Data reduction in the ITMS system through a data acquisition model with self-adaptive sampling rate

Long pulse or steady state operation of fusion experiments require data acquisition and processing systems that reduce the volume of data involved. The availability of self-adaptive sampling rate systems and the use of real-time lossless data compression techniques can help solve these problems. The former is important for continuous adaptation of sampling frequency for experimental requirements. The latter allows the maintenance of continuous digitization under limited memory conditions. This can be achieved by permanent transmission of compressed data to other systems. The compacted transfer ensures the use of minimum bandwidth. This paper presents an implementation based on intelligent test and measurement system (ITMS), a data acquisition system architecture with multiprocessing capabilities that permits it to adapt the system’s sampling frequency throughout the experiment. The sampling rate can be controlled depending on the experiment’s specific requirements by using an external dc voltage signal or by defining user events through software. The system takes advantage of the high processing capabilities of the ITMS platform to implement a data reduction mechanism based in lossless data compression algorithms which are themselves based in periodic deltas

Effects of a Whole-School Health Intervention on Clustered Adolescent Health Risks: Latent Transition Analysis of Data from the INCLUSIVE Trial

Whole-school interventions are a promising approach to preventing bullying and aggression while promoting broader health. The main analyses from a trial of the INCLUSIVE whole-school intervention reported reductions in bullying victimisation but not aggression and improved mental well-being. Latent transition analysis can examine how interventions ‘move’ people between classes defined by multiple outcomes over time. We examined at baseline what classes best defined individuals’ bullying, aggression and mental well-being and what effects did the intervention have on movement between classes over time? INCLUSIVE was a two-arm cluster-randomised trial with 20 high schools per arm, with 24-month and 36-month follow-ups. We estimated sequential latent class solutions on baseline data. We then estimated a latent transition model including baseline, 24-month and 36-month follow-up measurements. Our sample comprised 8179 students (4082 control, 4097 intervention arms). At baseline, classes were (1) bullying victims, (2) aggression perpetrators, (3) extreme perpetrators and (4) neither victims nor perpetrators. Control students who were extreme perpetrators were equally likely to stay in this class (27.0% probability) or move to aggression perpetrators (25.0% probability) at 24 months. In the intervention group, fewer extreme perpetrators students remained (5.4%), with more moving to aggression perpetrators (65.1%). More control than intervention extreme perpetrators moved to neither victims nor perpetrators (35.2% vs 17.8%). Between 24 and 36 months, more intervention students moved from aggression perpetrators to neither victims nor perpetrators than controls (30.1% vs 22.3%). Our findings suggest that the intervention had important effects in transitioning students to lower-risk classes

Using qualitative research to explore intervention mechanisms: findings from the trial of the Learning Together whole-school health intervention

Background: This study reports on qualitative research conducted within a randomised controlled trial to explore possible intervention mechanisms. It focuses on the ‘Learning Together’ whole-school intervention delivered in secondary schools in England from 2014 to 2017 aiming to prevent bullying and aggression and improve student health. Intervention schools received staff training in restorative practice, a social and emotional learning curriculum, and an external facilitator and manual to convene and run a student/staff action group tasked with coordinating the intervention, focusing this on local needs. / Methods: Informed by realist approaches to evaluation, we analysed qualitative data to explore intervention mechanisms and how these might interact with school contexts to generate outcomes. Qualitative analysis drew on 45 interviews and 21 focus groups across three case-study schools and employed thematic content analysis to explore how intervention resources were taken up and used by local actors, how participants described the intervention mechanisms that then ensued, and how these might have generated beneficial outcomes. / Results: The thematic content analysis identified three social mechanisms that recurred in participant accounts: (1) building student commitment to the school community, (2) building healthy relationships by modelling and teaching pro-social skills, and (3) de-escalating bullying and aggression and enabling re-integration within the school community. / Conclusions: Our analysis provides in-depth exploration of possible mechanisms and the contextual contingencies associated with these, allowing refinement of the initial intervention theory of change. / Trial registration: ISRCTN registry 10751359. Registered on 11 March 2014

Scale-free Networks from Optimal Design

A large number of complex networks, both natural and artificial, share the presence of highly heterogeneous, scale-free degree distributions. A few mechanisms for the emergence of such patterns have been suggested, optimization not being one of them. In this letter we present the first evidence for the emergence of scaling (and smallworldness) in software architecture graphs from a well-defined local optimization process. Although the rules that define the strategies involved in software engineering should lead to a tree-like structure, the final net is scale-free, perhaps reflecting the presence of conflicting constraints unavoidable in a multidimensional optimization process. The consequences for other complex networks are outlined.Comment: 6 pages, 2 figures. Submitted to Europhysics Letters. Additional material is available at http://complex.upc.es/~sergi/software.ht

Comparación de citología mediante aspirado de aguja fina e histología en el diagnóstico de lipidosis hepática en bovinos de matadero

