Resolving the Diplodia complex on apple and other Rosaceae hosts

Diplodia species are known as pathogens on many woody hosts, including fruit trees, worldwide. In this study a collection of Diplodia isolates obtained mostly from apple and other Rosaceae hosts were identified based on morphological characters and DNA sequence data from ITS and EF1-α loci. The results show that the diversity of species associated with twig and branch cankers and fruit rot of apples is larger than previously recognised. Four species were identified, namely D. seriata and D. malorum (which is here reinstated for isolates with D. mutila-like conidia). Diplodia intermedia sp. nov. is closely related to D. seriata, and D. bulgarica sp. nov. is morphologically and phylogenetically distinct from all Diplodia species reported from apples.publishe

Evolution of lifestyles in Capnodiales

The Capnodiales, which includes fungi known as the sooty moulds, represents the second largest order in Dothideomycetes, encompassing morphologically and ecologically diverse fungi with different lifestyles and modes of nutrition. They include saprobes, plant and human pathogens, mycoparasites, rock-inhabiting fungi (RIF), lichenised, epi-, ecto- and endophytes. The aim of this study was to elucidate the lifestyles and evolutionary patterns of the Capnodiales as well as to reconsider their phylogeny by including numerous new collections of sooty moulds, and using four nuclear loci, LSU, ITS, TEF-1α and RPB2. Based on the phylogenetic results, combined with morphology and ecology, Capnodiales s. lat. is shown to be polyphyletic, representing seven different orders. The sooty moulds are restricted to Capnodiales s. str., while Mycosphaerellales is resurrected, and five new orders including Cladosporiales, Comminutisporales, Neophaeothecales, Phaeothecales and Racodiales are introduced. Four families, three genera, 21 species and five combinations are introduced as new. Furthermore, ancestral reconstruction analysis revealed that the saprobic lifestyle is a primitive state in Capnodiales s. lat., and that several transitions have occurred to evolve lichenised, plant and human parasitic, ectophytic (sooty blotch and flyspeck) and more recently epiphytic (sooty mould) lifestyles.</p

Barriopsis iraniana and Phaeobotryon cupressi: two new species of the Botryosphaeriaceae from trees in Iran

Species in the Botryosphaeriaceae are well known as pathogens and saprobes of woody hosts, but little is known about the species that occur in Iran. In a recent survey of this family in Iran two fungi with diplodia-like anamorphs were isolated from various tree hosts. These two fungi were fully characterised in terms of morphology of the anamorphs in culture, and sequences of the ITS1/ITS2 regions of the ribosomal DNA operon and partial sequences of the translation elongation factor 1-α. Phylogenetic analyses placed them within a clade consisting of Barriopsis and Phaeobotryon species, but they were clearly distinct from known species in these genera. Therefore, they are described here as two new species, namely Barriopsis iraniana on Citrus, Mangifera and Olea, and Phaeobotryon cupressi on Cupressus sempervirens

Modelling of dielectric barrier discharge plasma actuators for direct numerical simulations

In recent years the development of devices known as plasma actuators has advanced the promise of controlling flows in new ways that increase lift, reduce drag and improve aerodynamic efficiencies; advances that may lead to safer, more efficient and quieter aircraft. The large number of parameters (location of the actuator, orientation, size, relative placement of the embedded and exposed electrodes, materials, applied voltage, frequency) affecting the performance of plasma actuators makes their development, testing and optimisation a very complicated task. Several approaches have been proposed for developing numerical models for plasma actuators. The discharge can be modelled by physics-based kinetic methods based on first principles, by semi-empirical phenomenological approaches and by PIV-based methods where the discharge is replaced by a steady-state body force. The latter approach receives a recent interest for its easy implementation in RANS and U-RANS solvers. Here, a forcing term extracted from experiments is implemented into our high-order Navier-Stokes solver (DNS) in order to evaluate its robustness and ability to mimic the effects of a surface dielectric barrier discharge. This experimental forcing term is compared to the numerical forcing term developed by Suzen & Huang (1, 2) with an emphasis on the importance of the wall-normal component of each model

