Retrieving the hemodynamic response function in resting state fMRI: methodology and application

In this paper we present a procedure to retrieve the hemodynamic response function (HRF) from resting state functional magnetic resonance imaging (fMRI) data. The fundamentals of the procedures are further validated by considering simultaneous electroencephalographic (EEG) recordings. The typical HRF shape at rest for a group of healthy subject is presented. Then we present the modifications to the shape of the HRF at rest following two physiological modulations: eyes open versus eyes closed and propofol-induced modulations of consciousness

The cost of human capital depreciation during unemployment

Skill erosion during unemployment was of particular concern as unemployment duration increased in the Great Recession. I argue that it generates an externality in job creation: firms ignore how their hiring decisions affect the unemployment pool’s skill composition, and hence the expected output produced by new hires. As a consequence, job creation is too low from a social point of view. But the extent to which it is too low varies over the cycle. This is because the externality’s magnitude, which depends on the impact of job creation on the pool’s skill composition, reduces when the share of unemployed workers who already have eroded skills increases

Intellectuele toe-eigening en discursief geweld in Focquenbrochs Afrikaense Thalia (1678)

In 1668, the Dutch medic and poet Willem Godschalck van Focquenbroch left Amsterdam for the African Gold Coast to become “fiscaal” (a kind of public prosecutor) on behalf of the Dutch West India Company (WIC) at Elmina Castle in Guinea, which was a bulwark of the Dutch transatlantic slave trade. In his posthumously published Afrikaense Thalia (African Thalia, 1678), a collection of poems and letters containing the well-known Afrikaense Brieven (African Letters), Focquenbroch testifies to his life and work in Elmina Castle through his alter ego “Focq”. In this article, I use Stephen Greenblatt’s notions of “wonder” and “possession” to demonstrate that Focq’s descriptions in the Afrikaense Brieven can be read as an expression of his initial wonder for, and subsequent appropriation of Guinea and its inhabitants. I argue that Focq’s literary-intellectual appropriation of the African Other, which at first sight seems rather innocent compared to the brutal physical appropriation of African people by the Dutch colonists, can nevertheless be considered violent at a discursive level. Focq’s conviction that he is superior to the Guineans because he possesses written language enables him to frame his writing in a discourse which stresses the superiority of the own culture and the culturelessness of the African Other. As such, Focq degrades and instrumentalizes the African Other in order to glorify and preserve the Self

Initiation of hydrogen induced cracks at secondary phase particles

The goal of this work is to propose a general mechanism for hydrogen induced crack initiation in steels based on a microstructural study of multiple steel grades. Four types of steels with strongly varying microstructures are studied for this purpose, i.e. ultra low carbon (ULC) steel, TRIP (transformation induced plasticity) steel, Fe-C-Ti generic alloy, and pressure vessel steel. A strong dependency of the initiation of hydrogen induced cracks on the microstructural features in the materials is observed. By use of SEM-EBSD characterization, initiation is found to always occur at the hard secondary phase particles in the materials

β2-adrenergic agonists modulate TNF-α induced astrocytic inflammatory gene expression and brain inflammatory cell populations

