Driving the transition to a circular economic model: A systematic review on drivers and critical success factors in circular economy

The circular economy (CE) is arising as a novel economic system that is restorative by design. In light of its capability to boost sustainable economic development and to cope with environmental challenges, it has recently attracted increasing attention from academics, practitioners, policymakers, and intergovernmental organizations. Despite the wide speculation on this issue, the scientific literature lacks a wide-ranging, systematic, and updated identification and classification of the main drivers and Critical Success Factors of CE initiatives, which appears increasingly necessary to facilitate future scientific work, practical implementations, and policy guidelines. With this aim, this paper develops a systematic literature review by starting with over 400 manuscripts. A final set of 55 selected papers was selected for singling out and classifying drivers and Critical Success Factors in the CE context. The results may provide clear indications for further research, may help business organizations in evaluating CE initiatives, and may guide policy makers in developing and refining CE normative frameworks

Simultaneous genome sequencing of symbionts and their hosts

Second-generation sequencing has made possible the sequencing of genomes of interest for even small research groups. However, obtaining separate clean cultures and clonal or inbred samples of metazoan hosts and their bacterial symbionts is often difficult. We present a computational pipeline for separating metazoan and bacterial DNA in silico rather than at the bench. The method relies on the generation of deep coverage of all the genomes in a mixed sample using Illumina short-read sequencing technology, and using aggregate properties of the different genomes to identify read sets belonging to each. This inexpensive and rapid approach has been used to sequence several nematode genomes and their bacterial endosymbionts in the last year in our laboratory and can also be used to visualize and identify unexpected contaminants (or possible symbionts) in genomic DNA samples. We hope that this method will enable researchers studying symbiotic systems to move from gene-centric to genome-centric approaches

Recommendation of RILEM TC 261-CCF: test method to determine the flexural creep of fibre reinforced concrete in the cracked state

