Solar Irradiance Variability and Climate

The brightness of the Sun varies on all time scales on which it has been observed, and there is increasing evidence that it has an influence on climate. The amplitudes of such variations depend on the wavelength and possibly on the time scale. Although many aspects of this variability are well established, the exact magnitude of secular variations (going beyond a solar cycle) and the spectral dependence of variations are under discussion. The main drivers of solar variability are thought to be magnetic features at the solar surface. The climate reponse can be, on a global scale, largely accounted for by simple energetic considerations, but understanding the regional climate effects is more difficult. Promising mechanisms for such a driving have been identified, including through the influence of UV irradiance on the stratosphere and dynamical coupling to the surface. Here we provide an overview of the current state of our knowledge, as well as of the main open questions

Delivering public sector efficiencies: The potential role of capability maturity models in construction

This paper is aimed at identifying the potential role of SPICE, especially SPICE level 3, to achieving the proposed UK public sector efficiencies. SPICE level 3 presents the process maturity framework to address the level III of the SPICE model. Building upon the developments of level II, SPICE 3 advocates establishment of a process improvement infrastructure to facilitate good practice sharing in construction organisations. The paper highlights the recommendations of Gershon reviews, in order to achieve the proposed UK public sector efficiencies. The potential benefits of SPICE level 3 is identified and further research in this regard is suggested

Sustainable production of organic wheat

The aim of the project is to use an ecological approach to analyse the interactions of a range of key agronomic variables in organic wheat production (wheat genotype, spatial arrangement of seed, seed density and wheat/white clover bi-cropping) to determine an optimal approach to improved and stabilised production. The fi rst set of data revealed that seedling competition was infl uenced by seed rate and drilling arrangement. Furthermore, the variety Hereward had increased emergence and establishment to Aristos. An interaction exists between wheat variety, seed rate and drilling arrangement on the level of canopy cover at different developmental stages – these factors are important for the suppression of weeds. The input of farmers in the selection of trial variables ensures results have a direct application to the industry. The results of yield and quality at harvest will provide further insights into the interaction of agronomic variables

Evolutionary breeding of healthy wheat: from plot to farm

Genetically diverse Composite Cross Populations (CCPs) may be useful in environmentally variable low-input systems as an alternative to pure line varieties. They are formed by hybridising lines with diverse evolutionary origins, bulking the F1 progeny, and allowing natural selection of the progeny in successive crop environments. CCPs derived from 10 high yielding parents (YCCPs), 12 high quality parents (QCCPs), or all 22 parents (YQCCPs), were grown at four sites (2 organic, 2 conventional) in the UK; they are currently (2006) in F5. The YCCPs out yielded the QCCPs, which had better quality characteristics. Although the CCPs performed within the range of the parents, the values obtained were often better than the mean of the parents. Some population samples are now being grown on farms and other sites in England, France, Germany and Hungary

The identification and production of varieties that increase the value of oats as a profitable component of organic production

Two experiments, one comprising husked, and the other naked, oats were established at Wakelyns Agroforestry, Suffolk in October 2004 to determine traits and varieties of oats suited to organic systems, and whether growing variety mixtures conferred any advantage. Unselected F2 breeding lines were also included for selection. Husked varieties had relatively higher yields; this may have been partly the result of poor establishment in the naked varieties. Variety height was found to be an important characteristic; tall oat varieties out-yielded the dwarfs. Two of the three variety mixtures containing the naked oat variety Expression yielded 8 and 9 % higher than the average of the component varieties. The data will be verified in the second year of replicated trials (2005/06), which will include the best performing husked and naked varieties, and a mixture of superior IGER-bred F2 breeding lines

SPICE 3: Facilitating organisational process improvement through good practice sharing

This paper describes the latest iteration of the SPICE research. SPICE 3 explains the process maturity framework to address the level III of the SPICE model. Building upon the developments of level II, SPICE 3 advocates establishment of a process improvement infrastructure to facilitate good practice sharing in construction organisations. To achieve SPICE level III process maturity, organisations should posses four key processes and five process enablers. The model developed helped the case study organisations to identify their process strengths and also areas requiring improvement

Liquefaction Induced Settlement of Structures

Soil liquefaction following earthquakes leads to excessive damage to a wide variety of structures. Settlement and rotation of structures following liquefaction have been witnessed in many of the recent earthquakes. Investigation of the mechanisms of failure of structure when the foundation soil suffers either partial or full liquefaction is therefore very important. Dynamic centrifuge tests were conducted at Cambridge and elsewhere on different boundary value problems in which liquefaction of soil models was investigated. Excess pore pressure data and the settlement data for the particular structure that is being investigated are recorded during the centrifuge tests. In this paper the centrifuge test results from a range of structures will be considered. The co-seismic and post seismic settlement of structures will be considered separately along with the excess pore pressure recorded generated during the cyclic loading. It will be argued that the co-seismic component of the settlement is much larger than the post-seismic settlement in many of the structures considered. Accordingly a hypothesis that the hydraulic conductivity k of the liquefied soil during the earthquake shaking is much higher than the normal hydraulic conductivity is proposed. A discussion on the micro-mechanical reasons for this increased hydraulic conductivity is presented

Developing a partcipatory approach to seed production and varietal selection

The performance of UK winter wheat varieties was tested under organic conditions involving farmer participation. Three breadmaking varieties (Hereward, Solstice and Xi19) and their mixture (1:1:1) were grown at 19 UK farms in 2003/04 and 2004/05. The variability of productivity on organic farms was illustrated with more variation among farm sites than among varieties. Seed health was generally high over all sites. Although the trials were successful, more time was needed at project initiation to improve farmer involvement. Some farmers expected more researcher visits, and were reticent about assessing the trials themselves. In contrast, some participants valued the variety performance data on their farms particularly when related to that of other growers. The balance between the goals of the researchers relative to the farmers needs to be defined at project initiation