Translation and articulation in biological motion perception

Recent models of biological motion processing focus on the articulational aspect of human walking investigated by point-light figures walking in place. However, in real human walking, the change in the position of the limbs relative to each other (referred to as articulation) results in a change of body location in space over time (referred to as translation). In order to examine the role of this translational component on the perception of biological motion we designed three psychophysical experiments of facing (leftward/rightward) and articulation discrimination (forward/backward and leftward/rightward) of a point-light walker viewed from the side, varying translation direction (relative to articulation direction), the amount of local image motion, and trial duration. In a further set of a forward/backward and a leftward/rightward articulation task, we additionally tested the influence of translational speed, including catch trials without articulation. We found a perceptual bias in translation direction in all three discrimination tasks. In the case of facing discrimination the bias was limited to short stimulus presentation. Our results suggest an interaction of articulation analysis with the processing of translational motion leading to best articulation discrimination when translational direction and speed match articulation. Moreover, we conclude that the global motion of the center-of-mass of the dot pattern is more relevant to processing of translation than the local motion of the dots. Our findings highlight that translation is a relevant cue that should be integrated in models of human motion detection

Morphodynamic variability of high-energy macrotidal beaches, Cornwall, UK

The full text is under embargo until 01.04.16

Self-esteem in Early Adolescence as Predictor of Depressive Symptoms in Late Adolescence and Early Adulthood:The Mediating Role of Motivational and Social Factors

Ample research has shown that low self-esteem increases the risk to develop depressive symptoms during adolescence. However, the mechanism underlying this association remains largely unknown, as well as how long adolescents with low self-esteem remain vulnerable to developing depressive symptoms. Insight into this mechanism may not only result in a better theoretical understanding but also provide directions for possible interventions. To address these gaps in knowledge, we investigated whether self-esteem in early adolescence predicted depressive symptoms in late adolescence and early adulthood. Moreover, we investigated a cascading mediational model, in which we focused on factors that are inherently related to self-esteem and the adolescent developmental period: approach and avoidance motivation and the social factors social contact, social problems, and social support. We used data from four waves of the TRAILS study (N = 2228, 51% girls): early adolescence (mean age 11 years), middle adolescence (mean age 14 years), late adolescence (mean age 16 years), and early adulthood (mean age 22 years). Path-analyses showed that low self-esteem is an enduring vulnerability for developing depressive symptoms. Self-esteem in early adolescence predicted depressive symptoms in late adolescence as well as early adulthood. This association was independently mediated by avoidance motivation and social problems, but not by approach motivation. The effect sizes were relatively small, indicating that having low self-esteem is a vulnerability factor, but does not necessarily predispose adolescents to developing depressive symptoms on their way to adulthood. Our study contributes to the understanding of the mechanisms underlying the association between self-esteem and depressive symptoms, and has identified avoidance motivation and social problems as possible targets for intervention

Predicting beach rotation using multiple atmospheric indices

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Surface InP Quantum Dots: Effect of Morphology on the Photoluminescence Sensitivity

Abstract An investigation of the photoluminescence sensitivity of epitaxial surface InP quantum dots grown on In 0.48 Ga 0.52 P buffer layer lattice matched to GaAs substrate is presented. The emission wavelength of such quantum dots can be defined through the quantum dot dimensions in the range 750 – 865 nm. Quantum dot exposure to polar solvent vapour (methanol and ethanol) determines in any investigated case a luminescence intensity enhancement. The response to alcohol vapours affects only the luminescence intensity while peak position and shape remain unchanged. Optimization of the sensor response by tailoring quantum dots size and coverage has been demonstrated

Affect, worry, and sleep:Between- and within-subject associations in a diary study

Contains fulltext : 240641.pdf (Publisher’s version ) (Open Access)Objectives: Little is known about the daily associations between affect, worry, and sleep problems, and previous studies did not distinguish differences between persons from differences within persons. We examined bidirectional associations of daily unpleasant affect (UA), pleasant affect (PA), and worry with sleep problems at both the between- and the within-persons level. Methods: The data came from a web-based diary study called "HowNutsAreTheDutch", in which 1,165 respondents filled out an online questionnaire 3 times a day, for 30 consecutive days. Daily levels of affect and worry were calculated by averaging the morning, afternoon, and evening scores. Sleep problems were assessed in the morning, with regard to the previous night. Bidirectional associations between affect, worry, and sleep problems were tested using Dynamic Structural Equation Modeling (DSEM). Results: High UA, low PA, high worry, and poor sleep were strongly associated at the between-person level. At the within-person level, better-than-usual sleep at night significantly predicted lower UA (ß = -0.31, p < .001) and worry (ß = -0.16, p < .001) and higher PA (ß = 0.29, p < .001) during the subsequent day. The effects from daytime affect and worry to sleep the subsequent night were also significant, but considerably weaker. Limitations: Women and highly educated individuals were overrepresented in our sample. Conclusions: Persons who sleep worse than usual at night are likely to experience less PA and more UA and worry the following day. Daytime UA, PA, and worry also predict sleep problems during the following night, but to a lesser extent than the reverse effects.8 p

Coupling cross-shore and longshore sediment transport to model storm response along a mixed sand-gravel coast under varying wave directions

publisher: Elsevier articletitle: Coupling cross-shore and longshore sediment transport to model storm response along a mixed sand-gravel coast under varying wave directions journaltitle: Coastal Engineering articlelink: http://dx.doi.org/10.1016/j.coastaleng.2017.09.009 content_type: article copyright: © 2017 Elsevier B.V. All rights reserved

The extreme 2013/2014 winter storms: Beach recovery along the southwest coast of England

publisher: Elsevier articletitle: The extreme 2013/2014 winter storms: Beach recovery along the southwest coast of England journaltitle: Marine Geology articlelink: http://dx.doi.org/10.1016/j.margeo.2016.10.011 content_type: article copyright: © 2016 The Authors. Published by Elsevier B.V

High-spectral-resolution pulsed photoluminescence study of molecular-beam-epitaxy-grown GaAs/AlxGa1−xAs multi-quantum-well structures using a very-low-power tunable pulsed dye laser

Ultralow-power, high-resolution, pulsed-laser photoluminescence (PL) and photoluminescence excitation (PLE) spectroscopies were carried out in molecular-beam-epitaxial GaAs/AlxGa1−xAs multi-quantum-well structures at 5 K. Fine structures were observed for the first time in the PLE spectra, both in the heavy-hole and light-hole excitonic regions. Most of the fine structures are considered to arise from monolayer fluctuations in the thicknesses of the GaAs wells. Dramatic changes in the line shapes and the peak positions of the PL and PLE spectra were observed by applying selective PL detection and excitation spectroscopic techniques