Applicability of Bevis Formula at Different Height Levels and Global Weighted Mean Temperature Model Based on Near-earth Atmospheric Temperature

Weighted mean temperature(T m)is a critical parameter in Global Navigation Satellite System(GNSS)technology to retrieve precipitable water vapor(PWV).It is convenient to obtain high-precision T m estimates near surface utilizing Bevis formula and surface temperature.However,some researches pointed out that the Bevis formula has large uncertainties in high-altitude regions.We investigate the applicability of the Bevis formula at different height levels and find that the Bevis formula has relatively high precision when the altitude is low,while with altitude increasing,the precision decreases gradually.To solve the problem,we analyze the relationship between T m and atmospheric temperature within the near-earth space range(the height range between 0~10 km)and find that they have a high correlation on a global scale.Accordingly,we build a global weighted mean temperature model based on near-earth atmospheric temperature.Validation results of the model show that this model can provide high-precision T m estimation at any height level in the near-earth space range.

Carrier phase-based ionospheric observables using PPP models

The ionosphere is one of the major error sources in Global Navigation Satellite System （GNSS） posi- tioning, navigation and timing. Estimating the ionospheric delays precisely is of great interest in the GNSS community. To date, GNSS observables for ionospheric estimation are most commonly based on carrier phase smoothed code measurements. However, leveling errors, which affect the performance of ionospheric modeling and differential code bias （DCB） estimation, exist in the carrier phase smoothed code observations. Such leveling errors are caused by the multipath and the short-term variation of DCB. To reduce these leveling errors, this paper investigates and estimates the ionospheric delays based on carrier phase measurements without the leveling errors. The line-of-sight ionospheric observables with high precision are calculated using precise point positioning （PPP） techniques, in which carrier phase measurements are the principal observables. Ionosphere-free and UofC PPP models are applied and compared for their effectiveness to minimize the leveling errors. To assess the leveling errors, single difference of ionospheric observables for a short baseline is examined. Results show that carrier phase- derived ionospheric observables from PPP techniques can effectively reduce the leveling errors. Furthermore, we compared the PPP ionosphere estimation model with the conventional carrier phase smoothed code method to assess the bias consistency and investigate the biases in the ionospheric observables.

LncRNA CFAR promotes cardiac fibrosis via the miR-449a-5p/LOXL3/mTOR axis

Cardiac fibrosis is one of the crucial pathological factors in the heart,and various cardiac conditions associated with excessive fibrosis can eventually lead to heart failure.However,the exact molecular mechanism of cardiac fibrosis remains unclear.In the present study,we show that a novel lnc RNA that we named cardiac fibrosis-associated regulator(CFAR)is a profibrotic factor in the heart.CFAR was upregulated in cardiac fibrosis and its knockdown attenuated the expression of fibrotic marker genes and the proliferation of cardiac fibroblasts,thereby ameliorating cardiac fibrosis.Moreover,CFAR acted as a ce RNA sponge for mi R-449a-5p and derepressed the expression of LOXL3,which we experimentally established as a target gene of mi R-449a-5p.In contrast to CFAR,mi R-449a-5p was found to be significantly downregulated in cardiac fibrosis,and artificial knockdown of mi R-449a-5p exacerbated fibrogenesis,whereas overexpression of mi R-449a-5p impeded fibrogenesis.Furthermore,we found that LOXL3 mimicked the fibrotic factor TGF-β1 to promote cardiac fibrosis by activating m TOR.Collectively,our study established CFAR as a new profibrotic factor acting through a novel mi R-449a-5p/LOXL3/m TOR axis in the heart and therefore might be considered as a potential molecular target for the treatment of cardiac fibrosis and associated heart diseases.

Analysis of the global T_m–T_s correlation and establishment of the latitude-related linear model

In this study,the correlation between Tm,a key variable in GNSS water vapor inversion,and surface temperature(Ts)was calculated on a global scale based on the global geodetic observing system(GGOS)atmosphere Tmdata and European centre for medium-range weather forecasts(ECMWF)surface temperature data.The results show that their correlation is mainly affected by latitudes,and the correlation is stronger at high latitudes and weaker at low latitudes.Although the correlation is relatively weak in the tropic areas,the temperature changes so little in a year in these areas that we can still achieve good Tmresults by linear regression model.Based on these facts,‘‘GGOS atmosphere’’Tmdata and ECMWF Tsdata from 2005 to2011 were used to establish the global latitude-related linear regression model.The new model has root mean square error(RMSE)of 3.2,3.3,and 4.4 K,respectively,compared with respect to the‘‘GGOS atmosphere’’data,COSMIC data,and radiosonde data and is more accurate than the Bevis Tm–Tsrelationship.

Acetyl salicylic acid attenuates cardiac hypertrophy through Wnt signaling

Ventricular hypertrophy is a powerful and independent predictor of cardiovascular morbid events. The vascular properties of low-dose acetyl salicylic acid （aspirin） provide cardiovascular benefits through the irreversible inhibition of platelet cyclooxygenase 1; however, the possible anti-hypertrophic properties and potential mechanism of aspirin have not been investigated in detail. In this study, healthy wild-type male mice were randomly divided into three groups and subjected to transverse aortic constriction （TAC） or sham operation. The TAC-operated mice were treated with the human equivalent of low-dose aspirin （10 mg·kg^-1· d^-1）; the remaining mice received an equal amount of phosphate buffered saline with 0.65% ethanol, which was used as a vehicle. A cardiomyocyte hypertrophy model induced by angiotensin II （10 nmol· L^-1） was treated with the human equivalent of low （10 or 100μmol·L^-1） and high （1000μmol·L^-1） aspirin concentrations in plasma. Changes in the cardiac structure and function were assessed through echocardiography and transmission electron microscopy. Gene expression was determined through RT-PCR and western blot analysis. Results indicated that aspirin treatment abrogated the increased thickness of the left ventricular anterior and posterior walls, the swelling of mitochondria, and the increased surface area in in vivo and in vitro hypertrophy models. Aspirin also normalized the upregulated hypertrophic biomarkers, p-myosin heavy chain （IS-MHC）, atrial natriuretic peptide （ANP）, and b-type natriuretic peptide （BNP）. Aspirin efficiently reversed the upregulation of β-catenin and P-Akt expression and the TAC- or ANG II-induced downregulation of GSK-3~. Therefore, low-dose aspirin possesses significant anti-hypertrophic properties at clinically relevant concentrations for anti-thrombotic therapy. The downregulation of β-catenin and Akt may be the underlying signaling mechanism of the effects of aspirin.