Regulation of Respiratory Chain Supercomplex Formation and the Involvement of Rcf-proteins

The mitochondrial oxidative phosphorylation machinery is comprised by five individual complexes and arranged in supramolecular structures, so-called supercomplexes, as it is shown for complex I, III, IV and V. In yeast S. cerevisiae complex I is substituted by three singular NADH dehydrogenases and therefore lacks multimeric complex I. Thus, it displays a suitable model for investigating the dynamics within supercomplex formation of complex III and IV. Although some players could be identified so far, it is mostly unknown which factors contribute to forming these complexes (III2IV(1-2)). Besides, the mechanism behind re-/arrangement of the supercomplexes to adapt to different conditions such as changing oxygen levels remains obscure. The yeast Rcf-proteins (respiratory supercomplex factors) Rcf1, Rcf2 and Rcf3 were identified as proteins with partly corresponding homologous domains and can interact independently with complex III and complex IV. This is a unique feature promoting an important role of the protein family for recruiting and/or association of the two complexes. Furthermore, they could serve as regulator of complex IV and prevent from undesired ROS production but the exact localization and functional domains remained unknown. A crosslinking approach on isolated yeast mitochondria could identify the interacting site of Rcf2 and Rcf3 at the periphery of complex IV contrary to first suggestions for the association at the interface of complex III and IV. During this investigation we discovered a putative novel subunit of complex IV – Min8 – and proved it as being involved in complex IV biogenesis. For determining the functionality of the different domains of Rcf-proteins, artificial fusion proteins out of Rcf1, Rcf2 and Rcf3 were constructed and expressed in various mutational strains. The effects of those proteins were assessed by various experiments addressing the respiration, complex biogenesis and ROS production. While Rcf1 operates on both, complex IV and supercomplex assembly suggesting an even higher dynamic than originally anticipated, Rcf2 and Rcf3 are acting predominantly at the site of supercomplexes. At the same time, we discovered that the functionality of transmembrane regions of Rcf2 depend on the overall topology of the protein. By further studying the involvement of the respective protein domains in supercomplex assembly, we found an interesting interaction of Rcf2 and its processed versions at the site of complex III2 under alleged hypoxic conditions in a COX5A mutant. This suggests a specific involvement within the adapting respiratory chain to altering oxygen levels.2021-06-0

Yu-Shiba-Rusinov States of Molecules on Pb(100)

(Metal-)Phthalocyanine molecules adsorbed on a superconducting Pb(100) surface are investigated with low-temperature scanning tunneling microscopy (STM). Although the molecules are originally diamagnetic, they acquire a net magnetic moment upon assembly into supramolecules or within self-assembled islands. This effect is revealed by the observation of Yu-Shiba-Rusinov (YSR) resonances on the respective molecules. H2-phthalocyanine (H2Pc) supramolecules are manually assembled on the surface via manipulation with the STM tip. It is shown that the lowest unoccupied molecular orbital (LUMO) of the central molecule shifts toward the Fermi level and thus becomes partially filled, which results in the net magnetic moment responsible for the YSR state. A phenomenological model is developed that explains the underlying molecular interactions. The magnetic moments are furthermore finely tuned by targeted repositioning of the inner hydrogen atoms of neighboring H2Pc molecules. In addition, lead phthalocyanine (PbPc) molecules on Pb(100) are investigated. The influence of different adsorption geometries and neighbor molecules is studied in detail, revealing a possible influence of the electrostatic dipole moments of molecular neighbors. The sharp YSR resonances are utilized for inelastic electron tunneling spectroscopy (IETS) of molecular vibrations of PbPc. A significantly higher sensitivity is obtained compared to earlier experiments, and thus 46 separate vibrational excitations are observed. Good agreement is found in comparison with on-surface DFT calculations allowing an assignment of the observed modes. The high spectral energy resolution is used to study energy shifts of the modes caused by different influences. Supplementary, three other molecules carrying YSR states are investigated. Finally, the construction, test, and redesign of a home-built non-evaporable getter (NEG) pump is presented

“Colonised by Wankers”

"Has Scotland suffered from colonial oppression by England for the last 300 years? While historiography may give an answer in the negative, this study reveals that the contemporary Scottish novel is haunted by strong feelings, marked by perceptions of abjection and inferiorisation in response to constructing the English as dominating. Drawing from an unprecedented corpus of contemporary Scottish novels, this study explores the postcolonial in Scottish fiction in order to investigate the underlying discursive power relations that shape the Scottish literary imagination. The study consequently demonstrates that the analysis of Scottish national identity profits from this new angle of interpretation of the Scottish novel as postcolonial. The analysis of discourses such as those of gender, class, space and place, and race reveals how the construction of the Scottish as marginalised permeates the width of the contemporary Scottish novel, by referring to diverse examples, such as James Kelman’s How late it was, how late or genre fiction such as Ian Rankin’s Set in Darkness. Thus, this study provides an insightful reading in the wake of current political developments such as the Scottish independence referendum.

