A configurational approach to leadership behavior through archetypal analysis

The behavioral approach to leadership, which has introduced leadership styles, has been of great importance to the leadership field. Despite its importance, scholars have recently argued and demonstrated that these styles have various conceptual, methodological, and empirical limitations that could hamper further development of the leadership field. Consequently, they have called for alternative approaches to study leadership. We argue that taking a configurational or person-oriented approach to leadership behavior, which focuses on ideal-type configurations of leadership behaviors to identify leadership archetypes, offers such an alternative. We demonstrate the potential of such an approach via the use of archetypal analysis, for a dataset of 46 behaviors across 6 leadership styles, including more than 150,000 respondents. Our results offer a clear indication for the existence of archetypes of leadership. We also suggest how the resulting archetypes can get a meaningful interpretation, and discuss implications for future research

Relating cultural distance to self-other agreement of leader-observer dyads: the role of hierarchical position

Multisource feedback is important for leadership development and effectiveness. An important asset of such feedback is that it provides information about the self-other agreement between leaders and observers. Self-other agreement relates to several positive individual, dyadic, and organizational outcomes. Given the increasingly intercultural context in organizations, it is imperative to understand whether and how cultural distance between leaders and observers relates to self-other agreement. We hypothesize that cultural distance within leader-observer dyads is negatively associated with self-other agreement. Moreover, we expect that this relationship is stronger for leader-superior than leader-subordinate dyads. We use a unique multi-cultural dataset of 7,778 leaders (52 nationalities) rated by 22,997 subordinates (56 nationalities) and 10,132 superiors (54 nationalities) to test our hypotheses. Results confirm that cultural distance is negatively associated with self-other agreement; we show that this relationship is driven by increased self-ratings and by reduced other-ratings. In addition, we find that these results are more pronounced for leader-superior than for leader-subordinate dyads. Implications for the theory and practice of self-other agreement and multisource feedback are discussed

