Physics-based Simulation of Continuous-Wave LIDAR for Localization, Calibration and Tracking

Light Detection and Ranging (LIDAR) sensors play an important role in the perception stack of autonomous robots, supplying mapping and localization pipelines with depth measurements of the environment. While their accuracy outperforms other types of depth sensors, such as stereo or time-of-flight cameras, the accurate modeling of LIDAR sensors requires laborious manual calibration that typically does not take into account the interaction of laser light with different surface types, incidence angles and other phenomena that significantly influence measurements. In this work, we introduce a physically plausible model of a 2D continuous-wave LIDAR that accounts for the surface-light interactions and simulates the measurement process in the Hokuyo URG-04LX LIDAR. Through automatic differentiation, we employ gradient-based optimization to estimate model parameters from real sensor measurements.Comment: Published at ICRA 202

In-vivo evaluation of biocompatibility of biodegradable Fe-Mn materials

The authors evaluated the biodegradability and biocompatibility of an alloy of iron and manganese in a bone model in vivo. Fe-Mn biodegradable materials with various porosities were first fabricated and characterized for microstructure, corrosion and mechanical properties. Resorption of a bioabsorbable wire of chemical formula Fe30Mn and no induced porosity was evaluated in-vivo. The Fe-Mn alloy behavior in-vivo was compared to that of a traditional permanent 316L stainless steel (SS) wire after bilateral transcondylar femoral implantation in 12 rats. Evaluation of biodegradation was performed over a period of 6 months using serial radiography, post-mortem histology and macroscopic implant surface analysis. Increased bone ingrowth was noted at the iron-manganese wire-bone interface, which indicates increased osseointegration of the implant. Please click Additional Files below to see the full abstract

Reductive glutamine metabolism is a function of the α-ketoglutarate to citrate ratio in cells

Reductively metabolized glutamine is a major cellular carbon source for fatty acid synthesis during hypoxia or when mitochondrial respiration is impaired. Yet, a mechanistic understanding of what determines reductive metabolism is missing. Here we identify several cellular conditions where the α-ketoglutarate/citrate ratio is changed due to an altered acetyl-CoA to citrate conversion, and demonstrate that reductive glutamine metabolism is initiated in response to perturbations that result in an increase in the α-ketoglutarate/citrate ratio. Thus, targeting reductive glutamine conversion for a therapeutic benefit might require distinct modulations of metabolite concentrations rather than targeting the upstream signalling, which only indirectly affects the process.German Science Foundation (Grant FE1185)National Institutes of Health (U.S.) (Ruth L. Kirschstein National Research Service Award Postdoctoral Fellowship F32 CA132358)National Institutes of Health (U.S.) (Grant 5-P30-CA14051-39)Damon Runyon Cancer Research FoundationBurroughs Wellcome FundSmith Family FoundationNational Institutes of Health (U.S.) (Grant 1R01CA160458-01A1