Fitting Unstructured Finite Mixture Models in Longitudinal Design: A Recommendation for Model Selection and Estimation of the Number of Classes

In longitudinal design, investigating interindividual differences of intraindividual changes enables researchers to better understand the potential variety of development and growth. Although latent growth curve mixture models have been widely used, unstructured finite mixture models (uFMMs) are also useful as a preliminary tool and are expected to be more robust in identifying classes under the influence of possible model misspecifications, which are very common in actual practice. In this study, large-scale simulations were performed in which various normal uFMMs and nonnormal uFMMs were fit to evaluate their utility and the performance of each model selection procedure for estimating the number of classes in longitudinal designs. Results show that normal uFMMs assuming invariance of variance–covariance structures among classes perform better on average. Among model selection procedures, the Calinski–Harabasz statistic, which has a nonparametric nature, performed better on average than information criteria, including the Bayesian information criterion.     

The Saljuq Turks’ Conversion to Islam: The Crusading Sources

This article contributes to the important debate over the conversion of the Turks to Islam. Previously, it was thought that the Turks abandoned their former steppe faith and customs very swiftly to become staunch Sunni Muslims, but this view has recently been challenged by a number of studies. The current consensus seems to be that the Turks’ adoption of Islam was a process of far longer duration, spanning many decades. This article broadens this discussion by demonstrating that the chronicles written by the First Crusaders contain much useful information that is pertinent to this question. It works through these texts, showing that they can shed new light on this point.     

The “Other” in the Crusading Period: Walter the Chancellor's Presentation of Najm al-Dīn Il-Ghāzī

This paper examines ideas surrounding the presentation of the Muslim “other” in Latin writings of the early period of the Crusades. Using a case-study approach of the views of one chronicler, Walter the Chancellor, in his work Bella Antiochena, on one individual Muslim, Najm al-Dīn Il-Ghāzī, the paper studies aspects of the image of Il-Ghāzī, the reasons for them, how and why they develop throughout the chronicle, and whether, from the other information given in the chronicle, it would be possible to interpret the information in other ways. The conclusions reached demonstrate that the reason for the vitriol in Walter's presentation was his wish to justify the Crusades and suggest that the writers of Outremer started to develop their own cross-cultural responses to Islam, independent of mainstream European thought, because of their situation.     

Beyond virtual museums: Experiencing immersive virtual reality in real museums

Contemporary museums are much more than places devoted to the placement and the exhibition of collections and artworks; indeed, they are nowadays considered as a privileged means for communication and play a central role in making culture accessible to the mass audience. One of the keys to approach the general public is the use of new technologies and novel interaction paradigms. These means, which bring with them an undeniable appeal, allow curators to modulate the cultural proposal by structuring different courses for different user profiles. Immersive Virtual reality (VR) is probably one of the most appealing and potentially effective technologies to serve this purpose; nevertheless, it is still quite uncommon to find immersive installations in museums. Starting from our 10 years’ experience in this topic, and following an in-depth survey about these technologies and their use in cultural contexts, we propose a classification of VR installations, specifically oriented to cultural heritage applications, based on their features in terms of interaction and immersion. On the basis of this classification, aiming to provide a tool for framing VR systems which would hopefully suggest indications related to costs, usability and quality of the sensorial experience, we analyze a series of live examples of which we point out strengths and weak points. We then summarize the current state and the very next future, identifying the major issues that prevent these technologies from being actually widespread, and outline proposals for a more pervasive and effective use of Immersive VR for cultural purposes.     

Influence of upright versus time trial cycling position on determination of critical power and W′ in trained cyclists

Body position is known to alter power production and affect cycling performance. The aim of this study was to compare mechanical power output in two riding positions, and to calculate the effects on critical power (CP) and W′ estimates. Seven trained cyclists completed three peak power output efforts and three fixed-duration trial (3-, 5- and 12-min) riding with their hands on the brake lever hoods (BLH), or in a time trial position (TTP). A repeated-measures analysis of variance showed that mean power output during the 5-min trial was significantly different between BLH and TTP positions, resulting in a significantly lower estimate of CP, but not W′, for the TTP trial. In addition, TTP decreased the performance during each trial and increased the percentage difference between BLH and TTP with greater trial duration. There were no differences in pedal cadence or heart rate during the 3-min trial; however, TTP results for the 12-min trial showed a significant fall in pedal cadence and a significant rise in heart rate. The findings suggest that cycling position affects power output and influences consequent CP values. Therefore, cyclists and coaches should consider the cycling position used when calculating CP.     

