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The Perseverance rover landed in Jezero crater, Mars, to investigate ancient lake and river deposits. We report observations of the crater floor, below the crater's sedimentary delta, finding that the floor consists of igneous rocks altered by water. The lowest exposed unit, informally named Séítah, is a coarsely crystalline olivine-rich rock, which accumulated at the base of a magma body. Magnesium-iron carbonates along grain boundaries indicate reactions with carbon dioxide-rich water under water-poor conditions. Overlying Séítah is a unit informally named Máaz, which we interpret as lava flows or the chemical complement to Séítah in a layered igneous body. Voids in these rocks contain sulfates and perchlorates, likely introduced by later near-surface brine evaporation. Core samples of these rocks have been stored aboard Perseverance for potential return to Earth.

Objective: The Small Parts Test Fixture (SPTF) (16 CFR 1501) was developed from cadavers of young children and foreign body (FB) data. Recent FB studies reveal that the SPTF misses outliers. Computerized tomography (CT) provides detailed dimensional data for young children. Our null hypothesis is that the SPTF (31.75 mm) is smaller than relevant portions of the aerodigestive tract., Methods: A 3-year retrospective review (2011-2014) of head/neck CT data for infants and children (N = 106) aged 6 months to 6 years was completed. Six measurements (mm) were recorded: 1) maxillary incisors to posterior edge of hard palate (MI/HP); 2) posterior edge of hard palate to first cervical (C1) vertebra (HP/C1); 3) soft palate to posterior pharyngeal wall; and 4) interpalatine tonsillar distance; 5, 6) larynx diameter, and width. Two ratios were calculated: 1) ratio of lengths (hard palate to soft palate), and 2) laryngeal dimensional ratio., Results: A linear trend of increasing dimensions with increased age was noted. The length measured MI/HP best correlates with known data of potential FBs causing injury or death. This MI/HP length can range from 33.8 to 45.8 mm for all children younger than 3 years of age and exceeds the SPTF diameter (31.75 mm). There were no statistical anatomical differences by gender in any of the age groups., Conclusion: Computed tomography measurements appear larger than SPTF values developed from cadavers. These CT data support enlargement of the SPTF to enhance safety for choking hazards in children., Level of Evidence: 4 Laryngoscope, 129:1468-1476, 2019., (© 2018 The American Laryngological, Rhinological and Otological Society, Inc.)

The Shallow Radar (SHARAD) on the Mars Reconnaissance Orbiter has imaged the internal stratigraphy of the north polar layered deposits of Mars. Radar reflections within the deposits reveal a laterally continuous deposition of layers, which typically consist of four packets of finely spaced reflectors separated by homogeneous interpacket regions of nearly pure ice. The packet/interpacket structure can be explained by approximately million-year periodicities in Mars' obliquity or orbital eccentricity. The observed approximately 100-meter maximum deflection of the underlying substrate in response to the ice load implies that the present-day thickness of an equilibrium elastic lithosphere is greater than 300 kilometers. Alternatively, the response to the load may be in a transient state controlled by mantle viscosity. Both scenarios probably require that Mars has a subchondritic abundance of heat-producing elements.

Mars' polar regions are covered with ice-rich layered deposits that potentially contain a record of climate variations. The sounding radar SHARAD on the Mars Reconnaissance Orbiter mapped detailed subsurface stratigraphy in the Promethei Lingula region of the south polar plateau, Planum Australe. Radar reflections interpreted as layers are correlated across adjacent orbits and are continuous for up to 150 kilometers along spacecraft orbital tracks. The reflectors are often separated into discrete reflector sequences, and strong echoes are seen as deep as 1 kilometer. In some cases, the sequences are dipping with respect to each other, suggesting an interdepositional period of erosion. In Australe Sulci, layers are exhumed, indicating recent erosion.

