Human intestinal maltase-glucoamylase: crystal structure of the N-terminal catalytic subunit and basis of inhibition and substrate specificity

Human maltase-glucoamylase (MGAM) is one of the two enzymes responsible for catalyzing the last glucose-releasing step in starch digestion. MGAM is anchored to the small-intestinal brush-border epithelial cells and contains two homologous glycosyl hydrolase family 31 catalytic subunits: an N-terminal subunit (NtMGAM) found near the membrane-bound end and a C-terminal luminal subunit (CtMGAM). In this study, we report the crystal structure of the human NtMGAM subunit in its apo form (to 2.0 A) and in complex with acarbose (to 1.9 A). Structural analysis of the NtMGAM-acarbose complex reveals that acarbose is bound to the NtMGAM active site primarily through side-chain interactions with its acarvosine unit, and almost no interactions are made with its glycone rings. These observations, along with results from kinetic studies, suggest that the NtMGAM active site contains two primary sugar subsites and that NtMGAM and CtMGAM differ in their substrate specificities despite their structural relationship. Additional sequence analysis of the CtMGAM subunit suggests several features that could explain the higher affinity of the CtMGAM subunit for longer maltose oligosaccharides. The results provide a structural basis for the complementary roles of these glycosyl hydrolase family 31 subunits in the bioprocessing of complex starch structures into glucose.

How large are actor and partner effects of personality on relationship satisfaction? The importance of controlling for shared method variance

Previous research suggests that the personality of a relationship partner predicts not only the individual’s own satisfaction with the relationship but also the partner’s satisfaction. Based on the actor–partner interdependence model, the present research tested whether actor and partner effects of personality are biased when the same method (e.g., self-report) is used for the assessment of personality and relationship satisfaction and, consequently, shared method variance is not controlled for. Data came from 186 couples, of whom both partners provided self- and partner reports on the Big Five personality traits. Depending on the research design, actor effects were larger than partner effects (when using only self-reports), smaller than partner effects (when using only partner reports), or of about the same size as partner effects (when using self- and partner reports). The findings attest to the importance of controlling for shared method variance in dyadic data analysis.

Family change theory: A preliminary evaluation on the basis of recent cross-cultural studies

Family change theory (Kagitcibasi, 1996, 2007) is an approach which can be used to explain how modernisation and globalisation processes affect the family. The most important assumption of the theory is that when traditional interdependent cultures modernise, they need not necessarily develop in the direction of the independent family model typical of Western individualistic societies. Instead, they may develop towards a family model of emotional interdependence that combines continuing emotional interdependencies in the family with declining material interdependencies and with rising personal autonomy. In this chapter a preliminary evaluation of the empirical status of family change theory is given based on a review of recent cross-cultural studies. It will be shown to what extent the few studies that have been systematically conducted in this respect have found results either supporting or not supporting aspects ofthe theory, and where the strengths and problems of this research lie.

Psychological adaptation to spousal loss in old age: The role of personality

Spousal loss is an inevitable critical life event for most individuals in old age, mostly associated with a negative impact on various well-being measures, ie. lower life satisfaction, higher rates of loneliness and depressive symptoms compared to married peers. While the negative effects on well-being are well documented in literature, the modifying factors accounting for the large variability in adaptation to loss are discussed controversially. The potential relevance of personality in the adaptation process has rarely been examined and findings regarding the role of time since loss are contradictory. Based on a vulnerability-stress-model this contribution aims a) to compare psychological well-being of bereaved individuals with married counterparts and b) to investigate the protective effects of different personality traits (Big Five, resilience), and the role of time since loss for adaptation in terms of life satisfaction, loneliness and depression. Data from a questionnaire study about the loss of a spouse in middle and old age in the German- and French-speaking parts of Switzerland are reported. The study is part of the Swiss National Centre of Competence in Research LIVES (Swiss National Science Foundation). The sample consists of 351 widowed persons (39% men, widowed since 0 - 5 years), and 605 married controls (50% men), aged 60 - 89 years. Group comparisons reveal the detrimental effect of spousal bereavement on all indicators of psychological adaptation. Results from hierarchical regression analyses show furthermore, that the effect of spousal loss on all psychological outcomes is moderated by personality traits. Separate analyses with the group of bereaved individuals suggest, that the protective effect of personality varies by the time passed since loss. Our results contribute to a better understanding of the variability in psychological adaptation to spousal loss in old age and give hints for counselling practice.

Who seeks career counselling? A prospective study of personality and career variables among Swiss adolescents

This study investigated whether career adaptability, personality, attitude towards career counselling and some demographic variables predict the help seeking behaviour in career counselling among 330 Swiss adolescents in eighth grade. The results indicated that boys were less likely to seek help and that career related variables and attitude but not personality significantly predicted help-seeking. Specifically, help seeking related positively to undecidedness and positive perception of career counselling. Implications for school and career counsellors and suggestions for future research are presented.

