Soil development, environmental history and the dating of terraced valley fill deposits in the North York Moors, with specific reference to Dovedale Howe Beck

Detailed investigation of the valley fill deposits of Dovedale Griff and Jugger Howe Beck, together with a sedimentological and palaeomagnetic investigation of the sediments of Lake Gormire, provide the basis for an integrated analysis of the temporal and palaeoenvironmental aspects of Holocene valley floor landform development in the North York Moors.A Holocene alluvial chronology is developed for Dovedale Griff and Jugger Howe Beck based on surface soil stratigraphy, radiocarbon dating, morphology and sediment stratigraphy. Surface soils developed into the deposits of the Dovedale Griff terrace fragments are divided statistically into three groups of soils using a combination of Principal Components Analysis and Cluster Analysis. The first principal component is shown to be a compound index of soil properties that represent some of the main morphological and chemical properties of brown podzolic soils and the grouped soils are shown to represent a chronosequence of brown podzolic soils. Each cluster of soils represents one soil stratigraphic unit.The age-calibrated surface soil stratigraphic units from Dovedale Griff are used in a Discriminant Analysis procedure to estimate the ages of undated valley floor surfaces in Jugger Howe Beck. An additional soil stratigraphic unit is identified from Jugger Howe Beck. This fourth unit is shown to have a freely drained phase and a gleyed phase.In Dovedale Griff the alluvial surfaces are dated to about 7100BP, 900BP and about 300BP. In Jugger Howe Beck the main alluvial surfaces are shown to be about 10000BP, 900BP and about 300BP in age. These phases of valley floor development are correlated with phases of instability and stability as revealed by erosion indicators from the sediments of Lake Gormire. Two main phases of synchronous behaviour between the three sites are Identified and their environmental significance discussed. These phases occurred at about 1000 - 900BP and again around about 300BP. A phase of synchronous behaviour between Jugger Howe Beck and Gormire are identified atabout 10000BP. Phases of site specific behaviour are also identified at 7100BP in Dovedale and 2500BP in Lake Gormire.The Holocene environmental changes in the North York Moors are placed In the context of valley floor development In upland Britain. Chronologies of valley floor development for upland regions may not reveal a common temporal pattern of response

Design and testing of prestressed concrete railway deck slabs

Prestressed deck slabs fabricated from conventional strength concrete are frequently used in Railway bridge applications. The purpose of this research program was to assess the behaviour of precast, prestressed concrete railway deck slabs fabricated from high performance concrete (HPC). Six full scale slab specimens 3.7 m by 2.135 m, manufactured from concrete containing silica fume with compressive strengths of 80, 90 and 99 MPa, were tested to ultimate capacity. A literature review was conducted on the mechanical properties and durability of high strength-high performance concrete. In addition, a laboratory test program was designed to determine the behaviour of the prestressed concrete slabs in flexural cracking, ultimate capacity, shear, ductility and bond development length of the strand. The slabs were simply supported and a statically loaded at midspan, ⅜ span and �$1

Kidney function in the very elderly with hypertension: data from the hypertension in the very elderly (HYVET) trial.

BACKGROUND: numerous reports have linked impaired kidney function to a higher risk of cardiovascular events and mortality. There are relatively few data relating to kidney function in the very elderly. METHODS: the Hypertension in the Very Elderly Trial (HYVET) was a randomised placebo-controlled trial of indapamide slow release 1.5mg ± perindopril 2-4 mg in those aged ≥80 years with sitting systolic blood pressures of ≥160 mmHg and diastolic pressures of <110 mmHg. Kidney function was a secondary outcome. RESULTS: HYVET recruited 3,845 participants. The mean baseline estimated glomerular filtration rate (eGFR) was 61.7 ml/min/1.73 m(2). When categories of the eGFR were examined, there was a possible U-shaped relationship between eGFR, total mortality, cardiovascular mortality and events. The nadir of the U was the eGFR category ≥60 and <75 ml/min/1.73 m(2). Using this as a comparator, the U shape was clearest for cardiovascular mortality with the eGFR <45 ml/min/1.73 m(2) and ≥75 ml/min/1.73 m(2) showing hazard ratios of 1.88 (95% CI: 1.2-2.96) and 1.36 (0.94-1.98) by comparison. Proteinuria at baseline was also associated with an increased risk of later heart failure events and mortality. CONCLUSIONS: although these results should be interpreted with caution, it may be that in very elderly individuals with hypertension both low and high eGFR indicate increased risk

