Lime stabilisation for earthworks: a UK perspective

Lime stabilisation is a versatile technique applied during earthworks operations. Modern soil recycling units are much more efficient at pulverising fill material and intermixing the added binder/water than machinery available 20 years ago. While supplier innovation adds flexibility to the site working method, specifications have not been sufficiently updated to permit optimal application. This review paper details the physico-chemical changes instigated through the lime-clay soil reaction, updating previous reviews. It aims to assist scientific debate, current practitioners and future specification changes. For example, the application of the minimum 24 h mellowing periods (mandatory to UK specifications) with high reactivity, quicklime powders is concluded to cause increased air voids in the compacted fill. Increased air voids are associated with reduced long-term strength and potential volume change from water ingress, which is of particular concern for sulfate swelling. Shorter mellowing periods and/or use of hydrated lime may lesson this issue; however, a 'one size fits all' approach is discouraged in preference to site-specific methodologies refined to suit the fill material and project requirements. The discussion also summarises working methods which may lower the risk of sulfate swell and defines areas requiring further practical research

IGF1 genotype, mean plasma level and breast cancer risk in the Hawaii/Los Angeles multiethnic cohort

The insulin-like growth factor 1 gene (IGF1) is a strong candidate gene for a breast cancer susceptibility model. We investigated a dinucleotide repeat 969 bp upstream from the transcription start site of the IGF1 gene for possible associations with plasma IGF1 levels and breast cancer risk in a multiethnic group of postmenopausal women. Furthermore, we investigated the relation between race/ethnicity, mean plasma IGF1 levels and breast cancer rates in the Hawaii/Los Angeles Multiethnic Cohort. The mean age-adjusted IGF1 level among Latino-American women, 116 ng ml(-1), was statistically significantly lower than the mean age-adjusted IGF1 levels for each of the three other racial/ethnic groups, African-American, Japanese-American and Non-Latino White women (146, 144 and 145 ng ml(-1), respectively) (P<0.0001). Latino-American women have the lowest breast cancer rates of any racial/ethnic group in the cohort. These results support the investigation of an expansion of the hypothesis for an important role of IGF1 in breast cancer tumorigenesis to different racial/ethnic groups and to postmenopausal women. It is unlikely that any involvement of IGF1 in breast cancer aetiology is mediated by the IGF1 dinucleotide repeat polymorphism, which was not significantly associated with circulating IGF1 levels nor breast cancer risk in this study. Research into relevant determinants of IGF1 levels in the blood must continue

White matter hyperintensities, executive function and global cognitive performance in vascular mild cognitive impairment

Vascular mild cognitive impairment (VaMCI) represents an early symptomatic stage of vascular cognitive impairment and might be associated to fronto-executive dysfunction. Methods Twenty-six individuals (age: 73.11±7.90 years; 65.4% female; schooling: 9.84±3.61 years) were selected through neuropsychological assessment and neuroimaging. Clinical and neuroimaging data of VaMCI individuals (n=15) were compared to normal controls (NC, n=11) and correlated with Fazekas scale. Results VaMCI performed significantly worse than NC in Trail-Making Test (TMT) B, errors in TMT B, difference TMT B-A and Cambridge Cognitive Examination (CAMCOG) final scores. Correlations were found among scores in modified Fazekas scale and performances in TMT B (time to complete and errors), difference TMT B-A and CAMCOG total score. Conclusion Extension of white matter hyperintensities might be correlated to poorer global cognition and impairments in a set of fronto-executive functions, such as cognitive speed, set shifting and inhibitory control in VaMCI

Studies of oxidation by fenton's reagent using redox titration. I. Oxidation of some organic compounds

Oxidations using Fenton's reagent have not been followed previously by redox titration. This procedure assists in defining the overall reaction and allows both an estimate of relative rates of oxidation and a measure of the consumption of peroxide by the organic substrate. The peroxide consumed in the complete oxidation of substrate to inactive compounds has been measured by titration at constant oxidation potential. Such measurements reflect the peroxide consumed by the substrate and its consecutive oxidation products and may therefore be used to assess the significance of oxidation pathways. </jats:p

Chemistry of Non-Enzymic Browning. XI. The Reactions of Bisulphite with Reducing Sugars

The reactions of reducing sugars with bisulphite have been studied at 100 �C and lower temperatures. Reducing sugars promoted the autoxidation of bisulphite to sulphur and sulphate, the ketoses being more effective than the aldoses. During the autoxidation the aldoses were oxidized, in part, to the corresponding aldonic acids. The ketose sugars reacted more rapidly and extensively than the aldoses, only 32 per cent. of unchanged fructose being recovered after 8 hr at 100 �C. Oxidation of the ketoses probably occurred via the osone and gave a complex mixture of keto acids. Ascorbic acid was converted to dehydroascorbic acid and an unidentified acid. The reactions offer possible explanations for the formation of sulphate and the loss of bisulphite observed during storage of foods treated with sulphur dioxide. An oxidative mechanism has been suggested for the inhibition of non-enzymic browning by sulphur dioxide. </jats:p