Leadership and Stress Orientations of Germans: An Examination Based on Gender, Age, and Government Work Experience

Today??s working adults often display different leadership orientations, as well as moderate to severe levels of stress depending on the situation and various demographic traits. In order to explore the stress, task orientation and relationship orientation variables of German people, this study examined the differences of 232 respondents in Germany based on their gender, age, and public sector work experience. The results showed that respondents had dissimilar scores on their leadership orientations. Younger respondents had significantly lower task and relationship orientation scores. Furthermore, females reported having a significantly higher level of stress perception. These findings are useful for expatriate managers and professionals who work with German-born workers. Besides, relevant literature on the German culture, suggestions and implications for future studies are presented.     

Mapping Prefrontal Cortex Functions in Human Infancy

It has long been thought that the prefrontal cortex, as the seat of most higher brain functions, is functionally silent during most of infancy. This review highlights recent work concerned with the precise mapping (localization) of brain activation in human infants, providing evidence that prefrontal cortex exhibits functional activation much earlier than previously thought. A systematic evaluation of the activation patterns in these neuroimaging studies mainly based on functional near‐infrared spectroscopy reveals that prefrontal cortex function can be broadly divided into two distinct anatomical clusters with different functional properties. One cluster of activations falls within the region of the medial prefrontal cortex and is mainly involved in affective processes; another cluster is located in lateral aspects of the prefrontal cortex and shows sensitivity to cognitive processes such as memory and attention. This distinction is in line with adult data and evolutionary models and may represent a developmentally continuous organization principle of prefrontal cortex function. All in all, this review is aimed at providing a synthesis of new findings that are emerging from the use of neuroimaging techniques with infants as well as at encouraging further theory‐driven research to understand the developmental origins of prefrontal cortex function.     

Testing for an excessive number of zeros in time series of bounded counts

For the modeling of bounded counts, the binomial distribution is a common choice. In applications, however, one often observes an excessive number of zeros and extra-binomial variation, which cannot be explained by a binomial distribution. We propose statistics to evaluate the number of zeros and the dispersion with respect to a binomial model, which is based on the sample binomial index of dispersion and the sample binomial zero index. We apply this index to autocorrelated counts generated by a binomial autoregressive process of order one, which also includes the special case of independent and identically (i. i. d.) bounded counts. The limiting null distributions of the proposed test statistics are derived. A Monte-Carlo study evaluates their size and power under various alternatives. Finally, we present two real-data applications as well as the derivation of effective sample sizes to illustrate the proposed methodology.     

Modelling of a thermomechanically coupled forming process based on functional outputs from a finite element analysis and from experimental measurements

In this paper, measurements from experiments and results of a finite element analysis (FEA) are combined in order to compute accurate empirical models for the temperature distribution before a thermomechanically coupled forming process. To accomplish this, Design and Analysis of Computer Experiments (DACE) is used to separately compute models for the measurements and the functional output of the FEA. Based on a hierarchical approach, a combined model of the process is computed. In this combined modelling approach, the model for the FEA is corrected by taking into account the systematic deviations from the experimental measurements. The large number of observations based on the functional output hinders the direct computation of the DACE models due to the internal inversion of the correlation matrix. Thus, different techniques for identifying a relevant subset of the observations are proposed. The application of the resulting procedure is presented, and a statistical validation of the empirical models is performed.     

Irregularly observed time series – some asymptotics and the block bootstrap

We consider time series being observed at random time points. In addition to Parzen's classical modelling by amplitude modulating sequences, we state another modelling using an integer-valued sequence as the observation times. Limiting results are presented for the sample mean and are generalized to the class of functions of smooth means. Motivated by the complicated limiting behaviour, (moving) block bootstrap possibilities are investigated. Conditional on the used modelling for the irregular spacings, one is lead to different interpretations for the block length and hence bootstrap approaches. The block length either can be interpreted as the time (resulting in an observation string of fixed length containing a random number of observations) or as the number of observations (resulting in an observation string of variable length containing a fixed number of values). Both bootstrap approaches are shown to be asymptotically valid for the sample mean. Numerical examples and an application to real-world ozone data conclude the study.     

At risk of exclusion? Degrees of ICT access and literacy among senior citizens

Drawing on data derived from a nationwide postal survey (n?=?1264) with a simple random sample of Swedes between ages 65 and 85 (response rate: 63%), the article analyses the general patterns of: (a) degrees of information and communication (ICT) access and (b) ICT-literacy among Swedish senior citizens. The overall patterns of access and literacy are analysed in light of senior citizens’ assets – conceptualized as material, discursive and social resources – and their age and gender. The analysis reveals a positive correlation between levels of material (e.g., income), discursive (e.g., English skills) and social (e.g., social networks) resources and access to ICT. With greater resources, the average number of devices increases. The analysis also reveals a positive correlation between discursive and social resources and ICT-literacy. Gender has no bearing on access to devices, but might have some effect on ICT-literacy. The correlation between age, access and literacy is negative. With increasing age, both access and literacy decreases. In this respect, the study reveals a generational effect. However, since all three resources tend to decrease over the life cycle, the results are also discussed in terms of an age effect. These data and our analyses are contextualized by a critical discussion that reflects on the implications of these general patterns: What do they mean for senior citizens’ abilities to be included and participate in a continuously digitalizing society?