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BackgroundIt is generally unknown to what extent organ transplant recipients can be physically challenged. During an expedition to Mount Kilimanjaro, the tolerance for strenuous physical activity and high-altitude of organ transplant recipients after various types of transplantation was compared to non-transplanted controls.MethodsTwelve organ transplant recipients were selected to participate (2 heart-, 2 lung-, 2 kidney-, 4 liver-, 1 allogeneic stem cell-and 1 small bowel-transplantation). Controls comprised the members of the medical team and accompanying family members (n = 14). During the climb, cardiopulmonary parameters and symptoms of acute mountain sickness were recorded twice daily. Capillary blood analyses were performed three times during the climb and once following return.ResultsEleven of the transplant participants and all controls began the final ascent from 4700 meters and reached over 5000 meters. Eight transplant participants (73%) and thirteen controls (93%) reached the summit (5895m). Cardiopulmonary parameters and altitude sickness scores demonstrated no differences between transplant participants and controls. Signs of hyperventilation were more pronounced in transplant participants and adaptation to high-altitude was less effective, which was related to a decreased renal function. This resulted in reduced metabolic compensation.ConclusionOverall, tolerance to strenuous physical activity and feasibility of a high-altitude expedition in carefully selected organ transplant recipients is comparable to non-transplanted controls.

For the semi-detailed characterization of inland valleys systems in the Ivory Coast, transect sampling was used to describe valley morphology, soils, and land use characteristics. Initially, for each valley one transect with a width of 200 to 400 m was proposed. More recently, use of a larger number of transects has been suggested. However, there is no statistical basis for either the number of transects to be described or their optimal width. Two sets of aerial photographs (1979, scale 1:50 000, and 1996, scale 1:20 000) of the Boundiali key area were processed and the results digitized. Using GIS, sets of transects with different width were made, and used for the determination of the sample size for estimating the land use ratio and the valley bottom ratio at valley system level with given confidence intervals. These results were validated with data from the field and with sets of pre-selected transects. The calculated sample size is based on simple random sampling and depends on both transect width and variability in the study area. For the characterization of inland valleys with reasonable confidence intervals, the sample size for random sampling is too large for the semi-detailed characterization method. Smaller samples of transects selected on the basis of sub-recent aerial photographs gave comparable results for land cover characteristics estimation as the larger samples for random sampling. There is scope for reducing sample size by formalizing criteria for transect placement on the basis of the earlier aerial photographs.

In dit project zullen met MIPS nieuwe procedures ontwikkeld worden voor het conditioneren en acclimatiseren van enten van groentengewassen. Met MIPS kunnen de effecten van conditionering en acclimatisering op groei, stress en stressgevoeligheid van de enten in de kas nauwkeurig en snel gemeten worden. Op deze wijze wordt een flink aantal conditionering/acclimatisering combinaties in relatief korte tijd geanalyseerd. Uiteindelijk zal uit deze combinaties een aantal geselecteerd worden voor evaluatie en validatie onder praktijkcondities.

In dit project zullen met MIPS nieuwe procedures ontwikkeld worden voor het conditioneren en acclimatiseren van enten van groentengewassen. Met MIPS kunnen de effecten van conditionering en acclimatisering op groei, stress en stressgevoeligheid van de enten in de kas nauwkeurig en snel gemeten worden. Op deze wijze wordt een flink aantal conditionering/acclimatisering combinaties in relatief korte tijd geanalyseerd. Uiteindelijk zal uit deze combinaties een aantal geselecteerd worden voor evaluatie en validatie onder praktijkcondities.

Building on past classifications, this article proposes a comprehensive characterization of rice-growing environments in West Africa on the basis of ecological and agronomic parameters. Using climate, soils, toposequence, land types and rice cropping system as classificatory principles, 18 different environments are distinguished and their characteristics are summarized in three sets of tables. Current constraints to rice production in each of the environments and the implications for rice research are briefly highlighted, as well as the need for field-level verification of the characterization.

