal with the modelling of the author’s mind in line with the modelling of the minds of fictional characters. Crucially, our approach to mind-modelling is text-driven. Therefore we are able to employ corpus linguistic techniques systematically to identify textual patterns that function as cues triggering character information. In this article, we explore our understanding of mind-modelling through the characterisation of Mr. Dick from David Copperfield by Charles Dickens. Using the CLiC tool (Corpus Linguistics in Cheshire) developed for the exploration of 19th-century fiction, we investigate the textual traces in non-quotations around this character, in order to draw out the techniques of characterisation other than speech presentation. We show that Mr. Dick is a thematically and authorially significant character in the novel, and we move towards a rigorous account of the reader’s modelling of authorial intention

Behavioral Modernity and the Cultural Transmission of Structured Information: The Semantic Axelrod Model

Cultural transmission models are coming to the fore in explaining increases in the Paleolithic toolkit richness and diversity. During the later Paleolithic, technologies increase not only in terms of diversity but also in their complexity and interdependence. As Mesoudi and O'Brien (2008) have shown, selection broadly favors social learning of information that is hierarchical and structured, and multiple studies have demonstrated that teaching within a social learning environment can increase fitness. We believe that teaching also provides the scaffolding for transmission of more complex cultural traits. Here, we introduce an extension of the Axelrod (1997} model of cultural differentiation in which traits have prerequisite relationships, and where social learning is dependent upon the ordering of those prerequisites. We examine the resulting structure of cultural repertoires as learning environments range from largely unstructured imitation, to structured teaching of necessary prerequisites, and we find that in combination with individual learning and innovation, high probabilities of teaching prerequisites leads to richer cultural repertoires. Our results point to ways in which we can build more comprehensive explanations of the archaeological record of the Paleolithic as well as other cases of technological change.Comment: 24 pages, 7 figures. Submitted to "Learning Strategies and Cultural Evolution during the Paleolithic", edited by Kenichi Aoki and Alex Mesoudi, and presented at the 79th Annual Meeting of the Society for American Archaeology, Austin TX. Revised 5/14/1

Authenticity, Culture and Language Learning

In philosophy, authenticity has been used with two meanings: one entails the notion of correspondence; the other entails the notion of genesis (Cooper, 1983: 15). As in certain branches of philosophy, language teaching has perhaps clung too long to the first of these notions of authenticity at the expense of the other. This paper reviews four key conceptualisations of authenticity which have emerged in the field of applied linguistics: text authenticity, authenticity of language competence, learner authenticity and classroom authenticity. If any of these types of authenticity is couched exclusively in terms of one usage or the other, it can lead to an impoverishment and objectification of the experience of language learning. Text authenticity can lead to a poverty of language; authenticity of competence can lead to a poverty of performance; learner authenticity can lead to a poverty of interpretation; classroom authenticity can lead to a poverty of communication. This paper proposes that a pedagogy of intercultural communication be informed by a more hybrid view of authenticity as a process of subjectification, derived from the Heideggerian concept of self-concern