El objetivo de este estudio fue comparar resultados de citología e histología en la detección de acúmulo de lípido hepatocelular en bovinos. La lipidosis hepática en ganado lechero es una enfermedad de gran importancia clínica y económica. La citología de aspirado de aguja fina (AAF) ha sido descrita como una técnica capaz de identificar lipidosis hepática en bovinos, sin embargo se carece de estudios que evalúen la exactitud del método. Este estudio corresponde a un primer paso para probar nuestra hipótesis de que la citología de AAF es un método de una exactitud razonable, económico y practicable para diagnosticar lipidosis hepática en bovinos. Se obtuvo 73 muestras a partir de hígados de matadero inmediatamente post mortem. Utilizando una escala de 1 a 4 se determinó la severidad de la lesión tanto para el porcentaje de células afectadas como para el promedio de citoplasma afectado. Se utilizaron muestras pareadas que representaron un espectro de las lesiones. La correlación entre el grado de afección de hepatocitos y citoplasma entre citología e histología fue altamente significativa. El puntaje dado para porcentaje de hepatocitos afectados fue diferente en ≤1 punto entre citología e histología en el 73% de los casos. Para el caso de porcentaje de citoplasma afectado esta diferencia de ≤1 punto entre ambas técnicas se presentó en el 95% de los casos. La prueba de concordancia de Kappa entre citología e histología fue adecuada. Estos hallazgos sugieren que la citología de aspirado de aguja fina puede ser un método aceptable para diagnosticar hígado graso en ganado bovino. Se requieren más estudios en animales vivos con sospecha clínica de lipidosis hepática

Brans-Dicke model constrained from Big Bang nucleosynthesis and magnitude redshift relations of Supernovae

The Brans-Dicke model with a variable cosmological term ($BD\Lambda$) has been investigated with use of the coupling constant of $\omega=10^4$. Parameters inherent in this model are constrained from comparison between Big Bang nucleosynthesis and the observed abundances. Furthermore, the magnitude redshift ($m-z$) relations are studied for $BD\Lambda$ with and without another constant cosmological term in a flat universe. Observational data of Type Ia Supernovae are used in the redshift range of $0.01<z<2$. It is found that our model with energy density of the constant cosmological term with the value of 0.7 can explain the SNIa observations, though the model parameters are insensitive to the $m-z$ relation.Comment: Submitted to A&A, 4 pages, 3 figure

Keck-Nirspec Infrared OH Lines: Oxygen Abundances in Metal-Poor Stars Down to [Fe/H] = -2.9

Infrared OH lines at 1.5 - 1.7 um in the H band were obtained with the NIRSPEC high-resolution spectrograph at the 10m Keck Telescope for a sample of seven metal-poor stars. Detailed analyses have been carried out, based on optical high-resolution data obtained with the FEROS spectrograph at ESO. Stellar parameters were derived by adopting infrared flux method effective temperatures, trigonometric and/or evolutionary gravities and metallicities from FeII lines. We obtain that the sample stars with metallicities [Fe/H] < -2.2 show a mean oxygen abundance [O/Fe] ~ 0.54, for a solar oxygen abundance of epsilon(O) = 8.87, or [O/Fe] ~ 0.64 if epsilon(O) = 8.77 is assumed.Comment: To be published in ApJ 575 (August 10

Evoked responses to rhythmic visual stimulation vary across sources of intrinsic alpha activity in humans

Rhythmic flickering visual stimulation produces steady-state visually evoked potentials (SSVEPs) in electroencephalogram (EEG) recordings. Based on electrode-level analyses, two dichotomous models of the underpinning mechanisms leading to SSVEP generation have been proposed: entrainment or superposition, i.e., phase-alignment or independence of endogenous brain oscillations from flicker-induced oscillations, respectively. Electrode-level analyses, however, represent an averaged view of underlying ‘source-level’ activity, at which variability in SSVEPs may lie, possibly suggesting the co-existence of multiple mechanisms. To probe this idea, we investigated the variability of SSVEPs derived from the sources underpinning scalp EEG responses during presentation of a flickering radial checkerboard. Flicker was presented between 6 and 12 Hz in 1 Hz steps, and at individual alpha frequency (IAF i.e., the dominant frequency of endogenous alpha oscillatory activity). We tested whether sources of endogenous alpha activity could be dissociated according to evoked responses to different flicker frequencies relative to IAF. Occipitoparietal sources were identified by temporal independent component analysis, maximal resting-state alpha power at IAF and source localisation. The pattern of SSVEPs to rhythmic flicker relative to IAF was estimated by correlation coefficients, describing the correlation between the peak-to-peak amplitude of the SSVEP and the absolute distance of the flicker frequency from IAF across flicker conditions. We observed extreme variability in correlation coefficients across sources, ranging from −0.84 to 0.93, with sources showing largely different coefficients co-existing within subjects. This result demonstrates variation in evoked responses to flicker across sources of endogenous alpha oscillatory activity. Data support the idea of multiple SSVEP mechanisms