Haemodynamic changes with paracetamol in critically-ill children.

PURPOSE: Paracetamol has been associated with a reduction in blood pressure, especially in febrile, critically-ill adults. We hypothesised that blood pressure would fall following administration of paracetamol in critically-ill children and this effect would be greater during fever and among children with a high body surface area to weight ratio. METHODS: A 12-month prospective observational study of children (0-16years) admitted to paediatric intensive care, who underwent pulse contour analysis and received paracetamol concurrently. RESULTS: Mean arterial blood pressure decreased significantly by 4.7% from baseline (95% CI 1.75-8.07%) in 31 children following 148 doses of paracetamol. The nadir was 2-hour post-dose. The effect was pronounced in children with fever at baseline (6.4%, 95% CI 2.8-10%), although this was not statistically significant. There was no simple relationship between this effect and body surface area to weight ratio. The association between a change in blood pressure and changes in heart rate or measured stroke volume was poor; therefore it was likely that a change in the systemic vascular resistance contributes most to this effect. CONCLUSION: There is a significant but modest reduction in blood pressure post-paracetamol in critically-ill children. This is likely related to a change in systemic vascular resistance

Left Ventricular Hypertrophy is a predictor of cardiovascular events in elderly hypertensives: hypertension in the the very elderly trial (HYVET)

Objective: We assessed the prognostic value of electrocardiographic left ventricular hypertrophy (LVH) using Sokolow-Lyon (SL-LVH), Cornell Voltage (CV-LVH) or Cornell Product (CP-LVH) Criteria in 3043 hypertensive people aged 80 years and over enrolled in the Hypertension in the Very Elderly Trial. Methods: Multivariate Cox proportional hazard models were used to estimate hazard ratios (HR) with 95% confidence intervals (CI) for all-cause mortality, cardiovascular diseases, stroke and heart failure in participants with and without LVH at baseline. The mean follow-up was 2.1 years. Results: LVH identified by CV- or CP-LVH Criteria was associated with a 1.6 to 1.9-fold risk of cardiovascular disease and stroke. The presence of CP-LVH was associated with an increased risk of heart failure (HR 2.38, 95% CL 1.16-4.86). In gender specific analyses, CV-LVH (HR 1.94, 95%Cl 1.06-3.55) and CP-LVH (HR 2.36, 95% CI 1.25-4.45) were associated with an increased risk of stroke in women and of heart failure in men, CV-LVH (HR 6.47, 95 % Cl 1.41-29.79) and CP-LVH (10.63, 95Cl % 3.58-31.57), respectively. There was no significant increase in the risk of any outcomes associated with SL LVH. LVH identified by these three methods was not a significant predictor of all-cause mortality. Conclusions: Use of Cornell Voltage and Cornell Product criteria for LVH predicted the risk of cardiovascular disease and stroke. Only Cornell Product was associated with an increased the risk of heart failure. This was particularly the case in men. The identification of electrocardiographic LVH proved to be important in very elderly hypertensive people

Fracture risk and the use of a diuretic (indapamide sr) ± perindopril: a substudy of the Hypertension in the Very Elderly Trial (HYVET)

