Causal Consistency of Structural Equation Models

Complex systems can be modelled at various levels of detail. Ideally, causal models of the same system should be consistent with one another in the sense that they agree in their predictions of the effects of interventions. We formalise this notion of consistency in the case of Structural Equation Models (SEMs) by introducing exact transformations between SEMs. This provides a general language to consider, for instance, the different levels of description in the following three scenarios: (a) models with large numbers of variables versus models in which the `irrelevant' or unobservable variables have been marginalised out; (b) micro-level models versus macro-level models in which the macro-variables are aggregate features of the micro-variables; (c) dynamical time series models versus models of their stationary behaviour. Our analysis stresses the importance of well specified interventions in the causal modelling process and sheds light on the interpretation of cyclic SEMs.Comment: equal contribution between Rubenstein and Weichwald; accepted manuscrip

Detection of movement related cortical potentials from EEG using constrained ICA for brain-computer interface applications

The movement related cortical potential (MRCP), a slow cortical potential from the scalp electroencephalogram (EEG), has been used in real-time brain-computer-interface (BCI) systems designed for neurorehabilitation. Detecting MPCPs in real time with high accuracy and low latency is essential in these applications. In this study, we propose a new MRCP detection method based on constrained independent component analysis (cICA). The method was tested for MRCP detection during executed and imagined ankle dorsiflexion of 24 healthy participants, and compared with four commonly used spatial filters for MRCP detection in an offline experiment. The effect of cICA and the compared spatial filters on the morphology of the extracted MRCP was evaluated by two indices quantifying the signal-to-noise ratio and variability of the extracted MRCP. The performance of the filters for detection was then directly compared for accuracy and latency. The latency obtained with cICA (-34 ± 29 ms motor execution (ME) and 28 ± 16 ms for motor imagery (MI) dataset) was significantly smaller than with all other spatial filters. Moreover, cICA resulted in greater true positive rates (87.11 ± 11.73 for ME and 86.66 ± 6.96 for MI dataset) and lower false positive rates (20.69 ± 13.68 for ME and 19.31 ± 12.60 for MI dataset) compared to the other methods. These results confirm the superiority of cICA in MRCP detection with respect to previously proposed EEG filtering approaches

Experiences of maltreatment in childhood and attention to facial emotions in healthy young women

Using reaction-time measures, research on the relationship between childhood maltreatment and biased attention to emotional stimuli in adults has obtained inconsistent results. To help clarify this issue, we conducted an eye-tracking study on the link between childhood maltreatment and allocation of attention to facial emotions analyzing gaze behavior in addition to manual reactions. In contrast to prior investigations, we excluded individuals with tendencies to minimize maltreatment experiences from analyses. Gaze behavior and manual response time of 58 healthy women were examined in a dot-probe task in which pairs of emotional (happy, sad, or disgusted) and neutral faces were presented. In our analyses, participants’ affectivity, level of alexithymia, and intelligence were controlled. Entry time and dwell time on facial expressions were used as indicators of attention allocation. Childhood maltreatment showed no effect on response latencies but was associated with shorter entry times on emotional faces and shorter dwell time on disgusted faces. Experiences of childhood maltreatment seem to be linked to an increased early vigilance to emotional social signals and to an attentional avoidance of hostile facial expressions at a later stage of perception. The present results suggest a vigilance-avoidance pattern of attention allocation associated with childhood maltreatment

Environmental drivers of distribution and reef development of the Mediterranean coral Cladocora caespitosa

Cladocora caespitosa is the only Mediterranean scleractinian similar to tropical reef-building corals. While this species is part of the recent fossil history of the Mediterranean Sea, it is currently considered endangered due to its decline during the last decades. Environmental factors affecting the distribution and persistence of extensive bank reefs of this endemic species across its whole geographic range are poorly understood. In this study, we examined the environmental response of C. caespitosa and its main types of assemblages using ecological niche modeling and ordination analysis. We also predicted other suitable areas for the occurrence of the species and assessed the conservation effectiveness of Mediterranean marine protected areas (MPAs) for this coral. We found that phosphate concentration and wave height were factors affecting both the occurrence of this versatile species and the distribution of its extensive bioconstructions in the Mediterranean Sea. A set of factors (diffuse attenuation coefficient, calcite and nitrate concentrations, mean wave height, sea surface temperature, and shape of the coast) likely act as environmental barriers preventing the species from expansion to the Atlantic Ocean and the Black Sea. Uncertainties in our large-scale statistical results and departures from previous physiological and ecological studies are also discussed under an integrative perspective. This study reveals that Mediterranean MPAs encompass eight of the ten banks and 16 of the 21 beds of C. caespitosa. Preservation of water clarity by avoiding phosphate discharges may improve the protection of this emblematic species.Spanish Ministry of Economy and Competitiveness [CTM2014-57949-R]info:eu-repo/semantics/publishedVersio

