A hierarchy of phase transitions in optimal neuronal coding:from binary to M-ary discrete optimal codes

We have investigated how optimal coding for neural systems changes with the time available for decoding. Optimization was in terms of maximizing information transmission. We have estimated the parameters for Poisson neurons that optimize Shannon transinformation with the assumption of rate coding. We observed a hierarchy of phase transitions from binary coding, for small decoding times, toward discrete (M-ary) coding with two, three and more quantization levels for larger decoding times. We postulate that the presence of subpopulations with specific neural characteristics could be a signiture of an optimal population coding scheme and we use the mammalian auditory system as an example.

Fiber-type transitions and satellite cell activation in low-frequency-stimulated muscles of young and aging rats

We examined satellite cell content and the activity of satellite cell progeny in tibialis anterior muscles of young (15 weeks) and aging (101 weeks) Brown Norway (BN) rats, after they were exposed for 50 days to a standardized and highly reproducible regime of chronic low-frequency electrical stimulation. Chronic low-frequency electrical stimulation was successful in inducing fast-to-slow fiber-type transformation, characterized by a 2.3-fold increase in the proportion of IIA fibers and fourfold and sevenfold decreases in the proportion of IID/X and IIB fibers in both young and aging BN rats. These changes were accompanied by a twofold increase in the satellite cell content in both the young and aging groups; satellite cell content reached a level that was significantly higher in the young group (p < .04). The total muscle precursor cell content (i.e., satellite cells plus progeny), however, did not differ between groups, because there was a greater number of satellite cell progeny passing through the proliferative and differentiative compartments of the aging group. The resulting 1.5-fold increase in myonuclear content was similar in the young and aging groups. We conclude that satellite cells and satellite cell progeny of aging BN rats possess an unaltered capacity to contribute to the adaptive response.

The verbal transformation effect and the perceptual organization of speech:influence of formant transitions and F0-contour continuity

This study explored the role of formant transitions and F0-contour continuity in binding together speech sounds into a coherent stream. Listening to a repeating recorded word produces verbal transformations to different forms; stream segregation contributes to this effect and so it can be used to measure changes in perceptual coherence. In experiment 1, monosyllables with strong formant transitions between the initial consonant and following vowel were monotonized; each monosyllable was paired with a weak-transitions counterpart. Further stimuli were derived by replacing the consonant-vowel transitions with samples from adjacent steady portions. Each stimulus was concatenated into a 3-min-long sequence. Listeners only reported more forms in the transitions-removed condition for strong-transitions words, for which formant-frequency discontinuities were substantial. In experiment 2, the F0 contour of all-voiced monosyllables was shaped to follow a rising or falling pattern, spanning one octave. Consecutive tokens either had the same contour, giving an abrupt F0 change between each token, or alternated, giving a continuous contour. Discontinuous sequences caused more transformations and forms, and shorter times to the first transformation. Overall, these findings support the notion that continuity cues provided by formant transitions and the F0 contour play an important role in maintaining the perceptual coherence of speech.

From Spanish paintings to murder:topic transitions in casual conversations between native and non-native speakers of English

This article explores some of the strategies used by international students of English to manage topic shifts in casual conversations with English-speaking peers. It therefore covers aspects of discourse which have been comparatively under-researched, and where research has also tended to focus on the problems rather than the communicative achievements of non-native speakers. A detailed analysis of the conversations under discussion, which were recorded by the participants themselves, showed that they all flowed smoothly, and this was in large measure due to the ways in which topic shifts were managed. The paper will focus on a very distinct type of topic shift, namely that of topic transitions, which enable a smooth flow from one topic to another, but which do not explicitly signal that a shift is taking place. It will examine how the non-native speakers achieved coherence in the topic transitions which they initiated, which strategies or procedures they employed, and show how their initiations were effective in enabling the proposed topic to be understood, taken up and developed. It therefore adds to our understanding of the interactional achievements of international speakers in informal, social contexts. © 2013 Elsevier B.V.

