Understanding Rapid Adjustments to Diverse Forcing Agents.

Rapid adjustments are responses to forcing agents that cause a perturbation to the top of atmosphere energy budget but are uncoupled to changes in surface warming. Different mechanisms are responsible for these adjustments for a variety of climate drivers. These remain to be quantified in detail. It is shown that rapid adjustments reduce the effective radiative forcing (ERF) of black carbon by half of the instantaneous forcing, but for CO2 forcing, rapid adjustments increase ERF. Competing tropospheric adjustments for CO2 forcing are individually significant but sum to zero, such that the ERF equals the stratospherically adjusted radiative forcing, but this is not true for other forcing agents. Additional experiments of increase in the solar constant and increase in CH4 are used to show that a key factor of the rapid adjustment for an individual climate driver is changes in temperature in the upper troposphere and lower stratosphere.

Quantifying the Importance of Rapid Adjustments for Global Precipitation Changes.

Different climate drivers influence precipitation in different ways. Here we use radiative kernels to understand the influence of rapid adjustment processes on precipitation in climate models. Rapid adjustments are generally triggered by the initial heating or cooling of the atmosphere from an external climate driver. For precipitation changes, rapid adjustments due to changes in temperature, water vapor, and clouds are most important. In this study we have investigated five climate drivers (CO2, CH4, solar irradiance, black carbon, and sulfate aerosols). The fast precipitation responses to a doubling of CO2 and a 10-fold increase in black carbon are found to be similar, despite very different instantaneous changes in the radiative cooling, individual rapid adjustments, and sensible heating. The model diversity in rapid adjustments is smaller for the experiment involving an increase in the solar irradiance compared to the other climate driver perturbations, and this is also seen in the precipitation changes.

Partnerships for the future. A new vision for the Catholic healthcare ministry.

Collaboration among healthcare providers will help them more effectively meet the needs of their communities in the 1990s. San Francisco-based Catholic Healthcare West (CHW), formed in 1986, strives to provide high-quality healthcare by collaborating with Catholic and non-Catholic providers. CHW leaders believe that Catholic providers make ideal partners; however, they have found that Catholic healthcare providers often must look outside the Catholic healthcare ministry to find these partnership opportunities in order to remain viable and effectively carry out their mission. Besides system-to-system or hospital-to-hospital linkages, collaboration is also achievable with other types of healthcare providers, such as physicians. In collaborations between Catholic and non-Catholic healthcare providers, Catholic providers must strive to maintain their Catholic identity. When evaluating potential partners, they must consider issues such as corporate culture, organizational compatibility, and sponsor influence. CHW leaders believe that for any merger or affiliation to be successful, it must clearly produce market and financial advantages for the new partnership and offer the community a significant improvement in quality of care and services.

Dissecting thoracic aortic aneurysm in a 16-year-old.

A 16-year-old boy presented with a one-hour history of left lower extremity pain and weakness, and was found to have a dissecting aortic aneurysm. The patient underwent emergency aortic angiography and immediate reparative aortic aneurysm surgery. He died on the fifth postoperative day. Because the majority of cases occur in the fifth to sixth decade of life, dissecting aortic aneurysm is a rare and usually fatal condition in adolescents. Potentially favorable outcome in this age group depends on prompt diagnosis and immediate medical and surgical intervention.

Atrial fibrillation--a marker for abnormal left ventricular function in coronary heart disease.

Retrospective study of 1176 patients with known coronary heart disease by cardiac catheterisation disclosed 10 patients (0.8%) with atrial fibrillation. Comparison with 25 randomly selected patients with coronary heart disease with sinus rhythm showed that atrial fibrillation correlated significantly with impaired haemodynamic function, mitral regurgitation, and abnormalities of left ventricular contraction. Atrial fibrillation is, therefore, a useful marker of extensive myocardial dysfunction.

Electron microscopic and peroxidase cytochemical analysis of pink pseudo-Chediak-Higashi granules in acute myelogenous leukemia.

Giant round pink inclusions (congruent to 2 micrometers) were seen in neutrophilic myeloblasts, promyelocytes, and myelocytes from three patients with acute myelogenous leukemia. On preliminary examination of the bone marrow smears, these inclusions looked like ingested red blood cells in that they were pink and not azurophilic. The bone marrow specimens were processed for the electron microscopic demonstration of peroxidase with 3,3'-diaminobenzidine and H2O2 at pH 7.6. In all three cases, the inclusions were determined to be large peroxidase-positive granules since they were limited by a single unit membrane and, unlike endocytized red blood cells, were not contained within phagocytic vasuoles. The granules were homogeneously dense for peroxidase and showed no obvious crystalline structure when examined stained or unstained on grid. We believe that they correspond to the giant pink round granules Van Slyck and Rebuck observed in immature leukemic granulocytes in 1974 and termed the pseudo-Chediak-Higashi anomaly. Like the giant purple granules seen in leukemia with this anomaly, these granules also appear to be an abnormal variant of peroxidase-positive azurophil (primary) granules. Their lack of azurophilia is due to the absence of sulfated glycoaminoglycans.

Renal arteriovenous fistula masquerading as severe valvar heart disease.

Two patients with renal arteriovenous fistulae are described, who presented in high output failure. Murmurs were detected in these patients on routine physical examination years before, and when cardiac failure ensued they were assumed to have decompensated valvar heart disease. Full investigation revealed the arteriovenous fistulae and both patients made a good recovery after surgical ligation.

Unusual complications of coronary bypass surgery.

Five patients after coronary bypass surgery developed unusual complications. Three developed new apical thrombi which are thought to be due to the trauma of the left ventricular vent or deterioration of the left ventricular contraction. Significant new mitral regurgitation in one patient probably is secondary to papillary muscle dysfunction as the result of stenosis distal to anastomoses. The leakage of angoigraphic material around distal anastomatic site is due to technical error. Although these unusual complications are very rare, however, they should be considered as potential source of morbidity in asymptomatic patients who leave the hospital after bypass surgery.