Automated movement tracking of young autistic children during free play is correlated with clinical features associated with autism.

LAY ABSTRACT: Play-based observations allow researchers to observe autistic children across a wide range of ages and skills. We recorded autistic children playing with toys in the center of a room and at a corner table while a caregiver remained seated off to the side and used video tracking technology to track children's movement and location. We examined how time children spent in room regions and whether or not they approached each region during play related to their cognitive, social, communication, and adaptive skills to determine if tracking child movement and location can meaningfully demonstrate clinical variation among autistic children representing a range of ages and skills. One significant finding was that autistic children who spent more time in the toy-containing center of the room had higher cognitive and language abilities, whereas those who spent less time in the center had higher levels of autism-related behaviors. In contrast, children who spent more time in the caregiver region had lower daily living skills and those who were quicker to approach the caregiver had lower adaptive behavior and language skills. These findings support the use of movement tracking as a complementary method of measuring clinical differences among autistic children. Furthermore, over 90% of autistic children representing a range of ages and skills in this study provided analyzable play observation data, demonstrating that this method allows autistic children of all levels of support needs to participate in research and demonstrate their social, communication, and attention skills without wearing any devices.

Potential of Attosecond Coherent Diffractive Imaging.

Attosecond science has been transforming our understanding of electron dynamics in atoms, molecules, and solids. However, to date almost all of the attoscience experiments have been based on spectroscopic measurements because attosecond pulses have intrinsically very broad spectra due to the uncertainty principle and are incompatible with conventional imaging systems. Here we report an important advance towards achieving attosecond coherent diffractive imaging. Using simulated attosecond pulses, we simultaneously reconstruct the spectrum, 17 probes, and 17 spectral images of extended objects from a set of ptychographic diffraction patterns. We further confirm the principle and feasibility of this method by successfully performing a ptychographic coherent diffractive imaging experiment using a light-emitting diode with a broad spectrum. We believe this work clears the way to an unexplored domain of attosecond imaging science, which could have a far-reaching impact across different disciplines.

Observing crystal nucleation in four dimensions using atomic electron tomography.

Nucleation plays a critical role in many physical and biological phenomena that range from crystallization, melting and evaporation to the formation of clouds and the initiation of neurodegenerative diseases1-3. However, nucleation is a challenging process to study experimentally, especially in its early stages, when several atoms or molecules start to form a new phase from a parent phase. A number of experimental and computational methods have been used to investigate nucleation processes4-17, but experimental determination of the three-dimensional atomic structure and the dynamics of early-stage nuclei has been unachievable. Here we use atomic electron tomography to study early-stage nucleation in four dimensions (that is, including time) at atomic resolution. Using FePt nanoparticles as a model system, we find that early-stage nuclei are irregularly shaped, each has a core of one to a few atoms with the maximum order parameter, and the order parameter gradient points from the core to the boundary of the nucleus. We capture the structure and dynamics of the same nuclei undergoing growth, fluctuation, dissolution, merging and/or division, which are regulated by the order parameter distribution and its gradient. These experimental observations are corroborated by molecular dynamics simulations of heterogeneous and homogeneous nucleation in liquid-solid phase transitions of Pt. Our experimental and molecular dynamics results indicate that a theory beyond classical nucleation theory1,2,18 is needed to describe early-stage nucleation at the atomic scale. We anticipate that the reported approach will open the door to the study of many fundamental problems in materials science, nanoscience, condensed matter physics and chemistry, such as phase transition, atomic diffusion, grain boundary dynamics, interface motion, defect dynamics and surface reconstruction with four-dimensional atomic resolution.

Methodological considerations in the use of Noldus EthoVision XT video tracking of children with autism in multi-site studies.

Animal models of autism spectrum disorders (ASD) contribute to understanding of the role of genetics and the biological mechanisms underlying behavioral phenotypes and inform the development of potential treatments. Translational biomarkers are needed that can both validate these models and facilitate behavioral testing paradigms for ASD in humans. Automated video tracking of movement patterns and positions recorded from overhead cameras is routinely applied in behavioral paradigms designed to elicit core behavioral manifestations of ASD in rodent models. In humans, laboratory-based observations are a common semi-naturalistic context for assessing a variety of behaviors relevant to ASD such as social engagement, play, and attention. We present information learned and suggest guidelines for designing, recording, acquiring, and evaluating video tracking data of human movement patterns based on our experience in a multi-site video tracking study of children with ASD in the context of a parent-child, laboratory-based play interaction.

Vaginal drug distribution modeling.

This review presents and applies fundamental mass transport theory describing the diffusion and convection driven mass transport of drugs to the vaginal environment. It considers sources of variability in the predictions of the models. It illustrates use of model predictions of microbicide drug concentration distribution (pharmacokinetics) to gain insights about drug effectiveness in preventing HIV infection (pharmacodynamics). The modeling compares vaginal drug distributions after different gel dosage regimens, and it evaluates consequences of changes in gel viscosity due to aging. It compares vaginal mucosal concentration distributions of drugs delivered by gels vs. intravaginal rings. Finally, the modeling approach is used to compare vaginal drug distributions across species with differing vaginal dimensions. Deterministic models of drug mass transport into and throughout the vaginal environment can provide critical insights about the mechanisms and determinants of such transport. This knowledge, and the methodology that obtains it, can be applied and translated to multiple applications, involving the scientific underpinnings of vaginal drug distribution and the performance evaluation and design of products, and their dosage regimens, that achieve it.

Dipeptide sulfonamides as endothelin ETA/ETB receptor antagonists.

Endothelin-1 (ET-1) is a potent mitogen and modulator of vascular tone. It is synthesized and released from endothelial cells and acts upon two receptor subtypes designated as ETA and ETB. In this study, a series of potent dipeptide sulfonamide dual-endothelin ETA/ETB receptor antagonists were prepared to investigate their potential benefit in vascular diseases. CGS 31398 inhibited [125I]ET-1 binding to human ETA and ETB receptors expressed in Chinese hamster ovary (CHO) cells (ETA/CHO, ETB/CHO) with respective IC50 values of 0.26 and 0.12 nM. However, in anesthetized rats, this compound markedly potentiated ET-1-induced renal vascular resistance, a response normally observed with selective ETB receptor antagonists. To determine whether species differences account for these results, a direct comparison was made between binding to rat and rabbit aortic membranes versus functional antagonism in isolated rat aortic rings. It was found that CGS 31398 had potent affinity for the ETA receptor in rat and rabbit aorta with IC50 values of 0.87 and 0.79 nM, respectively. Inhibition of ET-1-induced contractions of rat aorta by the compound was considerably weaker than expected (pKB = 6.4), while that of sarafotoxin S6c induced contraction of dog saphenous vein (100% inhibition at 100 nM) was consistent with corresponding binding data. These results suggest that although CGS 31398 is a potent dual inhibitor of ETA/ETB receptor binding, it surprisingly displays potent ETB and weak ETA receptor antagonism in functional assays.