742 research outputs found
In gesprek met Iris Kensmil: Cultuurkritiek in kunst, theorie en praktijk
No full textThis article is focused on Professor Buikema’s intellectual oeuvre and the relation between art and politics as it materialised in MOED (Museum of Equality and Difference). Astrid Kerchman and Rosa Wevers, MOED’s former project coordinators, reflect on their collaboration with Buikema through an interview with artist Iris Kensmil on the important role of art in complex social issues relating to emancipation, representation, and resistance. Drawing on the interview with Kensmil and Buikema’s Revolts in Cultural Critique (2020), Alessandra Benedicty-Kokken reflects on the meaning of feminist leadership within an institutional context
Delayed X-Ray Brightening Accompanied by Variable Ionized Absorption Following a Tidal Disruption Event
No full textSupermassive black holes can experience super-Eddington peak mass fallback rates following the tidal disruption of a star. The theoretical expectation is that part of the infalling material is expelled by means of an accretion disk wind, whose observational signature includes blueshifted absorption lines of highly ionized species in X-ray spectra. To date, however, only one such ultrafast outflow (UFO) has been reported in the tidal disruption event (TDE) ASASSN–14li. Here we report on the discovery of a transient absorption-like signature in X-ray spectra of the TDE AT2020ksf/Gaia20cjk (at a redshift of z = 0.092), following an X-ray brightening ∼230 days after UV/optical peak. We find that while no statistically significant absorption features are present initially, they appear on a timescale of several days and remain detected up to 770 days after peak. Simple thermal continuum models, combined with a power-law or neutral absorber, do not describe these features well. Adding a partial-covering, low-velocity ionized absorber improves the fit at early times but fails at late times. A high-velocity ( v _w ∼ 42,000 km s ^−1 ), ionized absorber (UFO) provides a good fit to all data. The few-day timescale of variability is consistent with expectations for a clumpy wind. We discuss several scenarios that could explain the X-ray delay, as well as the potential for larger-scale wind feedback. The serendipitous nature of the discovery could suggest a high incidence of UFOs in TDEs, alleviating some of the tension with theoretical expectations
The hydrodynamic stability of a ballast filled mattress in an offshore environment
No full textIn this research the hydrodynamic stability of a ballast filled mattress under waves is investigated. There is checked if this can be applied as scour protection around a suction bucket jacket: an offshore wind turbine foundation that uses a vacuum to suck itself in position. A ballast filled mattress is a mattress made from polyester with so called spacer threads that take up tensile forces when the mattress is trying to deform. The combination of stiffness and combined weight make the ballast filled mattress a possible new scour protection.JIP-HaSProCivil Engineering | Hydraulic Engineerin
Metabolic cutis laxa syndromes
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98094.pdf (Publisher’s version ) (Open Access)Cutis laxa is a rare skin disorder characterized by wrinkled, redundant, inelastic and sagging skin due to defective synthesis of elastic fibers and other proteins of the extracellular matrix. Wrinkled, inelastic skin occurs in many cases as an acquired condition. Syndromic forms of cutis laxa, however, are caused by diverse genetic defects, mostly coding for structural extracellular matrix proteins. Surprisingly a number of metabolic disorders have been also found to be associated with inherited cutis laxa. Menkes disease was the first metabolic disease reported with old-looking, wrinkled skin. Cutis laxa has recently been found in patients with abnormal glycosylation. The discovery of the COG7 defect in patients with wrinkled, inelastic skin was the first genetic link with the Congenital Disorders of Glycosylation (CDG). Since then several inborn errors of metabolism with cutis laxa have been described with variable severity. These include P5CS, ATP6V0A2-CDG and PYCR1 defects. In spite of the evolving number of cutis laxa-related diseases a large part of the cases remain genetically unsolved. In metabolic cutis laxa syndromes the clinical and laboratory features might partially overlap, however there are some distinct, discriminative features. In this review on metabolic diseases causing cutis laxa we offer a practical approach for the differential diagnosis of metabolic cutis laxa syndromes
Candidate Halpha sources in GBS