Supply market uncertainty:exploring consequences and responses within sustainability transitions

Often it is commercial, not technological, factors which hinder the adoption of potentially valuable innovations. In energy policy, much attention is given to analysing and incentivising consumer demand for renewable energy, but new technologies may also need new supply markets, to provide products and services to build, operate and maintain the innovative technology. This paper addresses the impact of supply constraints on the long-term viability of sustainability related innovations, using the case of bioenergy from organic waste. Uncertainties in the pricing and availability of feedstock (i.e. waste) may generate market deadlock and deter potential investors. We draw on prior research to conceptualise the problem, and identify what steps might be taken to address it. We propose a research agenda aimed at purchasing and supply scholars and centred on the need to understand better the interplay between market evolution and supply uncertainty and 'market shaping' - how stakeholders can legitimately influence supply market evolution - to support the adoption of sustainability related innovation.

Medication discrepancies at transitions in pediatrics:a review of the literature

Medication reconciliation is an important process in reducing medication errors in many countries. Canada, the USA, and UK have incorporated medication reconciliation as a priority area for national patient safety initiatives and goals. The UK national guidance excludes the pediatric population. The aim of this review was to explore the occurrence of medication discrepancies in the pediatric population. The primary objective was to identify studies reporting the rate and clinical significance of the discrepancies and the secondary objective was to ascertain whether any specific interventions have been used for medication reconciliation in pediatric settings. The following electronic bibliographic databases were used to identify studies: PubMed, OVID EMBASE (1980 to 2012 week 1), ISI Web of Science, ISI Biosis, Cumulative Index to Nursing and Allied Health Literature, and OVID International Pharmaceutical Abstracts (1970 to January 2012). Primary studies were identified that observed medication discrepancies in children under 18 years of age upon hospital admission, transfer and discharge, or had reported medication reconciliation interventions. Two independent reviewers screened titles and abstracts for relevant articles and extracted data using pre-defined data fields, including risk of bias assessment. Ten studies were identified with variances in reportage of stage and rate of discrepancies. Studies were heterogeneous in definitions, methods, and patient populations. Most studies related to admissions and reported consistently high rates of discrepancies ranging from 22 to 72.3 % of patients (sample size ranging from 23 to 272). Seven of the studies were low-quality observational studies and three studies were 'grey literature' non-peer reviewed conference abstracts. Studies involving small numbers of patients have shown that medication discrepancies occur at all transitions of care in children. Further research is required to investigate and demonstrate how implementing medication reconciliation can reduce discrepancies and potential patient harm. © 2013 Springer International Publishing Switzerland.

Gain dependent pulse regimes transitions in a dissipative dispersion-managed fibre laser

For the first time, we demonstrate the possibility to switch between three distinct pulse regimes in a dissipative dispersion-managed (DM) fibre laser by solely controlling the gain saturation energy. Nonlinear Schrödinger equation based simulations show the transitions between hyper-Gaussian similaritons, parabolic similaritons, and dissipative solitons in the same laser cavity. It is also shown that such transitions exist in a wide dispersion range from all-normal to slightly net-normal dispersion. This work demonstrates that besides dispersion and filter managements gain saturation energy can be a new degree of freedom to manage pulse regimes in DM fibre lasers, which offers flexibility in designing ultrafast fibre lasers. Also, the result indicates that in contrast to conservative soliton lasers whose intensity profiles are unique, dissipative DM lasers show diversity in pulse shapes. The findings not only give a better understanding of pulse shaping mechanisms in mode-locked lasers, but also provide insight into dissipative systems.

Computation of rare transitions in the barotropic quasi-geostrophic equations

We investigate the theoretical and numerical computation of rare transitions in simple geophysical turbulent models. We consider the barotropic quasi-geostrophic and two-dimensional Navier–Stokes equations in regimes where bistability between two coexisting large-scale attractors exist. By means of large deviations and instanton theory with the use of an Onsager–Machlup path integral formalism for the transition probability, we show how one can directly compute the most probable transition path between two coexisting attractors analytically in an equilibrium (Langevin) framework and numerically otherWe adapt a class of numerical optimization algorithms known as minimum action methods to simple geophysical turbulent models. We show that by numerically minimizing an appropriate action functional in a large deviation limit, one can predict the most likely transition path for a rare transition between two states. By considering examples where theoretical predictions can be made, we show that the minimum action method successfully predicts the most likely transition path. Finally, we discuss the application and extension of such numerical optimization schemes to the computation of rare transitions observed in direct numerical simulations and experiments and to other, more complex, turbulent systems.

