Measurement of psychological entitlement in 28 countries

This article presents the cross-cultural validation of the Entitlement Attitudes Questionnaire, a tool designed to measure three facets of psychological entitlement: active, passive, and revenge entitlement. Active entitlement was defined as the tendency to protect individual rights based on self-worthiness. Passive entitlement was defined as the belief in obligations to and expectations toward other people and institutions for the fulfillment of the individual’s needs. Revenge entitlement was defined as the tendency to protect one’s individual rights when violated by others and the tendency to reciprocate insults. The 15-item EAQ was validated in a series of three studies: the first one on a general Polish sample (N = 1,900), the second one on a sample of Polish students (N = 199), and the third one on student samples from 28 countries (N = 5,979). A three-factor solution was confirmed across all samples. Examination of measurement equivalence indicated partial metric invariance of EAQ for all national samples. Discriminant and convergent validity of the EAQ was also confirmed

The mental health continuum-short form: the structure and application for cross-cultural studies-A 38 nation study

Objective: The Mental Health Continuum-Short Form (MHC-SF) is a brief scale measuring positive human functioning. The study aimed to examine the factor structure and to explore the cross-cultural utility of the MHC-SF using bifactor models and exploratory structural equation modelling. Method: Using multigroup confirmatory analysis (MGCFA) we examined the measurement invariance of the MHC-SF in 38 countries (university students, N = 8,066; 61.73% women, mean age 21.55 years). Results: MGCFA supported the cross-cultural replicability of a bifactor structure and a metric level of invariance between student samples. The average proportion of variance explained by the general factor was high (ECV =.66), suggesting that the three aspects of mental health (emotional, social, and psychological well-being) can be treated as a single dimension of well-being. Conclusion: The metric level of invariance offers the possibility of comparing correlates and predictors of positive mental functioning across countries; however, the comparison of the levels of mental health across countries is not possible due to lack of scalar invariance. Our study has preliminary character and could serve as an initial assessment of the structure of the MHC-SF across different cultural settings. Further studies on general populations are required for extending our findings.info:eu-repo/semantics/acceptedVersio

Belief in a zero-sum game and subjective well-being across 35 countries

This article presents a short research report on the relationship between perceived antagonism in social relations measured using the Belief in a Zero-Sum Game (BZSG) scale, life satisfaction, and positive and negative affect. Given that individuals who believe that life is like a zero-sum game are likely to perceive their daily interactions with others as unfair, we expected that individuals with high BZSG experience more negative affect and fewer positive one, resulting in a lower satisfaction with life. In addition, we examined whether country-level BZSG may play a moderating role in these associations. Data were collected from student samples (N = 7146) in 35 countries. Multilevel modelling revealed that perceived social antagonism in social relations is negatively associated with satisfaction with life and that this relationship is mediated by both positive and negative affect at the individual level. The relation of individual BZSG and negative affect on satisfaction with life were weaker in societies with higher country-level BZSG, suggesting that the effects of BZSG may be less detrimental in these countries. These findings extend previous knowledge about predictors of life satisfaction and suggest that social beliefs might also be an important factor that influences subjective well-being. The contribution of the study is that the separate treatment of life satisfaction and positive and negative affect may be helpful in many research situations, particularly from a cross-cultural perspective.info:eu-repo/semantics/publishedVersio

Belief in a zero-sum game and subjective well-being across 35 countries

This article presents a short research report on the relationship between perceived antagonism in social relations measured using the Belief in a Zero-Sum Game (BZSG) scale, life satisfaction, and positive and negative affect. Given that individuals who believe that life is like a zero-sum game are likely to perceive their daily interactions with others as unfair, we expected that individuals with high BZSG experience more negative affect and fewer positive one, resulting in a lower satisfaction with life. In addition, we examined whether country-level BZSG may play a moderating role in these associations. Data were collected from student samples (N=7146) in 35 countries. Multilevel modelling revealed that perceived social antagonism in social relations is negatively associated with satisfaction with life and that this relationship is mediated by both positive and negative affect at the individual level. The relation of individual BZSG and negative affect on satisfaction with life were weaker in societies with higher country-level BZSG, suggesting that the effects of BZSG may be less detrimental in these countries. These findings extend previous knowledge about predictors of life satisfaction and suggest that social beliefs might also be an important factor that influences subjective well-being. The contribution of the study is that the separate treatment of life satisfaction and positive and negative affect may be helpful in many research situations, particularly from a cross-cultural perspective

