Failed attempts to improve the reliability of the alcohol Visual Probe Task following empirical recommendations

Introduction: The Visual Probe Task (VPT) is a computerised task used to measure attentional bias to substance-related stimuli. Little research has examined the psychometric properties of the VPT, despite concerns it demonstrates poor test-retest reliability and internal consistency. These issues can reduce confidence in inferences based on VPT performance. As such, we attempted to identify parameters under which the reliability of the alcohol VPT might be improved by applying recent empirical recommendations for outlier handling, bias calculation and task design from the anxiety literature. Methods: We reanalysed data from 3 previously published studies in our laboratory and 2 newly collected data-sets. We compared tasks which presented images on the left/right of the screen to above/below, whether participants responded to the location or content of the probe, and whether general alcohol-related images or images personalised to the individual were used. In each VPT we also applied a-priori outlier removal (2 and 3 standard deviations and median absolute difference) and data-driven outlier removal (Winsorising), in addition to calculating trial-level bias scores. Results: Across all studies and tasks internal consistency and test-retest reliability of attentional bias measures were inadequate. There was no consistent improvement in internal consistency or test-retest reliability as a function of outlier removal methods. Discussion: We were unable to demonstrate adequate reliability of the alcohol VPT, which further supports observations that these tasks may not yield reliable measures. Future research should focus on improving the reliability of these tasks or abandoning them in favour of more reliable alternatives

Webifying the computerized execution of Clinical Practice Guidelines

The means through which Clinical Practice Guidelines are dissemi-nated and become accessible are a crucial factor in their later adoption by health care professionals. Making these guidelines available in Clinical Decision Sup-port Systems renders their application more personal and thus acceptable at the moment of care. Web technologies may play an important role in increasing the reach and dissemination of guidelines, but this promise remains largely unful-filled. There is a need for a guideline computer model that can accommodate a wide variety of medical knowledge along with a platform for its execution that can be easily used in mobile devices. This work presents the CompGuide frame-work, a web-based and service-oriented platform for the execution of Computer-Interpretable Guidelines. Its architecture comprises different modules whose in-teraction enables the interpretation of clinical tasks and the verification of clinical constraints and temporal restrictions of guidelines represented in OWL. It allows remote guideline execution with data centralization, more suitable for a work en-vironment where physicians are mobile and not bound to a machine. The solution presented in this paper encompasses a computer-interpretable guideline model, a web-based framework for guideline execution and an Application Programming Interface for the development of other guideline execution systems.This work is part-funded by ERDF - European Regional Development Fund through the COMPETE Programme (operational programme for competitiveness) and by National Funds through the FCT – Fundação para a Ciência e a Tecnologia (Portuguese Foundation for Science and Technology) within project FCOMP-01-0124-FEDER-028980 (PTDC/EEI-SII/1386/2012). The work of Tiago Oliveira is supported by doctoral grant by FCT (SFRH/BD/85291/2012)

State and trait influences on attentional bias to food-cues: The role of hunger, expectancy, and self-perceived food addiction

Food-related attentional bias (AB) varies both between individuals (i.e. trait differences) and within individuals (i.e. state differences), as a function of a food’s momentary incentive value. People with self-perceived food addiction (SPFA) find food particularly rewarding and may therefore demonstrate increased AB to food-related cues, relative to those who do not perceive themselves as food addicts. However, these trait differences may interact with state factors, such as hunger and the perceived availability of food, to differentially affect AB to food-cues. In the current study, female participants (N=120) completed an eye-tracking task to assess AB to chocolate pictures in which the expectancy of receiving chocolate was manipulated on a trial-by-trial basis (0%, 50%, 100%). Participants were randomly allocated such that half completed the task when hungry (hungry condition), and half completed the task following a lunch meal (satiated condition). Participants also indicated the extent to which they perceived themselves to be ‘food addicts’ (SPFAs: n=37; Non-addicts: n=53; Undecided: n=28). Consistent with previous findings, there was a significant main effect of chocolate expectancy; food-related AB was greater on 100% and 50% trials, compared to 0% trials. However, there was no effect of hunger condition (hungry vs. satiated) on AB. Contrary to our hypotheses, SPFAs did not show increased AB to food-cues, and this was not moderated by hunger condition or the expectancy information. Exploratory analyses revealed that higher desire-to-eat (DtE) chocolate was associated with increased AB to chocolate pictures. These findings partially support contemporary theoretical models of AB by indicating a key role for state factors (reward expectancy, DtE) in determining AB to food- cues, while a trait factor (SPFA) was not a significant determinant of food AB

