bluuebunny/crossref_metadata_2025 huggingface dataset:
Child stunting is associated with weaker human capital among native Amazonians
Authors: Undurraga Eduardo A. , Behrman Jere R. , Emmett Susan D. , Kidd Celeste , Leonard William R. , Piantadosi Steven T. , Reyes‐García Victoria , Sharma Abhishek , Zhang Rebecca , Godoy Ricardo A.
Published: September 2017

Objectives

We assessed associations between child stunting, recovery, and faltering with schooling and human capital skills in a native Amazonian society of horticulturalists‐foragers (Tsimane').

Methods

We used cross‐sectional data (2008) from 1262 children aged 6 to 16 years in 53 villages to assess contemporaneous associations between three height categories: stunted (height‐for‐age Z score, HAZ<–2), moderately stunted (–2 ≤ HAZ≤–1), and nonstunted (HAZ>–1), and three categories of human capital: completed grades of schooling, test‐based academic skills (math, reading, writing), and local plant knowledge. We used annual longitudinal data (2002–2010) from all children (n = 853) in 13 villages to estimate the association between changes in height categories between the first and last years of measure and schooling and academic skills.

Results

Stunting was associated with 0.4 fewer completed grades of schooling (∼24% less) and with 13–15% lower probability of showing any writing or math skills. Moderate stunting was associated with ∼20% lower scores in local plant knowledge and 9% lower probability of showing writing skills, but was not associated with schooling or math and writing skills. Compared with nonstunted children, children who became stunted had 18–21% and 15–21% lower probabilities of showing math and writing skills, and stunted children had 0.4 fewer completed grades of schooling. Stunted children who recovered showed human capital outcomes that were indistinguishable from nonstunted children.

Conclusions

The results confirm adverse associations between child stunting and human capital skills. Predictors of growth recovery and faltering can affect human capital outcomes, even in a remote, economically self‐sufficient society.
Exome sequences of multiplex, multigenerational families reveal schizophrenia risk loci with potential implications for neurocognitive performance
Authors: Kos Mark Z. , Carless Melanie A. , Peralta Juan , Curran Joanne E. , Quillen Ellen E. , Almeida Marcio , Blackburn August , Blondell Lucy , Roalf David R. , Pogue‐Geile Michael F. , Gur Ruben C. , Göring Harald H.H. , Nimgaonkar Vishwajit L. , Gur Raquel E. , Almasy Laura
Published: September 2017

Schizophrenia is a serious mental illness, involving disruptions in thought and behavior, with a worldwide prevalence of about one percent. Although highly heritable, much of the genetic liability of schizophrenia is yet to be explained. We searched for susceptibility loci in multiplex, multigenerational families affected by schizophrenia, targeting protein‐altering variation with in silico predicted functional effects. Exome sequencing was performed on 136 samples from eight European‐American families, including 23 individuals diagnosed with schizophrenia or schizoaffective disorder. In total, 11,878 non‐synonymous variants from 6,396 genes were tested for their association with schizophrenia spectrum disorders. Pathway enrichment analyses were conducted on gene‐based test results, protein‐protein interaction (PPI) networks, and epistatic effects. Using a significance threshold of FDR < 0.1, association was detected for rs10941112 (p = 2.1 × 10−5; q‐value = 0.073) in AMACR, a gene involved in fatty acid metabolism and previously implicated in schizophrenia, with significant cis effects on gene expression (p = 5.5 × 10−4), including brain tissue data from the Genotype‐Tissue Expression project (minimum p = 6.0 × 10−5). A second SNP, rs10378 located in TMEM176A, also shows risk effects in the exome data (p = 2.8 × 10−5; q‐value = 0.073). PPIs among our top gene‐based association results (p < 0.05; n = 359 genes) reveal significant enrichment of genes involved in NCAM‐mediated neurite outgrowth (p = 3.0 × 10−5), while exome‐wide SNP‐SNP interaction effects for rs10941112 and rs10378 indicate a potential role for kinase‐mediated signaling involved in memory and learning. In conclusion, these association results implicate AMACR and TMEM176A in schizophrenia risk, whose effects may be modulated by genes involved in synaptic plasticity and neurocognitive performance.
The role of CLOCK gene in psychiatric disorders: Evidence from human and animal research
Authors: Schuch Jaqueline B. , Genro Julia P. , Bastos Clarissa R. , Ghisleni Gabriele , Tovo‐Rodrigues Luciana
Published: September 2017

The circadian clock system drives daily rhythms in physiology, metabolism, and behavior in mammals. Molecular mechanisms of this system consist of multiple clock genes, with Circadian Locomotor Output Cycles Kaput (CLOCK) as a core member that plays an important role in a wide range of behaviors. Alterations in the CLOCK gene are associated with common psychiatric disorders as well as with circadian disturbances comorbidities. This review addresses animal, molecular, and genetic studies evaluating the role of the CLOCK gene on many psychiatric conditions, namely autism spectrum disorder, schizophrenia, attention‐deficit/hyperactivity disorder, major depressive disorder, bipolar disorder, anxiety disorder, and substance use disorder. Many animal experiments focusing on the effects of the Clock gene in behavior related to psychiatric conditions have shown consistent biological plausibility and promising findings. In humans, genetic and gene expression studies regarding disorder susceptibility, sleep disturbances related comorbidities, and response to pharmacological treatment, in general, are in agreement with animal studies. However, the number of controversial results is high. Literature suggests that the CLOCK gene exerts important influence on these conditions, and influences the susceptibility to phenotypes of psychiatric disorders.
Genetic variants related to disease susceptibility and immunotolerance in the Duffy antigen receptor for chemokines (DARC, Fy) gene in the black lion tamarin (Leontopithecus chrysopygus, primates)
Authors: Ansel Ashley , Lewis James D. , Melnick Don J. , Martins Cristiana , Valladares‐Padua Claudio , Perez‐Sweeney Beatriz
Published: September 2017

