The development of children's problem behaviors: A twin-singlton comparison and the influence of parental divorce

Twin-family studies have largely contributed to our understanding of the etiology of behavioral and emotional problems in childhood. From these studies we learned that almost every behavioral or psychological trait is ‘heritable’ to some extent. We also learned that both nature and nurture play important roles in the etiology of behavioral and emotional problems, and that these factors may act independently of one another as well as interactively (i.e., gene-environment interplay). Moreover, twin studies have given insight into the important distinction between environmental factors shared by siblings (e.g., parental socio-economic status) and those not shared by siblings (e.g., peer groups) (Boomsma, Busjahn, & Peltonen, 2002; Hudziak & Faraone, 2010). An important assumption that is made when using twin data is that results from twin samples can be generalized to singleton populations. However, the validity of this assumption needs to be examined

Does Planck mass run on the cosmological horizon scale?

Einstein's theory of general relativity, which contains a universal value of the Planck mass, has been so far successfully invoked to explain gravitational dynamics from sub-millimeter scales to the scale of the cosmological horizon. However, one may envisage that in alternative theories of gravity, the effective value of the Planck mass (or Newton's constant), which quantifies the coupling of matter to metric perturbations, can run on the cosmological horizon scale. In this letter, we study the consequences of a glitch in the Planck mass from sub-horizon to super-horizon scales. We first give three examples of models that naturally exhibit this feature, and then show that current cosmological observations severely constrain this glitch to less than 1.2%. This is the strongest constraint to date, on natural (i.e. non-fine-tuned) deviations from Einstein gravity on the cosmological horizon scale.Comment: 5 pages, 1 figur

Non-linear Matter Spectra in Coupled Quintessence

We consider cosmologies in which a dark-energy scalar field interacts with cold dark matter. The growth of perturbations is followed beyond the linear level by means of the time-renormalization-group method, which is extended to describe a multi-component matter sector. Even in the absence of the extra interaction, a scale-dependent bias is generated as a consequence of the different initial conditions for baryons and dark matter after decoupling. The effect is enhanced significantly by the extra coupling and can be at the 2-3 percent level in the range of scales of baryonic acoustic oscillations. We compare our results with N-body simulations, finding very good agreement.Comment: 20 pages, 6 figures, typo correcte

Phenomenology of Gravitational Aether as a solution to the Old Cosmological Constant Problem

One of the deepest and most long-standing mysteries in physics has been the huge discrepancy between the observed vacuum density and our expectations from theories of high energy physics, which has been dubbed the Old Cosmological Constant problem. One proposal to address this puzzle at the semi-classical level is to decouple quantum vacuum from space-time geometry via a modification of gravity that includes an incompressible fluid, known as Gravitational Aether. In this paper, we discuss classical predictions of this theory along with its compatibility with cosmological and experimental tests of gravity. We argue that deviations from General Relativity (GR) in this theory are sourced by pressure or vorticity. In particular, the theory predicts that the gravitational constant for radiation is 33% larger than that of non-relativistic matter, which is preferred by (most) cosmic microwave background (CMB), Lyman-Alpha forest, and Lithium-7 primordial abundance observations, while being consistent with other cosmological tests at ~2-sigma level. It is further shown that all Parametrized Post-Newtonian (PPN) parameters have the standard GR values aside from the anomalous coupling to pressure, which has not been directly measured. A more subtle prediction of this model (assuming irrotational aether) is that the (intrinsic) gravitomagnetic effect is 33% larger than GR prediction. This is consistent with current limits from LAGEOS and Gravity Probe B at ~2-sigma level

Shifting the Universe: Early Dark Energy and Standard Rulers

The presence of dark energy at high redshift influences both the cosmic sound horizon and the distance to last scattering of the cosmic microwave background. We demonstrate that through the degeneracy in their ratio, early dark energy can lie hidden in the CMB temperature and polarization spectra, leading to an unrecognized shift in the sound horizon. If the sound horizon is then used as a standard ruler, as in baryon acoustic oscillations, then the derived cosmological parameters can be nontrivially biased. Fitting for the absolute ruler scale (just as supernovae must be fit for the absolute candle magnitude) removes the bias but decreases the leverage of the BAO technique by a factor 2.Comment: 6 pages, 3 figure

Without Pictorial Detour: Benjamin, Mies and the Architectural Image

It can be argued that architectural knowledge was of crucial importance to Walter Benjamin for elaborating his version of an anthropological historical materialism. Between 1929 and 1931 he encounters two publications on architectural history which had a decisive impact on his ensuing works: Sigfried Giedion’s Bauen in Frankreich, Bauen in Eisen, Bauen in Eisenbeton (1928) and Carl Linfert’s Die Grundlagen der Architekturzeichnung (1931). It can be argued that both works played a role in affirming, if not developing his historical method of awakening the dreaming collective into a ‘now of recognisability,’ a method which one can argue is based on a specific image-based epistemology. Especially the architectural image, whether in the form of a printed drawing, photographic illustration, or an actual built object, appears to have been crucial for placing the history of media technologies (architecture being one of these media) in a constellation with the ‘archaic symbol-worlds of mythologies.’ If architecture is, as Benjamin claims in his initial notes for The Arcades Project, ‘the most important testimony to latent “mythology,”’ the architectural image might very well be the agent that causes the moment of awakening, the instance when a constellation between technology and ancient symbol worlds is formed. In the second part of this essay, I will attempt to elaborate such a designation for the specificity of the architectural image by analysing a number of Ludwig Mies van der Rohe’s drawings and collages from the 1920s as architectural images in the Benjaminian sense

Defining microvascular injury in acute myocardial infarction and response after cell therapy using cardiovascular magnetic resonance imaging

Rossum, A.C. van [Promotor]Beek, A.M. [Copromotor]Nijveldt, R. [Copromotor