Fusionen und Übernahmen im Licht der Hybris - Überblick über den Forschungsstand

Zusammenfassung: Eine hohe Anzahl von Fusionen und Übernahmen scheitert. Gleichwohl sind Fusionen und Übernahmen an der Tagesordnung. Als eine Erklärung hierfür wird die Hybris-Hypothese diskutiert, d.h. die These, dass sich Entscheidungsträger der aufnehmenden Unternehmen systematisch überschätzen. Um diese These zu testen und um gegebenenfalls Maßnahmen gegen Hybris zu ergreifen, sind verlässliche Indikatoren für Hybris erforderlich. Die Arbeit stellt die in der Literatur entwickelten Indikatoren vor und diskutiert deren Vor- und Nachteil

Goffman\u2019s Return to Las Vegas: Studying Corruption as Social Interaction

In this paper, we argue that corruption research can benefit from studying corrupt transactions as a particular form of social interaction. We showcase the usefulness of a theoretical focus on social interaction by investigating online user reports on the website Frontdesktip.com. Through this focus, we can observe users sharing experiences and tips on the best ways of bribing hotel clerks in Las Vegas for attaining room upgrades and other complimentary extras. We employ a logistic regression analysis to examine what factors influence the \u201csuccessful\u201d performance of this bribery practice. Our study makes a twofold contribution to existing research on corruption. First, on the theoretical level, we show that the typified and scripted character of social interactions can help explain the occurrence of corrupt transactions. Second, on a methodological level, our study showcases online self-reports as a useful data source to study corrupt transactions in an unobtrusive way

P-Hacking, P-Curves, and the PSM–Performance Relationship: Is there evidential value?

Recent developments in the social sciences have demonstrated that we cannot uncritically aggregate the published research on a particular effect to conclude about its presence or absence. Instead, questionable research practices such as p-hacking (conducting additional analyses or collecting new data to obtain significant results) and selective publication of significant results can produce a body of published research that misleads readers even if it contains many significant results. It is, therefore, necessary to assess the evidential value of the research on a certain effect, i.e., one must rule out that it is the result of questionable research practices. We introduce the p-curve method to public administration research and apply it to the research on the relationship between public service motivation (PSM) and individual performance, in order to demonstrate how the evidential value of a body of published research can be assessed. We find that this particular literature contains evidential value

A Case of Henoch-Schonlein Purpura Associated with Rotavirus Infection in an Elderly Asian Male and Review of the Literature.

BACKGROUND Henoch-Schönlein purpura (HSP), a small vessel vasculitis mediated by deposition of immune-complexes containing IgA in the skin, gut, and glomeruli, often presents with abdominal pain, purpuric rash in the lower extremities and buttocks, joint pain, and hematuria. The disease most commonly targets children but can affect adults who tend to have a worse prognosis. CASE REPORT We discuss a case of HSP in an elderly Chinese male who presented with severe proximal bowel inflammation, vasculitic rash, and proteinuria; he was found to have positive stool rotavirus and giardia. He improved significantly with high dose steroids. We believe rotavirus may have been a triggering event in this patient. A brief review of the literature is also presented. CONCLUSIONS This is the first case report describing a classic presentation of HSP in an adult following a rotavirus infection. HSP can cause significant morbidity and mortality in adult patients predominantly from progressive renal failure; therefore careful management and monitoring is important. GI infections seem to be a common trigger for HSP and this case report suggests that rotavirus may be part of the spectrum

Do synergies exist in related acquisitions? A meta-analysis of acquisition studies

Mergers and acquisitions (M&A) aim to increase the wealth of shareholders of the acquiring company, in particular by creating synergies. It is often assumed that relatedness is a source of synergies. Our study distinguishes between business, cultural, technological, and size relatedness. It discusses the reasons why these different forms of relatedness can lead to an acquisition success and we conduct a meta-analysis of 67 prior M&A studies. Results indicate that positive effects can be expected under specific conditions only and have a limited overall impact on acquisition success. A moderator analysis finds that synergies stemming from relatedness depend on industry-, country-, and investor-characteristic

Abusive supervision, public service motivation, and employee deviance: The moderating role of employment sector

Purpose – The purpose of this paper is to examine abusive supervision and public service motivation (PSM) as antecedents of deviant workplace behaviours. Design/methodology/approach – The study was conducted in a cross-sectional research design with survey data from 150 employees in the public, private and non-profit sector in Germany and the USA. Findings – Abusive supervision is positively associated with employee deviance, whereas PSM is negatively related to deviant behaviours. The employment sector moderates the negative relationship between PSM and employee deviance such that this relationship is stronger in the public and non-profit sector. Research limitations/implications – Limitations arise from the convenience sampling approach and the cross-sectional nature of the dataset. Practical implications – Human resource managers should consider behavioural integrity in the attraction, selection and training of both supervisors and subordinates. Private organisations can address the needs of strongly public service motivated employees by integrating associated goals and values into organisational missions and policies. Originality/value – This is the first study to introduce PSM into research on employee deviance. It shows that a pro-social motivation can drive anti-social behaviours when employees with high levels of PSM are members of profit-seeking organisations. Keywords Counterproductive work behaviour, Dark side of leadership, Destructive leadership, Person-organisation fit Paper type Research pape

Does coerced volunteering undermine the public service motivation of volunteers? A moderated mediation model

There has been an the increase within the past 20 years of mandatory volunteering programs within many school systems and in the past year in the UK’s Community Work Placement program. Consequently, there is the potential problem for volunteer coordinators who are managing individuals who have been coerced into volunteering. This coercion may undermine the motivation of volunteers and result in decreased performance. This study addresses the issue by examining the public service motivation (PSM) of 416 volunteers in southwestern UK. We use a moderated mediation model to test if coerced individuals have a poor person-organization fit (P-O fit) and thus a lower level of effort exerted. We found that those individuals who were coerced, but had low levels of PSM reported greater volunteer intensity then their non-coerced volunteers who also had low PSM levels. Whereas, when obligated, it strengthened the relationship between PSM and P-O fit. Consequently, this gives non-profit managers a clearer understanding of how to overcome the challenges coerced volunteers may present