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Simple Principle (simple + principle)
Selected AbstractsComparative ecology of seed mass in Psychotria (Rubiaceae): within- and between-species effects of seed mass on early performanceFUNCTIONAL ECOLOGY, Issue 4 2005H. PAZ Summary 1Experimental field data and interspecific comparative analyses were used to detect effects of seed mass on seedling performance within and among seven species of Psychotria sown in gaps and shaded rainforest sites. In addition we compared the effects of seed mass within and among species to detect concordance between the two ecological scales. We used two comparative methods: phylogenetically independent contrasts and cross-species correlations. 2Among species, we detected weak evidence of a positive correlation between seed mass and the probability of emergence in the shaded forest, and no effects of seed mass in gaps. 3Among species, no significant correlations between seed mass and either seedling survival or seedling recruitment were found in any habitat. Other variables specific to each subgenus appear to be more important than seed mass in determining survival in the shaded forest. 4There was a negative correlation between seed mass and relative growth rate (RGR) in both habitats. In gaps, small-seeded taxa exhibited particularly high RGR, compensating for the initial advantages of higher seed mass. 5All species studied exhibited recruitment in gaps equal to or higher than that in the shaded forest. However, recruitment success in shaded forest relative to gaps increased with seed mass, indicating a higher affinity for shaded forest among larger-seeded taxa, but this relationship was only detected using PICS analysis. 6.,Correlations between seed mass and seedling mass are similar within and among species, indicating a simple principle of mass transference. In contrast, correlations between seed mass and seedling emergence, seedling survival, seedling recruitment and RGR depend on the scale at which they are observed. [source] Preparing sagittae for examination of daily growth increments of young-of-the-year fishes: a modification of the embed methodJOURNAL OF FISH BIOLOGY, Issue 2 2005G. Plaza A modification (termed the slide-glass-embed-method, SGEM) of the embed method for preparing fish sagittae is described. The SGEM is based on a very simple principle: a dome of mixed resin containing the embedded sagittae loses hardness after being heated and can be easily cut with dissecting scissors. [source] The Limiting Density of Unit Root Test Statistics: A Unifying TechniqueJOURNAL OF TIME SERIES ANALYSIS, Issue 3 2000Mithat Gonen In this note we introduce a simple principle to derive a constructive expression for the density of the limiting distribution, under the null hypothesis, of unit root statistics for an AR(1)-process in a variety of situations. We consider the case of unknown mean and reconsider the well-known situation where the mean is zero. For long-range dependent errors we indicate how the principle might apply again. We also show that in principle the method also works for a near unit root case. Weak convergence and subsequent Karhunen-Loeve expansion of the weak limit of the partial sum process of the errors plays an important role, along with the evaluation of a certain normal type integral with complex mean and variance. For independent and long range dependent errors this weak limit is ordinary and fractional Brownian motion respectively. AMS 1991 subject classification. Primary 62M10; secondary 62E20. [source] A characterization of generalized concordance rules in multicriteria decision makingINTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 7 2003Didier Dubois This article proposes a principled approach to multicriteria decision making (MCDM) where the worth of decisions along attributes is not supposed to be quantified, as in multiattribute utility theory, or even measured on a unique scale. This approach actually generalizes additive concordance rules a la Electre and is rigorously justified in an axiomatic way by representation theorems. We indeed show that the use of a generalized concordance (GC) rule is the only possible approach when in a purely ordinal framework and that the satisfaction of very simple principles forces the use of possibility theory as the unique way of expressing the importance of coalitions of criteria. © 2003 Wiley Periodicals, Inc. [source] Paediatric airway management: basic aspectsACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 1 2009R. J. HOLM-KNUDSEN Paediatric airway management is a great challenge, especially for anaesthesiologists working in departments with a low number of paediatric surgical procedures. The paediatric airway is substantially different from the adult airway and obstruction leads to rapid desaturation in infants and small children. This paper aims at providing the non-paediatric anaesthesiologist with a set of safe and simple principles for basic paediatric airway management. In contrast to adults, most children with difficult airways are recognised before induction of anaesthesia but problems may arise in all children. Airway obstruction can be avoided by paying close attention to the positioning of the head of the child and by keeping the mouth of the child open during mask ventilation. The use of oral and nasopharyngeal airways, laryngeal mask airways, and cuffed endotracheal tubes is discussed with special reference to the circumstances in infants. A slightly different technique during laryngoscopy is suggested. The treatment of airway oedema and laryngospasm is described. [source] Towards effective nutritional management of waste outputs in aquaculture, with particular reference to salmonid aquaculture operationsAQUACULTURE RESEARCH, Issue 5 2010Dominique P Bureau Abstract Long-term sustainability of many fish culture operations may be dependent on their ability to reduce their waste outputs. The release of solid wastes is mainly a function of the digestibility of various dietary components, and the release of dissolved wastes is mainly a function of the metabolism of nutrients by the fish. Consequently, simple principles of nutrition and models have been effectively used to describe, predict and manage the excretion of wastes by fish. Nutritional strategies offer a direct and effective way of managing waste output by aquaculture operations. Very significant reduction in waste outputs per unit of fish produced, notably in terms for solid and phosphorus wastes, have been achieved over the past few decades by commercial fish culture operations. Further reduction in waste outputs could be achieved through fine-tuning of feed formulations, judicious use of feed additives and processing/refining of ingredients. A better understanding of the basis of the effect of various endogenous (biological) and exogenous (dietary, environmental) factors on nutrient utilization by fish could also contribute to the development of strategies for reducing waste outputs. The present paper provides a brief overview of issues and challenges related to potential environmental impacts of wastes, and of recent progresses relative to nutritional strategies aimed at better management of the release of wastes by aquaculture operations. [source] | ||||||||||