Adaptive Bayesian estimation in indirect Gaussian sequence space models

In an indirect Gaussian sequence space model lower and upper bounds are derived for the concentration rate of the posterior distribution of the parameter of interest shrinking to the parameter value $\theta^\circ$ that generates the data. While this establishes posterior consistency, however, the concentration rate depends on both $\theta^\circ$ and a tuning parameter which enters the prior distribution. We first provide an oracle optimal choice of the tuning parameter, i.e., optimized for each $\theta^\circ$ separately. The optimal choice of the prior distribution allows us to derive an oracle optimal concentration rate of the associated posterior distribution. Moreover, for a given class of parameters and a suitable choice of the tuning parameter, we show that the resulting uniform concentration rate over the given class is optimal in a minimax sense. Finally, we construct a hierarchical prior that is adaptive. This means that, given a parameter $\theta^\circ$ or a class of parameters, respectively, the posterior distribution contracts at the oracle rate or at the minimax rate over the class. Notably, the hierarchical prior does not depend neither on $\theta^\circ$ nor on the given class. Moreover, convergence of the fully data-driven Bayes estimator at the oracle or at the minimax rate is established

The making of a new South African craft : township craft and development discourse in post-apartheid Cape Town

Includes bibliographical references (leaves 90-93).The author discusses postdevelopment theory by exploring unintentional effects of development practices in Cape Town's craft scene. A heterodox research design is adopted, drawing on Pierre Bourdieu's ideas on cultural production, notions of authenticity, representation and the modern/traditional dichotomy as well as thoughts on the making of a New South African identity. This is applied to the dynamics of Cape Town's craft scene in the pursuit of answering four research questions: (i) What role does the township play in the image of post-apartheid South Africa? (ii) How does development discourse contribute to the re-imagining of post-apartheid South Africa through 'township craft'? (iii) Is development discourse conducive to maintaining and creating tensions between centres and peripheries in the New South Africa? (iv) To what extent can a heterodox research design contribute to the postdevelopment debate? Through the socio-semiotic analysis of qualitative data obtained from interviews with fourteen stakeholders in Cape Town's craft scene as well as observations made at sites, where 'township craft' is presented and/or produced, the author is able to give three main insights in relation to the stated questions: (i) The image of the township, represented through cultural commodities, plays a crucial role as a place of creativity and positive change in the making of a post-apartheid identity. (ii) Development discourse manifests itself in the making of a New South African identity through material culture in the form of 'township craft' and its conceptual as well as spatial contexts. (iii) The use of development discourse in the making and marketing of 'township craft' in combination with supposedly 'common knowledge' about the art/craft divide has the potential to create and maintain patterns of inequality between producers and sellers of 'township craft'. A recommendation is made to explore further possibilities of heterodox research designs for studies using a postdevelopment theoretical framework

New distinctions : the impact of class and race on the cultural preferences of youth in Cape Town and Belo Horizonte

Sociological treatments of the reproduction of social inequality in South Africa largely focus on its historical, political and economical aspects while references to popular culture are commonly used to describe differences, often in combination with racial discourse, rather than explain them. As a result much of South African cultural sociology, especially with regards to youth culture, is entailed in in-depth ethnographic descriptions of particular subcultures. Less common is scholarly work dealing with the role of taste and cultural preferences in the reconfiguration of common perceptions of 'otherness', both in class and race terms. This dissertation shifts the focus towards the structural aspects of popular culture and, particularly, youth culture. First, inspired by Bourdieu's work on distinction, it explores the segregating potential of contemporary youth culture in South Africa, especially where class and race con- notations meet. It then follows this thread of adapting Bourdieu's work to contemporary South African youth by identifying the media as a crucial factor alongside family and school for the preservation of racialised class characteristics. In a third step it takes the observations made in the South African context and compares them to youth culture in Brazil in order to establish the existence of common structures of difference that exist in different countries as a result of glocalization. The thesis established in this dissertation is that the cultural preferences of youth often come with class and race connotations. This interplay between class and race can be explained historic- ally as well as structurally through media consumption, which plays a significant role in the way young people learn to dress, speak, carry themselves and generally position themselves in relation to others. Due to global cultural flows these processes do not remain purely local phenomena but they find expression in localised forms as common structures of difference around the globe, thus structurally undermining local efforts to build a non-racial, non-classist society. These conclusions are based on primary research using a multi-method approach combining surveys on taste and racial attitudes with school-going youth in South Africa (Cape Town, n=1196) and Brazil (Belo Horizonte, n=860) with in-depth focus group interviews (only Cape Town). Using descriptive statistics and multiple regression analysis (survey data) combined with qualitative data analysis (interviews) it was possible to demonstrate that there are clear differences in the cultural and media preferences of South African youth along class and race lines, which are reflected, to a lesser extent, in the cultural and media preferences of Brazilian youth

Adaptive estimation of linear functionals in functional linear models

We consider the estimation of the value of a linear functional of the slope parameter in functional linear regression, where scalar responses are modeled in dependence of random functions. In Johannes and Schenk [2010] it has been shown that a plug-in estimator based on dimension reduction and additional thresholding can attain minimax optimal rates of convergence up to a constant. However, this estimation procedure requires an optimal choice of a tuning parameter with regard to certain characteristics of the slope function and the covariance operator associated with the functional regressor. As these are unknown in practice, we investigate a fully data-driven choice of the tuning parameter based on a combination of model selection and Lepski's method, which is inspired by the recent work of Goldenshluger and Lepski [2011]. The tuning parameter is selected as the minimizer of a stochastic penalized contrast function imitating Lepski's method among a random collection of admissible values. We show that this adaptive procedure attains the lower bound for the minimax risk up to a logarithmic factor over a wide range of classes of slope functions and covariance operators. In particular, our theory covers point-wise estimation as well as the estimation of local averages of the slope parameter

