Geostrophic current estimation using altimeter data at ground track crossovers in the northwest Pacific Ocean

Geostrophic current comprises a large portion of the ocean current, which plays an important role in global climate change. Based on classic oceanography, geostrophic current can be derived from pressure gradient. Assuming water density to be constant, we can estimate geostrophic current from Absolute Dynamic Topography （ADT）. In this paper, we use ADT data obtained from multi-satellite altimeters to extract sea surface tilts along- track at crossover points. The calculated tilts along these two tracks can be converted into orthogonal directions and are used to estimate geostrophic current. In northwest Pacific, computed geostrophic current velocities are evaluated with Argos data. In total, 771 pairs of temporally and spatially consistent Argos measurements along with estimated geostrophic velocity datasets are used for validation. In this study, the effect of different cut-off wavelengths of the low pass filter applied to ADT is discussed. Our results show that a cut-offwavelength of 75 km is the most suitable choice for the study area. The estimated geostrophic velocity and the Argos measurement are in good agreement with each other, with a correlation coefficient of 0.867 for zonal component, and 0.734 for meridional one. Furthermore, an empirical relationship between the estimated geostrophic velocity and Argos measurement is derived, providing us a favorable and convenient approach to estimate sea surface flow velocity from the geostrophic velocity derived from altimeter data. The experimental application of the derived method on Kuroshio reveals reasonable results compared with previous studies.

Clinical efficacy observation of thalamic pain treated with acupuncture under the guidance of evidence-based medicine

Objective To study the feasibility of the crossover trial design and the minimal imbalance index random distribution method in the clinical small-sample-size randomized controlled trial（RCT） research of thalamic pain treated with acupuncture under the guidance of evidence-based medicine（EBM）.Methods The crossover trial design was adopted.Eleven cases with the definite diagnosis were randomized into a program-I group（6 cases,treated with acupuncture before western medicine） and a program-II group（5 cases,treated with western medicine before acupuncture） according to the minimal imbalance index method.In the statistical analysis,the groups were named as an acupuncture group and a western medicine group separately,11 cases in each one.Acupuncture was applied to Xìmén（郄门 PC 4）,Yīnxì（阴郄 HT 6）,Xuèhǎi（血海 SP 10）,etc.In the control treatment,Carbamazepine was prescribed for oral administration.Either the duration of treatment or the wash-out period was 10 days.The visual analogue scale（VAS） was adopted for the efficacy assessment.Results The total effective was 100.0%（11/11） after treatment in either group.The remarkably effective rates were 63.6%（7/11） and 36.4%（4/11） in the acupuncture group and the western medicine group separately,without statistically significant difference in comparison.Conclusion The crossover trial design and the minimal imbalance index distribution method can accomplish RCT of the clinical acupuncture and moxibustion research with the small sample size involved.They can provide the high-quality evidences for clinical acupuncture research.Acupuncture therapy can achieve the same therapeutic effect as Carbamazepine,the common western medicine,and the efficacy of it is potentially superior to that of western medicine.