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Mixed mountain forests of European beech (Fagus sylvatica L.), Norway spruce (Picea abies (L.) Karst), and silver fir (Abies alba Mill.) cover a total area of more than 10 million hectares in Europe. Due to altitudinal zoning, these forests are particularly vulnerable to climate change. However, as little is known about the long-term development of the productivity and the adaptation and mitigation potential of these forest systems in Europe, reliable information on productivity is required for sustainable forest management. Using generalized additive mixed models this study investigated 60 long-term experimental plots and provides information about the productivity of mixed mountain forests across a variety of European mountain areas in a standardized way for the first time. The average periodic annual volume increment (PAI) of these forests amounts to 9.3 m3ha−1y−1. Despite a significant increase in annual mean temperature the PAI has not changed significantly over the last 30 years. However, at the species level, we found significant changes in the growth dynamics. While beech had a PAI of 8.2 m3ha−1y−1 over the entire period (1980–2010), the PAI of spruce dropped significantly from 14.2 to 10.8 m3ha−1y−1, and the PAI of fir rose significantly from 7.2 to 11.3 m3ha−1y−1. Consequently, we observed stable stand volume increments in relation to climate change. [ABSTRACT FROM AUTHOR]

The algorithm for the solution of the first biharmonic problem by the Trefftz method is presented. The solution is purely mathematical and follows Mikhlin [29] approach to the solution of the harmonic problem. As such it fills in the gap in the approximate methods of Mathematical Physics. Validity of the algorithm is demonstrated on two examples. The boundary values of the sought function and its normal derivative must be given explicitly to achieve correct results by the algorithm. For that reason, the presented algorithm is, however, not adequate for the plane problems of the theory of elasticity or for plates with free or simply supported edges. [ABSTRACT FROM AUTHOR]

Tree structural diversity is assessed by modelling stand diameter at breast height (DBH) distribution. The aim of this study was to verify the suitability of a mixture of two- and three-component Weibull and gamma models for describing irregular and multimodal DBH distributions. Investigations were carried out in natural Abies alba Mill. and Fagus sylvatica L. stands, representing the growing-up stage, in the Świętokrzyski National Park (Central Poland) and in the Pieniny National Park (Southern Poland). Sample plots (0.25-0.5 ha in area) were selected from a database used for forest dynamics analysis. The parameters of the mixture model were estimated using maximum likelihood estimation (MLE) and a combination of an expectation-maximisation (EM) algorithm with a Newton-type (NT) method. The multistart method (MM) of choosing initial values was used. The DBH distributions in mixed Abies- Fagus forests of complex structure were accurately approximated by two- and three-component mixture models. The root mean square error (RMSE) values varied from 3.4515 to 7.6682 for the Weibull mixture and from 3.6457 to 7.1419 for the gamma mixture. The results indicated that the mixture Weibull and gamma models were, in general, equally suitable for modelling irregular and multimodal DBH distributions. Finite mixture models may be used to characterise tree structural diversity, especially in uneven-aged stands of complex structure. [ABSTRACT FROM AUTHOR]

Stomach data were examined to assess the key factors that determine diet composition in some of the most important demersal fish species in Icelandic waters and to identify major feeding guilds. The data were collected during the groundfish surveys conducted by the Marine Research Institute in 1992. The factors examined included geographic position, depth, season, and fish size. Data were analysed using multivariate methods: canonical correspondence analysis (CCA), non-metric multi-dimensional scaling (NMDS), and hierarchical clustering. For the CCA, important explanatory variables for the observed feeding patterns were found using forward stepwise selection. Fish size was the most important explanatory variable for most species, reflecting distinct ontogenetic shifts in diets. A large variation in diet composition was observed, and the CCA model explained 6–16% of the total variation. The spatial and seasonal variability in diets reflected, in general, patterns of prey availability. Among the main predators, the two major feeding guilds were (i) species preying mainly on echinoderms, supplemented with fish and other benthic invertebrates, and (ii) species preying mainly on crustaceans and fish. [Copyright &y& Elsevier]

The effect of reduced fishing effort on the demersal fish community, following area closures in 1993, was analysed for two protected areas off the east coast of Iceland, Digranesflak and Breiddalsgrunn. The data were collected using a standardized bottom trawl during groundfish surveys in the period 1985–2004. The aspects of the fish community that were analysed included abundance by size class, mean size, species richness, diversity, and composition. The analysis was conducted for closed areas and adjacent reference (fished) areas, as well as for periods before and after the closure (and also after the re-opening in Breiddalsgrunn), using an ANOVA model and planned comparisons. The closure had a favourable impact on abundance of haddock (Melanogrammus aeglefinus) and small long rough dab (Hippoglossoides platessoides) in Digranesflak, and on exploitable sizes of haddock and cod (Gadus morhua) in Breiddalsgrunn. The mean size of haddock increased considerably within the protected areas relative to the reference areas: by 16cm in Digranesflak and by 10cm in Breiddalsgrunn. Species richness, diversity, and composition varied over the study period and between areas, but no effect of area closure was found. The observed changes in the fish community in Breiddalsgrunn were reversed within 7 years of the re-opening of the area to fishing. The possible causes for the observed patterns of response to area closures are discussed. [Copyright &y& Elsevier]

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A rat model of amiodarone-induced pulmonary toxicity is described. The rats were fed, by gavage, 175 mg/kg/day of amiodarone hydrochloride suspended in methyl cellulose. Controls received methyl cellulose alone. Groups of rats were examined after 1, 3, 6, 9, and 12 weeks of feeding. We found that drug-fed rats had significantly more macrophages, neutrophils, and lymphocytes in the bronchoalveolar lavage (BAL). The early increase in cellularity was due to an increase in macrophages, and the macrophage count peaked after 6 weeks of drug treatment. The number of neutrophils in the experimental animals remained high throughout the course of the experiment. An increasing number of lymphocytes was seen in the BAL between 6 and 12 weeks of drug treatment. Protein in the lavage fluid was significantly elevated after 12 weeks of amiodarone exposure. Histologic sections were abnormal after 3 weeks of drug treatment, characterized by interstitial thickening with accumulation of mononuclear cells and alveoli packed with large foamy macrophages. There was only minimal evidence of fibrosis. This model appears to be very similar to human amiodarone-induced pulmonary toxicity and should be useful for the study of the pathogenesis of amiodarone-induced toxicity. [ABSTRACT FROM AUTHOR]

In model-building investigations the response of interest y is often a function of two or more components. The usual procedure in such situations is to use this function to compute the values of y for each run and then obtain the fitted equation ŷ = F(x[sub 1], x[sub 2, · · ·, [x[sub k]) relating ŷ to relevant process variables. In this article we suggest a different method that wilt sometimes be preferable: first fit equations to the component responses (either individually or in subsets) and then combine these equations to obtain the desired function F. The proposed method is especially useful when the usual procedure fails to produce a satisfactory model. A chemical example illustrates how, by using this method, a second-order model can be obtained from a first-order design (a two-level factorial design). [ABSTRACT FROM AUTHOR]