Redoxnetzwerke des Malariaerregers Plasmodium : Validierung von Schlüsselenzymen für neue chemotherapeutische Ansätze

Die Malaria-assozierte Pathologie wird durch die Entwicklung von Plasmodien in den Erythrozyten ihres Wirtes verursacht. Um ein reduzierendes intrazelluläres Milieu in diesem Sauerstoff-reichen Umfeld zu erhalten, haben Malaria-Parasiten ein komplexes antioxidatives Netzwerk entwickelt, welches auf zwei zentralen Elektronen-Donatoren beruht, dem Glutathion und dem Thioredoxin. Die intrazellulären Spiegel dieser beiden redox-aktiven Peptide in reduzierter – und damit reduzierender Form – werden durch die entsprechenden NADPH-abhängigen Flavoenzyme Thioredoxinreduktase (TrxR) und Glutathionreduktase (GR) aufrechterhalten. Da Katalase und eine klassische Selen-abhängige Glutathionperoxidase in Plasmodium fehlen, spielen die auf den Enzymen Thioredoxin- und Glutathionreduktase basierenden Systeme eine besondere Rolle. Weitere Bestandteile der antioxidativen Abwehr sind verschiedene Mitglieder der Thioredoxin-Familie, vor allem das Plasmodien-spezifische Plasmoredoxin (Plrx), welches als zusätzliche Verteidigungslinie der Parasiten gegen oxidativen Stress diskutiert wird. Im Rahmen der vorliegenden Arbeit wurden antioxidative Proteine der Parasiten untersucht, die als Zielmoleküle für die rationale Medikamentenentwicklung von Bedeutung sind. Um zu klären, welche der beteiligten Proteine sich aufgrund einer essentiellen Funktion in den Blutstadien-Parasiten insbesondere dafür eignen, wurden die zugrunde liegenden Gene dreier Redox-Proteine mit Methoden der reversen Genetik untersucht. Dies geschah durch stabile Gen-Inaktivierung unter Nutzung von Integrations- und replacement-Strategien, im Falle der Glutathionreduktase ergänzt durch Gen-Komplementation mit dem entsprechenden Ortholog. Die Targetvalidierung individueller redox-aktiver Proteine ist eine unerlässliche Voraussetzung für die rationale Entwicklung neuer effektiver Antimalaria-Medikamente. Die erfolgreiche Herstellung von Plasmoredoxin knock out-Mutanten in Nagetiermalaria-Modellparasiten und die phänotypischen Analysen im Verlauf des Lebenszyklus offenbarten in vitro und in vivo keine essentiellen Funktionen dieses Proteins. Dieses Ergebnis kann mit funktioneller Redundanz innerhalb der Mitglieder der Thioredoxin-Familie erklärt werden, somit bietet sich eine weitere Arzneimittelentwicklung allein auf der Basis Plasmoredoxin-spezifischer Inhibitoren nicht an. Weiterhin konnten Thioredoxinreduktase-defiziente P. berghei-Mutanten erzeugt werden. Eine systematische Analyse dieser Parasiten im Verlauf des Plasmodium-Lebenszyklus zeigte an keiner Stelle eine lebensnotwendige Funktion der Thioredoxinreduktase. Dies steht im Gegensatz zu früheren in vitro-Studien bei P. falciparum, welche diesem Enzym eine essentielle Funktion zuschrieben. Da ein praktikables in vivo-Modell für humanpathogene Malaria-Parasiten nicht verfügbar ist, verdeutlicht das hier vorgestellte Ergebnis der Targetvalidierung für Thioredoxinreduktase die Bedeutung funktioneller Studien in Nagetiermalaria-Modellen für die präklinische Entwicklung neuer Medikamente gegen Malaria. Für eines der viel versprechendsten drug targets von Malaria-Parasiten, der Glutathionreduktase, konnte auf genetischer Ebene der Beweis erbracht werden, dass durch den Verlust der Funktion dieses Enzyms die Parasiten nicht lebensfähig sind. Somit nimmt die Glutathionreduktase in dem komplexen antioxidativen Netzwerk von Plasmodium eine zentrale und essentielle Rolle ein. Zusätzlich wurde in dieser Arbeit die molekulare Wirkungsweise des seit mehr als 100 Jahren klinisch genutzten Medikaments Methylenblau auf Malaria-Parasiten untersucht. Hierbei zeigte sich, dass diese Verbindung neben ihren inhibierenden Eigenschaften interessante Charakteristika als subversives Substrat verschiedener Disulfidreduktasen