The DARC (Duffy antigen receptor for chemokines) gene encodes the DARC protein, which serves multiple roles in the immune system, as a binding site for the malarial parasites Plasmodium vivax and Plasmodium knowlesi, a promiscuous chemokine receptor and a blood group antigen. Variation in DARC may play particularly significant roles in innate immunity, immunotolerance and pathogen entry in callitrichines, such as the black lion tamarin (Leontopithecus chrysopygus). We compared amino acid sequences of DARC in the black lion tamarin (BLT) to non‐human Haplorhine primates and Homo sapiens. Consistent with prior studies in other Haplorhines, we observed that the chemokine receptor experiences two opposing selection forces: (1) positive selection on the Plasmodium binding site and (2) purifying selection. We observed also that D21N, F22L, and V25L differentiated BLT from humans at a critical site for P. vivax and P. knowlesi binding. One amino acid residue, F22L, was subject to both positive selection and fixation in New World monkeys, suggesting a beneficial role as an adaptive barrier to Plasmodium entry. Unlike in humans, we observed no variation in DARC among BLTs, suggesting that the protein does not play a role in immunotolerance. In addition, lion tamarins differed from humans at the blood compatibility Fya/Fyb antigen‐binding site 44, as well as at the putative destabilizing residues A61, T68, A187, and L215, further supporting a difference in the functional role of DARC in these primates compared with humans. Further research is needed to determine whether changes in the Plasmodium and Fya/Fyb antigen‐binding sites disrupt DARC function in callitrichines.
Solid Electrolytes: Extremely Fast Charge Carriers in Garnet‐Type Li6La3ZrTaO12 Single Crystals
Authors: Stanje Bernhard , Rettenwander Daniel , Breuer Stefan , Uitz Marlena , Berendts Stefan , Lerch Martin , Uecker Reinhard , Redhammer Günther , Hanzu Ilie , Wilkening Martin
Published: September 2017

The development of all‐solid‐state electrochemical energy storage systems, such as lithium‐ion batteries with solid electrolytes, requires stable, electronically insulating compounds with exceptionally high ionic conductivities. Considering ceramic oxides, garnet‐type LiLaZrO and derivatives, see Zr‐exchanged LiLaZrTaO (LLZTO), have attracted great attention due to its high Li+ ionic conductivity of 10 S cm at ambient temperature. Despite numerous studies focussing on conductivities of powder samples, only few use time‐domain NMR methods to probe Li ion diffusion parameters in single crystals. Here we report on temperature‐variable NMR relaxometry measurements using both laboratory and spin‐lock techniques to probe Li jump rates covering a dynamic time window spanning several decades. Both techniques revealed a consistent picture of correlated Li ion jump diffusion in the single crystal; the data perfectly mirror a modified BPP‐type relaxation response being based on a Lorentzian‐shaped relaxation function. The rates measured could be parameterized with a single set of diffusion parameters. Results from NMR are completely in line with ion transport parameters derived from conductivity spectroscopy.
Toward Cost‐Effective Manufacturing of Silicon Solar Cells: Electrodeposition of High‐Quality Si Films in a CaCl2‐based Molten Salt
Authors: Yang Xiao , Ji Li , Zou Xingli , Lim Taeho , Zhao Ji , Yu Edward T. , Bard Allen J.
Published: September 2017

Electrodeposition of Si films from a Si‐containing electrolyte is a cost‐effective approach for the manufacturing of solar cells. Proposals relying on fluoride‐based molten salts have suffered from low product quality due to difficulties in impurity control. Here we demonstrate the successful electrodeposition of high‐quality Si films from a CaCl2‐based molten salt. Soluble SiIV−O anions generated from solid SiO2 are electrodeposited onto a graphite substrate to form a dense film of crystalline Si. Impurities in the deposited Si film are controlled at low concentrations (both B and P are less than 1 ppm). In the photoelectrochemical measurements, the film shows p‐type semiconductor character and large photocurrent. A p–n junction fabricated from the deposited Si film exhibits clear photovoltaic effects. This study represents the first step to the ultimate goal of developing a cost‐effective manufacturing process for Si solar cells based on electrodeposition.
Enzyme Encapsulation by a Ferritin Cage
Authors: Tetter Stephan , Hilvert Donald
Published: September 2017

