Quantitative trait variation in ASD probands and toddler sibling outcomes at 24 months

BACKGROUND: Younger siblings of children with autism spectrum disorder (ASD) are at increased likelihood of receiving an ASD diagnosis and exhibiting other developmental concerns. It is unknown how quantitative variation in ASD traits and broader developmental domains in older siblings with ASD (probands) may inform outcomes in their younger siblings. METHODS: Participants included 385 pairs of toddler siblings and probands from the Infant Brain Imaging Study. ASD probands (mean age 5.5 years, range 1.7 to 15.5 years) were phenotyped using the Autism Diagnostic Interview-Revised (ADI-R), the Social Communication Questionnaire (SCQ), and the Vineland Adaptive Behavior Scales, Second Edition (VABS-II). Siblings were assessed using the ADI-R, VABS-II, Mullen Scales of Early Learning (MSEL), and Autism Diagnostic Observation Schedule (ADOS) and received a clinical best estimate diagnosis at 24 months using DSM-IV-TR criteria (n = 89 concordant for ASD; n = 296 discordant). We addressed two aims: (1) to determine whether proband characteristics are predictive of recurrence in siblings and (2) to assess associations between proband traits and sibling dimensional outcomes at 24 months. RESULTS: Regarding recurrence risk, proband SCQ scores were found to significantly predict sibling 24-month diagnostic outcome (OR for a 1-point increase in SCQ = 1.06; 95% CI = 1.01, 1.12). Regarding quantitative trait associations, we found no significant correlations in ASD traits among proband-sibling pairs. However, quantitative variation in proband adaptive behavior, communication, and expressive and receptive language was significantly associated with sibling outcomes in the same domains; proband scores explained 9-18% of the variation in cognition and behavior in siblings with ASD. Receptive language was particularly strongly associated in concordant pairs (ICC = 0.50, p \u3c 0.001). CONCLUSIONS: Proband ASD symptomology, indexed by the SCQ, is a predictor of familial ASD recurrence risk. While quantitative variation in social communication and restricted and repetitive behavior were not associated among sibling pairs, standardized ratings of proband language and communication explained significant variation in the same domains in the sibling at 24 months, especially among toddlers with an ASD diagnosis. These data suggest that proband characteristics can alert clinicians to areas of developmental concern for young children with familial risk for ASD

System thermal-hydraulic modelling of the phénix dissymmetric test benchmark

Phénix is a French pool-type sodium-cooled prototype reactor; before the definitive shutdown, occurred in 2009, a final set of experimental tests are carried out in order to increase the knowledge on the operation and the safety aspect of the pool-type liquid metal-cooled reactors. One of the experiments was the Dissymmetric End-of-Life Test which was selected for the validation benchmark activity in the frame of SESAME project. The computer code validation plays a key role in the safety assessment of the innovative nuclear reactors and the Phénix dissymmetric test provides useful experimental data to verify the computer codes capability in the asymmetric thermal-hydraulic behaviour into a pool-type liquid metal-cooled reactor. This paper shows the comparison of the outcomes obtained with six different System Thermal-Hydraulic (STH) codes: RELAP5-3D©, SPECTRA, ATHLET, SAS4A/SASSYS-1, ASTEC-Na and CATHARE. The nodalization scheme of the reactor was individually achieved by the participants; during the development of the thermal-hydraulic model, the pool nodalization methodology had a special attention in order to investigate the capability of the STH codes to reproduce the dissymmetric effects which occur in each loop and into pools, caused by the azimuthal asymmetry of the boundary conditions. The modelling methodology of the participants is discussed and the main results are compared in this paper to obtain useful guide lines for the future modelling of innovative liquid metal pool-type reactors

On the numerical approximation of p-biharmonic and ∞-biharmonic functions

In [KP16] (arXiv:1605.07880) the authors introduced a second-order variational problem in L∞. The associated equation, coined the ∞-Bilaplacian, is a \emph{third order} fully nonlinear PDE given by Δ2∞u:=(Δu)3|D(Δu)|2=0. In this work we build a numerical method aimed at quantifying the nature of solutions to this problem which we call ∞-Biharmonic functions. For fixed p we design a mixed finite element scheme for the pre-limiting equation, the p-Bilaplacian Δ2pu:=Δ(|Δu|p−2Δu)=0. We prove convergence of the numerical solution to the weak solution of Δ2pu=0 and show that we are able to pass to the limit p→∞. We perform various tests aimed at understanding the nature of solutions of Δ2∞u and in 1-d we prove convergence of our discretisation to an appropriate weak solution concept of this problem, that of -solutions

AC electrokinetic phenomena over semiconductive surfaces: effective electric boundary conditions and their applications

