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Abstract: In this paper, the results of an extensive numerical study devoted to the evaluation of the inelastic flexural behaviour of aluminium alloy structures are provided. The main aim of the research is to determine the required ductility for applying simplified methods of plastic analysis (i.e. plastic hinge method) to structural systems made of materials characterised by a continuous hardening and with limited deformation capacity. Therefore, the cross-section rotational capacity necessary to attain predefined levels of load bearing capacity is evaluated for different structural schemes and then compared to the available rotational capacity corresponding to fixed thresholds of ultimate cross-section curvature. The influence of both geometrical (cross-section shape factor and structural scheme) and mechanical (material hardening and ultimate deformation capacity) parameters is taken into account. The parametric analysis is performed by using a numerical model implemented in the implicit non-linear FE code ABAQUS/Standard and calibrated on available experimental tests. On the basis of the above analysis, the limit values for the rotational capacity of a cross-section in bending necessary to guarantee adequate inelastic redistribution of internal forces for continuous beams and framed structures are given. Finally, new indications for the application of the modified plastic hinge method included in Eurocode 9 are provided. [Copyright &y& Elsevier]

Abstract: In this paper, the results of an extensive numerical analysis program devoted to the evaluation of the inelastic response of I-shaped aluminium alloy beams in non-uniform bending are presented. By using a numerical model implemented in the implicit FE code ABAQUS/Standard and largely calibrated with experimental tests, the main geometrical and mechanical parameters influencing the plastic behaviour of such beams are investigated. The results obtained in this study confirm the important role of the material hardening which, in addition to the local slenderness of compressed elements, has a strong influence on both ultimate moment and rotational capacity of the member. Moreover, it is shown that the influence of the other parameters, namely flange-to-web slenderness ratio, moment gradient, web slenderness and sectional area ratio, on the plastic capacity of the considered beams in terms of strength and deformability is of a secondary importance even if it is not negligible. On the whole, the results, which are obtained for two different tempers, emphasize the need to improve the present guidelines provided by the European code for aluminium structures relating to cross-sectional classification. More accurate class limits for outstand elements, which are able to account for the most important influential parameters on the plastic behaviour, are therefore proposed. [Copyright &y& Elsevier]

Objective: This study examines the potential role of candidate genes in moderating treatment effects of methylphenidate (MPH) in attention-deficit/hyperactivity disorder (ADHD).Method: Eighty-two subjects with ADHD aged 6 to 17 years participated in a prospective, double-blind, placebo-controlled, multiple-dose, crossover titration trial of immediate release MPH three times daily. The subjects were assessed on a variety of parent and clinician ratings and a laboratory math test. Data reduction based on principal components analysis identified statistically derived efficacy and side effect outcomes.Results: Attention-deficit/hyperactivity disorder symptom response was predicted by polymorphisms at the serotonin transporter (SLC6A4) intron 2 VNTR (p = .01), with a suggested trend for catechol-O-methyltransferase (COMT) (p = .04). Gene × dose interactions were noted on math test outcomes for the dopamine D4 receptor (DRD4) promoter (p = .008), DRD4 exon 3 VNTR (p = .006), and SLC6A4 promoter insertion/deletion polymorphism (5HTTLPR) (p = .02). Irritability was predicted by COMT (p = .02). Vegetative symptoms were predicted by 5HTTLPR (p = .003). No significant effects were noted for the dopamine transporter (SLC6A3) or synaptosomal-associated protein 25 (SNAP25).Conclusions: This article confirms and expands previous studies suggesting that genes moderate ADHD treatment response. The ADHD outcomes are not unitary but reflect both behavioral and learning domains that are likely influenced by different genes. Future research should emphasize candidate gene and genome-wide association studies in larger samples, symptom reduction as well as side effects outcomes, and responses over full therapeutic dose ranges to assess differences in both gene and gene × dose interactive effects. [ABSTRACT FROM AUTHOR]