Online interaction across three contexts: an analysis of culture and technological affordances

Students were linked virtually across three contexts: U.S., Malaysia, and China. Differences emerged in how student-created messages were constructed and interpreted; these impacted perceived relational affiliation. Messages constructed by students in Malaysia and China exhibited casual talk, greater self-disclosure, requests for personal information, and greater use of emoticons/emoji. Interactions were perceived as informal, friendly, and positive. U.S. students’ messages often showed institutional talk, less self-disclosure, and more attention to the instructor-assigned task. Asian-U.S. student pairs perceived their interactions as formal, less friendly, and less positive. This study shows how online technologies may be afforded and shaped by culture and interaction.     

Thomas Tryon,Sheep and the Politics of Eden

The English writer Thomas Tryon (1634–1703) believed that sheep were survivors from the original earthly paradise, and that as morally perfect beings they could serve as role models for humans. Tryon advocated vegetarianism, pacifism and an end to slavery as it was practiced in the Caribbean. He was an ambitious and influential reformer on several fronts, but the restoration of Eden was his ultimate goal. Tryon celebrated sheep-like meekness, a stance that complicated his reform efforts. His agenda and sheep-inspired persuasive strategy reflect the momentous intellectual and moral ferment surrounding human relations with animals in the seventeenth century.     

Heritage sporting events: theoretical development and configurations

ABSTRACT

Although sports heritage is increasingly recognized as a potential catalyst of tourism, heritage sporting events (HSEs) are still an emerging concept in the academic literature. Notions that associate sports events and heritage remain rare, and are usually analysed through the scope of nostalgia sport tourism. This can be partly explained by an inclination to associate the notion of heritage with conventional ideas about folklore and traditional culture. Through a constructivist approach of heritage, this contribution argues that contemporary sports events, which would generally have competition as their primary focus, might also be perceived as HSEs. A comprehensive framework, built on a multi-disciplinary literature review, is presented to show the process that transforms an initial resource (a sports event) into an accomplished resource (a HSE), which might represent a competitive advantage for the territory. A qualitative–comparative analysis is conducted among 24 sports events in the French-speaking part of Switzerland, to observe the configurations of HSEs and understand which characteristics are necessary for the perceptions of a sports event as a heritage good. Interestingly, this contribution shows that if the event needs to be sustainable in the territory to be perceived as a HSE, it is not sufficient. Indeed, a differentiation strategy should be set up to distinguish the event from other more or less similar events, to be perceived as an authentic feature of the territory by the local population.     

Assessment of leg muscles mechanical capacities: Which jump,loading, and variable type provide the most reliable outcomes?

This study aimed to explore the strength of the force–velocity (F–V) relationship of lower limb muscles and the reliability of its parameters (maximum force [F₀], slope [a], maximum velocity [V₀], and maximum power [P₀]). Twenty-three men were tested in two different jump types (squat and countermovement jump: SJ and CMJ), performed under two different loading conditions (free weight and Smith machine: Free and Smith) with 0, 17, 30, 45, 60, and 75?kg loads. The maximum and averaged values of F and V were obtained for the F–V relationship modelling. All F–V relationships were strong and linear independently whether observed from the averaged across the participants (r?≥?0.98) or individual data (r?=?0.94–0.98), while their parameters were generally highly reliable (F₀ [CV: 4.85%, ICC: 0.87], V₀ [CV: 6.10%, ICC: 0.82], a [CV: 10.5%, ICC: 0.81], and P₀ [CV: 3.5%, ICC: 0.93]). Both the strength of the F–V relationships and the reliability of their parameters were significantly higher for (1) the CMJ over the SJ, (2) the Free over the Smith loading type, and (3) the maximum over the averaged F and V variables. In conclusion, although the F–V relationships obtained from all the jumps tested were linear and generally highly reliable, the less appropriate choice for testing the F–V relationship could be through the averaged F and V data obtained from the SJ performed either in a Free weight or in a Smith machine. Insubstantial differences exist among the other combinations tested.     

The Byzantines and Saladin: Some Further Arguments

This is the second of two articles by the same author arguing against the thesis that there was a conspiracy between the Byzantine emperors and Saladin, sultan of Egypt and Syria, against the crusader states and the Third Crusade in the 1180s. While the focus of the first article was primarily on the Latin sources, the present study shifts the focus to the Arabic primary material, hitherto largely neglected or inadequately treated by modern historians. Through a critical re-examination and re-interpretation of the Arabic sources, backed by the introduction and discussion of new Latin material when necessary, this article presents expanded arguments on the relations between the Byzantine Empire, the Sultanate of Konya and Saladin in the 1180s. The conclusions lend further support to the view that the Byzantine rulers and Saladin never concluded an alliance against the Latin settlers of Outremer and the Third Crusade.