The importance of socio-cultural factors on sports behaviour of adolescents and young adults in Switzerland – a conceptualisation on the basis of the habitus-approach

Sport participation has often been the topic in sports science and it could be shown that in Europe the population of northern and western countries are more often physically active than southern and eastern countries (European Commission, 2014). In Switzerland the physical activity of the Swiss population also differs between the linguistic regions. The German speaking population is more often physically active than the French or Italian speaking part (Stamm & Lamprecht, 2008). To explain the differences in sport participation structural and cultural factors have been discussed. Because within a country homogenous structural conditions can be assumed, the aim of this study is to analyse how socio-cultural factors correlate with sport participation of adolescents and young adults. In order to analyse this research question, Bourdieu’s concept of habitus (1984) has been used as theoretical background. This sport-related concept of habitus considers cultural determined values, the attribution of meaning and patterns of action which is socially determined and have an influence on individual actions and therefore also on the sport practise. On this basis, a qualitative study including guideline-based interviews with German (n=5) and French (n=3) speaking adolescents and young adults at the age of 16 to 24 (M=21.4) were held in two different linguistic regions of Switzerland. To analyse the interviews the documentary method was applied (Bohnsack, 2010). Initial findings reveal that there are different sport related values, attributions of meanings and patterns of action also called framework of orientations concerning topics like body, health and leisure which correlate with the habitual sports practise in the two different linguistic regions. This study illustrates that the habitus is culturally shaped and that it could help to understand the meaning of socio-cultural factors for sport participation.

Molecular and cellular basis of bone resorption.

Osteoclast research has an exciting history and a challenging future. More than 3 decades ago, it became evident that bone-resorbing osteoclasts are of hematopoietic origin and are ultimately linked to the "basic multicellular unit," where they team up with the other cell types, including bone-forming osteoblasts. Since 2 decades, we have learned about the signaling pathways controlling genes relevant for osteoclastogenesis and bone resorption. It took another decade until the hypothesized "osteoclast differentiation" factor was discovered and was translated into an approved pharmacologic strategy. Here, the focus is on another molecular target, cathepsin K, a cysteine protease being released by the osteoclast into the resorption compartment. Genetic deletion and pharmacological blocking of cathepsin K reduces bone resorption but with ongoing bone formation. This observation not only holds great promise to become a new pharmacologic strategy, but it also provides new insights into the coordinated work of cells in the "basic multicellular unit" and thus, bridges the history and future of osteoclast research. This article is a short primer on osteoclast biology for readers of the special issue on odanacatib, a cathepsin K inhibitor.

Increased Resting State Network Connectivity in Synesthesia: Evidence for a Neural Basis of Synesthetic Consistency

Studying individual differences in conscious awareness can potentially lend fundamental insights into the neural bases of binding mechanisms and consciousness (Cohen Kadosh and Henik, 2007). Partly for this reason, considerable attention has been devoted to the neural mechanisms underlying grapheme–color synesthesia, a healthy condition involving atypical brain activation and the concurrent experience of color photisms in response to letters, numbers, and words. For instance, the letter C printed in black on a white background may elicit a yellow color photism that is perceived to be spatially colocalized with the inducing stimulus or internally in the “mind's eye” as, for instance, a visual image. Synesthetic experiences are involuntary, idiosyncratic, and consistent over time (Rouw et al., 2011). To date, neuroimaging research on synesthesia has focused on brain areas activated during the experience of synesthesia and associated structural brain differences. However, activity patterns of the synesthetic brain at rest remain largely unexplored. Moreover, the neural correlates of synesthetic consistency, the hallmark characteristic of synesthesia, remain elusive.

Granular computing as a basis of human–data interaction: a cognitive cities use case

The article proposes granular computing as a theoretical, formal and methodological basis for the newly emerging research field of human–data interaction (HDI). We argue that the ability to represent and reason with information granules is a prerequisite for data legibility. As such, it allows for extending the research agenda of HDI to encompass the topic of collective intelligence amplification, which is seen as an opportunity of today’s increasingly pervasive computing environments. As an example of collective intelligence amplification in HDI, we introduce a collaborative urban planning use case in a cognitive city environment and show how an iterative process of user input and human-oriented automated data processing can support collective decision making. As a basis for automated human-oriented data processing, we use the spatial granular calculus of granular geometry.

Change mechanisms of schema-centered group psychotherapy with personality disorder patients

Background This study addressed the temporal properties of personality disorders and their treatment by schema-centered group psychotherapy. It investigated the change mechanisms of psychotherapy using a novel method by which psychotherapy can be modeled explicitly in the temporal domain. Methodology and Findings 69 patients were assigned to a specific schema-centered behavioral group psychotherapy, 26 to social skills training as a control condition. The largest diagnostic subgroups were narcissistic and borderline personality disorder. Both treatments offered 30 group sessions of 100 min duration each, at a frequency of two sessions per week. Therapy process was described by components resulting from principal component analysis of patients' session-reports that were obtained after each session. These patient-assessed components were Clarification, Bond, Rejection, and Emotional Activation. The statistical approach focused on time-lagged associations of components using time-series panel analysis. This method provided a detailed quantitative representation of therapy process. It was found that Clarification played a core role in schema-centered psychotherapy, reducing rejection and regulating the emotion of patients. This was also a change mechanism linked to therapy outcome. Conclusions/Significance The introduced process-oriented methodology allowed to highlight the mechanisms by which psychotherapeutic treatment became effective. Additionally, process models depicted the actual patterns that differentiated specific diagnostic subgroups. Time-series analysis explores Granger causality, a non-experimental approximation of causality based on temporal sequences. This methodology, resting upon naturalistic data, can explicate mechanisms of action in psychotherapy research and illustrate the temporal patterns underlying personality disorders.