Investigating invariant item ordering in the Mental Health Inventory : an illustration of the use of different methods

Invariant item ordering is a property of scales whereby the items are scored in the same order across a wide range of the latent trait and across a wide range of respondents. In the package ‘mokken’ in the statistical software R, the ability to analyse Mokken scales for invariant item ordering has recently been available and techniques for inspecting visually the item response curves of item pairs, have also been included. While methods to assess invariant item ordering are available, there have been indications that items representing extremes of distress in mental well-being scales, such as suicidal ideation, may lead to claiming invariant item ordering where it does not exist. We used the Mental Health Inventory to see if invariant item ordering was indicated in any Mokken scales derived and to see if this was being influenced by extreme items. A Mokken scale was derived indicating invariant item ordering. Visual inspection of the item pairs indicated that the most difficult item (suicidal ideation) was located far from the remaining cluster of items. Removing this item lowered invariant item ordering to an unacceptable level

Collision-induced conformational changes in glycine

We present quantum dynamical calculations on the conformational changes of glycine in collisions with the He, Ne, and Ar rare-gas atoms. For two conformer interconversion processes (III-->I and IV-->I), we find that the probability of interconversion is dependent on several factors, including the energy of the collision, the angle at which the colliding atom approaches the glycine molecule, and the strength of the glycine-atom interaction. Furthermore, we show that attractive interactions between the colliding atom and the glycine molecule catalyze conformer interconversion at low collision energies. In previous infrared spectroscopy studies of glycine trapped in rare-gas matrices and helium clusters, conformer III has been consistently observed, but conformer IV has yet to be conclusively detected. Because of the calculated thermodynamic stability of conformer IV, its elusiveness has been attributed to the IV-->I conformer interconversion process. However, our calculations present little indication that IV-->I interconversion occurs more readily than III-->I interconversion. Although we cannot determine whether conformer IV interconverts during experimental Ne- and Ar-matrix depositions, our evidence suggests that the conformer should be present in helium droplets. Anharmonic vibrational frequency calculations illustrate that previous efforts to detect conformer IV may have been hindered by the overlap of its IR-absorption bands with those of other conformers. We propose that the redshifted symmetric –CH2 stretch of conformer IV provides a means for its conclusive experimental detection

Metacognition in the audiovisual McGurk illusion:perceptual and causal confidence

Almost all decisions in everyday life rely on multiple sensory inputs that can come from common or independent causes. These situations invoke perceptual uncertainty about environmental properties and the signals' causal structure. Using the audiovisual McGurk illusion, this study investigated how observers formed perceptual and causal confidence judgements in information integration tasks under causal uncertainty. Observers were presented with spoken syllables, their corresponding articulatory lip movements or their congruent and McGurk combinations (e.g. auditory B/P with visual G/K). Observers reported their perceived auditory syllable, the causal structure and confidence for each judgement. Observers were more accurate and confident on congruent than unisensory trials. Their perceptual and causal confidence were tightly related over trials as predicted by the interactive nature of perceptual and causal inference. Further, observers assigned comparable perceptual and causal confidence to veridical 'G/K' percepts on audiovisual congruent trials and their causal and perceptual metamers on McGurk trials (i.e. illusory 'G/K' percepts). Thus, observers metacognitively evaluate the integrated audiovisual percept with limited access to the conflicting unisensory stimulus components on McGurk trials. Collectively, our results suggest that observers form meaningful perceptual and causal confidence judgements about multisensory scenes that are qualitatively consistent with principles of Bayesian causal inference. This article is part of the theme issue 'Decision and control processes in multisensory perception'.</p

Long Proteins with Unique Optimal Foldings in the H-P Model

It is widely accepted that (1) the natural or folded state of proteins is a global energy minimum, and (2) in most cases proteins fold to a unique state determined by their amino acid sequence. The H-P (hydrophobic-hydrophilic) model is a simple combinatorial model designed to answer qualitative questions about the protein folding process. In this paper we consider a problem suggested by Brian Hayes in 1998: what proteins in the two-dimensional H-P model have unique optimal (minimum energy) foldings? In particular, we prove that there are closed chains of monomers (amino acids) with this property for all (even) lengths; and that there are open monomer chains with this property for all lengths divisible by four.Comment: 22 pages, 18 figure

The Distance Geometry of Music

We demonstrate relationships between the classic Euclidean algorithm and many other fields of study, particularly in the context of music and distance geometry. Specifically, we show how the structure of the Euclidean algorithm defines a family of rhythms which encompass over forty timelines (\emph{ostinatos}) from traditional world music. We prove that these \emph{Euclidean rhythms} have the mathematical property that their onset patterns are distributed as evenly as possible: they maximize the sum of the Euclidean distances between all pairs of onsets, viewing onsets as points on a circle. Indeed, Euclidean rhythms are the unique rhythms that maximize this notion of \emph{evenness}. We also show that essentially all Euclidean rhythms are \emph{deep}: each distinct distance between onsets occurs with a unique multiplicity, and these multiplicies form an interval $1,2,...,k-1$. Finally, we characterize all deep rhythms, showing that they form a subclass of generated rhythms, which in turn proves a useful property called shelling. All of our results for musical rhythms apply equally well to musical scales. In addition, many of the problems we explore are interesting in their own right as distance geometry problems on the circle; some of the same problems were explored by Erd\H{o}s in the plane.Comment: This is the full version of the paper: "The distance geometry of deep rhythms and scales." 17th Canadian Conference on Computational Geometry (CCCG '05), University of Windsor, Canada, 200