Ferritins, conserved across all kingdoms of life, are protein nanocages that evolved to mineralize iron. The last several decades have shown that these cages have considerable technological and medical potential owing to their stability and tolerance to modification, as well as their ability to template nanoparticle synthesis and incorporate small molecules. Here we show that it is possible to encapsulate proteins in a ferritin cage by exploiting electrostatic interactions with its negatively charged interior. Positively supercharged green fluorescent protein is efficiently taken up by Archaeoglobus fulgidus ferritin in a tunable fashion. Moreover, several enzymes were readily incorporated when genetically tethered to this fluorescent protein. These fusion proteins retained high catalytic activity and showed increased tolerance to proteolysis and heat. Equipping ferritins with enzymatic activity paves the way for many new nanotechnological and pharmacological applications.
The First Gold(III) Formate: Evidence for β‐Hydride Elimination
Authors: Kumar Roopender , Krieger Jean‐Philippe , Gómez‐Bengoa Enrique , Fox Thomas , Linden Anthony , Nevado Cristina
Published: September 2017

The first stable gold(III) formate and experimental evidence for its β‐hydride elimination are described. A catalytic dehydrogenation of formic acid together with mechanistic studies shed light on potential pathways operating in fundamental gold‐catalyzed transformations.
Selective C−O Bond Cleavage of Sugars with Hydrosilanes Catalyzed by Piers’ Borane Generated In Situ
Authors: Zhang Jianbo , Park Sehoon , Chang Sukbok
Published: September 2017

Described herein is the selective reduction of sugars with hydrosilanes catalyzed by using Piers’ borane [(C6F5)2BH] generated in situ. The hydrosilylative C−O bond cleavage of silyl‐protected mono‐ and disaccharides in the presence of a (C6F5)2BH catalyst, generated in situ from (C6F5)2BOH, takes place with excellent chemo‐ and regioselectivities to provide a range of polyols. A study of the substituent effects of sugars on the catalytic activity and selectivity revealed that the steric environment around the anomeric carbon (C1) is crucial.
First microsatellite data on Proteus anguinus reveal weak genetic structure between the caves of Postojna and Planina
Authors: Zakšek Valerija , Konec Marjeta , Trontelj Peter
Published: September 2017

The European cave salamander, Proteus anguinus, or proteus, is the largest obligate cave animal in the world. It is an endangered and charismatic species of high conservation importance for subterranean waters. Conservation genetic studies are hampered by the extreme size and repetitiveness of its nuclear genome.

The aim of the study was to develop and characterize the first microsatellite markers for proteus, and test their informativeness at the level of individuals, populations and between populations in the Postojna and Planina caves in Slovenia.

Twenty‐three novel polymorphic microsatellite markers were amplified in 201 individuals from both caves using three multiplex reactions. The number of alleles per locus varied from three to nine. The loci are largely unlinked and conform to Hardy–Weinberg genotype frequencies. Genetic equilibrium and an FST value of 0.0024 suggest a nearly panmictic population in both caves separated by some 10 km of subterranean river course, while Bayesian clustering detected weak genetic structure.

The microsatellites described fill the gap of urgently needed nuclear markers in Proteus that can be applied in genetic mark–recapture studies, population monitoring and identification of management units to assist conservation efforts.
Scientists' data reuse behaviors: A multilevel analysis
Authors: Kim Youngseek , Yoon Ayoung
Published: September 2017

This study explores the factors that influence the data reuse behaviors of scientists and identifies the generalized patterns that occur in data reuse across various disciplines. This research employed an integrated theoretical framework combining institutional theory and the theory of planned behavior. The combined theoretical framework can apply the institutional theory at the individual level and extend the theory of planned behavior by including relevant contexts. This study utilized a survey method to test the proposed research model and hypotheses. Study participants were recruited from the Community of Science's (CoS) Scholar Database, and a total of 1,528 scientists responded to the survey. A multilevel analysis method was used to analyze the 1,237 qualified responses. This research showed that scientists' data reuse intentions are influenced by both disciplinary level factors (availability of data repositories) and individual level factors (perceived usefulness, perceived concern, and the availability of internal resources). This study has practical implications for promoting data reuse practices. Three main areas that need to be improved are identified: Educating scientists, providing internal supports, and providing external resources and supports such as data repositories.
Modular Organization of the Thermobifida fusca Exoglucanase Cel6B Impacts Cellulose Hydrolysis and Designer Cellulosome Efficiency
Authors: Setter‐Lamed Eva , Moraïs Sarah , Stern Johanna , Lamed Raphael , Bayer Edward A.
Published: September 2017

Cellulose deconstruction can be achieved by three distinct enzymatic paradigms: free enzymes, multifunctional enzymes, and self‐assembled, multi‐enzyme complexes (cellulosomes). To study their comparative efficiency, the simple and efficient cellulolytic system of the aerobic bacterium, Thermobifida fusca, is developed as an enzymatic model. In previous studies, most of its cellulases are successfully converted to the cellulosomal mode and exhibited high cellulolytic activities, except for Cel6B, a key exoglucanase of the T. fusca enzymatic system. Here, the impact of the modular organization of Cel6B on enzymatic activity is investigated. The position of the cellulose‐binding module (CBM), its family and linker segment are shown to affect activity. Surprisingly, exchange of the native family‐2 CBM to family‐3 generates an increase in Cel6B activity on cellulosic substrates. Conversion of Cel6B to the cellulosomal mode by fusing a cohesin to the catalytic module enables formation of divalent enzyme complexes with dockerin‐bearing enzymes. The resultant pseudo‐cellulosomes, containing Cel6B combined with endoglucanase Cel5A, exhibits enhanced enzymatic activity, compared to mixtures of wild‐type enzymes or bifunctional enzymes, unlike similar pseudo‐cellulosomes containing endoglucanase Cel6A or proccessive endoglucanase Cel9A. Insight into the different enzymatic paradigms benefits ongoing development of efficient cellulolytic systems for conversion of plant‐derived biomass into valuable sugars.

