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This study focused on the Badia region of Jordan and examined how low spatial resolution Along Track Scanning Radiometer (ATSR-2) and Advanced Very High Resolution Radiometer (AVHRR) data can be used to detect and monitor changes in grazing land vegetation in semi-arid environments. Comparisons were made between a wide range of different vegetation indices calculated using the red and near-infrared wavebands of both ATSR-2 and AVHRR imagery and field data collected at a series of sampling sites exhibiting a wide range of percentage vegetation covers. For the ATSR-2 data both the nadir and forward sensor view angles were considered. Poor correlations were found between the vegetation indices and field-measured vegetation cover for the Badia region. It was found that highly reflective soils, very sparse vegetation, and the xerophytic nature of vegetation in and regions limited the use of such indices. Furthermore, due to factors such as angle of view, spatial resolution and problems in geo-location, the forward view of ATSR-2 was not found to add any advantages in terms of the ability to detect and monitor the sparsely vegetated surfaces. As an alternative to vegetation indices, a hybrid geometric optical/empirically based model was developed for the area. Using the information given in the red/near-infrared scattergram of a satellite image, the model allowed percentage vegetation cover to be predicted from the remotely sensed data. Strong correlations (r² = 0.91) were found between the model-predicted percentage vegetation cover and that measured at the field sites. The estimates of percentage vegetation cover derived using the model were similar for both the ATSR-2 and the AVHRR imagery, suggesting that the model results are independent of sensor type. These results suggest that the geometric optical/ empirical model can improve the ability to map vegetation resources in and environments, and that the consistency of the results from the two different sensors should enable long term monitoring of the region.

Molecular farming is an experimental application of biotechnology to modify crops in order to produce proteins and chemicals for medicinal and commercial interests. The vast majority in the developing world cannot afford the high cost of therapeutics produced by existing methods. We not only need to produce new therapeutics but also need to produce cheaper versions of the existing ones. Molecular farming could offer a viable option for this growing need for biopharmaceuticals. Part of the thesis deals with investigating ways to produce DesB30 form of human insulin in transgenic tobacco. The human insulin was synthesized in vitro as strep-tag II-mini-insulin fusion protein. Expression of mini-insulin by transgenic tobacco was confirmed by RT-PCR, western blotting and ELISA. However, sufficient levels of purified insulin could not be obtained to carry out further functional assays. Strategies for increasing the yield of insulin by transgenic tobacco are discussed and further increases in yield would need to be developed for this to become a viable and cost effective source of this important pharmaceutical. The second part of the thesis describes the production of a recombinant microbial polysaccharide in tobacco. Seven type 2 pneumococcal polysaccharide biosynthetic genes were expressed in a single tobacco plant, utilizing the plant Kex2 (Kexin protease 2) like protease system for multiple gene expression. Expression of these genes in transgenic tobacco was confirmed by RT-PCR and western blotting. Correct processing of the expressed proteins by the Kex2 protease system was confirmed. However, In planta production of type 2 polysaccharide could not be confirmed mainly as a result of high background from the wild type plant polysaccharide extracts. Strategies to overcome these issues are described. The usefulness of Kex2 protease system for multiple gene expression and metabolic pathways engineering is also discussed.

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The aims of this study were to understand the extent and causes of movements between local rat populations in an agricultural environment. This aim was achieved by examining the movement of rats between farm buildings and fields using trapping, tracking plates and video surveillance. There were temporal variations in rat captures; with more rats caught in autumn than in other seasons. Rats in reproductive condition were caught throughout the year. There was a significant difference between the weight of male and female rats, with males heavier than females, and body fat levels were demonstrated to increase with age. Rats were predominantly caught moving from farm buildings towards the fields during the spring and predominantly moved from fields into farm buildings during autumn. More fecund males moved into the farm during autumn accompanied by non-breeding females. Video monitoring of a single trap system provided evidence that rats are active during both day and night. The level of activity was relatively low in this study with an average of 5 sightings per day. Their direction of movement was not consistent and trapping appeared not to change rat behaviour. It appeared that farm buildings provided the most suitable habitat for brown rats all year round and their density remained constant if no control measures were taken. Small mammals dominated the Field habitat and there was little spatial overlap between brown rats and small mammals around farm buildings. In summer brown rats increased in the Field and in autumn small mammals showed their highest abundance in the Farm habitat. However, there was some potential for small mammals to compete for resources with brown rats in open field areas during summer. Farm sites contained more food than agricultural land. Food was available throughout the year at both sites, but was most abundant during winter at farm sites and during autumn in field sites. At the farm site supplemental feeding attracted rats and small mammals. An examination of skull morphology among three rat populations showed significant differences, though there was no evidence of a strong geographical component to variation. There was no significant difference in skull morphology between the sexes, though there was a significant interaction between sex and population. Variation in skull morphology among populations was probably linked to diet type, and food availability as well as genetic drift arising through reproductive isolation of the study populations.

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No description available.

Organic farmers and growers in Britain are, technically, a clearly defined group. Producers who wish to sell their crops as organic are now legally required to comply with certain standards, and there were voluntary 'symbol schemes' for many years previously. There are detailed production standards for organic vegetables, fruit, arable crops, meat, eggs and dairy produce. These not only restrict the use of 'agrochemicals' and many conventional veterinary products, but include positive requirements about fertility-building rotations, animal welfare and environmental management. Despite being united in working to defined standards, there is great diversity in the circumstances of organic producers. Organic enterprises range from mixed farms of a thousand or more acres to market gardens of less than an acre. Some organic producers have farms which have been in their family for generations, while others have moved out from the city in order to work with the land. There are farmer who have only converted part of their land to organic and still use agrochemicals on the rest, while other producers may have no experience of conventional methods. Producers also have widely differing motivations for farming or growing organically. There can be personal reasons for the choice: farmers may want to use more 'traditional' methods, or avoid being 'controlled' by agrochemical companies; growers have frequently chosen to 'get out of the rat-race'. Producers are also commonly concerned about one or more specific issues such as wildlife, health, or sustaining soil fertility. A few produce organically in the hope of thereby increasing their profits. Although discrete reasons, such as the above, are often sufficient to lead people to farm or grow organically, some producers regard 'being really organic' as a 'way of life' involving an integrated set of values. Such people talk in terms of 'developing a relationship with nature' and may interpret this in a spiritual or religious context; they typically try to 'live well' in ways defined not by consumerist norms but by their sense of ecological and social ethics. 'Really organic' people generally aspire to 'sow seeds of change' in the wider world - usually by setting an example in the way they live, and sometimes also by the ways they market produce, but only rarely by political activism. This study is based on extended interviews with thirty-seven organic producers across Britain, a postal survey of all Soil Association symbol-holders, and participant observation on ten organic holdings - both farms and market gardens.

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