Guided self-study in preclinical physiotherapy students: A feasibility study

Background: Literature describing the impact of guided self-study (G-SS) in knowledge changes and skills improvements in undergraduate students is scarce. Objectives: The aims of our study were to evaluate the feasibility of a G-SS programme in a full-time undergraduate physiotherapy degree course and to assess the effectiveness of the G-SS on changes in knowledge and development of skills (hands-on). Method: Fifty-three first-semester undergraduate physiotherapy students were randomly divided into a G-SS group and a control group (CG). The G-SS group received six clinical cases and prepared each case during an 8-day cycle. The control group received self-study learning units of the original curriculum content. Primary outcome parameters were (1) time of task, (2) responsiveness of students and (3) programme differentiation. Knowledge changes and skills changes were tested using a multiple-choice questionnaire and the objective structured clinical examination (OSCE). Results: Students’ responsiveness was 32%. This was below the a priori set 83%. No differences in programme differentiation were found. The OSCE grade was significantly higher in the G-SS compared to CG (p = 0.003). Conclusion: The G-SS programme in its current form was not feasible regarding students’ responsiveness. Therefore, a slight modification of our study protocol (e.g., better time planning in the academic calendar) is needed to improve students’ willingness to participate in the G-SS programme. Clinical implications: Adaptation of the school timetable should allow undergraduate physiotherapy students to prepare clinical cases under conditions of lower workload. Guided self-study as compared to CG is superior in knowledge change and (hands-on) skills improvement

Locating Generation X:Taste and Identity in Transitional South Africa

When Douglas Coupland (1991) published Generation X in 1991. South Africa was undergoing massive political and social transformations. The preceding years had been marked by political turmoil, the danger of imminent civil war and violent clashes between the apartheid state‟s security forces and angry protesters against the apartheid regime. The government‟s racist policies were ostracised by the international community – boycotts and sanctions were throttling an economy already at the brink of collapse due to the monstrous costs of an institutionally divided society and the lack of a sizeable affluent and welleducated middle-class. In 1989 Nelson Mandela was released from prison, and at the time of Coupland‟s writing negotiations were in full motion in preparation for the country‟s adoption of a new constitution and its first democratic elections in 1994. Thus the characteristics of Coupland‟s (anti-)heroes, their aimlessness, whininess, “slackness” and very fictionality stand in stark contrast not only to the US black and white youth protesters of the 1960s, but also to the ambitions, anger, harshness and the very reality of most young South Africans during the late 1980s and early 1990s

The impact of guided self-study on knowledge and skills in Swiss pre-clinical physiotherapy students - a feasibility study protocol

Physiotherapy education in Europe must incorporate self-study units in the curriculum due to the bologna reform. Studies investigating the impact of guided self-study (G-SS) on knowledge and skills in pre-clinical Swiss physiotherapy students are scarce. This study protocol describes a prospective randomized feasibility education study that will primarily examine the feasibility of establishing G-SS using retired physiotherapists as tutors in undergraduate physiotherapy students at the Bern University of Applied Sciences, School of Health Professions. Secondary objective will be to evaluate the effectiveness of six G-SS cycles with retired physiotherapists as tutors on knowledge and skills of pre-clinical undergraduate physiotherapy students. Students of the physiotherapy degree course will be allocated into a G-SS group or control group (CG). G-SS consists of an 8-day cycle. Feasibility outcome are the fidelity of implementation that include exposure dosage and students' responsiveness, and the degree of acceptability. Success criteria of feasibility are (1) exposure dosage calculated as the number of 90-min presentations that are conducted, and the content of cases and competences and (2) students' responsiveness, with at least a 83% willingness to participate. Acceptability of intervention from the undergraduate students' perspective will be evaluated by a questionnaire with open, semi-structured questions (post intervention). This study will provide new information regarding the feasibility of embedding G-SS in the curriculum and about the students' responsiveness and their acceptability for G-SS. Study protocol version 1 Trial registration: German Register of Clinical Studies (DKRS: DRKS00015518)

Amused, accepted, and used? Attitudes and emotions towards automated vehicles, their relationships, and predictive value for usage intention

Automated vehicles (AVs) have left the laboratories and can be experienced in several projects, e.g. at the premises of a clinic in Germany. With this transition, research on AV attitudes no longer needs to rely on questionnaires with hypothetical scenarios and simulations. Previous research – limited by the unavailability of AVs – has provided ambivalent results regarding age and gender differences in attitudes towards AVs. We present research results about the role of age and gender in connection with attitudes such as acceptance, perceived safety, and trust, as well as intention to use. We additionally demonstrate relationships between those constructs and emotions such as amusement, fear, and surprise. Data were collected from participants (n = 125) after having experienced an AV ride with level 4 automation on two campuses of a clinic in Berlin, Germany. Results reveal strong correlations between all attitudes (0.55 ≤ r ≤ 0.71; p < 0.01) and show acceptance and perceived safety to be solid predictors of intention to use AVs. We also found age to be a significant predictor for usage intention even when other attitudes are considered (β = −0.22; p < 0.01). MANOVA results point to gender differences in all constructs, but with limited confidence (5.40 ≤ F ≤ 18.34; p ≤ 0.02). However, we reject our hypothesis that young men are highly accepting, trusting, and intending to use AVs compared to other combinations of age and gender. We recommend using a mix of attitude, emotion, and behavioural (intention) measures in future research on AVs together with more transparency regarding construct definitions and study materials