Partitioning 3-homogeneous latin bitrades

A latin bitrade $(T^{\diamond}, T^{\otimes})$ is a pair of partial latin squares which defines the difference between two arbitrary latin squares $L^{\diamond} \supseteq T^{\diamond}$ and $L^{\diamond} \supseteq T^{\otimes}$ of the same order. A 3-homogeneous bitrade $(T^{\diamond}, T^{\otimes})$ has three entries in each row, three entries in each column, and each symbol appears three times in $T^{\diamond}$. Cavenagh (2006) showed that any 3-homogeneous bitrade may be partitioned into three transversals. In this paper we provide an independent proof of Cavenagh's result using geometric methods. In doing so we provide a framework for studying bitrades as tessellations of spherical, euclidean or hyperbolic space.Comment: 13 pages, 11 figures, fixed the figures. Geometriae Dedicata, Accepted: 13 February 2008, Published online: 5 March 200

A Bayesian test for the appropriateness of a model in the biomagnetic inverse problem

This paper extends the work of Clarke [1] on the Bayesian foundations of the biomagnetic inverse problem. It derives expressions for the expectation and variance of the a posteriori source current probability distribution given a prior source current probability distribution, a source space weight function and a data set. The calculation of the variance enables the construction of a Bayesian test for the appropriateness of any source model that is chosen as the a priori infomation. The test is illustrated using both simulated (multi-dipole) data and the results of a study of early latency processing of images of human faces. [1] C.J.S. Clarke. Error estimates in the biomagnetic inverse problem. Inverse Problems, 10:77--86, 1994.Comment: 13 pages, 16 figures. Submitted to Inverse Problem

Asuntojen, varastojen ja muiden sisätilojen tuhoeläimet

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Anisotropic excitonic effects in the energy loss function of hexagonal boron nitride

We demonstrate that the valence energy-loss function of hexagonal boron nitride (hBN) displays a strong anisotropy in shape, excitation energy and dispersion for momentum transfer q parallel or perpendicular to the hBN layers. This is manifested by e.g. an energy shift of 0.7 eV that cannot be captured by single-particle approaches and is a demonstration of a strong anisotropy in the two-body electron-hole interaction. Furthermore, for in-plane directions of q we observe a splitting of the -plasmon in the M direction that is absent in the K direction and this can be traced back to band-structure effects.Comment: 10 pages, 4 figure

Assessment of the systemic effects of budesonide inhaled from Easyhaler®and from Turbuhaler®in healthy male volunteers

AbstractThe main objective of this study was to show dose-dependent equivalence in the systemic activity of budesonide 800 μ g day−1and 1600 μ g day−1delivered from either Easyhaler®or Turbuhaler®in healthy male subjects.This single-centre study was carried out according to a randomized, double-blind, double-dummy, five-way cross-over design over a 9-week period. All subjects received 1 week of treatment with the following, in randomized order, with a washout week between each treatment: budesonide Easyhaler®800 μ g day−1plus placebo Turbuhaler®; budesonide Easyhaler®1600 μ g day−1plus placebo Turbuhaler®; placebo Easyhaler®plus Pulmicort®Turbuhaler®800 μ g day−1; placebo Easyhaler®plus Pulmicort®Turbuhaler®1600 μ g day−1; placebo Easyhaler®plus placebo Turbuhaler®. The final inhalation of study drug was performed at the study centre, where blood and urine samples were collected.Fifteen subjects were recruited and all completed the study. Mean serum cortisol AUC0–20values (the primary outcome variable) were comparable for each device at the two dose levels, and met the defined criteria for equivalence (90% CI 0·8–1·25 for between-treatment difference). Budesonide 800 μ g day−1caused minimal suppression of serum cortisol AUC0-20values. Budesonide 1600 μ g day−1statistically significantly suppressed serum cortisol AUC0–20values compared with placebo. Mean morning serum cortisol values were within the reference range in all treatment groups. At a budesonide dose of 800 μ g day−1mean urine cortisol/creatinine ratio was statistically significantly higher with Easyhaler®than with Turbuhaler®, but there was no significant difference between the devices at the 1600 μ g day−1dose. Serum budesonide concentrations were equivalent for each device at both dose levels. Adverse drug reactions were infrequent and mild in nature and there were no clinically significant changes in laboratory safety variables.In conclusion, in healthy male volunteers, budesonide 800μ g day−1and 1600 μ g day−1inhaled from Easyhaler®had comparable systemic effects to the same doses inhaled via Turbuhaler®