From 1995 until July 1st, 2005, the CAMASE Register of Agro-ecosystems Models was available as a searchable database on the Internet, hosted by Wageningen UR Library. This electronic-only edition of the Register contains the data present in the Register after the final update in June 1996.

From 1995 until July 1st, 2005, the CAMASE Register of Agro-ecosystems Models was available as a searchable database on the Internet, hosted by Wageningen UR Library. This electronic-only edition of the Register contains the data present in the Register after the final update in June 1996.

LUSA (Land Use Systems Analysis), a new methodology to develop sustainable agro-ecosystems as part of land-use planning, combines high-tech assessment methodologies, such as multicriteria computer models, with participatory methodologies. LUSA has been tested in Sub-Saharan West Africa

In vitro techniques have been introduced in potato seed production systems in recent years. This research project aimed at studying the morphological and physiological changes in plants and crops in the last three phases of a seed production system that included an in vitro multiplication, an in vitro normalisation (growing cuttings to rooted plantlets), a transplant production, and a tuber production (field) phase.Leaf area was identified as an important plant parameter for plant growth in the normalisation and transplant production phases. Explants and plantlets with larger initial leaf area performed better than those with smaller initial leaf area. In vitro treatments mainly affected leaf area of transplants through their effects on early above-ground leaf area. Leaf area increase was better described by logistic than by exponential or expolinear curves in all phases of growth, suggesting restriction of leaf area increase in all phases.Low temperature decreased leaf and stem dry weights in all phases, and increased tuber fresh and dry yields, average tuber weight, leaf/stem ratio, specific leaf area and harvest index in the tuber production phase. Growing in vitro plants at low normalisation temperatures increased leaf and total plant dry weights early in the transplant production and tuber production phases. It resulted in higher tuber yields, heavier individual tubers and higher harvest index.Fertilising plants with higher nitrogen (40 versus 10 mg N per plant) during transplant production resulted in plants with higher groundcover in the field. This led to higher interception of solar radiation and higher tuber yield in one of the two experiments. Growing plants at higher temperature (26/20 versus 12/18 °C) during transplant production increased leaf area at the end of the transplant production phase. After transplanting to the field, it resulted in crops with higher groundcover, which intercepted more incoming solar radiation. Yield tended to be higher, but differences could not be assessed as statistically significant. A glasshouse experiment showed that high temperature during transplant production increased leaf and stem dry weights in the tuber production phase, but reduced tuber dry weights and harvest index when temperatures during tuber production were high. Thus, high temperature during transplant production may favour haulm growth and light interception in the field, but may also reduce dry matter partitioning to tubers.Conditions in the tuber production phase were found to be of greater importance for final yield than conditions and treatments in earlier phases.Strategies to optimise the production and use of propagules and transplants should focus on achieving leafy starting material, reducing stress during changes in environment and optimising conditions during tuber production. Production of transplants should be adjusted to the expected growth conditions in the tuber production phase.Key words:Solanum tuberosum L., in vitro plantlet, seed production, normalisation, transplant production, tuber production, acclimatisation, leaf area, groundcover, logistic growth, temperature, nitrogen, dry matter production, specific leaf area, harvest index, radiation interception, radiation use efficiency.