Seksueel overdraagbare aandoeningen, waaronder HIV, in Nederland in 2007

Net als in 2006 was chlamydia in 2007 de meest gediagnosticeerde bacterikle geslachtsziekte in de soacentra, vooral bij jongeren. Het percentage positieve chlamydiatesten nder heteroseksuele mannen en vrouwen daalde enigszins, voor het eerst sinds vier jaar (van 10,6% naar 10,1%). In 2006 stabiliseerde dit percentage bij mannen die seks hebben met mannen (MSM), en die trend zette door in 2007. Het percentage positieve gonorroe-, syfilis- en hivtesten nam net als voorgaande jaren af in 2007 (respectievelijk 2,4%, 0,9% en ,5%). Deze infecties werden het meest gediagnosticeerd bij MSM. In 2007 zijn er 306 nieuwe hivdiagnoses gesteld in de soacentra, ongeveer een derde van de 864 hivpositieven die dat jaar landelijk in de hivcentra zijn gemeld. Eind 2007 waren in totaal 14.019 personen in Nederland met hiv geregistreerd. Het aandeel van MSM onder de nieuw hivinfecties nam in 2007 verder toe. Net als eerdere jaren werd in de soacentra bij MSM die bekend zijn met hun positieve hivstatus vaak nog een andere geslachtsziekte gevonden (45%). In deze groep is sinds 2004 regelmatig LGV, een agressieve variant van chlamydia, en sinds 2007 hepatitis C gediagnosticeerd. Versterkte surveillance en innovatieve interventies zijn nodig om verdere verspreiding onder MSM en naar andere groepen te voorkomen. Onder bepaalde migrantengroepen in Nederland (onder andere afkomstig uit Suriname, de Nederlandse Antillen en Aruba) komen hiv, chlamydia, gonorroe en syfilis relatief vaker voor dan onder autochtone Nederlanders. Ook deze constatering vraagt om vernieuwende maatregelen die op de bevolkingsgroepen zijn toegespitst. De soacentra bieden soazorg aan hoogrisicogroepen. In 2007 hebben ruim 78.000 personen zich daar laten testen, een toename van 13% ten opzichte van 2006. Net als in 2006 was chlamydia in 2007 de meest gediagnosticeerde bacterikle geslachtsziekte in de soacentra, vooral bij jongeren. Het percentage positieve chlamydiatesten onder heteroseksuele mannen en vrouwen daalde enigszins, voor het eerst sinds vier jaar (van 10,6% naar 10,1%). In 2006 stabiliseerde dit percentage bij mannen die seks hebben met mannen (MSM), en die trend zette door in 2007. Het percentage positieve gonorroe-, syfilis- en hivtesten nam net als voorgaande jaren af in 2007 (respectievelijk 2,4%, 0,9% en 0,5%). Deze infecties werden het meest gediagnosticeerd bij MSM.In 2007, chlamydia was the most common bacterial sexually transmitted infection (STI) diagnosed in Dutch STI centres. Similar to previous years, infections were reported especially in young heterosexuals. The proportion of positive chlamydia tests among heterosexual men and women decreased slightly for the first time in four years (from 10.6% to 10.1%). In 2006, this proportion had stabilized in men who have sex with men (MSM) with the trend continuing in 2007. The positivity rate for gonorrhoea (2.4%), syphilis (0.9%) and HIV (0.5%) continued to decrease in 2007. These infections were most frequently diagnosed in MSM. In 2007, 306 new positive HIV cases were diagnosed in STI centres in the Netherlands. This number amounts to about one third of the total number of 864 positive HIV cases registered nationally. At the end of 2007, a total of 14,019 HIV cases in care were registered in the Netherlands. The proportion of MSM among new HIV cases rose further in 2007. In line with previous years, concurrent STIs were diagnosed very frequently among MSM visiting STI centres (45%) who had known HIV positive status. In this group of men, Lymphogranuloma Venereum (LGV) an aggressive type of chlamydia, has been reported frequently since 2004; this has also been the case for hepatitis C since 2007. In this group of men, strengthened surveillance and innovative interventions are warranted in order to prevent further transmission both among MSM and to other population groups. In some specific migrant groups in the Dutch population -- for example, people from Surinam, the Netherlands Antilles and Aruba -- HIV, chlamydia, gonorrhoea and syphilis are more common than in the autochthonous Dutch population. This indicates the need for targeted intervention by risk profile. The specialised STI centres in the Netherlands offer STI testing and care targeted at high risk groups. In 2007, approximately 78,000 people used this service amounting to a rise of 13% compared to 2006

The EMBRACE web service collection

The EMBRACE (European Model for Bioinformatics Research and Community Education) web service collection is the culmination of a 5-year project that set out to investigate issues involved in developing and deploying web services for use in the life sciences. The project concluded that in order for web services to achieve widespread adoption, standards must be defined for the choice of web service technology, for semantically annotating both service function and the data exchanged, and a mechanism for discovering services must be provided. Building on this, the project developed: EDAM, an ontology for describing life science web services; BioXSD, a schema for exchanging data between services; and a centralized registry (http://www.embraceregistry.net) that collects together around 1000 services developed by the consortium partners. This article presents the current status of the collection and its associated recommendations and standards definitions

UV-induced ligand exchange in MHC class I protein crystals

High-throughput structure determination of protein−ligand complexes is central in drug development and structural proteomics. To facilitate such high-throughput structure determination we designed an induced replacement strategy. Crystals of a protein complex bound to a photosensitive ligand are exposed to UV light, inducing the departure of the bound ligand, allowing a new ligand to soak in. We exemplify the approach for a class of protein complexes that is especially recalcitrant to high-throughput strategies: the MHC class I proteins. We developed a UV-sensitive, “conditional”, peptide ligand whose UV-induced cleavage in the crystals leads to the exchange of the low-affinity lytic fragments for full-length peptides introduced in the crystallant solution. This “in crystallo” exchange is monitored by the loss of seleno-methionine anomalous diffraction signal of the conditional peptide compared to the signal of labeled MHC β2m subunit. This method has the potential to facilitate high-throughput crystallography in various protein families

An overview of the first 5 years of the ENIGMA obsessive–compulsive disorder working group: The power of worldwide collaboration

