Dynamic shear behaviour of truss towers for wind turbines

The global interest in renewable energy sources has increased the attention to the manufacturing of wind turbine towers, since they are largely diffused in seismic areas too. Different types of towers have been produced in recent years. Among them, the truss structures assure a reduced mass and the modular characteristics necessary for easy transportation. Reduced costs of production, installation and maintenance are typical of these structures. Nonlinear dynamics is an efficient framework to analyze structures subjected to variable actions, i.e. to assess the seismic safety of wind turbine towers in case of earthquake actions. This study outlines a procedure to evaluate the post-elastic behavior of truss towers for wind turbines. Rigid-plastic behaviour is taken into account to develop approximate solutions for the problem of a tower modeled as a vertical cantilever beam and subjected to harmonic base motion. A comparison with the results of a finite element model is proposed

Genetic (RAPD) Diversity between Oleria onega agarista and Oleria onega ssp. ( Ithomiinae , Nymphalidae, Lepidoptera) in North-Eastern Peru

Oleria onega agarista Felder and Felder and Oleria onega ssp. nov. are two Ithomiinae subspecies from north-eastern Peru, that differ for some morphological and behavioural traits. Two contact zones are known near the town of Tarapoto: Ahuashiyacu, where both subspecies cohabit but do not seem to hybridise, and Estero (near the village of Shapaja), where they apparently hybridise. Genetic differences between the two subspecies and between populations were investigated with random amplified polymorphic DNA (RAPD) markers. Both Cluster and Principal Coordinates Analyses (CCoA and PCoA) performed using these data, provided a clear but weak discrimination between the two subspecies. Genetic diversity is much higher within the populations than between them. Moreover, the geographically more distant populations are grouped together by the genetic data. Morphological traits on the wing patterns of the hybrids are intermediary between the two butterflies subspecies, while RAPDs data place them closer to O. onega agarista than to O. onega ssp. The individuals of the Ahuashiyacu population are clearly separated into two groups, those of O. onega ssp. and O. onega agarista, by both morphology and RAPDs data. Moreover, none of those individuals show RAPD similarity with the hybrids, suggesting that hybridisation has not occurred in this populatio

Novel and rare fusion transcripts involving transcription factors and tumor suppressor genes in acute myeloid leukemia

Approximately 18% of acute myeloid leukemia (AML) cases express a fusion transcript. However, few fusions are recurrent across AML and the identification of these rare chimeras is of interest to characterize AML patients. Here, we studied the transcriptome of 8 adult AML patients with poorly described chromosomal translocation(s), with the aim of identifying novel and rare fusion transcripts. We integrated RNA-sequencing data with multiple approaches including computational analysis, Sanger sequencing, fluorescence in situ hybridization and in vitro studies to assess the oncogenic potential of the ZEB2-BCL11B chimera. We detected 7 different fusions with partner genes involving transcription factors (OAZ-MAFK, ZEB2-BCL11B), tumor suppressors (SAV1-GYPB, PUF60-TYW1, CNOT2-WT1) and rearrangements associated with the loss of NF1 (CPD-PXT1, UTP6-CRLF3). Notably, ZEB2-BCL11B rearrangements co-occurred with FLT3 mutations and were associated with a poorly differentiated or mixed phenotype leukemia. Although the fusion alone did not transform murine c-Kit+ bone marrow cells, 45.4% of 14q32 non-rearranged AML cases were also BCL11B-positive, suggesting a more general and complex mechanism of leukemogenesis associated with BCL11B expression. Overall, by combining different approaches, we described rare fusion events contributing to the complexity of AML and we linked the expression of some chimeras to genomic alterations hitting known genes in AML

Simplified Design of Masonry Ring-Beams Reinforced by Flax Fibers for Existing Buildings Retrofitting

Seismic events have repeatedly highlighted the vulnerability of existing masonry buildings. Seismic retrofitting is frequently focused on improving the connection between walls and roof for ensuring behavior able to resist loads from any horizontal direction. This paper deals with the design of masonry ring-beams made of clay bricks reinforced by natural fibers. Various solutions to ensure a masonry building box-behavior are possible, but this is a good combination of both static and conservation requirements, as it allows the use of bio-composites and grouts. It is a relevant possible alternative to the traditional reinforced concrete ring-beams, which are proven to be very ineffective under earthquakes. A simplified model for designing clay brick beams reinforced by flax fibers is provided, and a comparison with customary and traditional floor/roof masonry ring-beams is carried out

Retrofit assessment of masonry buildings through simplified structural analysis

The current seismic prevention strategy is based on a unitary approach aimed at a risk mitigation, also at territorial level. The Italian guidelines for the assessment and mitigation of seismic risk of cultural heritage provides indications for the seismic analysis of protected cultural heritage, with the aim of specifying a path of knowledge, assessing the level of safety and planning possible improvements. The Italian building heritage is very vast and heterogeneous and was devastated by earthquakes due to its high vulnerability; therefore, the seismic risk mitigation also requires the availability of simple and handy analysis tools. The aim of this paper is the illustration of an easy, although approximate, procedure for the evaluation of the seismic safety index and the optimization of strengthening interventions. The procedure is applied to buildings located in the province of Caserta. The analyses are performed with reference to two types of buildings that are particularly recurrent and representative of the building heritage of this area and placed in areas with different seismic hazard