Statistics of Mars' topography from the Mars Orbiter Laser Altimeter: Slopes, correlations, and physical Models

Data obtained recently by the Mars Orbiter Laser Altimeter (MOLA) were used to study the statistical properties of the topography and slopes on Mars. We find that the hemispheric dichotomy, manifested as an elevation difference, can be described by long baseline tilts but in places is expressed as steeper slopes. The bimodal hypsometry of elevations on Mars becomes unimodal when referenced to the center of figure, contrary to the Earth, for which the bimodality is retained. However, ruling out a model in which the elevation difference is expressed in a narrow equatorial topographic step cannot be done by the hypsometry alone. Mars' slope distribution is longer tailed than those of Earth and Venus, indicating a lower efficiency of planation processes relative to relief-building tectonics and volcanics. We define and compute global maps of statistical estimators, including the interquartile scale, RMS and median slope, and characteristic decorrelation length of the surface. A correspondence between these parameters and geologic units on Mars is inferred. Surface smoothness is distinctive in the vast northern hemisphere plains, where slopes are typically <0.5°. Amazonis Planitia exhibits a variation in topography of <1 m over 35-km baselines. The region of hematite mineralization in Sinus Meridiani is also smooth, with median slopes lower than 0.4°, but does not form a closed basin. The shallower long-wavelength portion of the lowlands' topographic power spectrum relative to the highlands' can be accounted for by a simple model of sedimentation such as might be expected at an ocean's floor. The addition of another process such as cratering is necessary to explain the spectral slope in short wavelengths. Among their application, these MOLA-derived roughness measurements can help characterize sites for landing missions

Data Sources for Improving Estimates of the Global Burden of Injuries: Call for Contributors

Kavi Bhalla and colleagues invite individuals and organizations to provide local injury data sources to help inform estimates of the global burden of injuries

Fantastic reality and playfulness as a means for adaptive emotion regulation

This study explores the interplay between Fantastic Reality Ability (FRA), assessed using the FRAME scale, and playfulness, measured with the OLIW-S, in relation to cognitive emotion regulation strategies among 298 Israeli adults. Participants completed self-report measures evaluating FRA, playfulness, and emotion regulation processes. Results revealed robust positive associations between FRA and various facets of playfulness, and specific connections to adaptive emotion regulation. Particularly, higher levels of FRA coping and lighthearted playfulness emerged as significant predictors of adaptive emotion regulation, while maladaptive regulation showed associations with lower FRA control and distinct playfulness facets. These findings highlight the potential of cultivating imaginative capabilities and embracing playful approaches to bolster emotional resilience and adaptive coping strategies during challenging circumstances and crises. Practical implications for interventions aimed at enhancing psychological well-being are discussed, emphasizing the integration of FRA and playfulness in developing effective coping strategies

Improving the Efficiency of Physical Examination Services

The objective of our project was to improve the efficiency of the physical examination screening service of a large hospital system. We began with a detailed simulation model to explore the relationships between four performance measures and three decision factors. We then attempted to identify the optimal physician inquiry starting time by solving a goal-programming problem, where the objective function includes multiple goals. One of our simulation results shows that the proposed optimal physician inquiry starting time decreased patient wait times by 50% without increasing overall physician utilization

Application of operations research in studies of ambulatory care services

published_or_final_versionCommunity MedicineDoctoralDoctor of Philosoph