Effects of remote annual forcing in the eastern tropical Atlantic Ocean

An ocean model is used to study the effects of remote annual forcing in the eastern tropical Atlantic. The model is linear, viscid and continuously stratified. The ocean basin is an idealized version of that of the tropical Atlantic, and the wind stress forcing the model is an idealized representation of the annual variation of the equatorial trades in the western Atlantic. Solutions are represented as expansions of the baroclinic modes of the system. The response of each mode is found numerically, not by integrating the equations of motion forward in time, but at a fixed frequency (2π year–1) using techniques that are typically used in models of the tides. Prominent features of the solution are the following. When the remote trades strengthen, sea level drops and the pycnocline rises markedly throughout the Gulf of Guinea. At 4W the annual response is tightly trapped to the equator and to the coast of Africa near 5N. In contrast, the response propagates offshore along the southern coast of Africa near 10E. Events propagate upward everywhere in the Gulf of Guinea and poleward (nearly) everywhere along the coast of Africa. These features compare favorably with observations. A single baroclinic mode does not dominate the response. Instead, waves associated with several modes superpose to form beams that propagate energy vertically as well as horizontally (McCreary, 1984). Along the equator the response is predominantly a combination of a beam of equatorial Kelvin waves and a lowest order (l – 1) Rossby beam. Along the coast of Africa at 5N it is primarily a beam of coastal Kelvin waves

Psychosocial Risk Factors for Health-Related Quality of Life in Adult Congenital Heart Disease

Background: There is variability in the impact of adult congenital heart disease (ACHD) on health-related quality of life (HRQoL). A greater insight into the impact of ACHD may be gained from investigating HRQoL in various diagnostic groups and considering the importance of psychosocial risk factors for poor HRQoL. / Objective: We compared the HRQoL of people with ACHD with normative data from the general population and among 4 diagnostic groups and identified risk factors for poor HRQoL in ACHD from a comprehensive set of sociodemographic, clinical, and psychosocial factors. / Methods: We conducted a cross-sectional study with 303 participants from 4 diagnostic groups Simple, Tetralogy of Fallot, Transposition of the Great Arteries, Single Ventricle who completed measures of illness perceptions, coping, social support, mood, and generic and disease-specific HRQoL. Data were analyzed using 1-sample t tests, analysis of variance, and hierarchical multiple regressions. / Results: There was diminished psychosocial HRQoL in the Simple group compared with the general population. Consistently significant risk factors for poor HRQoL included younger age, a perception of more severe symptoms due to ACHD, depression, and anxiety. Clinical factors were poor predictors of HRQoL. / Conclusions: The findings highlight the need to develop intervention studies aiming to improve HRQoL in people with ACHD and the routine assessment of illness perceptions and mood problems during key periods in people's lives. This will help address patient misconceptions that could be tackled by clinicians or specialist nurses during routine outpatient appointments and identify people in need of psychological support

Cognitive dysfunction in Adult Congenital Heart Disease with different structural complexity

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. 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. 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. 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

Climate fluctuations of tropical coupled system: The role of ocean dynamics

The tropical oceans have long been recognized as the most important region for large-scale ocean–atmosphere interactions, giving rise to coupled climate variations on several time scales. During the Tropical Ocean Global Atmosphere (TOGA) decade, the focus of much tropical ocean research was on understanding El Niño–related processes and on development of tropical ocean models capable of simulating and predicting El Niño. These studies led to an appreciation of the vital role the ocean plays in providing the memory for predicting El Niño and thus making seasonal climate prediction feasible. With the end of TOGA and the beginning of Climate Variability and Prediction (CLIVAR), the scope of climate variability and predictability studies has expanded from the tropical Pacific and ENSO-centric basis to the global domain. In this paper the progress that has been made in tropical ocean climate studies during the early years of CLIVAR is discussed. The discussion is divided geographically into three tropical ocean basins with an emphasis on the dynamical processes that are most relevant to the coupling between the atmosphere and oceans. For the tropical Pacific, the continuing effort to improve understanding of large- and small-scale dynamics for the purpose of extending the skill of ENSO prediction is assessed. This paper then goes beyond the time and space scales of El Niño and discusses recent research activities on the fundamental issue of the processes maintaining the tropical thermocline. This includes the study of subtropical cells (STCs) and ventilated thermocline processes, which are potentially important to the understanding of the low-frequency modulation of El Niño. For the tropical Atlantic, the dominant oceanic processes that interact with regional atmospheric feedbacks are examined as well as the remote influence from both the Pacific El Niño and extratropical climate fluctuations giving rise to multiple patterns of variability distinguished by season and location. The potential impact of Atlantic thermohaline circulation on tropical Atlantic variability (TAV) is also discussed. For the tropical Indian Ocean, local and remote mechanisms governing low-frequency sea surface temperature variations are examined. After reviewing the recent rapid progress in the understanding of coupled dynamics in the region, this study focuses on the active role of ocean dynamics in a seasonally locked east–west internal mode of variability, known as the Indian Ocean dipole (IOD). Influences of the IOD on climatic conditions in Asia, Australia, East Africa, and Europe are discussed. While the attempt throughout is to give a comprehensive overview of what is known about the role of the tropical oceans in climate, the fact of the matter is that much remains to be understood and explained. The complex nature of the tropical coupled phenomena and the interaction among them argue strongly for coordinated and sustained observations, as well as additional careful modeling investigations in order to further advance the current understanding of the role of tropical oceans in climate

Psychosocial Risk Factors for Health-Related Quality of Life in Adult Congenital Heart Disease

Background There is variability in the impact of adult congenital heart disease (ACHD) on health-related quality of life (HRQoL). A greater insight into the impact of ACHD may be gained from investigating HRQoL in various diagnostic groups and considering the importance of psychosocial risk factors for poor HRQoL. Objective We compared the HRQoL of people with ACHD with normative data from the general population and among 4 diagnostic groups and identified risk factors for poor HRQoL in ACHD from a comprehensive set of sociodemographic, clinical, and psychosocial factors. Methods We conducted a cross-sectional study with 303 participants from 4 diagnostic groups Simple, Tetralogy of Fallot, Transposition of the Great Arteries, Single Ventricle who completed measures of illness perceptions, coping, social support, mood, and generic and disease-specific HRQoL. Data were analyzed using 1-sample t tests, analysis of variance, and hierarchical multiple regressions. Results There was diminished psychosocial HRQoL in the Simple group compared with the general population. Consistently significant risk factors for poor HRQoL included younger age, a perception of more severe symptoms due to ACHD, depression, and anxiety. Clinical factors were poor predictors of HRQoL. Conclusions The findings highlight the need to develop intervention studies aiming to improve HRQoL in people with ACHD and the routine assessment of illness perceptions and mood problems during key periods in people's lives. This will help address patient misconceptions that could be tackled by clinicians or specialist nurses during routine outpatient appointments and identify people in need of psychological support