Novelty statement

The protein engineering of the modular arrangement of a key exoglucanase from a highly cellulolytic bacterium, Thermobifida fusca, served to explore and compare three major enzymatic paradigms for cellulose degradation. This approach revealed highly active chimaeric forms of the exoglucanase that act in synergy together with a potent endoglucanase in bifunctional enzymes or divalent pseudo‐cellulosome‐like complexes. Such engineered enzymes could be further integrated into larger enzymatic complexes, thereby providing a significant step forward towards conversion of the entire T. fusca free cellulolytic system into the cellulosomal modex and the enhanced conversion of cellulosic biomass into soluble sugars.
Significant events in an Internet‐delivered (Space from Depression) intervention for depression
Authors: Richards Derek , Dowling Mairéad , O'Brien Emma , Viganò Noemi , Timulak Ladislav
Published: September 2017

Objective

The advantages and effectiveness of Internet interventions have been established. Little is known about the critical processes of change in Internet‐delivered interventions and of the psychological experience of users. These are both clinically relevant and have a link to the overall outcome of therapy. The goal of this article was to gain an insight into the important therapeutic processes in an 8‐week supported online self‐administered CBT‐based treatment for depression.

Method

Respondents were participants (N = 88) in a randomised controlled trial with an initial score of 14–28 on the Beck Depression Inventory (BDI‐II), who completed at least one module of the online intervention, and at least one Helpful Aspects of Therapy (HAT) questionnaire.

Analysis

The HAT data were analysed using descriptive–interpretative qualitative analysis to (i) identify helpful and hindering events, (ii) describe key events and (iii) describe the corresponding impacts of these events on the clients.

Results

In total, six helpful events were reported (provision of information, core CBT activities, mindfulness, platform accessibility and usability, supporter, personal stories and examples) and eight associated impacts (applying new coping skills/behavioural change, awareness and insight, improved well‐being, support/validation, expression/relief, self‐efficacy/empowerment/sense of achievement, personal connection). In total, five hindering events were identified (platform features/design, external factors, internal factors, supporters' feedback and content of the programme) and five associated impacts (disappointment, frustration/irritation, confusion, mood deterioration and being self‐critical/blaming) were reported.

Conclusions

The current results support previous findings that CBT principles are important in online delivery. The role of the supporter emerges as a key ingredient in online delivery worthy of further investigation.
Bioluminescence Resonance Energy Transfer (BRET)‐coupled Annexin V‐functionalized Quantum Dots for Near‐Infrared Optical Detection of Apoptotic Cells
Authors: Tsuboi Setsuko , Jin Takashi
Published: September 2017

Deregulation in apoptosis induces numerous diseases such as cancer, cardiovascular, and neurodegenerative diseases. Detection of apoptotic cells is crucial for understanding the mechanism of these diseases and for therapy development. Although optical imaging using visible‐emitting fluorescent probes, such as FITC‐labeled annexin V, is widely used for the detection of apoptotic cells, there are very limited probes that can be used in the near‐infrared region (NIR) over 700 nm. Compared with visible light, NIR light is highly permeable in turbid biological samples and tissues. In addition, optical imaging in the NIR region shows low autofluorescence from biological samples, leading to clearer images with high signal to background ratios. Here, we report the synthesis of bioluminescence resonance energy transfer (BRET)‐coupled annexin V‐functionalized quantum dots (QDs) and their application to NIR optical detection of apoptotic cells.
Late‐onset hemophagocytic lymphohistiocytosis with neurological presentation
Authors: Benezech Sarah , Walzer Thierry , Charrier Emily , Heidelberg Damien , De Saint‐Basile Geneviève , Bertrand Yves , Belot Alexandre
Published: September 2017

Key Clinical Message

Missense mutations in genes involved in familial hemophagocytic lymphohistiocytosis can delay the onset of this life‐threatening disease. In children and adults, early recognition of aspecific features as neurological symptoms is crucial as urgent treatment is required.
Live‐attenuated vaccines in a cryopyrin‐associated periodic syndrome patient receiving canakinumab treatment during infancy
Authors: Watanabe Misa , Nishikomori Ryuta , Fujimaki Yuki , Heike Toshio , Ohara Akira , Saji Tsutomu
Published: September 2017

Key Clinical Message

We successfully immunized the neonatal‐onset multisystem inflammatory disease (NOMID) patient with live‐attenuated vaccines for measles, rubella, varicella, and mumps and achieved sufficient antibody titer under canakinumab therapy without complications.
Multiple Functionalized Hyperbranched Polyethoxysiloxane Promotes Suzuki Coupling Asymmetric Transfer Hydrogenation One‐Pot Enantioselective Organic Transformations
Authors: Zhang Genwei , Liu Rui , Chou Yajie , Wang Yu , Cheng Tanyu , Liu Guohua
Published: September 2017

