Estimating Autonomous Vehicle Localization Error Using 2D Geographic Information

Accurately and precisely knowing the location of the vehicle is a critical requirement for safe and successful autonomous driving. Recent studies suggest that error for map-based localization methods are tightly coupled with the surrounding environment. Considering this relationship, it is therefore possible to estimate localization error by quantifying the representation and layout of real-world phenomena. To date, existing work on estimating localization error have been limited to using self-collected 3D point cloud maps. This paper investigates the use of pre-existing 2D geographic information datasets as a proxy to estimate autonomous vehicle localization error. Seven map evaluation factors were defined for 2D geographic information in a vector format, and random forest regression was used to estimate localization error for five experiment paths in Shinjuku, Tokyo. In the best model, the results show that it is possible to estimate autonomous vehicle localization error with 69.8% of predictions within 2.5 cm and 87.4% within 5 cm

Evaluating the Capability of OpenStreetMap for Estimating Vehicle Localization Error

Accurate localization is an important part of successful autonomous driving. Recent studies suggest that when using map-based localization methods, the representation and layout of real-world phenomena within the prebuilt map is a source of error. To date, the investigations have been limited to 3D point clouds and normal distribution (ND) maps. This paper explores the potential of using OpenStreetMap (OSM) as a proxy to estimate vehicle localization error. Specifically, the experiment uses random forest regression to estimate mean 3D localization error from map matching using LiDAR scans and ND maps. Six map evaluation factors were defined for 2D geographic information in a vector format. Initial results for a 1.2 km path in Shinjuku, Tokyo, show that vehicle localization error can be estimated with 56.3% model prediction accuracy with two existing OSM data layers only. When OSM data quality issues (inconsistency and completeness) were addressed, the model prediction accuracy was improved to 73.1%

Effects of chicken manure and vermicompost teas on herb yield, secondary metabolites and antioxidant activity of lemon basil (Ocimum x citriodorum Vis.)

Effects of chicken manure tea (CMT) and vermicompost tea (VCT) as soil drench on vegetative growth, herb yield, essential oil content, total phenolics, total flavonoids and antioxidant activity of lemon basil (Ocimum × citriodorum Vis.) was evaluated in a two-year field experiment. The greatest plant height and number of leaves and flowers, shoot fresh and dry weight and leaf chlorophyll content were obtained using CMT at either 1:5 or 1:10 dilutions with no significant differences. The highest number of lateral branches and flavonoid content were obtained when CMT at 1:5 dilution was applied. Essential oil content was at its highest level (0.618%) when CMT or VCT were used at 1:10 dilution, while the greatest total phenolic content and total antioxidant activity were obtained at 1:5 dilution of VCT. The results emphasize the possibility of using organic-based compost teas for enhancing herbal yield and important secondary metabolites in aromatic medicinal plants

Quantifying cell-generated forces: Poisson's ratio matters

Quantifying mechanical forces generated by cellular systems has led to key insights into a broad range of biological phenomena from cell adhesion to immune cell activation. Traction force microscopy (TFM), the most widely employed force measurement methodology, fundamentally relies on knowledge of the force-displacement relationship and mechanical properties of the substrate. Together with the elastic modulus, the Poisson’s ratio is a basic material property that to date has largely been overlooked in TFM. Here, we evaluate the sensitivity of TFM to Poisson’s ratio by employing a series of computer simulations and experimental data analysis. We demonstrate how applying the correct Poisson’s ratio is important for accurate force reconstruction and develop a framework for the determination of error levels resulting from the misestimation of the Poisson’s ratio. In addition, we provide experimental estimation of the Poisson’s ratios of elastic substrates commonly applied in TFM. Our work thus highlights the role of Poisson’s ratio underpinning cellular force quantification studied across many biological systems

A survival analysis of socio-demographic and clinical predictors among hospitalized COVID-19 patients in Southern Iran

