"Nonspecific" chest pain associated with high long-term mortality: results from the primary prevention study in G?teborg, Sweden

BACKGROUND: The syndrome angina pectoris with effort-related chest pain or discomfort is usually easy to recognize. However, vague and nonspecific symptoms may cause little reason for extensive evaluation. The prognosis of such patients in the general population has so far not been well described. HYPOTHESIS: The study was undertaken to investigate long-term prognosis in men with chest pain considered to be nonspecific in comparison with men with typical angina pectoris (AP) or prior myocardial infarction (MI), and men without chest pain. METHODS: At the second screening of the G?teborg Primary Prevention Study in 1974-1977, 6,488 men aged 51 to 59 years at baseline were available for the present analysis. Men who had responded positively to a postal questionnaire about chest pain during exercise or at rest were interviewed by a physician according to a Rose questionnaire at the screening examination. Those with typical or probable AP were further examined by single experienced physician. The following four groups were formed: Group 1: men who did not complain of chest pain (n = 5,545). Group 2: men who had not consulted any doctor because of chest pain, but who had chest pain according to a questionnaire (n = 441); these men were not considered to have AP according to a three-step examination by experienced physicians. Group 3: typical AP (n = 232). Group 4: men who had suffered an MI (n = 134). RESULTS: During 16 years of follow-up, coronary heart disease (CHD) mortality for Groups 1-4 was 8.0, 19.5, 24.8, and 48.5%, respectively. Mortality from all cardiovascular diseases was 11.5, 24.5, 31.2, and 59.0%, respectively. Noncardiovascular disease mortality was 14.1, 17.7, 14.3, and 8.7%, respectively. Thus, the relative risk (RR) for CHD mortality among men with nonspecific chest pain (Group 2) was 2.77 [95% confidence interval (CI) 2.20, 3.50], for all cardiovascular disease mortality 2.46 (95% CI 2.00, 3.02), and for noncardiovascular disease mortality 1.60 (95% CI 1.28, 2.00). Total mortality in this group was as high (44%) as among those with typical AP (45%), but the highest mortality was found among men with a previous MI (68%). In men without chest pain it was 26%. Patients of Groups 2-4 had higher levels of cardiovascular risk factors than those in Group 1. Neither any specific questions in the Rose questionnaire, nor electrocardiographic changes at rest (uncommon) were of prognostic significance. Serum cholesterol, systolic blood pressure, diabetes, and smoking were significant predictors of outcome, both with respect to fatal CHD and to total mortality during the 16-year follow-up. CONCLUSION: We found a high cardiovascular as well as noncardiovascular mortality among patients with chest pain who had not been considered to have AP at a three-step examination procedure. It is important to be suspicious of early CHD symptoms in men (and women?) with "nonspecific" chest symptoms and to analyze their cardiovascular risk factor pattern further because they are at considerably higher risk for future events than those in whom CHD is not suspected.     

Region-Based Active Contours with Exponential Family Observations

In this paper, we focus on statistical region-based active contour models where image features (e.g. intensity) are random variables whose distribution belongs to some parametric family (e.g. exponential) rather than confining ourselves to the special Gaussian case. In the framework developed in this paper, we consider the general case of region-based terms involving functions of parametric probability densities, for which the anti-log-likelihood function is a special case. Using shape derivative tools, our effort focuses on constructing a general expression for the derivative of the energy (with respect to a domain), and on deriving the corresponding evolution speed. More precisely, we first show by an example that the estimator of the distribution parameters is crucial for the derived speed expression. On the one hand, when using the maximum likelihood (ML) estimator for these parameters, the evolution speed has a closed-form expression that depends simply on the probability density function. On the other hand, complicating additive terms appear when using other estimators, e.g. method of moments. We then proceed by stating a general result within the framework of multi-parameter exponential family. This result is specialized to the case of the anti-log-likelihood function with the ML estimator and to the case of the relative entropy. Experimental results on simulated data confirm our expectations that using the appropriate noise model leads to the best segmentation performance. We also report preliminary experiments on real life Synthetic Aperture Radar (SAR) images to demonstrate the potential applicability of our approach.     