Maximal 2-rainbow domination number of a graph

AbstractA 2-rainbow dominating function (2RDF) of a graph G is a function f from the vertex set V(G) to the set of all subsets of the set {1,2} such that for any vertex v∈V(G) with f(v)=0̸ the condition ⋃u∈N(v)f(u)={1,2} is fulfilled, where N(v) is the open neighborhood of v. A maximal 2-rainbow dominating function on a graph G is a 2-rainbow dominating function f such that the set {w∈V(G)|f(w)=0̸} is not a dominating set of G. The weight of a maximal 2RDF f is the value ω(f)=∑v∈V|f(v)|. The maximal 2-rainbow domination number of a graph G, denoted by γmr(G), is the minimum weight of a maximal 2RDF of G. In this paper we initiate the study of maximal 2-rainbow domination number in graphs. We first show that the decision problem is NP-complete even when restricted to bipartite or chordal graphs, and then, we present some sharp bounds for γmr(G). In addition, we determine the maximal rainbow domination number of some graphs

Heat generation mechanisms of DBD plasma actuators

During the last twenty years DBD plasma actuators have been known by their ability for boundary layer flow control applications. However, their usefulness is not limited to this application field, they also present great utility for applications within the field of heat transfer, such as a way to improve the aerodynamic efficiency of film cooling of gas turbine blades, or de-icing and ice formation prevention. Nevertheless, there is a relative lack of information about DBD’s thermal characteristics and its heat generation mechanisms. This happens due to the extremely high electric fields in the plasma region and consequent impossibility of applying intrusive measurement techniques. Against this background, this work describes the physical mechanisms behind the generation of heat associated to the DBD plasma actuators operation. An experimental technique, based on calorimetric principles, was devised in order to quantify the heat energy generated during the plasma actuators operation. The influence of the dielectric thickness, as well as the dielectric material, were also evaluated during this work. The results were exposed and discussed with the purpose of a better understanding of the heat generation mechanisms behind the operation of DBD plasma actuators

Steerable3D: An ImageJ plugin for neurovascular enhancement in 3-D segmentation

PurposeImage processing plays a fundamental role in the study of central nervous system, for example in the analysis of the vascular network in neurodegenerative diseases. Synchrotron X-ray Phase-contrast micro-Tomography (SXPCT) is a very attractive method to study weakly absorbing samples and features, such as the vascular network in the spinal cord (SC). However, the identification and segmentation of vascular structures in SXPCT images is seriously hampered by the presence of image noise and strong contrast inhomogeneities, due to the sensitivity of the technique to small electronic density variations. In order to help with these tasks, we implemented a user-friendly ImageJ plugin based on a 3D Gaussian steerable filter, tuned up for the enhancement of tubular structures in SXPCT images.MethodsThe developed 3D Gaussian steerable filter plugin for ImageJ is based on the steerability properties of Gaussian derivatives. We applied it to SXPCT images of ex-vivo mouse SCs acquired at different experimental conditions.ResultsThe filter response shows a strong amplification of the source image contrast-to-background ratio (CBR), independently of structures orientation. We found that after the filter application, the CBR ratio increases by a factor ranging from ~6 to ~60. In addition, we also observed an increase of 35% of the contrast to noise ratio in the case of injured mouse SC.ConclusionThe developed tool can generally facilitate the detection/segmentation of capillaries, veins and arteries that were not clearly observable in non-filtered SXPCT images. Its systematic application could allow obtaining quantitative information from pre-clinical and clinical images

The use of Artificial Neural Networks to estimate seismic damage and derive vulnerability functions for traditional masonry

This paper discusses the adoption of Artificial Intelligence-based techniques to estimate seismic damage, not with the goal of replacing existing approaches, but as a mean to improve the precision of empirical methods. For such, damage data collected in the aftermath of the 1998 Azores earthquake (Portugal) is used to develop a comparative analysis between damage grades obtained resorting to a classic damage formulation and an innovative approach based on Artificial Neural Networks (ANNs). The analysis is carried out on the basis of a vulnerability index computed with a hybrid seismic vulnerability assessment methodology, which is subsequently used as input to both approaches. The results obtained are then compared with real post-earthquake damage observation and critically discussed taking into account the level of adjustment achieved by each approach. Finally, a computer routine that uses the ANN as an approximation function is developed and applied to derive a new vulnerability curve expression. In general terms, the ANN developed in this study allowed to obtain much better approximations than those achieved with the original vulnerability approach, which has revealed to be quite non-conservative. Similarly, the proposed vulnerability curve expression was found to provide a more accurate damage prediction than the traditional analytical expressions.SFRH/BPD/122598/2016info:eu-repo/semantics/publishedVersio