Abstract Neuroimaging has played an important part in advancing our understanding of the neurobiology of obsessive?compulsive disorder (OCD). At the same time, neuroimaging studies of OCD have had notable limitations, including reliance on relatively small samples. International collaborative efforts to increase statistical power by combining samples from across sites have been bolstered by the ENIGMA consortium; this provides specific technical expertise for conducting multi-site analyses, as well as access to a collaborative community of neuroimaging scientists. In this article, we outline the background to, development of, and initial findings from ENIGMA's OCD working group, which currently consists of 47 samples from 34 institutes in 15 countries on 5 continents, with a total sample of 2,323 OCD patients and 2,325 healthy controls. Initial work has focused on studies of cortical thickness and subcortical volumes, structural connectivity, and brain lateralization in children, adolescents and adults with OCD, also including the study on the commonalities and distinctions across different neurodevelopment disorders. Additional work is ongoing, employing machine learning techniques. Findings to date have contributed to the development of neurobiological models of OCD, have provided an important model of global scientific collaboration, and have had a number of clinical implications. Importantly, our work has shed new light on questions about whether structural and functional alterations found in OCD reflect neurodevelopmental changes, effects of the disease process, or medication impacts. We conclude with a summary of ongoing work by ENIGMA-OCD, and a consideration of future directions for neuroimaging research on OCD within and beyond ENIGMA

Involvement of the TPR2 subdomain movement in the activities of ϕ29 DNA polymerase

The polymerization domain of ϕ29 DNA polymerase acquires a toroidal shape by means of an arch-like structure formed by the specific insertion TPR2 (Terminal Protein Region 2) and the thumb subdomain. TPR2 is connected to the fingers and palm subdomains through flexible regions, suggesting that it can undergo conformational changes. To examine whether such changes take place, we have constructed a ϕ29 DNA polymerase mutant able to form a disulfide bond between the apexes of TPR2 and thumb to limit the mobility of TPR2. Biochemical analysis of the mutant led us to conclude that TPR2 moves away from the thumb to allow the DNA polymerase to replicate circular ssDNA. Despite the fact that no TPR2 motion is needed to allow the polymerase to use the terminal protein (TP) as primer during the initiation of ϕ29 TP–DNA replication, the disulfide bond prevents the DNA polymerase from entering the elongation phase, suggesting that TPR2 movements are necessary to allow the TP priming domain to move out from the polymerase during transition from initiation to elongation. Furthermore, the TPR2-thumb bond does not affect the equilibrium between the polymerization and exonuclease activities, leading us to propose a primer-terminus transference model between both active sites

From DNA sequence to application: possibilities and complications

The development of sophisticated genetic tools during the past 15 years have facilitated a tremendous increase of fundamental and application-oriented knowledge of lactic acid bacteria (LAB) and their bacteriophages. This knowledge relates both to the assignments of open reading frames (ORF’s) and the function of non-coding DNA sequences. Comparison of the complete nucleotide sequences of several LAB bacteriophages has revealed that their chromosomes have a fixed, modular structure, each module having a set of genes involved in a specific phase of the bacteriophage life cycle. LAB bacteriophage genes and DNA sequences have been used for the construction of temperature-inducible gene expression systems, gene-integration systems, and bacteriophage defence systems. The function of several LAB open reading frames and transcriptional units have been identified and characterized in detail. Many of these could find practical applications, such as induced lysis of LAB to enhance cheese ripening and re-routing of carbon fluxes for the production of a specific amino acid enantiomer. More knowledge has also become available concerning the function and structure of non-coding DNA positioned at or in the vicinity of promoters. In several cases the mRNA produced from this DNA contains a transcriptional terminator-antiterminator pair, in which the antiterminator can be stabilized either by uncharged tRNA or by interaction with a regulatory protein, thus preventing formation of the terminator so that mRNA elongation can proceed. Evidence has accumulated showing that also in LAB carbon catabolite repression in LAB is mediated by specific DNA elements in the vicinity of promoters governing the transcription of catabolic operons. Although some biological barriers have yet to be solved, the vast body of scientific information presently available allows the construction of tailor-made genetically modified LAB. Today, it appears that societal constraints rather than biological hurdles impede the use of genetically modified LAB.