SEIS: Insight's Seismic Experiment for Internal Structure of Mars.

By the end of 2018, 42 years after the landing of the two Viking seismometers on Mars, InSight will deploy onto Mars' surface the SEIS (Seismic Experiment for Internal Structure) instrument; a six-axes seismometer equipped with both a long-period three-axes Very Broad Band (VBB) instrument and a three-axes short-period (SP) instrument. These six sensors will cover a broad range of the seismic bandwidth, from 0.01 Hz to 50 Hz, with possible extension to longer periods. Data will be transmitted in the form of three continuous VBB components at 2 sample per second (sps), an estimation of the short period energy content from the SP at 1 sps and a continuous compound VBB/SP vertical axis at 10 sps. The continuous streams will be augmented by requested event data with sample rates from 20 to 100 sps. SEIS will improve upon the existing resolution of Viking's Mars seismic monitoring by a factor of ∼ 2500 at 1 Hz and ∼ 200 000 at 0.1 Hz. An additional major improvement is that, contrary to Viking, the seismometers will be deployed via a robotic arm directly onto Mars' surface and will be protected against temperature and wind by highly efficient thermal and wind shielding. Based on existing knowledge of Mars, it is reasonable to infer a moment magnitude detection threshold of M w ∼ 3 at 40 ∘ epicentral distance and a potential to detect several tens of quakes and about five impacts per year. In this paper, we first describe the science goals of the experiment and the rationale used to define its requirements. We then provide a detailed description of the hardware, from the sensors to the deployment system and associated performance, including transfer functions of the seismic sensors and temperature sensors. We conclude by describing the experiment ground segment, including data processing services, outreach and education networks and provide a description of the format to be used for future data distribution. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s11214-018-0574-6) contains supplementary material, which is available to authorized users.

Teaching children with autism through task variation in physical education.

The purpose of the study was to determine whether the technique of task variation (with maintenance tasks interspersed) (TV) is more effective in the acquisition of gross motor skills for students with autism than a constant task (CT) condition in a physical education setting. Subjects were 12 male students with autism, ages 11 to 15 years. The study included pretest-posttest administration of the I CAN assessment of Gross Motor Skills to assess skills such as overhand throw, kick, and vertical jump. After a 6-week treatment period, the TV condition was significantly more effective than the CT condition, at the .05 level.

Analysis of neuroelectric implant integrity.

A 10-year follow-up study of neuroelectric implant integrity has been completed for 27 subjects who were treated for movement disorders associated with cerebral palsy. Data used for analysis included X-ray material, clinical data, and results from electrophysiological testing. Of the 21 subjects with subcutaneous receivers placed in the thoracic region, 81% experienced wire (67%) or receiver (14%) failure. Of the 6 subjects with subcutaneous receivers placed in the occipital region, there were no wire failures and one (17%) receiver failure. The occipital units lasted a minimum of 5.2 years without complications, whereas the thoracic units failed as early as 6 months after surgery, and lasted an average of 3.8 years. All wire fractures occurred between C1 and T1. Two types of fracture occurred, one consisting of a clean break and the other consisting of a scenario of bending and kinking, then thinning and fraying, and finally progressive multiple fragmentation. With a few exceptions the clean breaks occurred between C1 and C3, while the fraying scenario occurred between C6 and T1. Mechanisms for failure are discussed, as are results from material tests of wire samples.

The comparative strengths of internal fixation techniques.

The strengths of internal fixation techniques have been compared by transecting human cadaver metacarpals, reducing and fixing the fractures, and then applying forces to mechanically bend the bone during simulated flexion. Kirschner wires alone, intraosseous wire loops with and without Kirschner wires, and bone plates were tested. Intraosseous loops were tested in three configurations, each with four different wire gauges. Intraosseous loops were stronger than Kirschner wires. Right-angle loops were the best of the intraosseous configurations. The addition of a Kirschner wire strengthened the best dorsopalmar intraosseous loops but not the best right-angle loops. Dorsal bone plates were comparable with the best intraosseous loop configurations of 26-gauge wire.

Effects of subject position on balance platform measurements.

The high cost of commercially available force plates instrumented to quantify postural sway can be prohibitive to both research and clinical institutions. Therefore custom plate design and construction within the institutional environment is not uncommon. Some plate designs, however, may give erroneous measurements depending upon subject position. We report here on the existence of a kern boundary on the plate surface. Loads placed inside this boundary result in support compression, while those placed outside cause at least one support to experience tension. The findings indicate that the type of force transducer used for corner support (unidirectional or bidirectional), the type of connection between the plate and transducers, plate weight, subject weight, plate dimensions and transducer preloads are all critical to accurate measurements.