The State-of-the-Art of Collaborative Technologies for Initial Vocational Education: A Systematic Literature Review

Future workplaces require collaboration skills in which members of different work communities use technologies to solve complex problems. Vocational education and training (VET) programs need to meet the challenge to prepare students to be part of a competent workforce. Particularly initial vocational education is under pressure to develop learners’ collaboration skills and abilities. To date, however, no attempt has been made to perform a comprehensive review of the use of computer-supported collaborative learning (CSCL) technologies across different vocational education settings to account for contextual factors of VET. In this systematic review, 26 published studies were analyzed with respect to their demographics, research methodology, use of technology, and measured outcomes. This review illuminates that research on CSCL still leaves the vocational learning context as an under-represented field of study. At the same time, technologies offer a range of new types of learning possibilities for vocational education. As the direct result of that development, vocational education is increasingly taking place in new technology-enhanced learning settings. Education can benefit from the opportunities of CSCL technologies, but on the other hand, such technologies create new challenges for facilitating vocational learning. Therefore, this review also identifies three topic areas specific to vocational learning (collaborative writing-to-learn, simulations and game-like solutions, and tangible objects) and enumerates desirable lines for future research

Spatiotemporal signatures of lexical–semantic prediction

Although there is broad agreement that top-down expectations can facilitate lexical-semantic processing, the mechanisms driving these effects are still unclear. In particular, while previous electroencephalography (EEG) research has demonstrated a reduction in the N400 response to words in a supportive context, it is often challenging to dissociate facilitation due to bottom-up spreading activation from facilitation due to top-down expectations. The goal of the current study was to specifically determine the cortical areas associated with facilitation due to top-down prediction, using magnetoencephalography (MEG) recordings supplemented by EEG and functional magnetic resonance imaging (fMRI) in a semantic priming paradigm. In order to modulate expectation processes while holding context constant, we manipulated the proportion of related pairs across 2 blocks (10 and 50% related). Event-related potential results demonstrated a larger N400 reduction when a related word was predicted, and MEG source localization of activity in this time-window (350-450 ms) localized the differential responses to left anterior temporal cortex. fMRI data from the same participants support the MEG localization, showing contextual facilitation in left anterior superior temporal gyrus for the high expectation block only. Together, these results provide strong evidence that facilitatory effects of lexical-semantic prediction on the electrophysiological response 350-450 ms postonset reflect modulation of activity in left anterior temporal cortex

Speaker age estimation for elderly speech recognition in European Portuguese

Phone-like acoustic models (AMs) used in large-vocabulary automatic speech recognition (ASR) systems are usually trained with speech collected from young adult speakers. Using such models, ASR performance may decrease by about 10% absolute when transcribing elderly speech. Ageing is known to alter speech production in ways that require ASR systems to be adapted, in particular at the level of acoustic modeling. In this study, we investigated automatic age estimation in order to select age-specific adapted AMs. A large corpus of read speech from European Portuguese speakers aged 60 or over was used. Age estimation (AE) based on i-vectors and support vector regression achieved mean error rates of about 4.2 and 4.5 years for males and females, respectively. Compared with a baseline ASR system with AMs trained using young adult speech and a WER of 13.9%, the selection of five-year-range adapted AMs, based on the estimated age of the speakers, led to a decrease in WER of about 9.3% relative (1.3% absolute). Comparable gains in ASR performance were observed when considering two larger age ranges (60-75 and 76-90) instead of six five-year ranges, suggesting that it would be sufficient to use the two large ranges only.info:eu-repo/semantics/acceptedVersio