besitzt. Bei Anwesenheit von Methylenblau werden diese Enzyme zu pro-oxidativen, H2O2-produzierenden Verbindungen, welche die reduzierenden zellulären Bedingungen herausfordern, statt sie zu bewahren.Malaria-associated pathology is caused by the continuous expansion of Plasmodium parasites inside host erythrocytes. To maintain a reducing intracellular milieu in this oxygen-rich environment, malaria parasites have evolved a complex antioxidative network based on two central electron donors, glutathione and thioredoxin. The intracellular levels of these redox-active peptides in reduced and thus reducing forms are maintained by the respective NADPH-dependent flavoenzymes thioredoxin reductase (TrxR) and glutathione reductase (GR). As catalase and classical selenium-dependant glutathione peroxidase are absent in Plasmodium, the systems based on thioredoxin reductase and glutathione reductase play a prominent role. Further components of the antioxidative defense comprise different members of the thioredoxin family, especially Plasmodium-specific plasmoredoxin which has been discussed as an additional defense line against oxidative stress. In the framework of this thesis, antioxidative parasite proteins that are of interest as targets for rational drug development were investigated. To clarify which proteins are particularly suitable as drug target due to an essential function for blood stage parasites, the respective genes of three redox proteins were studied employing reverse genetics. This was achieved by stable gene inactivation with integration and replacement strategies, in the case of glutathione reductase supplemented by gene complementation of the respective ortholog. Target validation of individual redox-active proteins is an indispensable prerequisite for the rational development of new and effective antimalarial drugs. The successful generation of plasmoredoxin knockout mutants in the rodent model malaria parasite and phenotypic analysis during life cycle progression revealed both in vitro and in vivo a non-vital function of this protein. This finding can be explained by functional redundancy among the members of the thioredoxin family and discourages future drug discovery efforts that aim at specifically targeting plasmoredoxin. Furthermore P. berghei thioredoxin reductase-deficient parasites could be generated in this thesis. A systematic phenotypic analysis of this mutant throughout the Plasmodium life cycle demonstrated no essential function for thioredoxin reductase at any phase of the parasite life cycle. This is in contrast to previous in vitro studies which attributed an essential role to thioredoxin reductase in P. falciparum. As a feasible in vivo model for human pathogen malaria parasites is not available, the presented target validation result of thioredoxin reductase highlights the importance of functional studies in rodent malaria models to guide preclinical development of novel antimalaria intervention strategies. For one of the most promising drug targets of malaria parasites, glutathione reductase, this work provides the genetic proof that in the case of this enzyme loss of function results in non-viable malaria parasites in vivo. Hence, glutathione reductase occupies an essential position in the complex antioxidant network of Plasmodium parasites. Furthermore, the molecular mode of action of methylene blue, which has been clinically used as an antimalarial drug for over 100 years, against malaria parasites has been investigated. It could be shown that this compound – besides its inhibitory potential – has interesting characteristics as a subversive substrate of different disulfide reductases. In the presence of methylene blue, they turn into pro-oxidant, H2O2-producing enzymes which challenge the reducing cellular milieu that they are meant to protect in the absence of this perturbing drug