A new aircraft architecture based on the ACHEON Coanda effect nozzle: flight model and energy evaluation

Purpose Aeronautic transport has an effective necessity of reducing fuel consumption and emissions to deliver efficiency and competitiveness driven by today commercial and legislative requirements. Actual aircraft configurations scenario allows envisaging the signs of a diffused technological maturity and they seem very near their limits. This scenario clearly shows the necessity of radical innovations with particular reference to propulsion systems and to aircraft architecture consequently. Methods This paper presents analyses and discusses a promising propulsive architecture based on an innovative nozzle, which allows realizing the selective adhesion of two impinging streams to two facing jets to two facing Coanda surfaces. This propulsion system is known with the acronym ACHEON (Aerial Coanda High Efficiency Orienting Nozzle). This paper investigates how the application of an all-electric ACHEONs propulsion system to a very traditional commuter aircraft can improve its relevant performances. This paper considers the constraints imposed by current state-of-the-art electric motors, drives, storage and conversion systems in terms of both power/energy density and performance and considers two different aircraft configurations: one using battery only and one adopting a more sophisticated hybrid cogeneration. The necessity of producing a very solid analysis has forced to limit the deflection of the jet in a very conservative range (±15°) with respect to the horizontal. This range can be surely produced also by not optimal configurations and allow minimizing the use of DBD. From the study of general flight dynamics equations of the aircraft in two-dimensional form it has been possible to determine with a high level of accuracy the advantages that ACHEON brings in terms of reduced stall speed and of reduced take-off and landing distances. Additionally, it includes an effective energy analysis focusing on the efficiency and environmental advantages of the electric ACHEON based propulsion by assuming the today industrial grade high capacity batteries with a power density of 207 Wh/kg. Results It has been clearly demonstrated that a short flight could be possible adopting battery energy storage, and longer duration could be possible by adopting a more sophisticated cogeneration system, which is based on cogeneration from a well-known turboprop, which is mostly used in helicopter propulsion. This electric generation system can be empowered by recovering the heat and using it to increase the temperature of the jet. It is possible to transfer this considerable amount of heat to the jet by convection and direct fluid mixing. In this way, it is possible to increase the energy of the jets of an amount that allows more than recover the pressure losses in the straitening section. In this case, it is then possible to demonstrate an adequate autonomy of flight and operative range of the aircraft. The proposed architecture, which is within the limits of the most conservative results obtained, demonstrates significant additional benefits for aircraft manoeuvrability. In conclusion, this paper has presented the implantation of ACHEON on well-known traditional aircraft, verifying the suitability and effectiveness of the proposed system both in terms of endurance with a cogeneration architecture and in terms of manoeuvrability. It has demonstrated the potential of the system in terms of both takeoff and landing space requirements. Conclusions This innovation opens interesting perspectives for the future implementation of this new vector and thrust propulsion system, especially in the area of greening the aeronautic sector. It has also demonstrated that ACHEON has the potential of renovating completely a classic old aircraft configuration such as the one of Cessna 402

Issues of ideology in English language education worldwide: an overview

The relatively limited consideration of ideology in mainstream theory and research of teaching the English language to speakers of other languages has arguably prevented the problematization of many taken-for-granted perceptions and practices of the field. In this article I attempt to bring part of this marginalized body of scholarship on issues of ideology in the area of English language teaching (ELT) to highlight its potential insights for the field. The article sets out from a view of ideology as the most fundamental beliefs in any social practice, which may provide a less-formidable conception of the term and lessen the divergence among the minority of ELT researchers and professionals that do concern themselves with ideology. Then, after a brief sketch of the notion of ideology of language (education), I present an overview of aspects of this marginal but vibrant stream of thought on issues of ideology in ELT worldwide. Overall, the discussion is aimed to act as a call for the further understanding and embracement of sociopolitically-sensitive and ideologically-informed approaches to ELT theory, research, and practice