Validity Ecological

Ito A. and Oikawa T. (2002). A simulation model of the carbon cycle in land ecosystems (Sim-CYCLE) A description based on dry-matter production theory and plot scale validation. Ecological Modelling, 151, 143-176. 

In some cases carefully parameterized, tested, and validated ecological models can substitute field studies and experiments. This is shown by the following example from rabies management in red fox populations. 

Member States shall ensure the efficient organization of separate collection and, where appropriate, the setting up of a deposit system. Furthermore, Member States may introduee measures such as economic instruments in order to encourage recycling. These measures must be introduced after consultation with the parties concerned, be based on valid ecological and economic criteria and avoid distortions of competition. 

Multi-residue Method S19 of the DFG Manual,including Cieanup Procedure Xll-6 (gel-chromatographic cleanup), has been used successfully in many laboratories because of its broad applicability for the gas-chromatographic determination of pesticide residues in foodstuffs. DFG method S19 is also included in the respective European Standards. Subsequently, a modification of the extraction and partition step has been implemented. The modified method requires less experimental effort and eliminates the use of dichloromethane, which is an undesirable solvent for toxicological and ecological reasons. As the results from validation studies demonstrate,... 

The major function of cutin is to serve as the structural component of the outer barrier of plants. As the major component of the cuticle it plays a major role in the interaction of the plant with its environment. Development of the cuticle is thought to be responsible for the ability of plants to move onto land where the cuticle limits diffusion of moisture and thus prevents desiccation [141]. The plant cuticle controls the exchange of matter between leaf and atmosphere. The transport properties of the cuticle strongly influences the loss of water and solutes from the leaf interior as well as uptake of nonvolatile chemicals from the atmosphere to the leaf surface. In the absence of stomata the cuticle controls gas exchange. The cuticle as a transport-limiting barrier is important in its physiological and ecological functions. The diffusion across plant cuticle follows basic laws of passive diffusion across lipophylic membranes [142]. Isolated cuticular membranes have been used to study this permeability and the results obtained appear to be valid... 

In situations with no observed data, one possible means to evaluate status is to use a similar analogous site for which data are available, and to assume that the assessment made from the observed data can be applied validly to both sites. The site for which data are available must have good status according to the WFD. For instance, bodies subject to similar pressures and with similar characteristics could be grouped. It is noteworthy that proximity cannot be taken on its own as an indication of similarity since the features of the catchments, such as climate, topography and ecology, can change abruptly. 

Boyle, T.P., S.E. Finger, R.L. Paulson and C.F. Rabeni. 1985. Comparison of laboratory and field assessment of fluorene. Part II. Effects on the ecological structure and function of experimental pond ecosystems. Pages 134-151 in T.P. Boyle (ed.). Validation and Predictability of Laboratory Methods for Assessing the Fate and Effects of Contaminants in Aquatic Ecosystems. ASTM STP 865. American Society for Testing and Materials, Philadelphia, PA. 

Risk assessment Some participants suggested that further development and validation of appropriate methods to assess the ecological risks of chemical agents are required. Dose-response curves should be established at the community and ecosystem levels. Several participants suggested that when applying for an exemption of chemicals according to the Stockholm Convention, China might need to support its application with risk-based analysis. 

Kabourakis, E. (1996). Prototyping and dissemination of ecological olive production systems a methodology for designing and a first step towards validation and dissemination of prototype ecological olive production systems (POPS) in Crete. Landbouw University Wageningen Wageningen. 

Barkley, R.A. (1991) The ecological validity of laboratory and analogue assessment methods of ADHD symptoms. J Abnorm Child Psychol 19 149-178. 

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