Non-thermal transitions in a model inspired by moral decisions

This work introduces a model in which agents of a network act upon one another according to three different kinds of moral decisions. These decisions are based on an increasing level of sophistication in the empathy capacity of the agent, a hierarchy which we name Piaget's ladder. The decision strategy of the agents is non-rational, in the sense they are arbitrarily fixed, and the model presents quenched disorder given by the distribution of its defining parameters. An analytical solution for this model is obtained in the large system limit as well as a leading order correction for finite-size systems which shows that typical realisations of the model develop a phase structure with both continuous and discontinuous non-thermal transitions.

Designed for Patience. The Significance of International Factors in the Ukrainian and Belarusian Transitions

This paper focuses on Belarus in order to find explanation as to why could Lukashenko remain the authoritarian leader of Belarus, while in Ukraine the position of the political elite had proved less stable and collapsed in 2004. We seek to determine whether the internal factors (macroeconomic conditions, standard of living, the oppressive nature of the political system) play a significant role in the operation of the domino effect. This article emphasises the determining role of immanent internal factors, thus the political stability in Belarus can be explained by the role of the suppressing political regime, the hindrance of democratic rights and the relatively good living conditions that followed the transformational recession. Whilst in Ukraine, the markedly different circumstances brought forth the success of the Orange Revolution.

Three essays on self-employment transitions, organizational capital, and firm formation

This dissertation explores how economic, organizational, and personal factors affect self-employment transitions, occupational decisions, and firm formation activities of individuals at different positions in the skill distribution. The first essay of my dissertation studies how local unemployment rates differentially affect entry into self-employment by individuals at different places in the skill distribution. The empirical results show a positive correlation between local unemployment rates and entry into self-employment for low-ability workers, but not for high-ability workers. Including employer size to eliminate possible distortions showed that the positive association between unemployment and self-employment among low-ability workers is in fact driven by the small firm effect. Controlling for firm size yields a negative association between unemployment and self-employment among high-ability workers. Effects of organizational capital, human capital and physical capital, on the firm formation activities of people at distinct skill levels depend on the type of the industry which is chosen for the new firm. Two types of industries, capital-intensive and ability-intensive, are utilized to explore this hypothesis in the second essay. A capital-intensive industry requires more physical investment, and consequently more funds, whereas, an ability-intensive industry requires more human capital. It is shown that high human capital requirements are associated with higher earnings among the most able individuals, and therefore makes them more likely to found firms in an ability-intensive industry. Wealthy people are more likely to establish both capital-intensive and ability-intensive firms, even though the amount of funds necessary for two industry types differs. Moreover, entry into both industries is predicted to happen later in life due to the removal of entry barriers constituted by required investment spending using savings when old. Empirical mixed results are observed. The third essay investigates earning differentials between future entrepreneurs and their non-entrepreneurial colleagues. Results show that high-ability firm-owners in an ability-intensive industry were earning more than those that remained in wage-work, whereas, low-ability firm-owners in a capital-intensive industry were earning less than those remaining in paid-work.

Family Literacy Practices: Traditions and Transitions

Family literacy practices are discussed from a historical perspective, highlighting the similarities and differences from ancient to modern times. The content of a family literacy workshop is discussed and scripted lessons for parents are presented.

French Truffles and Forest Transitions

Truffle production in France has declined by more than 90% over the last 100 years. Commonly cited causes include a massive rural exodus that led to more open canopy forests becoming less intensively managed and reverting to closed canopy forests, the latter which do not favor truffle production. Scholars have labeled such a process as a forest transition, when a location goes from previously losing forest cover to regrowth and net gains in forest cover. Scholars have single out France as a place with a marked forest transition. Commonly these increases in forest cover are assumed to be a beneficial public good. Here, I question if it is accurate to view forest transitions as being universally beneficial, especially considering that this changing ecology has had strongly deleterious impacts on truffle production and those who rely on it for revenue. In this study I will use remote sensed images to examine if a forest transition did in fact occur in the department of Lot, France and what are the impacts forest trends have had on truffle cultivation. I will further estimates potential losses of revenue from truffle production which has resulted from any existing forest transition.

Origin of scale-free intermittency in structural first-order phase transitions

16 pages, 22 figures