Joint observation of the concentric gravity wave event on the Tibetan Plateau

A concentric gravity wave event was captured by a photographer in NagarzêCounty(90.28°N,28.33°E)between 02:00 and 04:00(local time)on May 11,2019.This concentric gravity wave event was also observed by the Suomi National Polar-orbiting Partnership satellite and the all-sky airglow imager at Yangbajing station(90.5°E,30.1°N).The temporal and spatial information on gravity waves from the photographs provided a rare opportunity to study the propagation of gravity waves over the Tibetan Plateau.According to wind and temperature data from the MERRA-2 reanalysis(Modern-Era Retrospective analysis for Research and Applications,Version 2)and empirical models(NRLMSISE-00[Naval Research Laboratory Mass Spectrometer and Incoherent Scatter Radar Exosphere]and HWM[horizontal wind model]),we inversely derived the propagation trajectory from the observed wave pattern to the source region by using the ray-tracing method.The source of the concentric gravity wave was identified as deep convection in Bangladesh(90.6°E,25.0°N).The maximum background wind speed in the propagation direction(31.05 m/s)was less than the phase speed of 53 m/s,which is consistent with the wind-filtering theory.

SPA: A Quantitation Strategy for MS Data in Patient-derived Xenograft Models

With the development of mass spectrometry(MS)-based proteomics technologies,patient-derived xenograft(PDX),which is generated from the primary tumor of a patient,is widely used for the proteome-wide analysis of cancer mechanism and biomarker identification of a drug.However,the proteomics data interpretation is still challenging due to complex data deconvolution from the PDX sample that is a cross-species mixture of human cancerous tissues and immunodeficient mouse tissues.In this study,by using the lab-assembled mixture of human and mouse cells with different mixing ratios as a benchmark,we developed and evaluated a new method,SPA(shared peptide allocation),for protein quantitation by considering the unique and shared peptides of both species.The results showed that SPA could provide more convenient and accurate protein quantitation in human–mouse mixed samples.Further validation on a pair of gastric PDX samples(one bearing FGFR2 amplification while the other one not)showed that our new method not only significantly improved the overall protein identification,but also detected the differential phosphorylation of FGFR2 and its downstream mediators(such as RAS and ERK)exclusively.The tool pdx SPA is freely available at https://github.com/LiLab-Proteomics/pdx SPA.