The effectiveness and cost-effectiveness of strength and balance Exergames to reduce falls risk for people aged 55 years and older in UK assisted living facilities: A multi-centre, cluster randomised controlled trial

Background: Falls are the leading cause of fatal and non-fatal unintentional injuries in older people. The use of Exergames (active, gamified video-based exercises) is a possible innovative, community-based approach. This study aimed to determine the effectiveness of a tailored OTAGO/FaME based strength and balance Exergame programme for improving balance, maintaining function and reducing falls risk in older people. Methods: A two-arm cluster randomised controlled trial recruiting adults aged 55 years and older living in 18 assisted-living (sheltered housing) facilities (clusters) in the UK. Standard care (physiotherapy advice and leaflet) was compared to a tailored 12-week strength and balance Exergame programme, supported by physiotherapists or trained assistants. Complete-case analysis (intention to treat) was used to compare Berg Balance Scale (BBS) at baseline and at 12 weeks. Secondary outcomes included: fear of falling, mobility, falls risk, pain, mood, fatigue, cognition, healthcare utilisation and health-related quality of life; self-reported physical activity and falls. Results: Eighteen clusters were randomised (9 to each arm) with 56 participants allocated to the intervention and 50 to the control (78% female, mean age 78 years). Fourteen participants withdrew over the 12 weeks (both arms), mainly for ill health. There was an adjusted mean improvement in balance (BBS) of 6.2 (95% CI 2.4 to 10.0), reduced fear of falling (p=0.007) and pain (p=0.02) in Exergame group. Mean attendance at sessions was 69% (mean exercising time of 33 minutes/week). 24% of control group and 20% of Exergame group fell over trial period. The change in falls rates significantly favoured the intervention (incident rate ratio 0.31 (95% CI 0.16 to 0.62, p=0.001)). The point estimate of the incremental cost effectiveness ratio (ICER) was £15,209.80 per QALY. Using 10,000 bootstrap replications, at the lower bound of the NICE threshold of £20,000 per QALY, there was a 61% probability of Exergames being cost-effective, rising to 73% at the upper bound of £30,000 per QALY. Conclusions: Exergames, as delivered in this trial, improve balance, pain and fear of falling and are a cost-effective fall prevention strategy in assisted living facilities for people aged 55 years or older

Striking Denervation of Neuromuscular Junctions without Lumbar Motoneuron Loss in Geriatric Mouse Muscle

Reasons for the progressive age-related loss of skeletal muscle mass and function, namely sarcopenia, are complex. Few studies describe sarcopenia in mice, although this species is the mammalian model of choice for genetic intervention and development of pharmaceutical interventions for muscle degeneration. One factor, important to sarcopenia-associated neuromuscular change, is myofibre denervation. Here we describe the morphology of the neuromuscular compartment in young (3 month) compared to geriatric (29 month) old female C57Bl/6J mice. There was no significant difference in the size or number of motoneuron cell bodies at the lumbar level (L1–L5) of the spinal cord at 3 and 29 months. However, in geriatric mice, there was a striking increase (by ∼2.5 fold) in the percentage of fully denervated neuromuscular junctions (NMJs) and associated deterioration of Schwann cells in fast extensor digitorum longus (EDL), but not in slow soleus muscles. There were also distinct changes in myofibre composition of lower limb muscles (tibialis anterior (TA) and soleus) with a shift at 29 months to a faster phenotype in fast TA muscle and to a slower phenotype in slow soleus muscle. Overall, we demonstrate complex changes at the NMJ and muscle levels in geriatric mice that occur despite the maintenance of motoneuron cell bodies in the spinal cord. The challenge is to identify which components of the neuromuscular system are primarily responsible for the marked changes within the NMJ and muscle, in order to selectively target future interventions to reduce sarcopenia

Order-of-magnitude estimation of the quantities of PCDD/F formed in underground coal gasification (UCG) flares

The technology of underground coal gasification to produce synthesis gas requires a flare to dispose of vented surplus gas. Since any coal seam will contain chlorine, there is the potential to produce dioxins (PCDD/F) in the flare flame, provided that chlorinated products are released during the gasification reactions. Because of the sulphur present in coals, it is unlikely that significant amounts of heterogeneous (solid phase) PCDD/F will form. Using an established model for dioxin formation, an estimate is made of the likely amount of homogeneous (gas phase) PCDD/F generated in the flame. The result suggests that any release to air will be well below international regulatory limits