Utilization of amphiphilic poly(ethylene glycol) monomethyl ether modified hyperbranched polyethoxysiloxane as a support for the construction of bifunctional heterogeneous catalysts enables a highly efficient catalytic system thanks to its amphiphilic nature in aqueous organic transformations. Herein, through a three‐component self‐assembly procedure, we incorporate palladium/phosphine and chiral ruthenium/diamine functionality within poly(ethylene glycol) monomethyl ether modified hyperbranched polyethoxysiloxane, fabricating a multiple functionalized polyethoxysiloxane based mesoporous material. Structural analyses and characterizations disclose that well‐defined dual single‐site active centers are distributed uniformly within monodisperse mesoporous silica nanoparticles. As a bifunctional heterogeneous catalyst, this material performs the one‐pot enantioselective tandem reaction of Pd‐catalyzed Suzuki cross‐coupling and Ru‐catalyzed asymmetric transfer hydrogenation, affording various chiral biaryl alcohols with high yields and up to 99 % enantioselectivity. Furthermore, the catalyst can be recovered and recycled eight times without loss of its catalytic activity, demonstrating the practicability of the preparation of optically pure biaryl alcohols in one‐pot organic transformation.
Uncovering the 3 D Structure of Combustion‐Synthesized Noble Metal‐Ceria Nanocatalysts
Authors: Roiban Lucian , Koneti Siddardha , Morfin Franck , Nguyen Thanh‐Son , Mascunan Pascale , Aouine Mimoun , Epicier Thierry , Piccolo Laurent
Published: September 2017

With its unique redox properties, ceria is an oxide with a range of applications, including automotive catalytic converters, which consist of platinum‐group metal nanoparticles on ceria‐containing supports. In this work, the 3 D architecture of a ceria‐based material synthesized by the widely employed glycine‐nitrate solution combustion method is revealed for the first time. Together with N2 adsorption volumetry, scanning transmission electron microscopy (STEM) and scanning electron microscopy (SEM), STEM tomography provides a comprehensive picture of the multimodal porous network of a pre‐reduced Pt‐CeO2 catalyst, from the nanometer to the micrometer scale. This material consists of ceria nanocrystallites forming 3 D aggregates and puzzle‐like 2 D walls separating large roundish mesopores and macropores. The small voids between imperfectly assembled crystallites give rise to some microporosity. In addition, it is demonstrated that a significant proportion of platinum nanoparticles (3–4 nm) are not located at the ceria surface following the one‐step synthesis process, about half of them are buried within ceria. This result is valid for another metal (Rh) and another fuel (oxalyl dihydrazide), and has important implications for heterogeneous catalysis.
Controlled Fabrication of Interconnected Porous Carbon Nanosheets for Supercapacitors with a Long Cycle Life
Authors: Chen Nannan , Ma Kongjun , Bai Zhengyu , Mi Hongyu , Li Zhiwei , Zhang Qing , Qiu Jieshan
Published: September 2017

The pursuit of promising precursors and simple preparation approaches boosts the development of sustainable carbon‐related energy systems. In this work, a relatively low‐cost and eco‐friendly ternary precursor system is presented for the fabrication of interconnected sheet‐structured porous carbon materials by the combination of template‐assisted pyrolysis and post‐activation. The variation of effect factors permitted the formation of tunable microstructures with multilevel pore channels, and the optimized sample (APC3‐700) with multiple desired properties (such as, large surface area, hierarchical interconnected pores, and nitrogen doping) was successfully synthesized. Due to the large electrode/electrolyte interface, short pathway for mass/charge transfer, high electrochemical activity, and low transport resistance, APC3‐700 proved to be a favorable material with high capacitance (225 F g−1 at 1 A g−1) and a high rate profile (remaining 91 % at 20 A g−1). In particular, the symmetrical supercapacitor assembled demonstrated a long cycle life with almost no capacitance decaying over 20 000 cycles. The method used may be employed for the widespread development of nanosheet‐connected carbon materials from different sources for efficient enhancement of energy storage.
03.16: Multiplanar K‐joints on cold‐formed open sections: An experimental study with high strength steels
Authors: Manoleas Panagiotis , Koltsakis Efthymios , Veljkovic Milan
Published: September 2017

The design, laboratory investigation and main results of an experimental programme on the joints of an innovative 3D truss made of high strength steel (HSS) is presented. An entire truss of triangular cross‐section was fabricated (two compression chords and a single tension chord) to provide realistic loading conditions. Both compression and tension chords were fabricated by cold forming hot‐rolled HSS plates by means of press braking. The chords were as follows:

— an open angle‐type profile with 45° contained angle as tension chord (U‐chord),

— a semi‐closed octagonal profile made of 3 sectors bolted along their length every 1.2 diameters as compression chords (P‐chord).

The focus of this study is on the tension chords joints where a pair of tension and a pair of compression diagonals converge. Joints were tested to ultimate load by introducing shear to one bay of the truss at a time. Two design approaches for the joints were tested resulting in four individual tests.

