Baltic Sea ice SAR segmentation and classification using modified pulse-coupled neural networks

A method for segmentation and classification of Baltic Sea ice synthetic aperture radar (SAR) images, based on pulse-coupled neural networks (PCNNs), is presented. Also, automated training, which is based on decomposing the total pixel value distribution into a mixture of class distributions, is presented and discussed. The algorithms have been trained and tested using logarithmic scale Radarsat-1 ScanSAR Wide mode images over the Baltic Sea ice. Before the decomposition into mixture of class distributions, an incidence angle correction, specifically designed for these Baltic Sea ice SAR images, is applied. Because the data distributions in the uniform areas of these images are very close to Gaussian distributions, the data are decomposed into a mixture of Gaussian distributions, using the Expectation-Maximazation algorithm. Only uniform image areas are used in the decomposition phase. The mixture of distributions is compared to the distributions of the Baltic Sea ice classes, based on earlier scatterometer measurements and visual video interpretations of the sea ice classes. The parameter values for the PCNN segmentation are defined based on this mixture of distributions. The PCNN segmentation results are also compared to the operational sea ice information of digitized ice charts and to visual interpretation of the sea ice class.     

Urban small area variation in adolescents' health behaviour

Our previous study indicated that region plays a relatively small role in adolescents' health behaviour. Here, the regional patterning of health behaviour is studied further by shifting the focus to small areas. First, we test whether small area socioeconomic, demographic and housing characteristics correlate with health behaviour. The analysis then turns to the relationship between these characteristics and their individual level correlates. We wish to ascertain if behaviour is related to small area characteristics similarly for both genders and for adolescents' socioeconomic characteristics. The Adolescent Health and Lifestyle Survey data from 1989-1995 (16- and 18-year-olds, n = 1048, response rate 71%) were linked with data describing 33 subareas of Helsinki, the capital of Finland. Smoking, alcohol use, abstention from dietary fat and physical activity were used as lifestyle indicators. Gender apparently influences the extent to which the area plays a role. Logistic regression demonstrated that prolonged unemployment predicted low prevalence of abstention from dietary fat (traditional dietary patterns) among girls and heavy drinking among boys. High total rate of unemployment predicted lower physical activity among girls. Also owner-occupied housing correlated positively with girls' physical activity. Although the individual level socioeconomic characteristics were not as strongly related to health behaviour as the small area factors, a low level of education predicted smoking and alcohol use and, among girls, decreased physical activity. We conclude that small area characteristics, especially the level of unemployment of the area, may be even more strongly related to health behaviour than individual socioeconomic characteristics.     

Inhomogeneous compression of PEMFC gas diffusion layer: Part II. Modeling the effect

The effect of inhomogeneous compression of GDL on the mass and charge transfer in PEMFC is studied. The model utilizes experimentally evaluated GDL parameters as a function of thickness. The modeling results are compared with a conventional model that excludes the effects. As a result, it is shown that the inhomogeneous compression has a significant effect on the current density distribution because of the varying contact resistance between GDL and electrode. This also implies that there are possible hot spots occurring inside the electrode, and thus inhomogeneous compression can have significant effects on the lifetime and local performance of the cell. According to the achieved results, the inhomogeneous compression of GDL cannot be neglected.     

Sex difference in the incidence of insulin-dependent diabetes mellitus: an analysis of the recent epidemiological data. World Health Organization DIAMOND Project Group

Myocarditis is thought to be commonly caused by various viruses, and accumulating evidence links viral myocarditis with the eventual development of dilated cardiomyopathy. Recently, the importance of hepatitis C virus infection was noted in patients with dilated and hypertrophic cardiomyopathy. Cytokines are being increasingly recognized as an important factor in the pathogenesis and pathophysiology of myocarditis and cardiomyopathy. Elevated levels of circulating cytokines have been reported in patients with heart failure, and various cytokines have been shown to depress myocardial contractility in vitro and in vivo. A number of reports have shown that cytokines generated by activated immune cells cause an increase in nitric oxide (NO) via induction of NO synthase. Increased generation of NO may induce negative inotropism and myocardial damage. This review discusses the etiology and pathogenesis of myocarditis and cardiomyopathy from this point of view.     

