De contrasterende Holocene sediment successie langsheen het westelijk en oostelijk deel van de Belgische kust: oorzaak en gevolgen = The contrasting Holocene sediment succession along the western and eastern part of the Belgian coast: cause and consequences

A series of drillings and cone penetration tests carried out for the sea wall fortification along the shoreline was subject to a sedimentological and stratigraphical examination, revealing a difference in sediment succession between the western and the eastern part. In the western part, the Holocene sequence along the shoreline is entirely made up of coastal barrier deposits. In the eastern direction, starting from Middelkerke, such deposits are lacking, and the Holocene sequence consists of mudflat clay and peat layers incised by late Holocene tidal channels filled with sand and/or mud. This indicates considerable coastal erosion during the late Holocene in the eastern part. The difference in sediment succession may be caused by the very different morphology of the pre-Holocene subsoil in the west and the east. A fluvial valley characterizes the west. In the east, on the other hand, the Pleistocene subsoil consists of coversands, which may have formed a headland probably extending far to the north. In the palaeovalley, a tidal flat was formed from the start of the Holocene transgression, while the eastern headland did not come under the influence of the Holocene transgression until much later. Less sediment supply by interception of the longshore drift and a lowered shoreface profile caused strong shoreface erosion from the time when, 2400 to 2000 years ago, the tidal environment re-occupied the coastal plain. This shoreface erosion most probably affected the headland in a timespan of 1000 to 2000 years.This situation resulted in the eastern part of the coast still being subject to coastal erosion and consequently much more vulnerable than the western part

Adjunctive quetiapine for serotonin reuptake inhibitor-resistant obsessive-compulsive disorder: A meta-analysis of randomised controlled treatment trials

Small studies have shown positive effects from adding a variety of antipsychotic agents in patients with obsessive–compulsive disorder who are unresponsive to treatment with serotonin reuptake inhibitors. The evidence, however, is contradictory. This paper reports a meta-analysis of existing double-blind randomized placebo-controlled studies looking at the addition of the second-generation antipsychotic quetiapine in such cases. Three studies fulfilled the inclusion criteria. Altogether 102 individuals were subjected to analysis using Review Manager (4.2.7). The results showed evidence of efficacy for adjunctive quetiapine (< 400 mg/day) on the primary efficacy criterion, measured as changes from baseline in total Yale–Brown Obsessive Compulsive Scale scores (P = 0.008), the clinical significance of which was limited by between-study heterogeneity. The mechanism underlying the effect may involve serotonin and/or dopamine neurotransmission

Local Runup Amplification By Resonant Wave Interactions

Until now the analysis of long wave runup on a plane beach has been focused on finding its maximum value, failing to capture the existence of resonant regimes. One-dimensional numerical simulations in the framework of the Nonlinear Shallow Water Equations (NSWE) are used to investigate the Boundary Value Problem (BVP) for plane and non-trivial beaches. Monochromatic waves, as well as virtual wave-gage recordings from real tsunami simulations, are used as forcing conditions to the BVP. Resonant phenomena between the incident wavelength and the beach slope are found to occur, which result in enhanced runup of non-leading waves. The evolution of energy reveals the existence of a quasi-periodic state for the case of sinusoidal waves, the energy level of which, as well as the time required to reach that state, depend on the incident wavelength for a given beach slope. Dispersion is found to slightly reduce the value of maximum runup, but not to change the overall picture. Runup amplification occurs for both leading elevation and depression waves.Comment: 10 pages, 7 Figures. Accepted to Physical Review Letters. Other author's papers can be downloaded at http://www.lama.univ-savoie.fr/~dutykh

Conceptual inconsistencies in finite-dimensional quantum and classical mechanics

Utilizing operational dynamic modeling [Phys. Rev. Lett. 109, 190403 (2012); arXiv:1105.4014], we demonstrate that any finite-dimensional representation of quantum and classical dynamics violates the Ehrenfest theorems. Other peculiarities are also revealed, including the nonexistence of the free particle and ambiguity in defining potential forces. Non-Hermitian mechanics is shown to have the same problems. This work compromises a popular belief that finite-dimensional mechanics is a straightforward discretization of the corresponding infinite-dimensional formulation.Comment: 5 pages, 2 figure

Enhancement and suppression of tunneling by controlling symmetries of a potential barrier

We present a class of 2D systems which shows a counterintuitive property that contradicts a semi classical intuition: A 2D quantum particle "prefers" tunneling through a barrier rather than traveling above it. Viewing the one particle 2D system as the system of two 1D particles, it is demonstrated that this effect occurs due to a specific symmetry of the barrier that forces excitations of the interparticle degree of freedom that, in turn, leads to the appearance of an effective potential barrier even though there is no "real" barrier. This phenomenon cannot exist in 1D.Comment: 10 pages and 7 figure

Wigner phase space distribution as a wave function

We demonstrate that the Wigner function of a pure quantum state is a wave function in a specially tuned Dirac bra-ket formalism and argue that the Wigner function is in fact a probability amplitude for the quantum particle to be at a certain point of the classical phase space. Additionally, we establish that in the classical limit, the Wigner function transforms into a classical Koopman-von Neumann wave function rather than into a classical probability distribution. Since probability amplitude need not be positive, our findings provide an alternative outlook on the Wigner function's negativity.Comment: 6 pages and 2 figure

Assessment of occlusive arterial disease of abdominal aorta and lower extremities arteries: value of multidetector CT angiography using an adaptive acquisition method

We evaluated 16-detector-row CT in the assessment of occlusive peripheral arterial disease (PAD) of the abdominal aorta and lower extremities using an adaptive method of acquisition to optimise arterial enhancement especially for the distal foot arteries. Thirty-four patients underwent transcatheter angiography (TCA) and CT angiography within 15days. For each patient, table speed and rotation were selected according to the calculated optimal transit time of contrast material obtained after a single bolus test and two dynamic acquisitions at aorta and popliteal arteries. Analysis included image quality and detection of stenosis equal or greater than 50% on a patient basis and on an arterial segment basis. Sensitivity and specificity of CT were calculated with the TCA considered as the standard of reference. CT was conclusive in all segments with no technical failures even in difficult cases with occluded bypasses and aneurysms. On patient-basis analysis, the overall sensitivity and specificity to detect significant stenosis greater than 50% were both 100%. Segmental analysis shows high values of sensitivity and specificity ranging from 91 to 100% and from 81 to 100%, respectively, including distal pedal arteries. Sixteen-detector-row CT angiography using an adaptive acquisition improves the image quality and provides a reliable non-invasive technique to assess occlusive peripheral arterial disease, including distal foot arterie