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

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

Estimating base resistance and N value in rotary press-in

In the Press-in Method, press-in machines use static jacking force to install prefabricated piles, while gaining a reaction force by grasping several of the previously installed piles. The emergence of this piling technique in 1975 solved problems in urban piling construction such as noise and vibration associated with the piling work, restricted construction conditions due to the existing structures, and so on. Among a variety of press-in methods, rotary press-in is a relatively new technique to install tubular piles into hard ground by applying axial and rotational jacking force at the same time. An additional feature of the Press-in Method is that it allows continuous measurement of penetration depth and jacking force during piling work. The concept of a PPT, Pile Penetration Test, has been developed to apply this feature to improving the efficiency of piling work and foundation design. This paper highlights the technique to estimate base resistance and N value from the data acquired during rotary press-in.This is the author accepted manuscript. The final version is available at http://www.sciencedirect.com/science/article/pii/S0038080615000839

Thermal conductivity of a sandy soil

The thermal properties of soils are of great importance in many thermo-active ground structures such as energy piles and borehole heat exchangers. In this paper the effect of the porosity and degree of saturation on the thermal conductivity of a sandy soil that has not been previously thermally tested is investigated using steady state experimental tests. The steady state apparatus used in these tests was designed to provide high performance in controlling all boundary conditions. Twenty thermal conductivity experimental tests have been carried out at different porosity and saturation values. The performance of selected prediction methods have been validated against the experimental results. The validation shows that none of the selected models can be used effectively in predicting the thermal conductivity of Tripoli sand at all porosity and saturation values. However, some can provide good agreement at dry or nearly dry condition while others perform well at high saturations. The performance of most of the selected models also increases as the soil approaches a two phase state where conduction plays the dominant role in controlling heat transfer. An empirical equation of thermal conductivity expressed as a function of water content and porosity has been developed based on the experimental results obtained.This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.applthermaleng.2016.06.01

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

Optical studies of two LMC X-ray transients : RX J0544.1-7100 and RX J0520.5-6932

We report observations which confirm the identities of the optical counterpart to the transient sources RX J0544.1-7100 and RX J0520.5-6932. The counterparts are suggested to be a B-type stars. Optical data from the observations carried out at ESO and SAAO, together with results from the OGLE data base, are presented. In addition, X-ray data from the RXTE all-sky monitor are investigated for long term periodicities. A strong suggestion for a binary period of 24.4d is seen in RX J0520.5-6932 from the OGLE data.Comment: 6 pages, 7 figure

Measuring horizontal stresses during jacked pile installation

Jacking is an installation technique for displacement piles which is commonly used onshore in urban environments owing to its low noise and vibration. During pile jacking, stress changes occur in the soil which are substantial close to the pile, but also extend a significant radial distance. These stresses are difficult to measure accurately owing to arching around stress sensors. In the field, stress measurements are commonly made by means of an adjacent pile whose stiffness changes the stress field within the soil. Accurate measurements of stresses due to the installation of a single pile under laboratory conditions are needed in order to quantify this error. In this paper, null gauges that do not suffer from membrane deflection are used to measure horizontal stress changes during the jacked installation of a cylindrical pile in dry sand. Stresses are measured by means of both an adjacent pre-installed square pile and in-soil sensors. The paper also presents a comparison between the centrifuge results and the radial stress distribution estimated using conventional methods, such as Boussinesq's elastic analysis and elasto-plastic spherical cavity expansion. The research was funded by Giken Ltd. and the Coleman-Cohen Exchange Programme to whom a great acknowledgement is addressedThis is the author accepted manuscript. The final version is available from ICE via http://dx.doi.org/10.1680/geng.14.0006

Vascular endothelial growth factor directly inhibits primitive neural stem cell survival but promotes definitive neural stem cell survival

There are two types of neural stem cells (NSCs). Primitive NSCs [leukemia inhibitory factor (LIF) dependent but exogenous fibroblast growth factor (FGF) 2 independent] can be derived from mouse embryonic stem (ES) cells in vitro and from embryonic day 5.5 (E5.5) to E7.5 epiblast and E7.5-E8.5 neuroectoderm in vivo. Definitive NSCs (LIF independent but FGF2 dependent) first appear in the E8.5 neural plate and persist throughout life. Primitive NSCs give rise to definitive NSCs. Loss and gain of functions were used to study the role of vascular endothelial growth factor (VEGF)-A and its receptor, Flk1, in NSCs. The numbers of Flk1 knock-out mice embryo-derived and ES cell-derived primitive NSCs were increased because of the enhanced survival of primitive NSCs. In contrast, neural precursor-specific, Flk1 conditional knock-out mice-derived, definitive NSCs numbers were decreased because of the enhanced cell death of definitive NSCs. These effects were not observed in cells lacking Flt1, another VEGF receptor. In addition, the cell death stimulated by VEGF-A of primitive NSC and the cell survival stimulated by VEGF-A of definitive NSC were blocked by Flk1/Fc-soluble receptors and VEGF-A function-blocking antibodies. These VEGF-A phenotypes also were blocked by inhibition of the downstream effector nuclear factor kappa B (NF-kappa B). Thus, both the cell death of primitive NSC and the cell survival of definitive NSC induced by VEGF-A stimulation are mediated by bifunctional NF-kappa B effects. In conclusion, VEGF-A function through Flk1 mediates survival (and not proliferative or fate change) effects on NSCs, specifically