Clearing price distributions in call auctions

We propose a model for price formation in financial markets based on clearing of a standard call auction with random orders, and verify its validity for prediction of the daily closing price distribution statistically. The model considers random buy and sell orders, placed following demand- and supply-side valuation distributions; an equilibrium equation then leads to a distribution for clearing price and transacted volume. Bid and ask volumes are left as free parameters, permitting possibly heavy-tailed or very skewed order flow conditions. In highly liquid auctions, the clearing price distribution converges to an asymptotically normal central limit, with mean and variance in terms of supply/demand-valuation distributions and order flow imbalance. By means of simulations, we illustrate the influence of variations in order flow and valuation distributions on price/volume, noting a distinction between high- and low-volume auction price variance. To verify the validity of the model statistically, we predict a year's worth of daily closing price distributions for 5 constituents of the Eurostoxx 50 index; Kolmogorov-Smirnov statistics and QQ-plots demonstrate with ample statistical significance that the model predicts closing price distributions accurately, and compares favourably with alternative methods of prediction

A virtual place of memory: Virtual reality as a method for communicating conflicted heritage at Camp Westerbork

An important goal of the project Accessing Campscapes: inclusive strategies for using European Conflicted Heritage (iC-ACCESS), has been to develop inclusive approaches for the presentation and communication of contending perspectives on Nazi and Stalinist sites (Dolghin et al. 2017). A key objective for treating these 'heritagescapes' has been to 'develop state-of-the-art strategies and implement innovative tools which provide sustainable in-situ and virtual forms of investigation, presentation and representation' (Van der Laarse 2020). A central issue which is gaining increasing attention in heritage studies and management is the dilemma of preserving and exhibiting material remnants of Wehrmacht and SS-barracks or residencies at Holocaust memorial camps which are generally framed as victimhood sites. The Commander's house at Herinneringscentrum Westerbork is a case in point and can be placed in different perspectives on the history of the camp terrain and all related sensibilities on its meaning as an object of heritage. In order to realise an application that can accommodate these perspectives, iC-ACCESS project leader Prof. dr. R. van der Laarse contracted two laboratories specialised consecutively in 3D visualisation technologies and spatial information to cooperate on its development, the 4D Research Lab (University of Amsterdam, The Netherlands) and the SPINlab (Vrije Universiteit Amsterdam). This paper illustrates the ideas, discussions and choices related to the production of the 'Campscapes – Westerbork Commander's House App', provides a concise technical description of the actual application and presents a short prospection on potential future developments

The Vector-Tensor Supermultiplet with Gauged Central Charge

The vector-tensor multiplet is coupled off-shell to an N=2 vector multiplet such that its central charge transformations are realized locally. A gauged central charge is a necessary prerequisite for a coupling to supergravity and the strategy underlying our construction uses the potential for such a coupling as a guiding principle. The results for the action and transformation rules take a nonlinear form and necessarily include a Chern-Simons term. After a duality transformation the action is encoded in a homogeneous holomorphic function consistent with special geometry.Comment: 8 pages, LATE

Europa gaat op jacht naar zijn eigen metalen: om de omslag naar duurzame energie te maken, zijn allerlei metalen nodig, zoals lithium. Kan Europa op dat vlak zelfvoorzienend worden?

Industrial Ecolog

The galaxy environment in GAMA G3C groups using the Kilo Degree Survey Data Release 3

We aim to investigate the galaxy environment in GAMA Galaxy Groups Catalogue (G3C) using a volume-limited galaxy sample from the Kilo Degree Survey Data Release 3. The k-Nearest Neighbour technique is adapted to take into account the probability density functions (PDFs) of photometric redshifts in our calculations. This algorithm was tested on simulated KiDS tiles, showing its capability of recovering the relation between galaxy colour, luminosity and local environment. The characterization of the galaxy environment in G3C groups shows systematically steeper density contrasts for more massive groups. The red galaxy fraction gradients in these groups is evident for most of group mass bins. The density contrast of red galaxies is systematically higher at group centers when compared to blue galaxy ones. In addition, distinct group center definitions are used to show that our results are insensitive to center definitions. These results confirm the galaxy evolution scenario which environmental mechanisms are responsible for a slow quenching process as galaxies fall into groups and clusters, resulting in a smooth observed colour gradients in galaxy systems.Comment: 14 pages, Accepted to MNRA

Structure and localization of mRNA encoding a pigment dispersing hormone (PDH) in the eyestalk of the crayfish Orconectes limosus

AbstractThe pigment-dispersing hormone (PDH) is produced in the eyestalks of Crustacea where it induces light-adapting movements of pigment in the compound eye and regulates the pigment dispersion in the chromatophores. To study this hormone at the mRNA level, we cloned and sequenced cDNA encoding PDH in the crayfish Orconectes limosus. The structure of the PDH preprohormone consists of a signal peptide, a PDH precursor-related peptide (PPRP) and the highly conserved PDH peptide at the carboxy-terminal end. In situ hybridization in combination with immunocytochemistry revealed four cell clusters expressing PDH in the optic ganglia of the eyestalk. Three clusters stained both with the PDH cRNA probe and the PDH antiserum, however, the perikarya in the lamina ganglionaris (LG) only stained with the PDH antiserum, suggesting the presence of a PDH-like peptide in the LG

Describing and measuring leadership within school teams by applying a social network perspective

Despite the growing number of studies that acknowledge a crucial role of distributed leadership within schools, limited knowledge exists on how to describe and measure this multi-faceted concept. In a social network study with 130 respondents, from 14 Dutch school teams carrying out collaborative innovation, we theoretically describe three core aspects of the social interaction process of distributed leadership: collective, dynamic, or relational. Furthermore, we empirically explore how to measure all these three aspects of distributed leadership from a social network perspective, whereas most research focuses on either collective or dynamic. Our findings indicate that three network measures (density, reciprocity, indegree centralization) form a coherent combination to measure distributed leadership in school teams in terms of collective, relational, and dynamic, respectively. Furthermore, based on the combination of measures we found differences in distributed leadership between school teams. Thus, adding the relational aspect in addition to the collective and dynamic aspects seems to be informative to measure distributed leadership. Our study motivates to take a social network perspective, instead of the mostly used aggregation approaches, to measure distributed leadership in school teams