Design of beams and slabs of self-compacting concrete fittings working to flexion

Numerous experimental studies indicate that addition of fibers substantially increases the shear strength of concrete and mortar beams, and that stirrups and reinforcing fibers combination can be really effective. When steel fibers are used as a supplement or substitute for vertical stirrups or folded bars, we obtain the following characteristics: The fibers are distributed randomly by the volume of the concrete with a closer separation than can be achieved with the Armor; The tensile strength at first crack, the ultimate tensile strength and the shear friction resistance are increased

Excess mortality in Glasgow: further evidence of ‘political effects’ on population health

Objectives: The aim of the study was to update previous analyses of ‘excess mortality’ in Glasgow (Scotland) relative to the similar postindustrial cities of Liverpool and Manchester (England). The excess is defined as mortality after adjustment for socio-economic deprivation; thus, we sought to compare changes over time in both the deprivation profiles of the cities and the levels of deprivation-adjusted mortality in Glasgow relative to the other cities. This is important not only because the original analyses are now increasingly out of date but also because since publication, important (prepandemic) changes to mortality trends have been observed across all parts of the United Kingdom. Study design and methods: Replicating as far as possible the methods of the original study, we developed a three-city deprivation index based on the creation of spatial units in Glasgow that were of similar size to those in Liverpool and Manchester (average population sizes of approximately 1600, 1500 and 1700 respectively) and an area-based measure of ‘employment deprivation’. Mortality and matching population data by age, sex and small area were obtained from national agencies for two periods: 2003–2007 (the period covered by the original study) and 2014–2018. The rates of employment deprivation for each city's small areas were calculated for both periods. Indirectly standardised mortality ratios (SMRs) were calculated for Glasgow relative to Liverpool and Manchester, standardised by age and three-city deprivation decile. For context, city-level trends in age-standardised mortality rates by year, sex and city were also calculated. Results: There was evidence of a stalling of improvement in mortality rates in all three cities from the early 2010s. After adjustment for area deprivation, all-cause mortality in Glasgow in 2014–2018 was c.12% higher than in Liverpool and Manchester for all ages (SMR 112.4, 95% CI 111.1–113.6) and c.17% higher for deaths under 65 years (SMR 117.1, 95% CI 114.5–119.7). The excess was higher for males (17% compared with 9% for deaths at all ages; 25% compared with 5% for 0–64 years) and for particular causes of death such as suicide and drug-related and alcohol-related causes. The results were broadly similar to those previously described for 2003–2007, although the excess for premature mortality was notably lower. In part, this was explained by changes in levels of employment deprivation, which had decreased to a greater degree in the English cities: this was particularly true of Manchester (a reduction of −43%, compared with −38% in Liverpool and −31% in Glasgow) where the overall population size had also increased to a much greater extent than in the other cities. Conclusions: High levels of excess mortality persist in Glasgow. With the political causes recently established – the excess is a ‘political effect’, not a ‘Glasgow effect’ – political solutions are required. Thus, previously published recommendations aimed at addressing poverty, inequality and vulnerability in the city are still highly relevant. However, given the evidence of more recent, UK-wide, political effects on mortality – widening mortality inequalities resulting from UK Government ‘austerity’ measures – additional policies at UK Government level to protect, and restore, the income of the poorest in society are also urgently needed

Effects of Chronic Atrial Fibrillation on Active and Passive Force Generation in Human Atrial Myofibrils

Rationale: Chronic atrial fibrillation (cAF) is associated with atrial contractile dysfunction. Sarcomere remodeling may contribute to this contractile disorder. Objective: Here, we use single atrial myofibrils and fast solution switching techniques to directly investigate the impact of cAF on myofilament mechanical function eliminating changes induced by the arrhythmia in atrial myocytes membranes and extracellular components. Remodeling of sarcomere proteins potentially related to the observed mechanical changes is also investigated. Methods and Results: Myofibrils were isolated from atrial samples of 15 patients in sinus rhythm and 16 patients with cAF. Active tension changes following fast increase and decrease in [Ca2+] and the sarcomere length\u2013passive tension relation were determined in the 2 groups of myofibrils. Compared to sinus rhythm myofibrils, cAF myofibrils showed (1) a reduction in maximum tension and in the rates of tension activation and relaxation; (2) an increase in myofilament Ca2+ sensitivity; (3) a reduction in myofibril passive tension. The slow \u3b2-myosin heavy chain isoform and the more compliant titin isoform N2BA were up regulated in cAF myofibrils. Phosphorylation of multiple myofilament proteins was increased in cAF as compared to sinus rhythm atrial myocardium. Conclusions: Alterations in active and passive tension generation at the sarcomere level, explained by translational and post-translational changes of multiple myofilament proteins, are part of the contractile dysfunction of human cAF and may contribute to the self-perpetuation of the arrhythmia and the development of atrial dilatation

Mesoscale productivity fronts and local fishing opportunities in the European Seas

This study evaluates the relationship between both commercial and scientific spatial fisheries data and a new satellite-based estimate of potential fish production (Ocean Productivity available to Fish, OPFish) in the European Seas. To construct OPFish, we used productivity frontal features derived from chlorophyll-a horizontal gradients, which characterize 10%–20% of the global phytoplankton production that effectively fuels higher trophic levels. OPFish is relatively consistent with the spatial distribution of both pelagic and demersal fish landings and catches per unit of effort (LPUEs and CPUEs, respectively). An index of harvest relative to ocean productivity (HP index) is calculated by dividing these LPUEs or CPUEs with OPFish. The HP index reflects the intensity of fishing by gear type with regard to local fish production. Low HP levels indicate lower LPUEs or CPUEs than expected from oceanic production, suggesting over-exploitation, while high HP levels imply more sustainable fishing. HP allows comparing the production-dependent suitability of local fishing intensities. Our results from bottom trawl data highlight that over-exploitation of demersal species from the shelves is twice as high in the Mediterranean Sea than in the North-East Atlantic. The estimate of HP index by dominant pelagic and demersal gears suggests that midwater and bottom otter trawls are associated with the lowest and highest overfishing, respectively. The contrasts of fishing intensity at local scales captured by the HP index suggest that accounting for the local potential fish production can promote fisheries sustainability in the context of ecosystem-based fisheries management as required by international marine policies