First Report of Alternaria dauci Causing Leaf Blight of Coriander (Coriandrum sativum) in Algeria

International audienceCoriander (Coriandrum sativum, family Apiaceae) is an important condiment plant in Algeria

From point cloud to BIM: a survey of existing approaches

International audienceIn order to handle more efficiently projects of restoration, documentation and maintenance of historical buildings, it is essentialto rely on a 3D enriched model for the building. Today, the concept of Building Information Modelling (BIM) is widely adoptedfor the semantization of digital mockups and few research focused on the value of this concept in the field of cultural heritage.In addition historical buildings are already built, so it is necessary to develop a performing approach, based on a first step ofbuilding survey, to develop a semantically enriched digital model. For these reasons, this paper focuses on this chain startingwith a point cloud and leading to the well-structured final BIM; and proposes an analysis and a survey of existing approacheson the topics of: acquisition, segmentation and BIM creation. It also, presents a critical analysis on the application of this chainin the field of cultural heritag

Alternaria species associated with early blight epidemics on tomato and other Solanaceae crops in northwestern Algeria

Early blight is a common disease of Solanaceae crops worldwide. The occurrence of Alternaria spp. was studied during three epidemics on tomato in northwestern Algeria. Alternaria was detected in more than 80 % of the diseased plant samples and accounted for more than 50 % of the total fungal isolates recovered from these samples. Morphological and molecular investigations revealed that small-spored isolates producing beaked conidia, i.e. belonging to the section alternaria, were prominent in most of the surveyed locations representing more than 80 % of the total Alternaria isolates in three locations (Mascara, Ain Témouchent and Sidi Belabbèsse). Based on their sporulation patterns they were recognized as A. alternata and A. tenuissima. Small-spored isolates producing conidia without beak and assigned to A. consortialis were also found at a low frequency (< 1 %). Large-spored isolates producing conidia ended by typical long beaks and identified as A. linariae (syn. A. tomatophila), A. solani and A. grandis were also recovered from all the sampled areas and represented 33.8 %, 6.3 % and 1.3 % of the total Alternaria isolates, respectively. Pathogenicity tests on tomato with a selection of 85 strains representative of the isolates collection revealed that all the tested isolates were able to produce extending lesions on inoculated leaves albeit with variable intensity. Large-spored species included the most aggressive isolates. Small-spored Alternaria, although less aggressive than large-spored Alternaria, had the ability to provoke brown necrotic spots and circumstantially developed synergistic interactions in mixed infections with moderately aggressive isolates of A. linariae

Geochemical indices allow estimation of heavy metal background concentration in soils

Defining background concentrations for heavy metals in soils is essential for recognizing and managing soil pollution. However, background concentrations of metals in soils can vary naturally by several orders of magnitude. Moreover, many soils have also been subject to unquantifiable anthropogenic inputs of metals, in some cases, for centuries. Hence determination of heavy metal background concentrations in soils has to date been fraught with difficulty. Here we demonstrate that there are associations between the background heavy metal and Fe or Mn contents in soils which appear to be consistent for seven important heavy metals of environmental concern. The relationships are remarkably independent of both soil type and climatic setting. These observations provide the basis for a series of general equations from which it is proposed Southeast Asian including Australian, and possibly worldwide background concentrations for As, Cr, Co, Cu, Ni, Pb, and Zn in soils can be derived.R. E. Hamon, M. J. McLaughlin, R. J. Gilkes, A. W. Rate, B. Zarcinas, A. Robertson, G. Cozens, N. Radford and L. Bettena

Leveraging mathematical models of disease dynamics and machine learning to improve development of novel malaria interventions

BACKGROUND: Substantial research is underway to develop next-generation interventions that address current malaria control challenges. As there is limited testing in their early development, it is difficult to predefine intervention properties such as efficacy that achieve target health goals, and therefore challenging to prioritize selection of novel candidate interventions. Here, we present a quantitative approach to guide intervention development using mathematical models of malaria dynamics coupled with machine learning. Our analysis identifies requirements of efficacy, coverage, and duration of effect for five novel malaria interventions to achieve targeted reductions in malaria prevalence. METHODS: A mathematical model of malaria transmission dynamics is used to simulate deployment and predict potential impact of new malaria interventions by considering operational, health-system, population, and disease characteristics. Our method relies on consultation with product development stakeholders to define the putative space of novel intervention specifications. We couple the disease model with machine learning to search this multi-dimensional space and efficiently identify optimal intervention properties that achieve specified health goals. RESULTS: We apply our approach to five malaria interventions under development. Aiming for malaria prevalence reduction, we identify and quantify key determinants of intervention impact along with their minimal properties required to achieve the desired health goals. While coverage is generally identified as the largest driver of impact, higher efficacy, longer protection duration or multiple deployments per year are needed to increase prevalence reduction. We show that interventions on multiple parasite or vector targets, as well as combinations the new interventions with drug treatment, lead to significant burden reductions and lower efficacy or duration requirements. CONCLUSIONS: Our approach uses disease dynamic models and machine learning to support decision-making and resource investment, facilitating development of new malaria interventions. By evaluating the intervention capabilities in relation to the targeted health goal, our analysis allows prioritization of interventions and of their specifications from an early stage in development, and subsequent investments to be channeled cost-effectively towards impact maximization. This study highlights the role of mathematical models to support intervention development. Although we focus on five malaria interventions, the analysis is generalizable to other new malaria interventions