Electrokinetic boundary conditions are derived for AC electrokinetic (ACEK) phenomena over leaky dielectric (i.e., semiconducting) surfaces. Such boundary conditions correlate the electric potentials across the semiconductor-electrolyte interface (consisting of the electric double layer (EDL) inside the electrolyte solutions and the space charge layer (SCL) inside the semiconductors) under AC electric fields with arbitrary wave forms. The present electrokinetic boundary conditions allow for evaluation of induced zeta potential contributed by both bond charges (due to electric polarization) and free charges (due to electric conduction) from the leaky dielectric materials. Subsequently, we demonstrate the applications of these boundary conditions in analyzing the ACEK phenomena around a semiconducting cylinder. It is concluded that the flow circulations exist around the semiconducting cylinder and are shown to be stronger under an AC field with lower frequency and around a cylinder with higher conductivity.Comment: 29 pages, 4 figure

Simulations of the adsorption of ionic species at polarisable liquid liquid interfaces

The adsorption of ions at the interface between two immiscible electrolyte solutions (ITIES) is primarily controlled by the potential distribution across the interface, which in turn is influenced by the adsorption process. In the present paper, we simulate the effect of the adsorption of charged species on the charge distribution at the ITIES based on the classical description of the interface employing the Gouy–Chapman model. The inner layer is considered as a charged plane, where the ionic adsorption takes place. The potential at this plane is determined by the electro-neutrality condition. Various adsorption isotherms are considered, including potential dependent isotherms based on the Langmuir and Frumkin adsorption models. The potential distribution and the charge density profile are derived by solving the Poisson–Boltzman equation numerically. We show that the charge distribution in the interfacial region is significantly affected by the adsorption of ionic species. Under certain conditions, the adsorption results in a non-monotonic potential distribution with a potential trap at the interface

Copper staining/labeling and scanning electrochemical microscopy readout of proteins on poly(vinylidene difluoride) membranes

Scanning Electrochemical Microscopy (SECM) is used in combination with copper labeling to visualize roteins on surfaces. Proteins are adsorbed on a poly(vinylidene difluoride) (PVDF) membrane and stained using a standard protocol involving copper salts. The latter are then reduced to copper metal and further detected by SECM with ferrocene methanol as a redox mediator in aqueous solution. During the SECM scan, the potential is held at a value at which the oxidation of the redox mediator occurs and a positive feedback current is detected when scanning over copper clusters. A negative feedback is observed elsewhere

Reactivity of Monolayer-Protected Gold Nanoclusters at Dye-Sensitized Liquid/Liquid Interfaces

Hexanethiolate monolayer-protected gold nanoclusters (MPCs) were used as redox quenchers at the polarizable water/1,2-dichloroethane (DCE) interface. Photocurrent responses originating from the heterogeneous quenching of photoexcited water soluble porphyrin complexes by MPCs dissolved in the DCE phase were observed. As MPCs can function as both electron acceptors and donors, the photocurrent results from the superposition of two simultaneous processes, which correspond to the oxidation and reduction of MPCs. The magnitude of the net photocurrent is essentially determined by the balance of the kinetics of these two processes, which can be controlled by tuning the Galvani potential difference between the two phases. We show that, within the available potential window, the apparent electron-transfer rate constants follow classical Butler−Volmer dependence on the applied potential difference

Detection of proteins on membranes and in microchannels using copper staining combined with Scanning Electrochemical Microscopy

Scanning Electrochemical Microscopy (SECM) and copper staining are combined to achieve visualisation of proteins on surfaces. Proteins are adsorbed on a polyvinylidene fluoride (PVDF) membrane or on a polyethylene terephthalate (PET) surface and stained using a standard protocol involving copper salts. Salts are then reduced to copper and detected by SECM with ferrocene methanol as a redox mediator in aqueous solution. During the SECM scan, the potential is held at a value at which the oxidation of the redox mediator occurs and a positive feedback current is detected when scanning over copper clusters. A negative feedback is observed elsewhere. This method enables unspecific protein adsorption mapping on polymeric membranes and into microchannels without any requirement of enzymatic activity or affinity to a labelled secondary reporter

CdSe Sensitized Thin Aqueous Films: Probing the Potential Distribution Inside Multilayer Assemblies

Ultrathin polypeptide multilayer films are assembled by the sequential electrostatic adsorption of monolayers of poly-L-lysine and poly-L-glutamic acid onto carboxylic acid terminated alkanethiol-modified gold surfaces. The polypeptide multilayer films are hydrophilic, can incorporate electroactive species such as ferri/ferrocyanide, and are stable when immersed in organic solvents such as 1,2-dichloroethane. Cadmium selenide quantum dots stabilized by negatively charged citrate groups are electrostatically attached to the multilayer film assembly in order to act as photoactive species. Photocurrent responses originating from the CdSe sensitized ultrathin multilayer film are investigated as functions of the applied potential, the thickness of the film and the presence of quenchers in the organic phase. A theoretical model is proposed in order to analyze the kinetics of the photoinduced electron-transfer reactions and to probe the potential distribution within the film