Background: The NF-kappa B signaling pathway orchestrates many of the intricate aspects of neuroinflammation. Astrocytic beta(2)-adrenergic receptors have emerged as potential regulators in central nervous system inflammation and are potential targets for pharmacological modulation. The aim of this study was to elucidate the crosstalk between astrocytic beta(2)-adrenergic receptors and the TNF-alpha induced inflammatory gene program. Methods: Proinflammatory conditions were generated by the administration of TNF-alpha. Genes that are susceptible to astrocytic crosstalk between beta(2)-adrenergic receptors (stimulated by clenbuterol) and TNF-alpha were identified by qPCR-macroarray-based gene expression analysis in a human 1321 N1 astrocytoma cell line. Transcriptional patterns of the identified genes in vitro were validated by RT-PCR on the 1321 N1 cell line as well as on primary rat astrocytes. In vivo expression patterns were examined by intracerebroventricular administration of clenbuterol and/or TNF-alpha in rats. To examine the impact on the inflammatory cell content of the brain we performed extensive FACS analysis of rat brain immune cells after intracerebroventricular clenbuterol and/or TNF-alpha administration. Results: Parallel transcriptional patterns in vivo and in vitro confirmed the relevance of astrocytic beta(2)-adrenergic receptors as modulators of brain inflammatory responses. Importantly, we observed pronounced effects of beta(2)-adrenergic receptor agonists and TNF-alpha on IL-6, CXCL2, CXCL3, VCAM1, and ICAM1 expression, suggesting a role in inflammatory brain cell homeostasis. Extensive FACS-analysis of inflammatory cell content in the brain demonstrated that clenbuterol/TNF-alpha co-administration skewed the T cell population towards a double negative phenotype and induced a shift in the myeloid brain cell population towards a neutrophilic predominance. Conclusions: Our results show that astrocytic beta(2)-adrenergic receptors are potent regulators of astrocytic TNF-alpha-activated genes in vitro and in vivo, and ultimately modulate the molecular network involved in the homeostasis of inflammatory cells in the central nervous system. Astrocytic beta(2)-adrenergic receptors and their downstream signaling pathway may serve as potential targets to modulate neuroinflammatory responses

Bridging Ruptures: The Re-Emergence of the Antwerp Diamond District after WW II

“Diamonds love Antwerp” – these three words constitute the present slogan of the Antwerp World Diamond Centre, the organisation concerned with the promotion of the diamond trade and industry in the Scheldt city and keeping the latter an important diamond hub in the age of globalisation with new diamond centres evolving especially in low-cost countries like China and Thailand (The New York Times, May 31 2005; EVEN-ZOHAR 2006, 371ff.). In fact, diamonds seem to have loved Antwerp even in the past as the city has been a major centre for trading and polishing the precious stones since the 15th century (WALGRAVE 1993, 37). Despite some ups and downs there had not been any interruption of the commercial activities in this sector until World War II reached Belgium and trading as well as processing diamonds gradually were discontinued (LAUREYS 2005, chapter 5f). Surprisingly, however, the Belgian diamond sector experienced a long-lasting boom after 1945, contributing significantly to the country’s economic power even though the former infrastructure had partly been taken away or destroyed, many workers had fled, been deported or killed and other diamond centres had evolved during the years of the German occupation (VAN DYCK 1989). Given these aspects, the paper on hand addresses the question whether the window of locational opportunity arising after the abrupt break of the trajectory was restricted by past structures that actually have favoured the re-emergence of the cluster at its former location. By doing so, two aspects of conceptual interest are concerned as well: On the one hand, evolutionary literature up to now has emphasised chance as the major determinant of the emergence of regional trajectories thereby neglecting the underlying social processes. Furthermore, due to the concentration on concepts like path-dependency and lock-in potential ruptures in the development of clusters were only seldom taken into account yet (BATHELT/BOGGS 2005; 2003)

Behind blue lights : exploring police officers’ resilience after the terrorist attack at Brussels Airport on March 22, 2016

This case study on the terrorist attack at Brussels Airport on March 22, 2016, explores the experiences of police officers concerning (a) their coping strategies after the terrorist attack and (b) the (in)formal workplace social support that affects their resilience. A qualitative, exploratory research method was used to answer the research questions, consisting of a content analysis of the police organization, participant observation, and 31 in-depth interviews with police officers who were on active duty during the terrorist attack. This research shows that the interviewed police officers primarily adopt engagement coping strategies after the terrorist attack. The most cited one is talking to others, followed by engaging in positive action, behavioral distraction, self-evaluation, positive self-talk, and emotional numbing. Second, this study revealed that (in)formal workplace social support plays a significant role in fostering police officers’ resilience after a terrorist attack. Informally, getting acknowledged for the efforts made during the terrorist attack and for psychological loss afterward is crucial in this process. Besides, emotional support from both colleagues and supervisors is identified as essential. However, the ruling ‘macho’ culture within the police organization is perceived as hampering to talk freely about emotions. Formally, respondents place emphasis on a proper debriefing and a well-organized, easily accessible psychological aftercare. This scientific contribution provides insight into the best practices the police organization can apply to promote its employees’ resilience and performance