First report of tomato early blight caused by Alternaria grandis in Algeria

Tomatoes (Solanum lycopersicum) are widely cultivated in Algeria throughout the year. In northwestern growing areas, characterized by temperate humid climates, severe early blight symptoms (i.e., black lesions surrounded by a yellow halo) on tomato leaves are regularly observed. In 2013, diseased samples were collected from various cultivars in five farms of the Mostaganem region where average disease incidence reached 50%. Plant material was cut into ∼2-mm pieces, surface sterilized in 0.1% (v/v) Na hypochlorite for 2 min, transferred into potato agar medium, and incubated for 48 h at 25°C. Fungal mycelium developing from the lesion margins was transferred to potato carrot agar medium and further incubated for 7 days alternating darkness and cool-white fluorescent light to induce sporulation. Both small- and large-spored Alternaria isolates were obtained. While most of the large-spored isolates had morphological characteristics of A. linariae (syn. A. tomatophila) (Woudenberg et al. 2014), large-spored isolates from one location (Mamache) produced ovoid conidia whose length and width were 149.8 ± 8.9 µm and 16.4 ± 1.3 µm, respectively, ended by a single beak measuring up to 120 µm. Based on these morphological characteristics and host origin, these isolates were initially described as A. solani (Simmons 2000). To confirm the identification at the species level, DNA was extracted from mycelium of four representative isolates. As polymorphism in the ITS regions of rDNA is too low to delineate species within the Alternaria section Porri (Woudenberg et al. 2014), partial regions of the glyceraldehyde-3-phosphate dehydrogenase (gpd) and of the calmodulin (cal) genes were amplified using published primer sets (Gannibal et al. 2014; Woudenberg et al. 2014). For two isolates (NB250 and NB252), the sequences of the amplified products (GenBank Accession Nos. KR911747, KR911752 KR911765, and KR911767) were 100% identical to corresponding sequences of A. solani isolate CBS 109157 (GQ180080 and KJ397981). The gpd and cal sequences of the remaining isolates (NB248 and NB249, GenBank Accession Nos. KR911748, KR911754, KR911763, and KR911764) shared 100% sequence homology to A. grandis isolate CBS109158 (JQ646341 and JQ646249) and they were therefore assigned to this species. To confirm pathogenicity on tomato, the four isolates were spray inoculated (104 conidia/ml) on leaves of 3-week-old tomato plants (cv. Saint Pierre) in the greenhouse. Three replicates were performed for each test. Plants were rated for disease symptoms up to 21 days post inoculation (dpi). No symptom was observed on control plants treated with distilled water. All plants inoculated with A. solani and A. grandis isolates produced extending lesions on leaves albeit with variable virulence (affected leaf area from 50 to 80% at 21 dpi for NB249 and NB250, respectively). To our knowledge, this is the first report of A. grandis infecting tomato in Algeria and in Africa. Moreover, A. grandis has been reported on potato crops in North and South America (Simmons 2000; Rodrigues et al. 2010), but never on tomato. The fact that potato and tomato fields often coexist in close proximity in northwestern Algeria even with farmers using potato in rotation with tomato may favor the development of A. grandis on the latter plant species

Expanding the scope of leaf symbiosis: Caballeronia endophytes in Empogona and Tricalysia (Coffeeae, Rubiaceae)

Leaf symbiosis is a remarkable phenomenon observed in Rubiaceae host plants, where they interact with bacterial endophytes residing within their leaves. Although approximately 650 species from 8 genera across 4 tribes exhibit this symbiosis, its fiill extent within Rubiaceae remains unknown. Our primary objective is to investígate the potential presence of leaf endophytes in the African plant genera Empogona and Tricalysia and, if confirmed, determine their identity. To accomplish this, we extracted total DNA from the leaves of four Coffeeae tribe species {Empogona congesta, Tricalysia hensii, T. lasiodelphys, and T. semidecidua) and sequenced it. Subsequently, we filtered out bacterial reads. Through phylogenetic analysis o f the endophytes, we were able to ascertain their identity and establish their relationship with known symbiotic organisms. Notably, all four species harboured non-nodulated leaf endophytes, specifically identified as Caballeronia. Although these endophytes are distinct from one another, they are related to other nodulated and non-nodulated endophytes. Interestingly, we did not observe any discemible phylogenetic or geographic pattems among the endophytes or their host plants. Our findings demónstrate the presence of Caballeronia endophytes in the leaves o f Empogona and Tricalysia, two genera previously not associated with leaf symbiosis. This interaction is likely to have a broader distribution, and further discoveries are inevitable in the future

Investigation of the reactivity of AlCl3 and CoCl2 toward molten alkali-metal nitrates in order to synthesize CoAl2O4

Cobalt aluminate CoAl2O4 powder, constituted of nano-sized crystallites, is prepared, involving the reactivity of AlCl3 and CoCl2 with molten alkali-metal nitrates. The reaction at 450 °C for 2 h leads to a mixture of spinel oxide Co3O4 and amorphous γ-Al2O3. It is transformed into the spinel oxide CoAl2O4 by heating at 1000 °C. The powders are mainly characterized by XRD, FTIR, ICP, electron microscopy and diffraction, X-EDS and diffuse reflection. Their properties are compared to those of powders obtained by solid state reactions of a mechanical mixture of chlorides or oxides submitted to the same thermal treatment

La jeunesse : un levier de transformation pour les territoires ruraux en Ardèche ?

International audience'éducation populaire. Tous droits réservés pour tous pays. La reproduction ou représentation de cet article, notamment par photocopie, n'est autorisée que dans les limites des conditions générales d'utilisation du site ou, le cas échéant, des conditions générales de la licence souscrite par votre établissement. Toute autre reproduction ou représentation, en tout ou partie, sous quelque forme et de quelque manière que ce soit, est interdite sauf accord préalable et écrit de l'éditeur, en dehors des cas prévus par la législation en vigueur en France. Il est précisé que son stockage dans une base de données est également interdit. Powered by TCPDF (www.tcpdf.org) Document téléchargé depuis www.cairn.info-Université Grenoble-Alpes-130.190.247