Internal and external effects on cognition: Evidence from memory training in very preterm-born children and cognition in patients with carotid artery stenosis before and after treatment

The present synopsis aims to integrate one study about memory training in very preterm-born children and two studies about cognition in patients with carotid artery stenosis before and after treatments. Preterm-born children are at increased risk of cognitive deficits and behavioural problems compared with peers born at term. This thesis determined whether memory training would improve cognitive functions in school-age very preterm-born children. Memory strategy training produced significant improvements in trained and non-trained cognitive functions; a core working memory training revealed significant effects on short-term memory and working memory tasks. Six months after training, children in both training groups showed better working memory performance than children in the waiting control group. This is evidence that memory training – an external influence on cognition – induces plastic changes in very preterm-born children. Patients with carotid artery stenosis are known to be at increased risk of cognitive impairment. We showed that patients with symptomatic or asymptomatic carotid artery stenosis were at higher risk for cognitive deficits than expected in a normative sample. This thesis seeks to link cognitive plasticity to internal factors like carotid stenosis. An external factor, which influences blood flow to the brain is the nature of the carotid artery stenosis treatment. Research on the effects of carotid artery stenosis treatment on cognition has produced inconsistent results. We found significant improvement in frontal lobe functions, visual memory and motor speed one year after treatment independent of the treatment type (best medical treatment, carotid artery stenting, carotid artery endarterectomy); providing evidence for ‘treatment-induced’ cognitive plasticity. Baseline performance was negatively associated with improvement in various cognitive functions after training in very preterm-born children and after treatment in patients with carotid artery stenosis. The present synopsis aims to integrate these findings into the current and relevant literature, and discuss consequences as well as methodological considerations resulting from the studies constituting the thesis at hand.

Genome characterization, prevalence and distribution of a Macula-like virus from Apis mellifera and Varroa destructor

Around 14 distinct virus species-complexes have been detected in honeybees, each with one or more strains or sub-species. Here we present the initial characterization of an entirely new virus species-complex discovered in honeybee (Apis mellifera L.) and varroa mite (Varroa destructor) samples from Europe and the USA. The virus has a naturally poly-adenylated RNA genome of about 6500 nucleotides with a genome organization and sequence similar to the Tymoviridae (Tymovirales; Tymoviridae), a predominantly plant-infecting virus family. Literature and laboratory analyses indicated that the virus had not previously been described. The virus is very common in French apiaries, mirroring the results from an extensive Belgian survey, but could not be detected in equally-extensive Swedish and Norwegian bee disease surveys. The virus appears to be closely linked to varroa, with the highest prevalence found in varroa samples and a clear seasonal distribution peaking in autumn, coinciding with the natural varroa population development. Sub-genomic RNA analyses show that bees are definite hosts, while varroa is a possible host and likely vector. The tentative name of Bee Macula-like virus (BeeMLV) is therefore proposed. A second, distantly related Tymoviridae-like virus was also discovered in varroa transcriptomes, tentatively named Varroa Tymo-like virus (VTLV).

Socioemotional Wealth, Ambidexterity, and Family Firm Performance: An Empirical Study

While family business literature agrees that family firms are driven by both non-economic and financial motives, it is unclear how the prioritization of socioemotional wealth (SEW) over financial considerations affects family firms' financial performance. Based on a sample of 343 family firm owners from German-speaking Europe, this study reveals a significant and positive relationship between the firm owners' SEW considerations and their family businesses' financial performance. This relationship, in turn, is found to be mediated by organizational ambidexterity. A fine-grained analysis of the different SEW dimensions indicates that this pattern may be driven by two elements of socioemotional wealth only (family members' identification with the firm and emotional attachment). Our findings demonstrate that business families do not necessarily face a trade-off when prioritizing the preservation of their SEW over stabilizing or improving the financial performance of their business. The study enriches several streams of literature and opens up numerous avenues for future research.

Affective Commitment and Job Satisfaction among Non-family Employees: Investigating the Roles of Justice Perceptions and Psychological Ownership

Due to numerous characteristics often attributed to family firms, they constitute a unique context for non-family employees’ justice perceptions. These are linked to non-family employees’ pro-organizational attitudes and behaviors, which are essential for family firms’ success. Even though scholarly interest in non-family employees’ justice perceptions has increased, more research is still needed, also because the mechanism connecting justice perceptions and favorable outcomes is not fully understood yet. We address this gap by explicitly investigating non-family employees’ justice perceptions and by introducing psychological ownership as a mediator in the relationships between justice perceptions (distributive and procedural) and common work attitudes (affective commitment and job satisfaction). Our analysis of a sample of 310 non-family employees from Germany and German-speaking Switzerland reveals that psychological ownership mediates the relationships between distributive justice and affective commitment as well as job satisfaction. This represents valuable contributions to family business research, organizational justice and psychological ownership literature, and to practice.