Ultimate load levels, stiffness and failure modes varied between the considered joint configurations. Stiffening increased the ultimate load by as much as 170% of that of the unstiffened version achieving higher utilisation of the tension chord, thus making more efficient use of HSS. The stiffness loss at loads close to failure varied between 60% – 80%. Two distinctive failure modes were observed, one caused by cracking of the welds connecting the diagonal's gusset plates to the tension chord while the second by cross‐section tensile fracture of the circular hollow section (CHS) diagonal.
03.19: Seismic performance of full strength extended stiffened joint: American vs New European approach
Authors: Tartaglia Roberto , D'Aniello Mario , Rassati Gian A. , Swanson James A. , Landolfo Raffaele
Published: September 2017

Extended stiffened end‐plate bolted joints are widely used in seismic resistant steel frames. In the United States of America (USA) this type of joint is seismically pre‐qualified according to AISC 358. In Europe prequalification criteria are under development within the framework of the ongoing EQUALJOINT research project. Even though the design rules of both approaches are based on the principles of hierarchy of resistances, there are some differences. In order to clarify these aspects, this paper describes both design criteria and rules. In addition, the results of a large parametric finite element investigation are used for discussion.
03.26: Experimental assessment of friction dampers under impact loading
Authors: Santos Ana Francisca , Santiago Aldina , da Silva Luís Simões , Latour Massimo , Rizzano Gianvittorio
Published: September 2017

In order to enhance the knowledge of the behaviour of steel joints under accidental loading conditions, within the European research project FREEDAM, the behaviour of an innovative beam‐to‐column connection, in particular the dissipative component (friction damper) of the joint under tension, has been studied under impact and quasi‐static conditions.

This experimental campaign comprises a total of 6 quasi‐static tests and 35 impact tests on friction pads, that includes three different friction materials, two different plate thicknesses (10mm and 30mm) and two different bolt classes (class 8.8SB or 10.9HR). The impact tests were performed using an experimental layout capable of apply high loading rates by a pneumatic actuator, totally developed and tailored at the University of Coimbra. The results of impact tests compared with the quasi‐static tests show: i) an increase in the component resistance when subjected to impact loads, ii) a reduction in the ductility of the component.
03.33: Experimental assessment of tolerances for the fabrication of laser‐cut steel joints
Authors: Kanyilmaz Alper , Castiglioni Carlo Andrea , Brambilla Giovanni , Gjoka Kristian , Galazzi Andrea , Raso Sergio , Valli Alberto , Brugnolli Marco , Hojda Ralf
Published: September 2017

Circular hollow sections (CHS) represent several advantages, such as uniform behaviour in all directions, possibility to obtain composite behaviour by concrete infill, hence high strength, stability and good fire resistance. Moreover, their aesthetic appeal has a great potential for the decision maker's attention, be that the architect or the building owner. However, they are not widely adopted in practice due to the complexity and high cost of their joint details. EU‐RFCS project LASTEICON (Laser Technology for Innovative Connections in Steel Construction), started on July 2016 [1] proposes simpler joint solutions with reduced fabrication costs, to be adopted between CHS columns and I beams, making use of laser cutting technology (LCT). The primary objective of the LASTEICON project is to overcome the complexity of steel joints between CHS columns and I beams, and let engineers and architects exploit the outstanding structural properties of hollow section profiles. Laser cutting will allow the reduction of the shop fabrication time, obtaining higher precision high quality joint fabrication, and improving workplace safety reducing the amount of manual labor while increasing computer‐programmed automation. This paper presents the preliminary results obtained in the Work‐Package 1 of the LASTEICON project (www.lasteicon.eu), which consisted in a study of tolerance optimization for an efficient fabrication of I‐beam‐to‐CHS column joints.
03.35: Rivet shear strength in long connections
Authors: Tide Raymond H.R.
Published: September 2017

Rivet shear limit states are based on historical test data. Several different grades of rivets and plate material were used, which were accommodated by transforming the test data into a non‐dimensional form. Because an exact solution for rivet shear in a connection requires solving non‐linear simultaneous equations, a more practical empirical solution is proposed that eliminates this requirement. A statistical analysis was performed using the existing partial factor, of 1.25 to demonstrate that an acceptable reliability, β, close to or slightly greater than the desired 4.0 is obtained for all connection lengths when a length reduction factor R2 (βLF) of 0.90 is used, thus eliminating the need for a variable connection length reduction factor, βLF. The data was also analyzed for the case with no length reduction factor R2 (βLF) = 1.0. The statistical analysis of the test data indicates that there is no justification for a variable shear strength reduction due to connection length provided there is only a limited amount of second‐order effects in combination with gross and net areas equal to or greater than the specification limits.

The assembled research data, based on rivet strengths of 392 N/mm2 and 523 N/mm2, were compared with the Eurocode 3 (EN 1993) provisions to determine compatibility. It was determined that the research test data did not support the Eurocode 3 provisions for a variable shear strength for rivets in connections longer than a specified basic length based on rivet diameter.