[EN] To date there is no clear consensus about how creep of cracked FRC structural elements should be considered. In recent years, different methodologies have been developed for multiple stress cases. The absence of a standardised methodology to evaluate flexural creep in the cracked state has hindered general comparisons and conclusions that could lead to significant advances in this topic. Since 2014, the study of the creep behaviour of cracked FRC has been coordinated by the RILEM TC 261-CCF. All the available creep methodologies were analysed in terms of procedure, equipment and results. A comprehensive Round-Robin Test (RRT) on the creep behaviour of cracked sections of FRC was proposed and undertaken by a total of 19 participant laboratories from 14 countries all over the world. The analysis and conclusions of the RRT results and the different methodologies provided the basis for this recommendation. This recommendation focuses on the test method to evaluate the flexural creep of FRC specimens in the cracked state. Guidelines on specimen production, detailed test equipment, experimental setup and test procedure as well as the definitions of the most relevant parameters are provided.Llano-Torre, A.; Serna Ros, P. (2021). Recommendation of RILEM TC 261-CCF: test method to determine the flexural creep of fibre reinforced concrete in the cracked state. Materials and Structures. 54(3):1-20. https://doi.org/10.1617/s11527-021-01675-0S120543Theodorakopoulos D (1995) Creep characteristics of glass reinforced cement under flexural loading. Cement Concr Compos 17:267–279Chanvillard G, Roque O (1999) Behaviour of fibre reinforced concrete cracked section under sustained load. High Performance Fiber Reinforced Cement Composites (HPFRCC 3) Mainz, Germany, pp 239–250, RILEM PRO 06Kurt S, Balaguru P (2000) Post crack creep of polymeric fibre-reinforced concrete in flexure. Cem Concr Res 30(2):183–190Mackay J, Trottier JF (2004) Post-crack behavior of steel and synthetic FRC under flexural creep. In: Shotcrete, Proc. 2nd Intnl. Conf. on Engineering, Cairns, Australia (2004), pp 183–192Kusterle W (2009) Viscous material behaviour of solids- creep of polymer fibre reinforced concrete. In: Proc. 5th Central European Congress on Concrete Engineering. obv, Baden, pp 95–100Arango S, Serna P, Martí-Vargas JR, García-Taengua E (2012) A test method to characterize flexural creep behaviour of pre-cracked FRC specimens. Exp Mech 52(8):1067–1078Zerbino RL, Barragan BE (2012) Long-term behaviour of cracked steel fibre-reinforced concrete beams under sustained loading. ACI Mater J 109(2):215–224Abrishambaf A, Barros JAO, Cunha VMCF (2015) Time-dependent flexural behaviour of cracked steel fibre reinforced self-compacting concrete panels. Cem Concr Res 72:21–36Buratti N, Mazzotti C (2016) Experimental tests on the long-term behaviour of SFRC and MSFRC in bending and direct tension. In: Proceedings of the BEFIB 2016, 9th RILEM international symposium on fiber reinforced concrete, pp. 163–174, Vancouver, Canada, 19–21 Sept 2016Babafemi AJ, Boshoff WP (2015) Tensile creep of macro-synthetic fibre reinforced concrete (MSFRC) under uni-axial tensile loading. Cement Concr Compos 55:62–69Vrijdaghs R, di Prisco M, Vandewalle L (2018) Uniaxial tensile creep of a cracked polypropylene fiber reinforced concrete. Mater Struct 51:5. https://doi.org/10.1617/s11527-017-1132-5Vasanelli E, Micelli F, Aiello MA, Plizzari G (2013) Long term behaviour of FRC flexural beams under sustained load. Eng Struct 56:1858–1867Bernard ES (2010) Influence of fibre type on creep deformation of cracked fibre-reinforced shotcrete panels. ACI Mater J 107(5):474–480EFNARC (2012) Testing sprayed concrete—Creep test on square panelLarive C, Rogat D, Chamoley D, Regnard A, Pannetier T, Thuaud C (2016) Influence of fibres on the creep behaviour of reinforced sprayed concrete. In: Proceedings of ITA World Tunnel Congress WTC 2016, April 22‐28, San Francisco, United StatesMonetti DH, Llano-Torre A, Torrijos MC, Giaccio G, Zerbino R, Martí-Vargas JR, Serna P (2019) Long-term behavior of cracked fiber reinforced concrete under service conditions. Construct Build Mater; 196:649–658. https://doi.org/10.1016/j.conbuildmat.2018.10.230Llano-Torre A., Martí-Vargas JR, Serna P (2020) Flexural and compressive creep behavior of UHPFRC specimens. Construct Build Mater; 244:118254. https://doi.org/10.1016/j.conbuildmat.2020.118254Serna P, Llano-Torre A and Cavalaro S H P (ed) (2017) Creep behaviour in cracked sections of fibre reinforced concrete: proceedings of the international RILEM Workshop FRC-CREEP 2016. RILEM bookseries 14 (Dordrecht: Springer)Llano-Torre A, Serna P, Cavalaro SHP (2016) International round robin test on creep behavior of FRC supported by the RILEM TC 261-CCF. In: Proceedings of the BEFIB 2016, 9th RILEM international symposium on fiber reinforced concrete, pp 127–140, Vancouver, Canada, 19–21 Sept 2016Serna P, Llano-Torre A, García-Taengua E, Martí-Vargas JR (2015) Database on the long-term behaviour of FRC: a useful tool to achieve overall conclusions. In: Proceedings of the 10th international conference on mechanics and physics of Creep, Shrinkage, and Durability of Concrete and Concrete Structures, Vienna, September 2015, pp 1544–1553Llano-Torre A., Serna P. (eds) Round-Robin test on creep behaviour in cracked sections of FRC: experimental program, results and database analysis. RILEM State-of-the-Art Reports. Springer. https://doi.org/10.1007/978-3-030-72736-9ASTM International (2015) C1812/C1812M-15e1 Standard Practice for Design of Journal Bearing Supports to be Used in Fiber Reinforced Concrete Beam Tests. West Conshohocken, PA; ASTM International. https://doi.org/10.1520/C1812_C1812M-15E0

Creep and residual properties of cracked macro-synthetic fibre reinforced concretes

[EN] This study analysed the creep behaviour of five concretes incorporating 0.5% by volume of four macro-synthetic fibres (MSFs) and one steel fibre. After 28 d moist curing, prisms were pre-loaded up to a crack opening of 0.5 mm and held for 90 d in three different environments - ambient laboratory air, seawater at 45 degrees C and air flow at 45 degrees C. Sustained loads were then applied on three specimens from each group while the other prisms remained unloaded. The remaining residual capacity was evaluated by bending tests. It was concluded that the residual capacity of cracked MSF concretes is not affected by long-term loading.The authors wish to thank the technicians of ICITECH, where the experimental work was developed. The financial support of the project FISNE with reference BIA2012-35776, supported by the Spanish Ministry of Economy and Competiveness and the FEDER fund, is also gratefully acknowledged. The doctoral scholarship of M. E. Bossio was supported by the project EuroTANGO (European Commission - EACEA).Serna Ros, P.; Martí Vargas, JR.; Bossio, ME.; Zerbino, R. (2016). Creep and residual properties of cracked macro-synthetic fibre reinforced concretes. Magazine of Concrete Research. 68(4):197-207. https://doi.org/10.1680/macr.15.00111S19720768

