Evidence of remote forcing in the Equatorial Atlantic ocean

An analysis of sea-surface temperature (STT) and surface winds in selected areas of the Tropical Atlantic indicates that the nonseasonal variability of SST in the Eastern Equatorial Atlantic (Gulf of Guinea) is highly correlated with the nonseasonal variability of the zonal wind stress in the Western Equatorial Atlantic. A negative (positive) anomaly of the zonal wind stress near the North Brazilian coast is followed by a positive (negative) SST anomaly in the Gulf of Guinea about one month later. Furthermore, the correlation betweenthe local winds stress anomaly and STT anomaly in the Gulf of Guinea is considerably smaller. These preliminary results indicate that remote forcing in the Western Equatorial Atlantic ocean is an important factor affecting the Eastern Equatorial Atlantic sea-surface temperature. Recent equatorial theories are consistent with these observations. (Résumé d'auteur

The equatorial West Pacific fresh pool at the end of the La Nina event in October/November 1996

The salinity, temperature and current distributions have been measured during the TROPAC cruise (Oct./Nov. 1996) at two sections, i.e. 143°E and 150°E, during the final phase of the 1995/1996 La Niña. The results present evidence that the fresh pool and the salinity front at its eastern boundary had moved far to the west, and that a barrier layer existed in that phase. The observed currents support the idea that advective processes play an essential role in creating the thermohaline structure during this ENSO phase. In relation with this process, it is found that the westward subduction mechanism of relatively dense eastern equatorial waters may apply during that phase

Equatorial adjusment in the Eastern Atlantic

Observations suggest that the annual upwelling event in the Gulf of Guinea is not associated with changes in the local winds. A possible explanation is that a strong upwelling signal, generated by increased westward wind stress in the Western Atlantic as an equatorially trapped Kelvin wave. This explanation is analogous to current theories of El Nino in the Pacific Ocean. (Résumé d'auteur

Haemodynamic consequences of targeted single- and dual-site right ventricular pacing in adults with congenital heart disease undergoing surgical pulmonary valve replacement

Aims The purpose of this study was to create an epicardial electroanatomic map of the right ventricle (RV) and then apply post-operative-targeted single- and dual-site RV temporary pacing with measurement of haemodynamic parameters. Cardiac resynchronization therapy is an established treatment for symptomatic left ventricular (LV) dysfunction. In congenital heart disease, RV dysfunction is a common cause of morbidity—little is known regarding the potential benefits of CRT in this setting. Methods and results Sixteen adults (age = 32 ± 8 years; 6 M, 10 F) with right bundle branch block (RBBB) and repaired tetralogy of Fallot (n = 8) or corrected congenital pulmonary stenosis (n = 8) undergoing surgical pulmonary valve replacement (PVR) for pulmonary regurgitation underwent epicardial RV mapping and haemodynamic assessment of random pacing configurations including the site of latest RV activation. The pre-operative pulmonary regurgitant fraction was 49 ± 10%; mean LV end-diastolic volume (EDV) 85 ± 19 mL/min/m2 and RVEDV 183 ± 89 mL/min/m2 on cardiac magnetic resonance imaging. The mean pre-operative QRS duration is 136 ± 26 ms. The commonest site of latest activation was the RV free wall and DDD pacing here alone or combined with RV apical pacing resulted in significant increases in cardiac output (CO) vs. AAI pacing (P < 0.01 all measures). DDDRV alternative site pacing significantly improved CO by 16% vs. AAI (P = 0.018), and 8.5% vs. DDDRV apical pacing (P = 0.02). Conclusion Single-site RV pacing targeted to the region of latest activation in patients with RBBB undergoing PVR induces acute improvements in haemodynamics and supports the concept of ‘RV CRT’. Targeted pacing in such patients has therapeutic potential both post-operatively and in the long term

Proceedings of US - PRC international TOGA symposium

A series of 12 meridional transect along longitude 165°E in the Western Equatorial Pacific ocean were made between mid-1986 and mi-1988 : a time interval spanning an El Nino/Southern Oscillation (ENSO) event. Data collected on these cruises provide a detailed (albeit temporally sparse) view of the oceanic changes which occur in the Western Pacific during an ENSO event. The present work focuses on the evolution of the upper ocean thermohaline and zona velocity fields as revealed by high resolution hydrographic casts and direct near surface velocity measurements. (D'après résumé d'auteur

Cognitive Dysfunction in Adult Chd With Different Structural Complexity

OBJECTIVE: We carried out a cross-sectional study to assess cognitive function in a sample of adult CHD patients, within the Functioning in Adult Congenital Heart Disease study London. The association between cognitive functioning and disease complexity was examined. METHODS: A total of 310 patients participated in this study. Patients were classified into four structural complexity groups – tetralogy of Fallot, transposition of the great arteries, single ventricle, and simple conditions. Each patient underwent neuropsychological assessment to evaluate cognitive function, including memory and executive function, and completed questionnaires to assess depression and anxiety. RESULTS: Among all, 41% of the sample showed impaired performance (>1.5 SD below the normative mean) on at least three tests of cognitive function compared with established normative data. This was higher than the 8% that was expected in a normal population. The sample exhibited significant deficits in divided attention, motor function, and executive functioning. There was a significant group difference in divided attention (F=5.01, p=0.002) and the mean total composite score (F=5.19, p=0.002) between different structural complexity groups, with the simple group displaying better cognitive function. CONCLUSION: The results indicate that many adult CHD patients display impaired cognitive function relative to a healthy population, which differs in relation to disease complexity. These findings may have implications for clinical decision making in this group of patients during childhood. Possible mechanisms underlying these deficits and how they may be reduced or prevented are discussed; however, further work is needed to draw conclusive judgements

ENSO indices from sea surface salinity observed by Aquarius and Argo

Analysis of the first 26 months of data from the Aquarius satellite confirms the existence of a sharp sea surface salinity (SSS) front along the equator in the western equatorial Pacific. Following several earlier studies, we use the longitudinal location of the 34.8-psu isohaline as an index, termed Niño-S34.8, to measure the zonal displacement of the SSS front and consequently the eastern edge of the western Pacific warm pool. The on-going collection of the Array for Real-time Geostrophic Oceanography (ARGO) program data shows high correlations between Niño-S34.8 and the existing indices of El Niño, suggesting its potential important role in ENSO evolution. Further analysis of the ARGO data reveals that SSS variability in the southeastern tropical Pacific is crucial to identify the type of El Niño. A new SSS index, termed the southeastern Pacific SSS index (SEPSI), is defined based on the SSS variability in the region (0°-10°S, 150°-90°W). The SEPSI is highly correlated with the El Niño Modoki index, as well as the Trans-Niño index, introduced by previous studies. It has large positive anomalies during central Pacific El Niño or El Niño Modoki events, as a result of enhanced zonal sea surface temperature gradients between the central and eastern tropical Pacific, and can be used to characterize the type of El Niño. The processes that possibly control these SSS indices are also discussed. © 2014 The Oceanographic Society of Japan and Springer Japan