This investigation identified a riveted connection condition wherein with appropriate connection strength and quasi‐stiffness, there would be no need to reduce the rivet shear strength with increasing connection length. Typically it was found that this condition was achieved when both current Eurocode 3 checks for the limit state of yielding on the gross section and the limit state of fracture on the net section were satisfied.
04.01: Buckling of very short elastic cylinders with weld imperfections under uniform bending
Authors: Fajuyitan O. Kunle , Sadowski Adam J. , Wadee M. Ahmer
Published: September 2017

The length‐dependent domains of behaviour of thin elastic cylindrical shells under uniform bending have recently received significant research attention. Ovalisation is known to affect very long cylinders which undergo significant cross‐sectional flattening before failing by local buckling. This effect is restrained by the end boundary condition in shorter cylinders, which fail instead by local buckling at moments close to the classical analytical prediction. In very short cylinders, however, even this local buckling is restrained by the end boundary, and failure occurs instead through the development of a destabilising meridional fold on the compressed side. Although this is a limit point instability under bending, ovalisation does not play any role at all. This ‘very short’ length domain has only recently been explored for the first time with the aid of finite element modelling.

A brief overview of the nonlinear buckling behaviour of very short elastic cylinders under uniform bending is presented in this paper. Two types of edge rotational restraint are used to illustrate the influence of a varying support condition on the stability in this short length range. It is shown that short cylinders under bending do not suffer at all from local short‐wave buckling. Additionally, when the meridional dimension of such cylinders becomes particularly short the resulting numerical models may predict indefinite stiffening without a limit point, even when the shell is modelled using more complete 3D solid continuum finite elements. Idealised weld depressions, which are realistic representations of a systemic manufacturing defect, are used to demonstrate only a very mild sensitivity to geometric imperfections at such short lengths owing to a pre‐buckling stress state dominated by local compatibility bending. The topic should be of interest to researchers studying shell problems dominated by local bending with computational tools and designers of multi‐segment shells with very close segment spacing.
04.18: Determination of the plastic limit load for a cylindrical shell under general loading conditions using FEA
Authors: Słowiński Kamil , Piekarczyk Marek
Published: September 2017

This article is not available for publication.
04.21: Buckling of externally pressurised spherical shells: Experimental results compared with recent design recommendations
Authors: Błażejewski Paweł , Marcinowski Jakub , Rotter Michael
Published: September 2017

The buckling resistance of a steel spherical dome shell under external pressure is controlled by the geometry, material properties and fabrication quality class [1, 2]. A simple algorithm to determine the buckling resistance of such shells with a clamped boundary, in terms of the description used in [1], was recently developed by the authors [3, 4]. The assessment is based on the elastic critical pressure pRcr and the plastic resistance pressure pRpl, followed by evaluation of the imperfection sensitivity for the assumed fabrication quality class, assessment of the other buckling parameters that define the capacity curve, deduction of the characteristic value of the buckling resistance pRk, and determination of the design buckling resistance pRd. The new procedure was previously [3, 4] compared with the current design recommendations [2] and was found to give 30‐45% higher buckling resistances in some cases, making the new proposals less conservative.

The safety of the new proposals is here compared with many previous experimental results that have been presented in the literature. It is found that the new proposals are safe and more economic than the current rules.
05.02: Influence of rails on the stability of crane runway girders
Authors: Kraus Matthias , Mämpel Silvio , Crisan Andrei
Published: September 2017

Due to the stressing of crane runway girders, they are usually susceptible to lateral torsional buckling. In this paper, the contribution of crane rails to bending stiffness, torsional rigidity and load bearing capacity of crane runway girders is presented. The torsional and warping stiffness of the combined cross section is being determined by numerical approaches, i.e. two‐dimensional isoparametric finite elements for cross sections. The influence of the increased stiffness and cross sectional capacity is then considered for stability verifications based on an application of equivalent initial geometric imperfections. The corresponding non‐linear member analyses are performed using finite beam elements with seven degrees of freedom. In addition, the influence of the rails on the stress states of the total cross sections is evaluated and presented.
05.08: Lateral‐torsional buckling of beams of monosymmetrical cross‐sections loaded perpendicularly to the axis of symmetry: Theoretical analysis
Authors: Balázs Ivan , Melcher Jindřich
Published: September 2017

Determination of the critical moment is a crucial step of the process of assessment of the buckling resistance of a metal beam with no intermediate restraints between supports. The critical moment of an ideal beam depends, among others, on support conditions and variation of the bending moment along the span of the beam. It can be found as a solution of the eigenvalue problem of differential equations of bending. This complex procedure can generally provide a formula for the calculation of the critical moment with certain coefficients varying depending on the variation of the bending moment along the span and support conditions of the beam. The formula for the critical moment and numerical values of the coefficients taking into account the type of supports and variation of the bending moment for some common cases can be found in literature.