In vitro techniques have been introduced in potato seed production systems in recent years. This research project aimed at studying the morphological and physiological changes in plants and crops in the last three phases of a seed production system that included an in vitro multiplication, an in vitro normalisation (growing cuttings to rooted plantlets), a transplant production, and a tuber production (field) phase.Leaf area was identified as an important plant parameter for plant growth in the normalisation and transplant production phases. Explants and plantlets with larger initial leaf area performed better than those with smaller initial leaf area. In vitro treatments mainly affected leaf area of transplants through their effects on early above-ground leaf area. Leaf area increase was better described by logistic than by exponential or expolinear curves in all phases of growth, suggesting restriction of leaf area increase in all phases.Low temperature decreased leaf and stem dry weights in all phases, and increased tuber fresh and dry yields, average tuber weight, leaf/stem ratio, specific leaf area and harvest index in the tuber production phase. Growing in vitro plants at low normalisation temperatures increased leaf and total plant dry weights early in the transplant production and tuber production phases. It resulted in higher tuber yields, heavier individual tubers and higher harvest index.Fertilising plants with higher nitrogen (40 versus 10 mg N per plant) during transplant production resulted in plants with higher groundcover in the field. This led to higher interception of solar radiation and higher tuber yield in one of the two experiments. Growing plants at higher temperature (26/20 versus 12/18 °C) during transplant production increased leaf area at the end of the transplant production phase. After transplanting to the field, it resulted in crops with higher groundcover, which intercepted more incoming solar radiation. Yield tended to be higher, but differences could not be assessed as statistically significant. A glasshouse experiment showed that high temperature during transplant production increased leaf and stem dry weights in the tuber production phase, but reduced tuber dry weights and harvest index when temperatures during tuber production were high. Thus, high temperature during transplant production may favour haulm growth and light interception in the field, but may also reduce dry matter partitioning to tubers.Conditions in the tuber production phase were found to be of greater importance for final yield than conditions and treatments in earlier phases.Strategies to optimise the production and use of propagules and transplants should focus on achieving leafy starting material, reducing stress during changes in environment and optimising conditions during tuber production. Production of transplants should be adjusted to the expected growth conditions in the tuber production phase.Key words:Solanum tuberosum L., in vitro plantlet, seed production, normalisation, transplant production, tuber production, acclimatisation, leaf area, groundcover, logistic growth, temperature, nitrogen, dry matter production, specific leaf area, harvest index, radiation interception, radiation use efficiency.

As the result of a recent BBSRC-funded workshop between soil scientists, modellers, statisticians and others to discuss issues relating to the derivation of complex environmental models, a set of modelling guidelines is presented and the required associated research areas are discussed.

In this report, methods are developed to estimate yield potentials of biomass crops in various regions within the European Union (EU-12). Different production levels are considered; firstly, the potential production level that can be realized when the crop is optimally supplied with water and nutrients and free from pests, diseases and weeds. Secondly, the so-called water-limited production level is recognized. In the water-limited situation, nutrients are in optimal supply and the crop is free of pests, diseases and weeds, but yield is limited by the availability of water

In this report, methods are developed to estimate yield potentials of biomass crops in various regions within the European Union (EU-12). Different production levels are considered; firstly, the potential production level that can be realized when the crop is optimally supplied with water and nutrients and free from pests, diseases and weeds. Secondly, the so-called water-limited production level is recognized. In the water-limited situation, nutrients are in optimal supply and the crop is free of pests, diseases and weeds, but yield is limited by the availability of water

This article contributes to the development of a general applicable method to characterise landscapes by presenting a technique to obtain data on actual land use by means of transect surveys and farmer interviews. This technique is developed as an alternative to existing ones which generate data on land use mainly as a by-product. As part of a multiscale agro-ecological characterisation methodology, the Integrated Transect Method (ITM) generates data at the semi-detailed level, and bridges gaps between disciplines, scales, and agro-ecological zones. The method is illustrated using bio-physical results from inland valley agro-ecosystems in two agro-ecological zones in Cote d'Ivoire, West Africa. So-called ‘agro-ecosystem diagrams’ offered scope for easy presentation of collected information. Additionally, various quantified land and land use characteristics were used to scale up data from the level of the transect, via inland valleys and valley systems to the level of the agro-ecological subunit. Application of ITM showed that this technique can be used effectively as a tool to analyse bio-physical differences in land use within landscapes and compare differences between them under different agro-ecological conditions. The required integration of bio-physical and socio-economic parameters, however, is the subject of further study.