Simultaneous saccharification and fermentation of steam exploded duckweed: Improvement of the ethanol yield by increasing yeast titre

This study investigated the conversion of Lemna minor biomass to bioethanol. The biomass was pre-treated by steam explosion (SE, 210 °C, 10 min) and then subjected to simultaneous saccharification and fermentation (SSF) using CellicÒ CTec 2 (20 U or 0.87 FPU gﰂ1 substrate) cellulase plus b-glucosidase (2 U gﰂ1 substrate) and a yeast inoculum of 10% (v/v or 8.0 ﰀ 107 cells mLﰂ1). At a substrate concentration of 1% (w/v) an ethanol yield of 80% (w/w, theoretical) was achieved. However at a substrate concentration of 20% (w/v), the ethanol yield was lowered to 18.8% (w/w, theoretical). Yields were considerably improved by increasing the yeast titre in the inoculum or preconditioning the yeast on steam exploded liquor. These approaches enhanced the ethanol yield up to 70% (w/w, theoretical) at a substrate concen- tration of 20% (w/v) by metabolising fermentation inhibitors

Anisotropic vortex pinning in superconductors with a square array of rectangular submicron holes

We investigate vortex pinning in thin superconducting films with a square array of rectangular submicron holes ("antidots"). Two types of antidots are considered: antidots fully perforating the superconducting film, and "blind antidots", holes that perforate the film only up to a certain depth. In both systems, we observe a distinct anisotropy in the pinning properties, reflected in the critical current Ic, depending on the direction of the applied electrical current: parallel to the long side of the antidots or perpendicular to it. Although the mechanism responsible for the effect is very different in the two systems, they both show a higher critical current and a sharper IV-transition when the current is applied along the long side of the rectangular antidots

An evolutionarily-unique heterodimeric voltage-gated cation channel found in aphids

We describe the identification in aphids of a unique heterodimeric voltage-gated sodium channel which has an atypical ion selectivity filter and, unusually for insect channels, is highly insensitive to tetrodotoxin. We demonstrate that this channel has most likely arisen by adaptation (gene fission or duplication) of an invertebrate ancestral mono(hetero)meric channel. This is the only identifiable voltage-gated sodium channel homologue in the aphid genome(s), and the channel’s novel selectivity filter motif (DENS instead of the usual DEKA found in other eukaryotes) may result in a loss of sodium selectivity, as indicated experimentally in mutagenised Drosophila channels

Dynamics of coupled cell networks: synchrony, heteroclinic cycles and inflation

Copyright © 2011 Springer. The final publication is available at www.springerlink.comWe consider the dynamics of small networks of coupled cells. We usually assume asymmetric inputs and no global or local symmetries in the network and consider equivalence of networks in this setting; that is, when two networks with different architectures give rise to the same set of possible dynamics. Focussing on transitive (strongly connected) networks that have only one type of cell (identical cell networks) we address three questions relating the network structure to dynamics. The first question is how the structure of the network may force the existence of invariant subspaces (synchrony subspaces). The second question is how these invariant subspaces can support robust heteroclinic attractors. Finally, we investigate how the dynamics of coupled cell networks with different structures and numbers of cells can be related; in particular we consider the sets of possible “inflations” of a coupled cell network that are obtained by replacing one cell by many of the same type, in such a way that the original network dynamics is still present within a synchrony subspace. We illustrate the results with a number of examples of networks of up to six cells

Cosmological Magnetogenesis driven by Radiation Pressure

The origin of large scale cosmological magnetic fields remains a mystery, despite the continuous efforts devoted to that problem. We present a new model of magnetic field generation, based on local charge separation provided by an anisotropic and inhomogeneous radiation pressure. In the cosmological context, the processes we explore take place at the epoch of the reionisation of the Universe. Under simple assumptions, we obtain results (i) in terms of the order of magnitude of the field generated at large scales and (ii) in terms of its power spectrum. The amplitudes obtained (B ~ 8.10^(-6) micro-Gauss) are considerably higher than those obtained in usual magnetogenesis models and provide suitable seeds for amplification by adiabatic collapse and/or dynamo during structure formation.Comment: 9 pages, 2 figure