A New Photogrammetric Inspection Method for National Flags with Pentagrams

National flags are very important symbols of countries.They represent the countries’s authority and dignity of a country.However,there are some occasions where the flags were produced incorrectly(or as frauds)but still hung officially without a formal inspection.In this paper,we propose a photogrammetric inspection method for hanging national flags of China,for which only one single image is required to perform the inspection.The proposed method allows automatic estimation of the relative positions and orientation of the pentagrams,so exposure of inappropriate flags can be identified avoided.The method invokes a novel 2D geometric model of a pentagram(five-pointed star)to constrain an adjustment to estimate the camera’s exterior orientation parameters based on a single image of a statically hung flag.Conventional error parameters such as the radial distortion parameters are integrated into the pentagram model to form a calibration process to reduce the 3D reconstruction errors.Once the camera and the distortion parameters are estimated,the relative positions,orientations,and dimensions of all the five pentagrams can be readily computed with independent pentagram fitting so the flag quality can be verified using the national standard.More than 20 different hanging flags were captured to verify the proposed method.The results indicate that the method is flexible and accurate,with an accuracy of 1.1mm for the position/dimension,and 0.2°for the orientation on average.Since the method is based on the proposed geometric model of the pentagram,it can be readily adapted to form another system to verify other countries’national flags containing more than one pentagram.

Functional metabolomics reveal the role of AHR/GPR35 mediated kynurenic acid gradient sensing in chemotherapy-induced intestinal damage

Intestinal toxicity induced by chemotherapeutics has become an important reason for the interruption of therapy and withdrawal of approved agents. In this study, we demonstrated that chemotherapeutics-induced intestinal damage were commonly characterized by the sharp upregulation of tryptophan(Trp)àkynurenine(KYN)àkynurenic acid(KA) axis metabolism. Mechanistically,chemotherapy-induced intestinal damage triggered the formation of an interleukin-6(IL-6)àindoleamine2,3-dioxygenase 1(IDO1)àaryl hydrocarbon receptor(AHR) positive feedback loop, which accelerated kynurenine pathway metabolism in gut. Besides, AHR and G protein-coupled receptor 35(GPR35) negative feedback regulates intestinal damage and inflammation to maintain intestinal integrity and homeostasis through gradually sensing kynurenic acid level in gut and macrophage, respectively. Moreover, based on virtual screening and biological verification, vardenafil and linagliptin as GPR35 and AHR agonists respectively were discovered from 2388 approved drugs. Importantly, the results that vardenafil and linagliptin significantly alleviated chemotherapy-induced intestinal toxicity in vivo suggests that chemotherapeutics combined with the two could be a promising therapeutic strategy for cancer patients in clinic.This work highlights GPR35 and AHR as the guardian of kynurenine pathway metabolism and core component of defense responses against intestinal damage.

Reopen schools safely:simulating COVID-19 transmission on campus with a contact network agent-based model

As the COVID-19 vaccination has been quickly rolling out around the globe,the evaluation of the effects of vaccinating populations for the safe reopening of schools has become a focal point for educators,decision-makers,and the general public.Within this context,we develop a contact network agent-based model(CN-ABM)to simulate on-campus disease transmission scenarios.The CN-ABM establishes contact networks for agents based on their daily activity patterns,evaluates the agents’health status change in different activity environments,and then simulates the epidemic curve.By applying the model to a real-world campus environment,we identify how different community risk levels,teaching modalities,and vaccination rates would shape the epidemic curve.The results show that without vaccination,retaining under 50%of on-campus students can largely flatten the curve,and having 25%on-campus students can achieve the best result(peak value<1%).With vaccination,having a maximum of 75%on-campus students and at least a 45%vaccination rate can suppress the curve,and a 65%vaccination rate can achieve the best result.The developed CN-ABM can be employed to assist local government and school officials with developing proactive intervention strategies to safely reopen schools.