Comparison of legume-based cropping systems at Warra, Queensland. II. Mineral nitrogen accumulation and availability to the subsequent wheat crop

Mineral nitrogen release following legume-based cropping systems for restoring the fertility of a Vertisol and the yield response and N uptake of subsequent wheat crops was studied. Legume phases of pastures, including a 4 year grass+legume ley, and lucerne and medic leys (~1 year) were terminated in October 1988 or 1989 and rotated with wheat. Chickpea-wheat rotations matched those of lucerne and medic leys. Mineral N accumulations during a subsequent fallow period were determined by core sampling to 1.5 m in October, February and May. Grain yield and N uptake of wheat enabled comparisons of the fertility restorative effects of the various systems relative to continuous wheat cropping. Averaged for two fallow periods, increases in mineral N down to 1.2 m depth were 93, 91, 68, and 37 kg/ha following grass+legume, lucerne and medic leys, and chickpea, respectively, compared with the continuous wheat treatment. Wheat yields were generally lower in 1989 (1.85–2.88 t/ha) than in 1990 (2.08–3.59 t/ha) following all leys and crops due to seasonal conditions. There was a grain yield increase of 0.11 and 0.52 t/ha in 1989 and 1.23 and 1.26 t/ha in 1990 following lucerne and medic leys, respectively and 0.85 t/ha in 1990 following a 4 year grass+legume ley. Following chickpea there was a yield increase of 0.81 and 1.36 t/ha in 1989 and 1990 respectively. Nitrogen uptake by wheat was increased by 40 and 49 kg/ha in 1989 and 48 and 58 kg/ha in 1990 following lucerne and medic leys respectively and 63 kg/ha in 1990 following a 4 year grass+legume ley. Following chickpea N uptake by wheat was increased by 27 and 32 kg/ha in 1989 and 1990 respectively. Grain protein concentration of wheat was substantially higher following all pasture leys (11.7–15.8%) than following wheat (8.0–9.4%) or chickpea (9.4–10.1%). Therefore, there was substantial evidence of the effectiveness of pasture leys in soil fertility restoration, as reflected in mineral N, yield response and N uptake by subsequent wheat crops

Renewing the Exploration Approach for Mid-Enthalpy Systems: Examples from Northern England and Scotland

After a promising start in the 1970s and 80s, the UK rather fell behind other countries in the search for viable mid-enthalpy geothermal resources. This situation began to turn around in 2004, when the first of three deep geothermal exploration boreholes were drilled in northern England. What distinguished these from earlier drilling in Cornwall was the deliberate search for naturallyhigh permeability associated with major faults, especially those that have undergone strike-slip reactivation during the Cenozoic. Boreholes at Eastgate in the North Pennines targeted buried radiothermal granite, whereas the 1,821m-deep Science Central Borehole in Newcastle upon Tyne targeted a postulated deep sedimentary aquifer (the Fell Sandstones), which were inferred to be connected laterally to the granitic heat source by a major fault (the reactivation of the Iapetus geo-suture). The drilling was in both cases rewarded with impressive heat flows, and in the case of Eastgate with what is believed to be the highest permeability yet found in a deep granite batholith anywhere in the world. In parallel with these developments, a re-assessment was made of the preexisting geothermal heat flow database for the UK, applying newly-standardised correction protocols for palaeoclimatic and topographic distortions, which were found to be particularly marked in Scotland (where only shallow boreholes had been used to establish geothermal gradients in the original 1980s analysis), Similar prospects in northern England (similar to that drilled at Science Central) are now the focus of commercial exploration efforts. Appraisal of fault dispositions relative to the present-day maximum compressive stress azimuth are being used to identify the most promising areas for intersecting fault-related permeability at depth. New geophysical tools – most notably atomic dielectric resonance scanning – are also being appraised for their ability to directly detect features (such as hot brines) which are indicative of localised convection in target fault zones and aquifers

AD51B in Familial Breast Cancer

Common variation on 14q24.1, close to RAD51B, has been associated with breast cancer: rs999737 and rs2588809 with the risk of female breast cancer and rs1314913 with the risk of male breast cancer. The aim of this study was to investigate the role of RAD51B variants in breast cancer predisposition, particularly in the context of familial breast cancer in Finland. We sequenced the coding region of RAD51B in 168 Finnish breast cancer patients from the Helsinki region for identification of possible recurrent founder mutations. In addition, we studied the known rs999737, rs2588809, and rs1314913 SNPs and RAD51B haplotypes in 44,791 breast cancer cases and 43,583 controls from 40 studies participating in the Breast Cancer Association Consortium (BCAC) that were genotyped on a custom chip (iCOGS). We identified one putatively pathogenic missense mutation c.541C>T among the Finnish cancer patients and subsequently genotyped the mutation in additional breast cancer cases (n = 5259) and population controls (n = 3586) from Finland and Belarus. No significant association with breast cancer risk was seen in the meta-analysis of the Finnish datasets or in the large BCAC dataset. The association with previously identified risk variants rs999737, rs2588809, and rs1314913 was replicated among all breast cancer cases and also among familial cases in the BCAC dataset. The most significant association was observed for the haplotype carrying the risk-alleles of all the three SNPs both among all cases (odds ratio (OR): 1.15, 95% confidence interval (CI): 1.11–1.19, P = 8.88 x 10−16) and among familial cases (OR: 1.24, 95% CI: 1.16–1.32, P = 6.19 x 10−11), compared to the haplotype with the respective protective alleles. Our results suggest that loss-of-function mutations in RAD51B are rare, but common variation at the RAD51B region is significantly associated with familial breast cancer risk

New insights into the genetic etiology of Alzheimer's disease and related dementias

Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele

Drought Strategies and Resource Valuation in Pastoral Areas

Farm Management, Land Economics/Use,

Supplementary Irrigation of Pastures in Humid Areas

Crop Production/Industries,

Some Notes on 'Dynamic' Linear Programming: Comment

Research and Development/Tech Change/Emerging Technologies,