Slender double-tube ultra-high strength concrete-filled tubular columns under ambient temperature and fire

This paper presents the results of an experimental campaign where both the room temperature and the fire resistance of six double-tube concrete filled steel tubular slender columns with different combinations of concrete strength are studied. Firstly, the ultimate axial load of the specimens at room temperatura was experimentally obtained and afterwards the fire resistance of such columns subjected to a 20% of their load bearing capacity was measured. Given the reduced number of experimental results found in the literature on slender concrete filled tubular columns with double steel tubular cross-sections, the main objective of this paper is to compare the behaviour of such innovative cross-sections under ambient and high temperatures. The influence of filling the inner ring with concrete on the fire performance of these columns is studied in this paper, as well as the variation of thicknesses of the outer and inner steel tubes. Despite the fact that the tested columns are not covered by the scope of Eurocode 4, the current simple calculation models were applied in this paper in order to assess the validity of the standard to this typology of columns, unsafe results being found.The authors would like to express their sincere gratitude to the Spanish Ministry of Economy and Competitivity through the project BIA2012-33144 and to the European Community for the FEDER funds.Romero, ML.; Espinós Capilla, A.; Portoles Flaj, JM.; Hospitaler Pérez, A.; Ibáñez Usach, C. (2015). Slender double-tube ultra-high strength concrete-filled tubular columns under ambient temperature and fire. Engineering Structures. 99:536-545. https://doi.org/10.1016/j.engstruct.2015.05.026S5365459

Identifying Loci for the Overlap Between ADHD and ASD Using a Genome-wide QTL Linkage Approach

Background: Recent studies in the general population and clinical samples have shown that Pervasive Developmental Disorder (PDD) and Attention-Deficit/Hyperactivity Disorder (ADHD) overlap, both in symptoms and in underlying genetic influences.Objectives: In this study, the genetic basis for PDD symptoms in children with ADHD was addressed using a Quantitative Trait Locus linkage approach.Methods: Genome wide linkage analyses were performed in the Dutch participants of the International Multi-Center ADHD Genetics (IMAGE) study comprising 365 DSM-IV combined type ADHD probands and 439 of their siblings who were part of 365 families. The total and subscale scores of the Children’s Social Behavior Questionnaire (CSBQ; a measure of subtle PDD symptoms) with heritabilities >0.2 were used as quantitative traits. A total of 5407 autosomal single-nucleotide polymorphisms (SNPs) were used to run multipoint regression-based linkage analyses using MERLIN-regress software.Results: Suggestive linkage signals (LOD? 2.0) were found on chromosomes 2q, 3p, 7p, 7q, and 8p. The signal on chromosome 7q11.2 overlapped for three CSBQ scales, namely the total score (LOD 2.08), and the scales addressing withdrawn behavior (LOD 3.07) and understanding of social information (LOD 2.01), respectively. The regions on chromosome 7q11 and 8p21 that we identified have previously been found for autism, and the chromosome 7p13 finding overlaps with a linkage study for ADHD.Conclusions: Defining an ADHD subtype with PDD symptoms appears to be a valuable approach for detecting susceptibility loci for the overlap between ADHD and PD