Single-photon emission from Ni-related color centers in CVD diamond

Color centers in diamond are very promising candidates among the possible realizations for practical single-photon sources because of their long-time stable emission at room temperature. The popular nitrogen-vacancy center shows single-photon emission, but within a large, phonon-broadened spectrum (~100nm), which strongly limits its applicability for quantum communication. By contrast, Ni-related centers exhibit narrow emission lines at room temperature. We present investigations on single color centers consisting of Ni and Si created by ion implantation into single crystalline IIa diamond. We use systematic variations of ion doses between 10^8/cm^2 and 10^14/cm^2 and energies between 30keV and 1.8MeV. The Ni-related centers show emission in the near infrared spectral range (~770nm to 787nm) with a small line-width (~3nm FWHM). A measurement of the intensity correlation function proves single-photon emission. Saturation measurements yield a rather high saturation count rate of 77.9 kcounts/s. Polarization dependent measurements indicate the presence of two orthogonal dipoles.Comment: 8 pages, published in conference proceedings of SPIE Photonics Europe 201

From Abstract News Users to Living Citizens: Assessing Audience Engagement Through a Professional Lens

Journalists’ increasing focus on news users is often seen as diverting the news agenda away from the core issues that are important to democracy. Hence, the practices of connecting journalists to the audience tend to be assessed as detrimental to the democratic function of journalism: informing citizens and facilitating public opinion. However, this normative link between practice and ideals has rarely been empirically addressed when studying audience engagement. In this article we use a case study (BiobioChile) to provide a more precise understanding of the democratic relevance that everyday engagement with the audience—through and beyond metrics—entails for journalism. First, our analysis suggests that audiences can be integrated into journalism’s democratic framework by moving beyond the dilemma of informed citizenship versus news user’s metrics to include what we propose to call living citizens: empirical concrete living beings grounded in journalistic practice. Second, we distinguish three audience oriented roles—observer, listener and connector—aimed both at maximizing the attention of news users, and at making sense of their needs as living citizens. These roles cover verifiable routines and values, thereby enabling a better assessment of the fulfilment of the democratic ideals of journalism.publishedVersio

FPÖ und Christentum

In Folge der Revolution 1848 und erneut ab 1867 können liberale Kräfte die Macht der römisch-katholischen Kirche vor allem in Schule und Ehegesetzgebung zeitweilig verdrängen. Der um 1880 aufkommende Nationalismus setzt den Antiklerikalismus teilweise radikal in der Los-von-Rom-Bewegung unter Georg Schönerer fort. Regierungsbeteiligungen mit Konservativen in Monarchie und 1. Republik lassen Fragen der Trennung von Kirche und Staat ruhen. Kirche und Nationalsozialismus stehen einander meist feindlich gegenüber, ein versuchtes Arrangement scheitert sehr früh. Der Verband der Unabhängigen wird zunächst von kirchennahen Personen geführt, in der Freiheitlichen Parte Österreichs herrscht jedoch eine kühle Distanz zur Kirche bis etwa 1990. Die Ausländer*debatte führt zur Frontstellung mit den Kirchen, nur der rechte Flügel um Krenn fühlt sich angesprochen. Stadler bringt das Christentum programmatisch pointiert 1997 in die FPÖ, der islamfeindliche Hintergrund wird nach der Spaltung des BZÖ unter Strache stark forciert. Strache fordert auch Gesetzesänderungen bei der Abtreibung und tritt immer wieder als Verteidiger des Christentums auf. Die FPÖ vertritt nunmehr ein Kulturchristentum, also die von religiösen Inhalten entledigte Bezugnahme zum christlichen Abendland als bedrohter Heimat.The power of the roman catholic church was temporarily broken in the course of the revolution of 1848 and especially after 1867 by liberal actors opposed to the churches influence in matters of matrimony and schools. Nationalism continues this anticlerical pattern starting in the 1880s and even advocates apostasy under Georg Schönerer. Being alligned with conservatives in the governments of the monarchy and the 1st republic the German nationalists did not push questions of state and church. National Socialism was mostly opposed to the churches and vice versa, a common ground was sought by some but could not be found. After WWII the Federation of Independents (Verband der Unabhängigen) is led by individuals with an unusually positive relationship towards the church considering the ideological background of their party. The Freedom Party (Freiheitliche Partei Österreichs) is more in line with the traditional scepticism towards the roman catholic church until 1990, when differences regarding immigration policy cause a major rift. Approaching the right wing of the church under bishop Krenn, Ewald Stadler introcudes a very positive view of Christianity into the party program of 1997. Under the leadership of Heinz-Christian Strache the FPÖ follows this path and combines staunchly pro-christian policies with an anti-islam-rhetoric at odds with Christian values. The FPÖ thus tries to communicate a position of cultural Christianity as defending Western values in strictly nonreligious way

Probabilistic models of audiovisual perceptual decision making

Multisensory integration is a fundamental component of perceptual decision making and an excellent example of how the brain deals with the abundance of sensory uncertainty in order to create a coherent understanding of its environment. In this thesis I evaluate the two most popular computational models for describing multisensory integrative processes: maximum likelihood estimation (MLE) and Bayesian causal inference (BCI). Both models predict statistically-optimal sensory integration, but in so doing MLE makes the critical assumption that the brain always fuses sensory signals under certain experimental circumstances, whereas BCI allows for flexibility by assessing whether integration is appropriate for a particular set of stimuli. In two empirical studies on audiovisual spatial integration I expose considerable limitations of MLE in explaining human behavioral results and advocate the use of BCI to evaluate multisensory integration, even under conditions that were previously thought of as optimized for MLE. In a final empirical chapter I test an important prediction that both models make: that sensory uncertainty is reduced for integrated multisensory signals. I present behavioral evidence that confirms this prediction by showing that observers’ confidence levels increase as a result of audiovisual integration, thereby further validating the use of probabilistic models to describe multisensory perception