Neuropeptide Y: a novel link between the neuroendocrine system and cholesterol metabolism

High serum total and low-density lipoprotein (LDL) cholesterol levels constitute the main risk factor for atherosclerotic vascular diseases. Both genetic and environmental factors are involved in the regulation of serum cholesterol levels. Neuropeptide Y (NPY), which is widely expressed in both the central and peripheral nervous systems, is known to regulate food intake and energy balance but its role in cholesterol metabolism has remained almost untouched in former literature. A newly discovered association between a leucine(7)-to-proline(7) polymorphism (Pro(7)) in the signal peptide of NPY and a high cholesterol level may provide new ideas for the genetic regulation of cholesterol metabolism. The presence of the Pro(7) in NPY results in serum total cholesterol levels 0.6-1.4 mmol/L higher compared with subjects without this gene variant. The Pro(7) in NPY was detected in 14% of Finns but only in 6% of Dutchmen, and its impact on serum cholesterol concentration seems to be stronger in obese than in normal-weight subjects. At least among Finns, the Pro(7) in NPY is one of the strongest genetic factors identified thus far affecting serum cholesterol levels.     

The epidemic cycle of Chlamydia pneumoniae infection in eastern Finland, 1972-1987

The epidemic cycle of Chlamydia pneumoniae infection was examined in two areas in eastern Finland over a period of 15 years, 1972-87. The C. pneumoniae IgG antibody prevalence was determined with 5-year intervals in a random sample of the population aged 25-59 years. The total number of sera studied using immunofluorescence was 2387. In 1972 the antibody prevalence was 57% and it increased to 66% in 1977. Over the next 5 years the prevalence decreased to 44% in 1982, but by 1987 it had again increased to 59%. The temporal variation in prevalence was statistically significant (P < 0.001) and similar for both genders. Throughout the observation period the overall prevalence was 7-11% higher in men than in women (P < 0.01). The antibody prevalence increased with age, being the highest among the oldest study subjects of both genders. The periods of high and low prevalence alternated in an epidemic cycle (P < 0.001) of about 10 years.     

HLA antigens in psoriasis. A family study

HLA antigens were determined in 14 Finnish families with psoriatic members. The pedigrees of all families are presented. The results showed a clear association between HLA B13 and inheritable psoriasis, for all the 14 HLA analysed psoriatic patients in four families had B13. In one family all five psoriatic patients had the haplotype HLA-A10, Bw17; in two other families the association between Bw17 and psoriasis was less obvious. In three families six of the eight children with the haplotype A1, Bw37 had psoriasis. In all these families one parent had psoriasis or psoriatic relatives and the other parent contributed A1, Bw37. It is suggested that Bw37, in association with other genetic factors, indicates a high risk of developing psoriasis. In one family both the father with psoriatic arthritis and the son with post-urethritic Reiter's disease had A2, B27. This haplotype was also possibly associated with psoriatic arthritis in two families.     

An application of the GLUE methodology for estimating the parameters of the INCA-N model

The conceptual and parameter uncertainty of the semi-distributed INCA-N (Integrated Nutrients in Catchments-Nitrogen) model was studied using the GLUE (Generalized Likelihood Uncertainty Estimation) methodology combined with quantitative experimental knowledge, the concept known as 'soft data'. Cumulative inorganic N leaching, annual plant N uptake and annual mineralization proved to be useful soft data to constrain the parameter space. The INCA-N model was able to simulate the seasonal and inter-annual variations in the stream-water nitrate concentrations, although the lowest concentrations during the growing season were not reproduced. This suggested that there were some retention processes or losses either in peatland/wetland areas or in the river which were not included in the INCA-N model. The results of the study suggested that soft data was a way to reduce parameter equifinality, and that the calibration and testing of distributed hydrological and nutrient leaching models should be based both on runoff and/or nutrient concentration data and the qualitative knowledge of experimentalist.