A model for micro-slip between flat surfaces based on deformation of ellipsoidal elastic asperities—parametric study and experimental investigation

Micro-slip is a phenomenon that occurs between contacting surfaces when a frictional load, less than that necessary to produce macro-slip, is applied to the contacting surfaces. A model is evaluated for micro-slip between a flat smooth surface and a flat rough surface. The rough surface is covered with uniformly distributed ellipsoidal elastic asperities. The results from simulations of the model show that anisotropy, material combination and number of contacts of the contacting surfaces influence the tangential stiffness at zero displacement, the length of the micro-slip zone and the energy dissipated in the contact. An experimental investigation verifies the results computed by the model.     

Measuring active wood fracture surfaces

This report describes a measurement method, based on image processing, for calculating the proportion of active wood fractures in a sheet of particle board that has been pulled apart. This method gives an indirect measurement of the effectiveness of the glue in a particle board. The basic procedure is to separate different surfaces on both sides of the tensile fracture. The separation of the glue covered surfaces from wood surfaces has been enhanced by a development process. The separated surfaces for each side, represented in the form of a binary image, are added, and a proportion of the surface with coinciding wood surfaces represents the proportion of wood fractures. The error analysis covers the randomly obtained coinciding surfaces.     

Probe diffusion in κ-carrageenan gels determined by fluorescence recovery after photobleaching

The effects of free volume and heterogeneity on probe diffusion in κ-carrageenan gels were determined by fluorescence recovery after photobleaching (FRAP) and rheology. By changing the ionic conditions, biopolymer concentration and end temperature, different microstructures and aggregation kinetics in the κ-carrageenan gels were evaluated. The results of the FRAP measurements were compared to transmission electron microscopy (TEM) and nuclear magnetic resonance diffusometry (NMRd) data from previous studies. The results showed that the free diffusion rates of the probe (FITC dextran) in water were influenced by both temperature and ionic conditions. The free diffusion values were used for normalization of the diffusion rates in the κ-carrageenan gel measurements. The compatibility between FITC dextran with different molecular weights (10 and 500 kDa) and κ-carrageenan was evaluated. The results showed that the larger FITC dextran probe phase separates; therefore only the 10 kDa FITC dextran probe was used in the FRAP experiments. FRAP measurements and NMRd probe diffusion in combination with TEM in κ-carrageenan revealed that the void space, degree of aggregation and heterogeneity influence the probe diffusion rate. The κ-carrageenan gelation was analyzed at different end temperatures using rheology and FRAP. The FITC dextran probe diffusion was not influenced by κ-carrageenan aggregation, regardless of rheological gelation kinetics and storage modulus near the gel point. This indicates that the average void space between the gel strands is larger than the size of the probe. Good correlation between the microstructure and the probe diffusion rate in κ-carrageenan gel with different ionic conditions and constant biopolymer concentration were obtained with TEM and FRAP.     

Ten MVA air-gap armature winding: thermal, structural anddielectric results

This paper describes the armature winding built as part of MIT's 10 MVA superconducting generator project. The winding has a helical winding form, is an air-gap winding having no iron teeth in the active region, employs a limited voltage gradient insulation scheme and is cooled by an insulating fluid. Structurally, the winding employs bonded joints between the conductors and structural tubes, which are of filament-wound fiber-reinforced plastic. Preliminary tests indicated that thermal performance of this winding was satisfactory. On the other hand, the winding suffered a catastrophic insulation failure after only a short time at high voltage. The resulting fault gave the structural system of the armature winding (and the rest of the machine) a good test. In this paper the authors review the major aspects of the design of the winding, describe the thermal tests and then tell of the insulation failure. They can, at best, speculate about the cause of that failure, but they can, on the basis of this experience, make recommendations for further development of machines of this type     

Application of Ozone in Full-Scale to Reduce Filamentous Bulking Sludge at Öresundsverket WWTP

The return sludge of one of the four treatment lines at Öresundsverket WWTP in Sweden was subjected to ozonation in full-scale to reduce filamentous bulking sludge. The biological nitrogen and phosphorus removal capacity along with effluent parameters were studied throughout the trial. Samples were also taken to track possible changes in microbial population due to ozone. 2.8–5.0 g O₃ kg^?1 treated SS^?1 reduced the DSVI of the ozone-treated line from 170 to 100 mL g^?1 and the reference line remained at 150 mL g^?1. No adverse effect on the biological nitrification- or the phosphorus removal rates could be detected. The microbial population of the two lines did not exhibit any substantial changes which can be correlated to ozone addition.