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Panorpa vulgaris   has become a model insect for testing theories of sexual selection. This contribution summarizes that which has been learned in recent years and presents new data that clearly show that the mating system of P. vulgaris is not simply a resource-defense polygyny, as has previously been thought. In P. vulgaris neither the pattern in food exploitation nor the ratio of variance in the lifetime reproductive success of the two sexes is in accordance with that expected in resource defense polygynous mating systems. Lifetime mating duration is the most important proximate determinant of male fitness. Males employing alternative mating tactics obtain copulations of varying duration in relation to the following sequence: saliva secretion  1  food offering  1  no gift. The number of salivary masses which males provide to females during their lifetime is significantly correlated with the lifetime condition index. The condition index depends on the fighting prowess of males and their ability to find food items. Thus saliva secretion of Panorpa is considered a Zahavian handicap, which can serve as an honest quality indicator used by mating females. Our results confirm four main predictions of the indicator model of the theory of sexual selection: (a) the indicator signals high ecological quality of its bearer, (b) the indicator value increases with phenotypic quality, (c) the indicator value is positively correlated with the genetic quality affecting offspring fitness in a natural selection context, and (d) the quality indicator is more costly for low- than for high-quality individuals. The evolutionary consequences of the mating pattern and the sperm competition mechanism in P. vulgaris are discussed in the context the way in which sexual selection creates and maintains sperm mixing and the evolution of a promiscuous mating system.  相似文献   
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Weathering rates of base cations are crucial in critical load calculations and assessments of sustainable forestry. The weathering rate on a single site with detailed geological data can be modelled using the PROFILE model. For environmental assessments on a regional scale, the weathering rates for sites are scaled into regional maps. The step from sites to regional level requires focus on the spatial variation of weathering rates. In this paper, a method is presented by which weathering rates are calculated for 25589 Swedish sites with total elemental analysis for the soil. Based on a part of the results, a methodology for creating area covering maps by geostatistical analysis and kriging is described. A normative reconstruction model was used to transform total elemental analysis to mineralogy. Information from the Swedish Forest Inventory database and other databases were used to derive texture and other important information for the sites, e.g. climate, deposition and vegetation data. The calculated weathering rates show a regional pattern that indicates possibilities for interpolation of data in large parts of Sweden. Geostatistical analysis of an area in southern Sweden shows different properties for different base cations. Kriging was performed for potassium to demonstrate the method. It was concluded that different base cations and different regions have to be analysed separately, in order to optimise the kriging method.  相似文献   
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Safety climate in Finnish- and Swedish-speaking companies.   总被引:1,自引:0,他引:1  
The aim of this study was to compare assessments made by Finnish- and Swedish-speaking workers in Finland about the safety climate in their companies, because an earlier study showed that the accident frequency of Swedish-speaking workers was one third lower than that of Finnish-speaking workers. 148 Finnish-speaking and 138 Swedish-speaking workers from 14 small and medium-sized companies participated in this study. They filled out a Finnish safety climate questionnaire, the reliability of which was above the acceptable level. There were no differences between the language groups in the total variables of safety climate and safety action. Based on the differences in single items, we interpreted that Swedish-speaking workers stressed collective safety more, whereas Finnish-speaking workers put more emphasis on their personal responsibility for safety.  相似文献   
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Dendrogeomorphology is a powerful tool to determine past avalanche activity, but whether or not the obtained annually resolved chronologies are sufficiently detailed to infer avalanche–climate relationships (in terms of temporal resolution) remains an open question. In this work, avalanche activity is reconstructed in five paths of the French Alps and crossed with a set of snow and weather variables covering the period 1959–2009 on a monthly and annual (winter) basis. The variables which best explain avalanche activity are highlighted with an original variable selection procedure implemented within a logistic regression framework. The same approach is used for historical chronologies available for the same paths, as well as for the composite tree-ring/historical chronologies. Results suggest that dendrogeomorphic time series allow capturing the relations between snow or climate and avalanche occurrences to a certain extent. Weak links exist with annually resolved snow and weather variables and the different avalanche chronologies. On the contrary, clear statistical relations exist between these and monthly resolved snow and weather variables. In detail, tree rings seem to preferentially record avalanches triggered during cold winter storms with heavy precipitation. Conversely, historical avalanche data seem to contain a majority of events that were released later in the season and during episodes of strong positive temperature anomalies.  相似文献   
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Environmental Science and Pollution Research - Banana is one of the most important agricultural products of Ecuador. It relies on intensive monoculture cropping systems with a large volume of...  相似文献   
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This article shows oily sawdust gasification research on countercurrent installation. Experimental research was on a laboratory scale. The main purpose of the experiment was combustible gas production with higher CH4 concentration. Gas concentrations like CO, CO2, CH4, H2, and CnHm determine syngas composition. The technological parameter’s value defines experimental conditions. Value of this was fuel to air ratio. With fuel to air ratio change, syngas composition was a differential phenomenon where it depended on the process parameters like temperature. Additionally, evaluation of methane formation from CO, H2, and CO2 was done. Methanization coefficients were based on CO and CO2 hydrogenation reactions. Component’s activity was in analogs way to syngas components changed.

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