This thesis describes mutation breeding and tissue culture techniques developed for accelerated domestication of winged bean ( Psophocarpustetragonolobus (L.) DC.). The tissue culture techniques, which are the first steps towards genetic transformation of the crop, include: (1) direct adventitious shoot formation from the axes of cotyledon explants; (2) direct simultaneous regeneration of adventitious shoots and somatic embryos; and (3) direct somatic embryogenesis on the wounds of cotyledon explants. An optimised mutation breeding technique for economic significance, based on the early selection of chlorophyll mutations generated from gamma-radiated seeds, has been developed. The use of this scheme has resulted in the recovery of seed coat colour mutants which have succesfully served as an indirect method for selecting changes in tannin content and nodulation. A desired mutant with reduced tannin content and improved nodulation was selected.

This thesis describes mutation breeding and tissue culture techniques developed for accelerated domestication of winged bean ( Psophocarpustetragonolobus (L.) DC.). The tissue culture techniques, which are the first steps towards genetic transformation of the crop, include: (1) direct adventitious shoot formation from the axes of cotyledon explants; (2) direct simultaneous regeneration of adventitious shoots and somatic embryos; and (3) direct somatic embryogenesis on the wounds of cotyledon explants. An optimised mutation breeding technique for economic significance, based on the early selection of chlorophyll mutations generated from gamma-radiated seeds, has been developed. The use of this scheme has resulted in the recovery of seed coat colour mutants which have succesfully served as an indirect method for selecting changes in tannin content and nodulation. A desired mutant with reduced tannin content and improved nodulation was selected.

CAMACASE developed a comprehensive register of agro-ecosystems models, in order to: increase awareness among scientists of existing models; increase accessibility of these models; stimulate harmonization and compatibility of models; stimulate use of models

CAMACASE developed a comprehensive register of agro-ecosystems models, in order to: increase awareness among scientists of existing models; increase accessibility of these models; stimulate harmonization and compatibility of models; stimulate use of models

This second progress report focuses on designing a theoretical prototype by linking parameters to methods and designing the methods in this context until they are ready for initial testing. The report focuses also on testing and improving the prototype in general and the methods in particular until the objectives as quantified in the set of parameters have been achieved by pilot groups, regional networks and national networks

After discussing some general problems in measuring sustainability, an identification of measurable criteria for the major agroecological problems is proposed, derived from explicit issues of unsustainability. The proposed criteria are briefly discussed. Factors which might influence the effect of inclusion of livestock in an agricultural system on each criterion are also discussed. It is argued that identification of livestock-specific criteria is impossible because of the large heterogeneity of livestock production systems and the non-linear relation between livestock-specific criteria and agroecological criteria. Therefore, a system-specific analysis is needed to assess the overall effect of livestock inclusion in an agricultural system on each of the proposed general criteria for sustainability. These are: demand and supply of consumable livestock products; potential human population supporting capacity; land area utilized for agriculture; degree of equity in food distribution; variability of production; net annual soil losses; nutrient balances and losses; water availability and utilization; soil organic matter; fossil energy and drug utilization. Such a system-specific analysis will also allow formulation of measurable criteria for other objectives, and an assessment of trade-offs between the criteria. Recognition of such trade-offs, together with the reduced acceptability of external effects (both in time and space), might appear to be the most important notion of the sustainability concept.

