Progress in satellite gravity recovery from implemented CHAMP,GRACE and GOCE and future GRACE Follow-On missions

Firstly, the Earth＇s gravitational field from the past Challenging Minisatellite Payload （CHAMP） mission is determined using the energy conservation principle, the combined error model of the cumulative geoid height influenced by three instrument errors from the current Gravity Recovery and Climate Experiment （GRACE） and future GRACE Follow-On missions is established based on the semi-analytical method, and the Earth＇s gravitational field from the executed Gravity Field and Steady-State Ocean Circulation Explorer （GOCE） mission is recovered by the space-time-wise approach. Secondly, the cumulative geoid height errors are 1.727 × 10^-1 m, 1.839 × 10^-1 m and 9.025 × 10^ -2 m at degrees 70,120 and 250 from the implemented three-stage satellite gravity missions consisting of CHAMP, GRACE and GOCE, which preferably accord with those from the existing earth gravity field models involving EIGEN-CHAMP03S, EICEN-GRACE02S and GO_CONS GCF 2 DIR R1. The cumulative geoid height error is 6.847 × 10 ^-2 m at degree 250 from the future GRACE Follow-On mission. Finally, the complementarity among the four-stage satellite gravity missions including CHAMP, GRACE, GOCE and GRACE Follow-On is demonstrated contrastively.

A study on the effect of using mangrove leaf extracts as a feed additive in the progress of bacterial infections in marine ornamental fish

Objective:To ascertain the feasibility of using sustainable natural resources in maintaining disease free fish in such establishments.Methods:causative bacteria were identified by morphology and biochemical techniques.The antibacterial activity and disease resistant capability of mangrove plant leaf extract were investigated against fish pathogens.Results:The infected marine ornamental fishes were collected from the hatchery condition and inhibition activity at the concentration of 220,200,175 and 150μg/mL against Pseudomonas fluorescens,Pseudomonas aeruginosa,Vibrio parahaemolyticus,and Vibrio anguillarum respectively.The experimental trial reveals feeding marine ornamental fish with feed incorporated with a methanol leaf extract of Avicennia marina,increases their survival and reduces their susceptibility to infections from the isolated bacteria.Based on the in vitro assay,methanol extract of Avicennia marina was exhibited good Conclusions:The mangrove leaves have potential to control the infections caused by Pseudomonas fluorescens,Pseudomonas aeruginosa,Vibrio parahaemolyticus and Vibrio anguillarum.