Safe and complete contig assembly via omnitigs

Contig assembly is the first stage that most assemblers solve when reconstructing a genome from a set of reads. Its output consists of contigs -- a set of strings that are promised to appear in any genome that could have generated the reads. From the introduction of contigs 20 years ago, assemblers have tried to obtain longer and longer contigs, but the following question was never solved: given a genome graph $G$ (e.g. a de Bruijn, or a string graph), what are all the strings that can be safely reported from $G$ as contigs? In this paper we finally answer this question, and also give a polynomial time algorithm to find them. Our experiments show that these strings, which we call omnitigs, are 66% to 82% longer on average than the popular unitigs, and 29% of dbSNP locations have more neighbors in omnitigs than in unitigs.Comment: Full version of the paper in the proceedings of RECOMB 201

QSRA – a quality-value guided de novo short read assembler

<p>Abstract</p> <p>Background</p> <p>New rapid high-throughput sequencing technologies have sparked the creation of a new class of assembler. Since all high-throughput sequencing platforms incorporate errors in their output, short-read assemblers must be designed to account for this error while utilizing all available data.</p> <p>Results</p> <p>We have designed and implemented an assembler, Quality-value guided Short Read Assembler, created to take advantage of quality-value scores as a further method of dealing with error. Compared to previous published algorithms, our assembler shows significant improvements not only in speed but also in output quality.</p> <p>Conclusion</p> <p>QSRA generally produced the highest genomic coverage, while being faster than VCAKE. QSRA is extremely competitive in its longest contig and N50/N80 contig lengths, producing results of similar quality to those of EDENA and VELVET. QSRA provides a step closer to the goal of de novo assembly of complex genomes, improving upon the original VCAKE algorithm by not only drastically reducing runtimes but also increasing the viability of the assembly algorithm through further error handling capabilities.</p

Healthcare-associated outbreak of meticillin-resistant Staphylococcus aureus bacteraemia: role of a cryptic variant of an epidemic clone

BACKGROUND New strains of meticillin-resistant Staphylococcus aureus (MRSA) may be associated with changes in rates of disease or clinical presentation. Conventional typing techniques may not detect new clonal variants that underlie changes in epidemiology or clinical phenotype. AIM To investigate the role of clonal variants of MRSA in an outbreak of MRSA bacteraemia at a hospital in England. METHODS Bacteraemia isolates of the major UK lineages (EMRSA-15 and -16) from before and after the outbreak were analysed by whole-genome sequencing in the context of epidemiological and clinical data. For comparison, EMRSA-15 and -16 isolates from another hospital in England were sequenced. A clonal variant of EMRSA-16 was identified at the outbreak hospital and a molecular signature test designed to distinguish variant isolates among further EMRSA-16 strains. FINDINGS By whole-genome sequencing, EMRSA-16 isolates during the outbreak showed strikingly low genetic diversity (P < 1 × 10(-6), Monte Carlo test), compared with EMRSA-15 and EMRSA-16 isolates from before the outbreak or the comparator hospital, demonstrating the emergence of a clonal variant. The variant was indistinguishable from the ancestral strain by conventional typing. This clonal variant accounted for 64/72 (89%) of EMRSA-16 bacteraemia isolates at the outbreak hospital from 2006. CONCLUSIONS Evolutionary changes in epidemic MRSA strains not detected by conventional typing may be associated with changes in disease epidemiology. Rapid and affordable technologies for whole-genome sequencing are becoming available with the potential to identify and track the emergence of variants of highly clonal organisms

Effect of steel fibers on static and blast response of high strength concrete

The advantages of High Strength Fiber Reinforced Concrete (HSFRC) in static behavior highlighted by many researchers suggest it is a promising material to withstand dynamic loads. However, available experimental results regarding blast performance of HSFRC structural elements are still limited. The results of exploratory series of tests using a high strength concrete, over 100 MPa compressive strength, reinforced with long hooked-end steel fibers are presented in this paper. The results of static characterization tests performed on prisms and slabs and the results of blast tests on slabs are presented and analyzed. The improvements found in static flexure response with different fibers contents are compared with those found under blast loads. The effects of fibers controlling cracking, scabbing and spalling under close-in explosions are also addressed

A robust SNP barcode for typing Mycobacterium tuberculosis complex strains

Strain-specific genomic diversity in the Mycobacterium tuberculosis complex (MTBC) is an important factor in pathogenesis that may affect virulence, transmissibility, host response and emergence of drug resistance. Several systems have been proposed to classify MTBC strains into distinct lineages and families. Here, we investigate single-nucleotide polymorphisms (SNPs) as robust (stable) markers of genetic variation for phylogenetic analysis. We identify ~92k SNP across a global collection of 1,601 genomes. The SNP-based phylogeny is consistent with the gold-standard regions of difference (RD) classification system. Of the ~7k strain-specific SNPs identified, 62 markers are proposed to discriminate known circulating strains. This SNP-based barcode is the first to cover all main lineages, and classifies a greater number of sublineages than current alternatives. It may be used to classify clinical isolates to evaluate tools to control the disease, including therapeutics and vaccines whose effectiveness may vary by strain type