Development and analysis of microstructures for the transplantation of thermally sprayed coatings

Thermally sprayed coatings and tribological surfaces are a point of interest in many industrial sectors. They are used for better wear resistance of lightweight materials or for oil retention on surfaces. Lightweight materials are often used in the automotive industry as a weight-saving solution in the production of engine blocks. For this, it is necessary to coat the cylinder liners to ensure wear resistance. In most cases, the coating is sprayed directly onto the surface. Previous research has shown that it is possible to transfer these coatings inversely onto other surfaces. This was achieved with plasma sprayed coatings which were transplanted onto pressure-casted surfaces. These transplanted surfaces exhibited better adhesive strength, smoother surfaces, and lower form deviation compared to directly coated surfaces. Additionally, it was shown that even microstructures of a surface coated by plasma spraying can be transferred to pressure-casted surfaces. This paper presents the development and micromilling of different microstructures for transferring thermally sprayed coatings onto pressure-casted surfaces. In the development process, microstructures with different shapes and aspect ratios as well as thin tribological surfaces are designed in order to evaluate the advantages and limitations of the transplantation process. In subsequent experiments, the micromilling process and a simulation of the coating transplantation are presented and analyzed.DFG/Mo 881/9-1DFG/Bi 498/6-

Heterobimetallic conducting polymers based on salophen complexes via electrosynthesis

In this work, we report the first electrochemical synthesis of two copolymeric bimetallic conducting polymers by a simple anodic electropolymerization method. The adopted precursors are electroactive transition metal (M = Ni, Cu and Fe) salophen complexes, which can be easily obtained by direct chemical synthesis. The resulting films, labeled poly-NiCu and poly-CuFe, were characterized by cyclic voltammetry in both organic and aqueous media, attenuated total reflectance Fourier transform infrared spectroscopy, UV-vis spectroscopy, scanning electron microscopy, and coupled energy dispersive X-ray spectroscopy. The films are conductive and exhibit great electrochemical stability in both organic and aqueous media (resistant over 100 cycles without significant loss in current response or changes in electrochemical behavior), which makes them good candidates for an array of potential applications. Electrochemical detection of ascorbic acid was performed using both materials

FAST CHANGES IN DIRECTION DURING HUMAN LOCOMOTION ARE EXECUTED BY IMPULSIVE ACTIVATION OF MOTOR MODULES

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Defect distribution in a-plane GaN on Al2O3

The authors studied the structural and point defect distributions of hydride vapor phase epitaxial GaN film grown in the [11−20] a direction on (1−102) r-plane sapphire with metal-organic vapor phase deposited a-GaN template using transmission electron microscopy, secondary ion mass spectrometry, and positron annihilation spectroscopy. Grown-in extended and point defects show constant behavior as a function of thickness, contrary to the strong nonuniform defect distribution observed in GaN grown along the [0001] direction. The observed differences are explained by orientation-dependent and kinetics related defect incorporation.Peer reviewe

Review of the Phenomenology of Noncommutative Geometry

We present a pedagogical review of particle physics models that are based on the noncommutativity of space-time, $[\hat{x}_\mu,\hat{x}_\nu]=i \theta_{\mu \nu}$, with specific attention to the phenomenology these models predict in particle experiments either in existence or under development. We summarize results obtained for high energy scattering such as would occur for example in a future $e^+e^-$ linear collider with $\sqrt{s} = 500 GeV$, as well as low energy experiments such as those pertaining to elementary electric dipole moments and other \cpviolng observables, and finally comment on the status of phenomenological work in cosmology and extra dimensions.Comment: updated, references added, corrected typo