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Five unique soft robotic jellyfish were manufactured with eight pneumatic network tentacle actuators extending radially from their centers. These jellyfish robots were able to freely swim untethered in the ocean, to steer from side to side, and to swim through orifices more narrow than the nominal diameter of the jellyfish. Each of the five jellyfish robots were manufactured with a different composition of body and tentacle actuator Shore hardness. A three-factor study was performed with these five jellyfish robots to determine the impact that actuator material Shore hardness, actuation frequency, and tentacle stroke actuation amplitude had upon the measured thrust force. It was found that all three of these factors significantly impacted mean thrust force generation, which peaked with a half-stroke actuation amplitude at a frequency of 0.8 Hz.

This study investigated how violence influences children's sleep environments. Sixty-five children ages 8-16 years and a parent or guardian were recruited from agencies serving families experiencing violence. At baseline (5 weeks post-violent event), 6 months, and 12 months postbaseline, study staff collected sleep-behavior information and conducted systematic, qualitative assessments of sleep environments. Child sleep problems were generally frequent and persistent. However, 9 children reported improved sleep after the violent event, mainly because perpetrators were no longer present. Sleeping environments were dynamic via changes in location and modifications to improve safety and sleep. Incongruence between children's and parents' perceptions of environmental characteristics influencing sleep was common. Families' motivation to improve children's sleep represents a foundation to build upon when working with families victimized by violence.

Although sleep disturbances are commonly reported among children exposed to violence, objective evidence of such disturbances is rare. This longitudinal, home-based study assessed the effects of a known community- or family-violence incident on both actigraphy-derived and subjectively reported sleep outcomes of an ethnically mixed, urban sample of children aged 8-16 years. We hypothesized that increased event severity (child physical assault, witnessed homicide) would be associated with lower sleep duration and poorer sleep quality both at baseline and at 3-month follow-up. Covariate-adjusted analyses based on a generalized estimating equations approach showed that children physically assaulted during the event showed lower sleep duration and sleep efficiency and greater wake after sleep onset than those not physically assaulted. Physically assaulted children were more likely to have a later bedtime than non-assaulted children, but this difference decreased at 3 months. Children witnessing a homicide showed greater wake after sleep onset at baseline and reported greater sleep problems than those witnessing a non-homicide event, but these differences decreased at 3 months. They were also somewhat more likely to have greater nightly variation in sleep duration. Collectively, results suggest that violence exposure influences children's sleep, but that specific dimensions of sleep may exhibit different susceptibility to different characteristics of violence, especially over time. Language: en

Motor neuron loss is characteristic of many neurodegenerative disorders and results in rapid loss of muscle control, paralysis, and eventual death in severe cases. In order to investigate the neurotrophic effects of a motor neuron lineage graft, we transplanted human embryonic stem cell-derived motor neuron progenitors (hMNPs) and examined their histopathological effect in three animal models of motor neuron loss. Specifically, we transplanted hMNPs into rodent models of SMA (Δ7SMN), ALS (SOD1 G93A), and spinal cord injury (SCI). The transplanted cells survived and differentiated in all models. In addition, we have also found that hMNPs secrete physiologically active growth factorsin vivo, including NGF and NT-3, which significantly enhanced the number of spared endogenous neurons in all three animal models. The ability to maintain dying motor neurons by delivering motor neuron-specific neurotrophic support represents a powerful treatment strategy for diseases characterized by motor neuron loss.

Evidence that cell transplants can improve recovery outcomes in spinal cord injury (SCI) models substantiates treatment strategies involving cell replacement for humans with SCI. Most pre-clinical studies of cell replacement in SCI examine thoracic injury models. However, as most human injuries occur at the cervical level, it is critical to assess potential treatments in cervical injury models and examine their effectiveness using at-level histological and functional measures. To directly address cervical SCI, we used a C5 midline contusion injury model and assessed the efficacy of a candidate therapeutic for thoracic SCI in this cervical model. The contusion generates reproducible, bilateral movement and histological deficits, although a number of injury parameters such as acute severity of injury, affected gray-to-white matter ratio, extent of endogenous remyelination, and at-level locomotion deficits do not correspond with these parameters in thoracic SCI. On the basis of reported benefits in thoracic SCI, we transplanted human embryonic stem cell (hESC)-derived oligodendrocyte progenitor cells (OPCs) into this cervical model. hESC-derived OPC transplants attenuated lesion pathogenesis and improved recovery of forelimb function. Histological effects of transplantation included robust white and gray matter sparing at the injury epicenter and, in particular, preservation of motor neurons that correlated with movement recovery. These findings further our understanding of the histopathology and functional outcomes of cervical SCI, define potential therapeutic targets, and support the use of these cells as a treatment for cervical SCI.

Acoustic pharyngometry represents a simple, quick noninvasive method of measuring upper airway dimensions, which are predictive of sleep apnoea risk. The aim of the present study was to assess the genetic basis of upper airway size as determined using pharyngometry. Participants in the Cleveland Family Study aged >14 yrs underwent three acoustic pharyngometric measurements. Variance component models adjusted for age and sex were used to estimate the heritability of pharyngometry-derived airway measures. A total of 568 out of 655 (87%) subjects provided pharyngometric curves of sufficient quality. Although African-Americans tended to show narrower airways compared with white subjects, heritability patterns were similar in these two groups. The minimum cross-sectional area exhibited a heritability of 0.34 in white subjects and 0.39 in African-Americans, suggesting that 30–40% of the total variance in this measure is explained by shared familial factors. Estimates were unchanged after adjustment for body mass index or neck circumference. In contrast, oropharyngeal length did not show significant heritability in either ethnic group. The minimum cross-sectional area of the oropharynx is a highly heritable trait, suggesting the presence of an underlying genetic basis. These findings demonstrate the potential utility of acoustic pharyngometry in dissecting the genetic basis of sleep apnoea.