The formation of dioxins in combustion systems

Flame chemistry in incineration systems involves the formation of many organic products of incomplete combustion, including chlorinated species such as polychlorinated biphenyls (PCB), polychlorinated dibenzo-p-dioxins (PCDD), and polychlorinated dibenzofurans (PCDF). Because the latter are of environmental concern, a great deal of research has been expended on understanding their formation. There are two temperature windows in which they can form: the "homogeneous" route between 500 and 800°C and the "heterogeneous" one at 200 to 400°C. Homogeneous reactions, which are the result of the pyrolytic rearrangement of chlorinated precursors, such as chlorophenols and chlorobenzenes in the gas phase, have not been researched as extensively as the heterogeneous mechanism. Heterogeneous formation is a catalysed reaction, which takes place on the ash or soot particles present in combustion systems. There are conflicting views regarding the relative amounts of PCDD/F formed from precursors such as chlorophenols in comparison with the de novo process during commercial operations. The de novo reactions involve the oxidation and chlorination of any unburned carbon in the particulates. The reaction pathways for de novo PCDD/F are based on preexisting 3-ring carbon skeletons; single-ring chlorinated precursors are not intermediates. The formation process is driven by oxidation, and the rate is related to carbon burnoff. Dechlorination and decomposition proceed at elevated temperatures. The reaction appears to take place on the global (external) surface of the particles, but is determined by their carbon and chlorine contents. During de novo formation, chlorine is an active agent, either as chloride in the solid phase or as atomic chlorine in the gas. There is always a contribution from solid-phase chlorine, and gas-phase chlorine is active only at higher concentrations when the solid phase is depleted. An excess of chlorine appears to inhibit de novo formation. Different mechanisms are postulated for PCDD and PCDF. Single- and multiring species chlorinate differently, along different paths. The single-ring compounds formed are comparatively loosely held, while the multiring species tend to be strongly held. Much of the PCDD/F formed is retained on the solid surface and is unable to equilibrate with the gas phase under flue gas conditions. De novo catalysis is due mainly to copper, although iron and other metals are active at lower rates. Copper catalyses the oxidation of carbon, as well as the chlorination and dechlorination of organic products. In its two oxidation states it also acts as a "shuttle" for chlorine between gas and solid. The catalytic effect can be poisoned by sulfur or nitrogen compounds, such as sulfur dioxide and urea. All the formation models proposed to date both for the homo- and heterogeneous routes are inadequate, no doubt as a result of the complexity of the processes. The homogeneous route needs more fundamental research, and as regards the de novo route, more attention needs to be paid to the composition and nature of the ash's surface, including particle size and carbon/catalyst disposition

The distortion of the diffuse double layer and its effect on flow properties of dense flyash slurries

Flyashes obtained from power stations burning pulverised Curragh and Tarong coals were air classified to obtain a fine fraction (- 10 mu m). When dense aqueous slurries of these fines were subjected to rheological measurement in a rotating viscometer, the two ashes exhibited different packing propensities. In interpreting the experimental flow data, a new volumetric packing factor Phi was defined to include the volume of the diffuse double layer. When the Krieger-Dougherty equation was fitted to the data, the maximum packing fraction (Phi(m)) redesignated as the quasi-maximum packing fraction was found to vary at low shear rates. It is proposed that the differences in rheological behaviour and variation in Phi(m) is due to the surface chemistry of fine particles. The two flyashes produce leachates of different ionic strength and hence generate different thicknesses of diffuse double layer. Shearing at close packing produces distortion in the diffuse double layer, especially in dilute leachates with thick diffuse double layers. A particle packing model based on the unit cell is proposed to quantify the distortion of the diffuse double layer, and to explain its influence on Phi(m) and flow behaviour. (C) 2000 Elsevier Science B.V. All rights reserve

The formation of aerosols during the co-combustion of coal and biomass

The global drive to lessen the emission of greenhouse gases in the power industry has seen an increase in the co-combustion of coal with various types of biomass. The practice “represent possibly the best (cheapest and lowest risk) renewable energy option for many power producers”. Most reviews of the practice cite environmental benefits coupled with satisfactory technological performance. One environmental aspect which has been virtually ignored is the formation and release of ultra-fine aerosol particles, which have a damaging effect on the respiratory system. The emission of respirable aerosols during the combustion of both coal and biomass has received considerable attention, but there is little information available for the combustion of their mixture. The available evidence, reviewed here, indicates that the extent of their formation is increased by co-combustion, due to the high ash and sulphur content of coals, and the high alkali metal content of biomass

The effect of water absorption and the role of fines on the yield stress of dense fly ash slurries

Fly ashes obtained from power stations burning Curragh and Tarong coal were aircyclosized into fractions of different particle sizes. The grading of fractions were done according to the percentage of fines (−10 μm at d32 [sauter diameter]). The fraction with maximum fines was mixed with the original fly ash samples in different proportions and water absorption determined. The yield stress of a slurry consisting of different proportions of fraction with maximum fines and the original fly ash was measured. In this work the effect of water absorption and the role of fines on yield stress is presented

The influence of sample containment on the thermogravimetric measurement of carbon black reactivity

During the thermogravimetric measurement of carbon oxidation reactivity, the sample is contained in a crucible, and oxygen has access only through the top surface of the particle bed. Condensed carbons such as soot and carbon black have such large surface areas that oxygen mass transfer limitations control their combustion in such situations. A technique to describe the mass transfer processes has been developed, in which the gas phase and in-bed transfer processes have been decoupled. The gas phase is modelled by the CFD package fluent and diffusion within the bed is described by a mono-dimensional model. The procedure has been used to examine the accessibility of oxygen to samples contained in deep and shallow crucibles, and also the orientation of the flow with regard to the crucible mouth. In all cases, the transport of oxygen to the bed surface was dominated by molecular diffusion. Some existing experimental data for carbon black combustion were re-analysed to extract the true reactivities