RESUMEN
Bio-economic farm models are tools to evaluate ex-post or to assess ex-ante the impact of policy and technology change on agriculture, economics and environment. Recently, various BEFMs have been developed, often for one purpose or location, but hardly any of these models are re-used later for other purposes or locations. The Farm System Simulator (FSSIM) provides a generic framework enabling the application of BEFMs under various situations and for different purposes (generating supply response functions and detailed regional or farm type assessments). FSSIM is set up as a component-based framework with components representing farmer objectives, risk, calibration, policies, current activities, alternative activities and different types of activities (e.g., annual and perennial cropping and livestock). The generic nature of FSSIM is evaluated using five criteria by examining its applications. FSSIM has been applied for different climate zones and soil types (criterion 1) and to a range of different farm types (criterion 2) with different specializations, intensities and sizes. In most applications FSSIM has been used to assess the effects of policy changes and in two applications to assess the impact of technological innovations (criterion 3). In the various applications, different data sources, level of detail (e.g., criterion 4) and model configurations have been used. FSSIM has been linked to an economic and several biophysical models (criterion 5). The model is available for applications to other conditions and research issues, and it is open to be further tested and to be extended with new components, indicators or linkages to other models.
Asunto(s)
Agricultura/economía , Modelos Biológicos , Modelos Económicos , Agricultura/métodos , Conservación de los Recursos Naturales , Ambiente , Política AmbientalRESUMEN
The present study sought to evaluate the characteristics of tooth wear in subjects with an acidic diet in relation to subjects with substantially different nutritional patterns. The evaluation included medieval skulls (group 1, n = 102, abrasive nutrition), study models of individuals living on an acidic diet (group 2, n = 100) and randomly selected subjects (group 3, n = 100, average Western diet). Wear was visually recorded on oral, vestibular and occlusal/incisal surfaces using quantitative and morphological criteria. The mean age was 42.3 +/- 15.3 yr in group 1, 40.9 +/- 11.2 yr in group 2 and 36.7 +/- 11.7 yr in group 3. Group 1 exhibited the most pronounced substance loss, followed by groups 2 and 3. On occlusal surfaces, cupping was common in group 1 followed by group 2, but was rare in group 3. An inverse relation was found for facets. On buccal surfaces, no substance loss was observed in group 1, whereas in group 2, 63% had at least one tooth with a buccal lesion compared to 8% in group 3. The occlusal substance loss observed in subjects exposed to acids may be interpreted as increased abrasion/demastication of acid-softened dental hard tissues. The occurrence of concavities on smooth surfaces appears to be significant for the diagnosis of dental erosion.