No full textItem does not contain fulltextWe use optical photometry in three filters (r', i' and Halpha to create (r'-i', r'-Halpha) colour-colour diagrams of point sources in the Galactic Bulge Survey Fields (Jonker et al., 2011, Cat. J/ApJS/194/18; 2014, Cat. J/ApJS/210/18; Wevers et al. 2016, Cat. J/MNRAS/458/4530). We identify 1337 emission line candidates, 336 absorption line candidates, and 389 blue outliers in the catalogue. These samples likely contain a plethora of sources, ranging from chromospherically active stars, subluminous hot dwarfs, white dwarfs, CVs, planetary nebulae, LMXBs and variable stars to background AGN. (3 data files)
Assessing concentration and diversification in portfolio credit risk models
No full textThis thesis explores existing and proposes new methods for assessing concentration risk in default-only credit risk models. Within the existing methods, the analytic Granularity Adjustment is studied in the single factor Gaussian threshold and in the CreditRisk+ framework. These adjustments are tested on a sample portfolio in the presence of recovery risk, and we show that the CreditRisk+ adjustment is more conservative than the Gaussian threshold adjustment. Furthermore, we show that in the presence of recovery risk, the accuracy of the adjustment on exposure level deteriorates. Additionally, the Granularity Adjustment is extended to an independent single factor \textit{t}-threshold model to account for heavier tailed asset returns. Based on the independent single factor \textit{t}-threshold model, we suggest an ASRF equivalent that could serve as an alternative to the current IRB framework. Although much existing literature is focusing on developing analytical methods for measuring concentration risk, recent advances in computational speed make Monte Carlo methods an interesting substitute for measuring concentration risk. To this extend, we propose a split between Monte Carlo based Economic and Regulatory Concentration Risk and show that these measures do not coincide for a given portfolio. This method involves a novel way of assessing idiosyncratic risk in multi factor frameworks. In order to assess sector concentration risk, this thesis proposes a Diversification Factor and a Capital Diversification Index as risk management tools. Finally, this thesis provides a clear account of the effects of concentration, diversification and recovery risk on the portfolio loss distribution for both Gaussian and \textit{t}-threshold models. This thesis was carried out in close cooperation with ING Bank.Applied Mathematics | Financial Engineerin
Being Pakeha: The Politics of Location
No full textDiscusses the work and influence of New Zealand historian Michael King, in particular 'Being Pakeha' and 'Being Pakeha Now'. While commending King on his desire to explore and articulate the Maori worldview the author believes that the views and interpretations given are built on a historically privileged position.</jats:p
Urinary dopamine in aromatic L-amino acid decarboxylase deficiency: the unsolved paradox.
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87540.pdf (Publisher’s version ) (Open Access)INTRODUCTION: In aromatic L-amino acid decarboxylase (AADC) deficiency, a neurotransmitter biosynthesis defect, paradoxical normal or increased levels of urinary dopamine have been reported. Genotype/phenotype correlations or alternative metabolic pathways may explain this remarkable finding, but were never studied systematically. METHODS: We studied the mutational spectrum and urinary dopamine levels in 20 patients with AADC-deficiency. Experimental procedures were designed to test for alternative metabolic pathways of dopamine production, which included alternative substrates (tyramine and 3-methoxytyrosine) and alternative enzymes (tyrosinase and CYP2D6). RESULTS/DISCUSSION: In 85% of the patients the finding of normal or increased urinary levels of dopamine was confirmed, but a relation with AADC genotype could not be identified. Renal microsomes containing CYP2D were able to convert tyramine into dopamine (3.0 nmol/min/g protein) but because of low plasma levels of tyramine this is an unlikely explanation for urinary dopamine excretion in AADC-deficiency. No evidence was found for the production of dopamine from 3-methoxytyrosine. Tyrosinase was not expressed in human kidney. CONCLUSION: Normal or increased levels of urinary dopamine are found in the majority of AADC-deficient patients. This finding can neither be explained by genotype/phenotype correlations nor by alternative metabolic pathways, although small amounts of dopamine may be formed via tyramine hydroxylation by renal CYP2D6. CYP2D6-mediated conversion of tyramine into dopamine might be an interesting target for the development of new therapeutic strategies in AADC-deficiency.01 december 201
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