Background: This study aimed to evaluate the socio-demographic, clinical, and laboratory risk factors in hospitalized COVID-19 patients during the first 6 months of the SARS-CoV-2 epidemic. Method: This retrospective hospital-based cross-sectional study included all laboratory-confirmed cases of the COVID-19 virus that were admitted to the Shohadaye-Khalije-Fars Hospital in Bushehr, Iran, from February 22, 2020 to September 21, 2020. The patients' records were reviewed during the hospitalization period. The global COVID-19 clinical platform, i.e., the World Health Organization Rapid Case Report Form was used as the data collection tool. We conducted the survival analysis using the Kaplan–Meier and the Stepwise Cox regression analyses. Results: The analysis included 2108 confirmed cases of COVID-19 with a mean age of 47.81 years (SD 17.78); 56.8% men, 43.2% women and 6.3% (n = 133) deaths. After adjustment, it was found that factors associated with an increased risk of death consisted of chronic kidney disease, intensive care unit admission, cancer, and hemoptysis. The 7-day survival rate was 95.8%, which decreased to 95.1%, 94.0%, and 93.8% on days 14, 21, and 28 of hospitalization, respectively. Discussion and conclusion: Older COVID-19 patients with manifestation of hemoptysis and a past medical history of chronic kidney disease and cancer, should be closely monitored to prevent disease deterioration and death, and also should be admitted to the intensive care unit

Removal and Dispersal of Biofluid Films by Powered Medical Devices: Modelling Infectious Agent Spreading in Dentistry

Summary Medical procedures can disperse infectious agents and spread disease. Particularly, dental procedures may pose a high risk of disease transmission as they use high-powered instruments operating within the oral cavity that may contain infectious microbiota or viruses. Here we assess the ability of powered dental devices in removing the biofluid films and identified mechanical, hydrodynamic, and aerodynamic forces as the main underlying mechanisms of removal and dispersal processes. Our results indicate that potentially infectious agents can be removed and dispersed immediately after dental instrument engagement with the adherent biofluid film while the degree of their dispersal is rapidly depleted due to removal of the source and dilution by the coolant water. We found that droplets, created by high-speed drill interactions typically travel ballistically while aerosol-laden air tends to flow as a current over surfaces. Our mechanistic investigation offers plausible routes for reducing the spread of infection during invasive medical procedures

The multiscale hierarchical structure of Heloderma suspectum osteoderms and their mechanical properties

Osteoderms are hard tissues embedded in the dermis of vertebrates and have been suggested to be formed from several different mineralized regions. However, their nano architecture and micro mechanical properties had not been fully characterized. Here, using electron microscopy, µ-CT, atomic force microscopy and finite element simulation, an in-depth characterization of osteoderms from the lizard Heloderma suspectum, is presented. Results show that osteoderms are made of three different mineralized regions: a dense apex, a fibre-enforced region comprising the majority of the osteoderm, and a bone-like region surrounding the vasculature. The dense apex is stiff, the fibre-enforced region is flexible and the mechanical properties of the bone-like region fall somewhere between the other two regions. Our finite element analyses suggest that when combined into the osteoderm structure, the distinct tissue regions are able to shield the body of the animal by dampening the external forces. These findings reveal the structure-function relationship of the Heloderma suspectum osteoderm in unprecedented detail

Cytoskeletal Control of Antigen-Dependent T Cell Activation

Cytoskeletal actin dynamics is essential for T cell activation. Here, we show evidence that the binding kinetics of the antigen engaging the T cell receptor influences the nanoscale actin organization and mechanics of the immune synapse. Using an engineered T cell system expressing a specific T cell receptor and stimulated by a range of antigens, we found that the peak force experienced by the T cell receptor during activation was independent of the unbinding kinetics of the stimulating antigen. Conversely, quantification of the actin retrograde flow velocity at the synapse revealed a striking dependence on the antigen unbinding kinetics. These findings suggest that the dynamics of the actin cytoskeleton actively adjusted to normalize the force experienced by the T cell receptor in an antigen-specific manner. Consequently, tuning actin dynamics in response to antigen kinetics may thus be a mechanism that allows T cells to adjust the lengthscale and timescale of T cell receptor signaling

A practical approach to language complexity: a wikipedia case study

In this paper we present statistical analysis of English texts from Wikipedia. We try to address the issue of language complexity empirically by comparing the simple English Wikipedia (Simple) to comparable samples of the main English Wikipedia (Main). Simple is supposed to use a more simplified language with a limited vocabulary, and editors are explicitly requested to follow this guideline, yet in practice the vocabulary richness of both samples are at the same level. Detailed analysis of longer units (n-grams of words and part of speech tags) shows that the language of Simple is less complex than that of Main primarily due to the use of shorter sentences, as opposed to drastically simplified syntax or vocabulary. Comparing the two language varieties by the Gunning readability index supports this conclusion. We also report on the topical dependence of language complexity, that is, that the language is more advanced in conceptual articles compared to person-based (biographical) and object-based articles. Finally, we investigate the relation between conflict and language complexity by analyzing the content of the talk pages associated to controversial and peacefully developing articles, concluding that controversy has the effect of reducing language complexity