This research was inspired by the inability of agricultural research to deal adequately with phenomena of variation, diversity and heterogeneity in agriculture. Although these phenomena were observed as long ago as the beginning of this century, they are still causing concern. Until recently, analysis of variance was applied to any form of undesired variation in the experimental results. The statistical elimination of variation from the research coincided with attempts to uniformise agriculture in order to optimise production. For a long time, deviations from the standardised average were regarded as undesirable random effects.Recent research has shown that variations in yield are very common in agroecosystems. They may be large, especially under difficult climatic conditions, and may even be considered as an asset to farmers. There is evidence that variations are not random, but are the result of systematic interaction between environment, crop genotype and management. This agrodiversity has important relations with the higher-level heterogeneity of the environment and diversity of farm households. At present, no comprehensive approach to its analysis is available, largely because agrodiversity is basically multidimensional in nature and may comprise several levels of aggregation.The objective of this study was to contribute to the understanding of diversity in agroecosystems by focusing explicitly on variations of yield and their explanation at field and household level. Between 1991 and 1993, field work was done in one village in northern Cameroon. Yield variations of three crops, field properties, crop and management characteristics and household characteristics were assessed systematically. Various techniques for statistical analysis were employed to determine the magnitude of variation and to define the agrodiversity of Within the agroecosystern of the selected village, variations in yield were observed for rainfed sorghum, cotton and dry season sorghum. The magnitude of variation was more or less constant over the years of observation, but varied between the crops. Two rainfed sorghum cropping systems were distinguished and within one cropping system, three field types were defined according to their distance from the homestead. Thus stratified it was possible to reduce overall yield variation and to explain it within each stratum by a reduced number of variables. It was concluded that the composition of agrodiversity was not uniform over the strata. Yield levels, limitations and constraints of rainfed sorghum production were specific to each cropping system and field type.Of the three crops, yield variation was greatest in cotton, despite many efforts of the cotton agency to standardise its cultivation. This variation was explained by distinguishing between types of variables, each explaining cotton yield variation to a different degree and in a particular way. Dry season sorghum showed least variation in yield, although it is subject to great environmental stress. Crop genotype and management proved to be adapted to one dominant field property, i.e. the water holding capacity of the soil. All farmers, irrespective of ethnic or socio-economic origin, agreed about the need to adjust mouskouari sorghum cultivation to field characteristics that define the water availability. Processes at field level leading to agrodiversity could be summarised by (1) spatial differentiation of the fields, (2) mechanisation of labour and (3) adaptation of cultivation to the environment.Ethnic diversity explained the absolute difference in cotton production, and the distinction between rainfed sorghum cropping systems within the agroecosystem. Socio-economic diversity explained the relative differences in cotton yield, and the distinction between rainfed sorghum field types.Finally, gender differences highlighted variations in rainfed sorghum yields and in non-agricultural income. Gender differences and ethnic and socioeconomic diversity proved to be interrelated, resulting in at least three classes of women farmers.It must be concluded that within one agroecosystem, crop yields may vary considerably. The agrodiversity explaining these variations proves to be cropspecific, One agroecosystern may comprise several cropping systems and field types of the same crop. Agrodiversity is also spatially specific and is largely determined by ethnic and socio-economic diversity and gender differences at household level. The potentials and problems of crops and fields also prove to be specific to the farmer. Within the context of rural development, it is essential to distinguish between well defined target groups in order to prevent interventions from uneffective generalisation. To do so, variation, heterogeneity and diversity must be accepted as realistic phenomena in agroecosystems and considered as an important source of information.

LUSA (Land Use Systems Analysis), a new methodology to develop sustainable agro-ecosystems as part of land-use planning, combines high-tech assessment methodologies, such as multicriteria computer models, with participatory methodologies. LUSA has been tested in Sub-Saharan West Africa

Variation within agro-ecosystems is a universal but complex phenomenon which is present in each of the factors that determine the agro-ecosystem, i.e. the environment, genetic resources and management. Agrodiversity is defined as the variation resulting from the interaction between these factors. This variation manifests itself in many different forms, at different scales and levels of aggregation. Examples show that poor management of agrodiversity in high and low external input agriculture reduces output, output stability, resource-use efficiency and the production potential of the natural resource base. A better understanding of agrodiversity is required to improve its management. Also, analysis of variation in agro-ecosystems requires other approaches in research to be further developed in order to characterize, measure and understand relevant variation.

A quantitative analysis of the role of woody plants in semi-arid regions, focusing on the Sahel and Sudan zones in West-Africa, is given for the assessment of their benefits in agro-sylvopastoral land-use systems with productive and sustainability objectives.

This second progress report focuses on designing a theoretical prototype by linking parameters to methods and designing the methods in this context until they are ready for initial testing. The report focuses also on testing and improving the prototype in general and the methods in particular until the objectives as quantified in the set of parameters have been achieved by pilot groups, regional networks and national networks