BACKGROUND: The Hypertension in the Very Elderly Trial (HYVET) is a placebo controlled double blind trial of treating hypertension with indapamide Slow Release (SR) ± perindopril in subjects over the age of 80 years. The primary endpoints are stroke (fatal and non fatal). In view of the fact that thiazide diuretics and indapamide reduce urinary calcium and may increase bone mineral density, a fracture sub study was designed to investigate whether or not the trial anti-hypertensive treatment will reduce the fracture rate in very elderly hypertensive subjects. METHODS: In the trial considerable care is taken to ascertain any fractures and to identify risk factors for fracture, such as falls, co-morbidity, drug treatment, smoking and drinking habits, levels of activity, biochemical abnormalities, cardiac irregularities, impaired cognitive function and symptoms of orthostatic hypotension. POTENTIAL RESULTS: The trial is expected to provide 10,500 patient years of follow-up. Given a fracture rate of 40/1000 patient years and a 20% difference in fracture rate, the power of the sub study is 58% to detect this difference at the 5% level of significance. The corresponding power for a reduction of 25% is 78%. CONCLUSION: The trial is well under way, expected to complete in 2009, and on target to detect, if present, the above differences in fracture rate

Type 2 Diabetes as a Risk Factor for Dementia in Women Compared With Men: A Pooled Analysis of 2.3 Million People Comprising More Than 100,000 Cases of Dementia

Objective: Type 2 diabetes confers a greater excess risk of cardiovascular disease in women than in men. Diabetes is also a risk factor for dementia, but whether the association is similar in women and men remains unknown. We performed a meta-analysis of unpublished data to estimate the sex-specific relationship between women and men with diabetes with incident dementia. Research design and methods: A systematic search identified studies published prior to November 2014 that had reported on the prospective association between diabetes and dementia. Study authors contributed unpublished sex-specific relative risks (RRs) and 95% CIs on the association between diabetes and all dementia and its subtypes. Sex-specific RRs and the women-to-men ratio of RRs (RRRs) were pooled using random-effects meta-analyses. Results: Study-level data from 14 studies, 2,310,330 individuals, and 102,174 dementia case patients were included. In multiple-adjusted analyses, diabetes was associated with a 60% increased risk of any dementia in both sexes (women: pooled RR 1.62 [95% CI 1.45-1.80]; men: pooled RR 1.58 [95% CI 1.38-1.81]). The diabetes-associated RRs for vascular dementia were 2.34 (95% CI 1.86-2.94) in women and 1.73 (95% CI 1.61-1.85) in men, and for nonvascular dementia, the RRs were 1.53 (95% CI 1.35-1.73) in women and 1.49 (95% CI 1.31-1.69) in men. Overall, women with diabetes had a 19% greater risk for the development of vascular dementia than men (multiple-adjusted RRR 1.19 [95% CI 1.08-1.30]; P \u3c 0.001). Conclusions: Individuals with type 2 diabetes are at ∼60% greater risk for the development of dementia compared with those without diabetes. For vascular dementia, but not for nonvascular dementia, the additional risk is greater in women

COX-2 suppresses tissue factor expression via endocannabinoid-directed PPARδ activation

Although cyclooxygenase (COX)-2 inhibitors (coxibs) are effective in controlling inflammation, pain, and tumorigenesis, their use is limited by the recent revelation of increased adverse cardiovascular events. The mechanistic basis of this side effect is not well understood. We show that the metabolism of endocannabinoids by the endothelial cell COX-2 coupled to the prostacyclin (PGI2) synthase (PGIS) activates the nuclear receptor peroxisomal proliferator–activated receptor (PPAR) δ, which negatively regulates the expression of tissue factor (TF), the primary initiator of blood coagulation. Coxibs suppress PPARδ activity and induce TF expression in vascular endothelium and elevate circulating TF activity in vivo. Importantly, PPARδ agonists suppress coxib-induced TF expression and decrease circulating TF activity. We provide evidence that COX-2–dependent attenuation of TF expression is abrogated by coxibs, which may explain the prothrombotic side-effects for this class of drugs. Furthermore, PPARδ agonists may be used therapeutically to suppress coxib-induced cardiovascular side effects