The paper focuses on process of derivation of the formula for calculation of the elastic critical moment of beams of double symmetrical and monosymmetrical cross‐sections (channels) loaded perpendicularly to the plane of symmetry. Based on classical Vlasov's theory and variational method, a formula for the elastic critical moment of beams of double symmetrical cross‐sections and channels loaded perpendicularly to the plane of symmetry and coefficients for not only simple cases of loads but also selected special cases are derived using mathematical methods and presented in the paper. Numerical values of the above mentioned coefficients are summarized in tables and charts.
05.18: Maximum chord slenderness ratio of compressed stainless steel closely spaced built‐up members
Authors: Dobrić Jelena , Marković Zlatko , Budjevac Dragan , Spremić Milan
Published: September 2017

Structural response of compressed closely spaced built‐up member is more complex than that of solid cross‐section member, considering that built‐up member is restrained at discrete points along its length. Effects of longitudinal shear caused by interaction between the contact areas of the individual chords may affect the overall behaviour and reduce the flexural buckling resistance of built‐up member. In the numerous design codes, the effect of shear deformation is considered through the equivalent slenderness ratio that includes the overall slenderness ratio of entire built‐up member, and the local slenderness ratio of individual chord that depends on the distance between interconnections. The EN 1993‐1‐4 does not provide explicit design guidelines for stainless steel built‐up members and refers to application of the EN 1993‐1‐1. This paper presents a part of extensive experimental and numerical investigation of behaviour of compressed stainless steel built‐up members. The members are formed by two C‐section chords directly connected by bolts or by groove welds and oriented back‐to‐back. The chord members are press‐braked from flat strips of austenitic stainless steel grade 1.4301. The member lengths and distance between interconnection are varied. The structural response of built‐up members that are connected at the ends and at one‐half of the member length is highlighted. The experimental and numerical values of buckling resistance are compared with design values according to Eurocode 3. The purpose of this paper is estimation of acceptability of existing design guidelines for carbon steel in the calculation of stainless steel built‐up members. In addition, this paper examines if the requirement regarding to limitations of maximum chord slenderness ratio can be modified in case of stainless steel closely spaced built‐up members with compact or semi‐compact cross‐sections.
05.22: Stainless steel prestressed stayed columns
Authors: Pichal Radek , Machacek Josef
Published: September 2017

Behavior of stainless steel prestressed stayed columns with a central crossarm is investigated numerically in 3D, following 3 tests of a reasonable size. The paper discusses previous analyses concerning critical loading and strength capacity with respect to influence of geometrical and material properties, prestressing and boundary conditions. Critical buckling loads and post‐buckling paths with regards to 2D and 3D GMNIA (geometrically and materially nonlinear analysis with imperfections) are demonstrated using ANSYS software. The buckling of the main column in 3D is shown, resulting into deflection in between the arms of the central crossarm, while the value of critical loading is rather unaffected in comparison with 2D analysis. Other results cover influence of the imperfection level with both symmetrical and antisymmetrical imperfection mode, boundary conditions at central crossarm (fixed or sliding stays) and nonlinear stainless steel material.
05.26: Reliability assessment for local buckling of plates
Authors: Schillo Nicole , Taras Andreas , Feldmann Markus
Published: September 2017

In the current Eurocode 3‐1‐5 [10] for local buckling, the resistance curve used to represent the reduction factor of plated elements due to local failure is based on the so‐called “Winter‐curve”, which was derived using a semi‐empirical approach by George Winter in 1947. This design curve reproduces the mean reduction values achieved in the experiments conducted by Winter and other researchers. However, when applying the safety concept of the Eurocode (EN 1990) [8], an additional safety factor is necessary to ascertain a defined level of failure probability. Currently, this factor is set to 1.0 for applications in building structures.

In the study at hand, 131 stub column tests on welded, squared box sections from steel grades S275 up to S960 were evaluated to assess a realistic safety factor in conformity with the safety standard EC0 [8]. A considerable amount of tests where thereby classified as high strength steel. The results showed to be comparable for all steel grades in dependence of their local slenderness.

The evaluation of test results revealed a considerable scatter, which is partly attributed to the stability failure mode, but could be also found to be originated from lack of information concerning unintended eccentricities in the experimental test setups. Therefore, the data set was divided into two sets, one consisting of all data, and one including only tests where these information were available and thus had reduced scatter. The second set lead consequently to a more favourable safety factor than the first one.

For all sets using the procedure to derive a safety factor, assumptions have to be made regarding the property‐specific Coefficients of Variation (CoVs). Standard values often given in literature, although correct for their specific applications, cannot be simply adjusted when including high strength steel material. Additionally, as the resistance function for local buckling is complex, the impact of e.g. the thickness has to be taken into account carefully. Different approaches and variations are presented in this paper, leading to scientifically justified ‐values.
05.42: Evaluation of ultimate strength and plastic deformation capacity of square hollow section members under bending shear
Authors: Sato Kosuke , Ikarashi Kikuo
Published: September 2017

The purpose of this study is to evaluate ultimate strength and plastic deformation capacity of square hollow section members under bending shear governed by local buckling as a function of member shapes and loading conditions. First, elastic local buckling strength under bending shear derived from theoretical analysis is shown. A new normalized width–thickness ratio SH based on elastic local buckling strength and full plastic strength is proposed. Then, after understanding the elastic local buckling behavior purely determined by member shapes and loading conditions, the large deformation behavior under monotonic bending shear is examined using numerical analysis and structural testing. The ultimate strength and plastic deformation capacity are evaluated using the new normalized width–thickness ratio SH as a function of width–thickness ratio, aspect ratio, gradient of bending moment, and angle of applied force. Finally, the large deformation behavior under cyclic bending shear is examined using structural testing. The relation between the ultimate strength or plastic deformation capacity and the new normalized width–thickness ratio SH is reported.