Particle size may significantly affect the speed and stability of anaerobic digestion, and matching the choice of particle size reduction equipment to digester type can thus determine the success or failure of the process. In the current research the organic fraction of municipal solid waste was processed using a combination of a shear shredder, rotary cutter and wet macerator to produce streams with different particle size distributions. The pre-processed waste was used in trials in semi-continuous 'wet' and 'dry' digesters at organic loading rate (OLR) up to 6 kg volatile solids (VS) m -3 day -1 .The results indicated that while difference in the particle size distribution did not change the specific biogas yield, the digester performance was affected. In the 'dry' digesters the finer particle size led to acidification and ultimately to process failure at the highest 1 * Corresponding author: Tel.: +44 (0)2380 592188; fax: +44 (0)2380 677519; E-mail address: Y.Zhang@soton.ac.uk (Yue Zhang) 2 OLR. In 'wet' digestion a fine particle size led to severe foaming and the process could not be operated above 5 kg VS m -3 day -1 . Although the trial was not designed as a direct comparison between 'wet' and 'dry' digestion, the specific biogas yield of the 'dry' digesters was 90% of that produced by 'wet' digesters fed on the same waste at the same OLR.

Background Adverse childhood experiences (ACEs) increases vulnerability to externalising disorders such as substance misuse. The study aims to determine the prevalence of ACEs and its association with substance misuse. Methods Data from the Consortium on Vulnerability to Externalising Disorders and Addictions (cVEDA) in India was used (n = 9010). ACEs were evaluated using the World Health Organisation (WHO) Adverse Childhood Experiences International Questionnaire whilst substance misuse was assessed using the WHO Alcohol, Smoking and Substance Involvement Screening Test. A random-effects, two-stage individual patient data meta-analysis explained the associations between ACEs and substance misuse with adjustments for confounders such as sex and family structure. Results 1 in 2 participants reported child maltreatment ACEs and family level ACEs. Except for sexual abuse, males report more of every individual childhood adversity and are more likely to report misusing substances compared with females (87.3% vs. 12.7%). In adolescents, family level ACEs (adj OR 4.2, 95% CI 1.5–11.7) and collective level ACEs (adj OR 6.6, 95% CI 1.4–31.1) show associations with substance misuse whilst in young adults, child level ACEs such as maltreatment show similar strong associations (adj OR 2.0, 95% CI 1.1–3.5). Conclusion ACEs such as abuse and domestic violence are strongly associated with substance misuse, most commonly tobacco, in adolescent and young adult males in India. The results suggest enhancing current ACE resilience programmes and ‘trauma-informed’ approaches to tackling longer-term impact of ACEs in India. Funding Newton Bhabha Grant jointly funded by the Medical Research Council, UK (MR/N000390/1) and the Indian Council of Medical Research (ICMR/MRC-UK/3/M/2015-NCD-I).

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A repetitive pin-jointed, pre-twisted structure is analysed using a state variable transfer matrix technique. Within a global coordinate system the transfer matrix is periodic, but introduction of a local coordinate system rotating with nodal cross-sections results in an autonomous transfer matrix for this Floquet system. Eigenanalysis reveals four real unity eigenvalues, indicating tension-torsion coupling, and equivalent continuum properties such as PoissonÕs ratio, cross-sectional area, torsion constant and the tension-torsion coupling coefficient are determined. A variety of real and complex near diagonal Jordan decompositions are possible for the multiple (eight) complex unity eigenvalues and these are discussed in some detail. Analysis of the associated principal vectors shows that a bending moment produces curvature in the plane of the moment, together with shear deformation in the perpendicular plane, but no bending-bending coupling; the choice of a structure having an equilateral triangular cross-section is thought responsible for this unexpected behaviour, as the equivalent continuum second moments of area are equal about all cross-sectional axes. In addition, an asymmetric stiffness matrix is obtained for bending moment and shearing force coupling, and possible causes are discussed.

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