The ice-rich south polar layered deposits of Mars were probed with the Mars Advanced Radar for Subsurface and Ionospheric Sounding on the Mars Express orbiter. The radar signals penetrate deep into the deposits (more than 3.7 kilometers). For most of the area, a reflection is detected at a time delay that is consistent with an interface between the deposits and the substrate. The reflected power from this interface indicates minimal attenuation of the signal, suggesting a composition of nearly pure water ice. Maps were generated of the topography of the basal interface and the thickness of the layered deposits. A set of buried depressions is seen within 300 kilometers of the pole. The thickness map shows an asymmetric distribution of the deposits and regions of anomalous thickness. The total volume is estimated to be 1.6 x 10(6) cubic kilometers, which is equivalent to a global water layer approximately 11 meters thick.

A low-income mother is accused of child abuse after co-sleeping with, and then waking to find her 13-month-old daughter entangled and apparently strangling in the mother's hair. The baby was initially unconscious and cyanotic; revived by the time the parents reached the ER, clinical examination revealed a ligature mark on the neck and petechiae on the face. In a pro bono effort, her attorney teamed with RAM Consulting as an expert witness. RAM performed a six-part investigation including: (1) an anthropometric analysis, (2) determination of the strength of human hair, (3) characterization of the ligature mark, (4) an investigation into airway occlusion forces, (5) an investigation into the conditions required to initiate petechiae, and (6) a review of the literature. Our conclusion was that it is possible for a strangulation incident to occur when a young child is co-sleeping with a parent with long hair, and that this scenario may result in injury or death. Upon review of this report and RAM's deposition on this matter, the prosecuting attorney's expert witness withdrew her testimony and the judge dismissed the case.

Background: To develop design criteria for consumer products, based on foreign body injury and fatality data, to prevent airway obstruction injuries to children., Method: Beginning in 1988, RAM Consulting has created a worldwide database of foreign body injuries. This ongoing project now includes approximately 7000 data points from 51 children's hospitals in 15 countries located on five continents. Statistical analysis of these data, especially in terms of size, shape and consistency of the object and obstruction location and severity of injury for the patient has allowed the creation of an injury prevention criterion., Results: Analysis of these data reveals that adoption of an injury prevention criteria based on the use of a 1.50 in. (38.10 mm) diameter gauge for non-spherical objects and a 1.75 in. (44.50 mm) diameter gauge for spherical objects would greatly reduce airway obstruction injuries to children. Furthermore, the data show that this criterion is independent of country and culture. However, the data suggest that a child's exposure to the "mix" of objects that may cause airway obstruction varies with the country and culture of the child. For example, coins are well represented in the database, however, some countries make more coins than other countries and the exposure level may have made the difference in the occurrence of incidents., Conclusions: Airway obstruction injuries from consumer products could be greatly decreased by the adoption of the presented injury prevention criteria that is founded in a statistical analysis of known objects that have caused injury. This criteria is dependent on object characteristics and is independent of the country or culture of the child.

Accidental strangulation is a preventable problem, and there is limited scientific understanding of its mechanism in children. If the amount of external pressure that occludes the airway can be determined, design changes may be made to allow for production of household objects that would break apart at safe pressure levels. A force gauge was applied to the suprahyoid region in 90 children under standardized anesthesia. Three blinded observers performed the study. The anesthesiologist maintained the airway and used a stethoscope to auscultate for breath sounds and monitor the CO2 curves to evaluate obstruction. The recorder noted the numbers from the gauge. A single observer applied the force gauge. Age was the most significant variable in occluding the airway. Obstruction appears to occur at the level of the larynx. Increased knowledge regarding the external pressure required for airway occlusion would allow for the design and manufacture of products with a reduced potential for accidental strangulation.

Background: Accidental strangulation is a preventable problem with limited scientific understanding in children. Children's clothing and household furniture have the potential to cause strangulation. Localizing the site of obstruction would provide understanding and insight to preventing this unfortunate event., Methods: While undergoing the application of pressure to the submental and suprahyoid region in eight patients flexible endoscopy was performed to evaluate the location of obstruction., Results: Submental pressure occluded the nasopharynx and oropharynx. Suprahyoid pressure occluded the larynx., Conclusions: In suspension strangulation, airway obstruction appears to occur at the level of the larynx involving the epiglottis and the arytenoids. Increased knowledge regarding site of airway occlusion may help to decrease the hazard of accidental strangulation.