Characterization of the stemphylium blight pathogens and their effect on lentil yield

The disease stemphylium blight has become common in lentil fields in Saskatchewan, but the effect of this disease on developing lentil plants, has not been studied under field conditions. Even though Stemphylium botryosum is suspected to be the pathogen causing stemphylium blight in lentil around the world, there is no confirmation of the pathogenic species involved in stemphylium blight of lentil in Saskatchewan. The objectives of this study were to determine the effect on lentil seed quantity and quality of S. botryosum infection at the seedling, the early-flowering, the mid-flowering or the podding stages, and to characterize the pathogen or pathogens causing stemphylium blight in Saskatchewan lentil fields. Three field experiments were conducted over two years using green polyethylene low tunnels to create conducive environments and control the timing of infection. Cumulative disease severity, measured as area under the disease progress curve, in lentil treatments inoculated at the seedling stage was higher compared to treatments inoculated at later growth stages or to uninoculated control treatments, in which some stemphylium blight developed due to natural inoculum. Neither the amount of harvested seed, nor seed weight or seed size were reduced compared to the uninoculated control, even though disease severity was higher in inoculated versus uninoculated treatments. Seed infection levels of 2.6 to 3.4% in seed harvested from treatments that were inoculated at the seedling, early and mid-flower stages were significantly higher than those observed in seeds from uninoculated control treatments (0.6%) or from treatments inoculated at podding (1.2%). Field isolates of Stemphylium spp. were compared to the ex-type isolate by morphology, and additionally to sequence data of five Stemphylium spp. and one Alternaria sp. obtained from GenBank by molecular phylogenetic analyses of the internal transcribe spacer (ITS) and the glyceraldehyde 3 – phosphate dehydrogenase (gpd) gene regions. Morphology of colony and conidia were not informative since features overlapped except for three isolates. Results of the molecular phylogenetic analyses revealed that S. botryosum is one of two possible Stemphylium spp. involved in the development of stemphylium blight in lentil. The three isolates with different morphology were also consistently clustered as a species distinct from the Stemphylium species. Although yield loss could not be demonstrated here, further studies on the epidemiology of the pathogens causing stemphylium blight in Saskatchewan lentil fields are warranted in view of the fact that more than one candidate species was identified as the causal agent

Toluene and Styrene Photo-Oxidation Quantum Efficiency: Comparison between Doped and Composite Tungsten-containing Anatase-based Catalysts

In this work we analyze two series of samples containing tungsten and titania as cations with a W/Ti atomic ratio from 0 to 0.5. The samples are prepared by a single-pot procedure, rendering in all cases high surface area powders having a dominant anatase crystalline phase. The materials were characterized by a combination of X-ray diffraction and photoelectron spectroscopies, UV–vis and Raman spectroscopies and morphological measurements. Particular effort was carried out in analyzing the way tungsten and titani-um interact in the materials through a microscopy analysis combining dark field Scanning transmission electron microscopy (HAADF-STEM) an X-ray energy dispersive spectrometry (XEDS). Overall the results are able to spot out the samples that show a truly doped character with tungsten exclusively located at (surface and bulk) lattice positions of the anatase structure, from composite catalysts where nanosized tungsten entities are supported over the dominant anatase phase. Activity of the materials in toluene and styrene photo-transformation reactions was measured through the reaction rate and the quantum efficiency observables. The study shows that quantitative comparison requires the stringent calculation of the quantum efficiency and that both the reaction rate and the apparent quantum efficiency can lead to misleading results in terms of the most active sample(s) as well as the (positive/negative) magnitude with respect to the bare titania reference. The quantum efficiency shows that doped samples can always improve titania reference sample(s) while this is not the case for composite samples

Innovative Crop Productions for Healthy Food: The Case of Chia (Salvia hispanica L.)

Chia (Salvia hispanica L.) is an ancient crop from Central America which has been recently rediscovered as a source of ω-3 and nutraceuticals in seeds. Besides traditional seed consumption, innovative uses of the plant seeds and leaves have been proposed based on the high protein content and the production of mucilage which lends itself to a range of applications. This chapter reviews research on the plant’s genetics and breeding, quality, and uses. Agronomic studies which have only recently started worldwide are also presented along with results from case studies in Basilicata

Characterization of Aphanomyces euteiches pathotypes infecting peas in Western Canada

Saskatchewan Pulse GrowersPeer ReviewedAphanomyces root rot, caused by the soil-borne oomycete Aphanomyces euteiches Drechs., has developed into a serious disease in the pea and lentil-producing areas of the Great Plains of North America. Based on six pea differentials previously used to differentiate 11 pathotypes in France, pathotypes were identified among field isolates from Saskatchewan (14) and Alberta (18). Four isolates from the USA and standard isolates for pathotypes I and III designated in the French study were also included. Each isolate was tested twice in replicated experiments by inoculating French pea differentials Baccara, Capella, MN 313, 902131, 552 and PI 80693, along with the Canadian susceptible pea cultivar CDC Meadow and partially resistant USDA line PI 660736 under controlled conditions. Pea plants grown in vermiculite were inoculated 10 days after seeding by pipetting 5 mL of a suspension containing 1 x 103 zoospores mL-1 to the base of each plant. Root discoloration was scored 10 days post-inoculation using a 0-5 scale. Testing revealed that 38 of the isolates, including standard pathotype I isolate RB84 belonged to pathotype I, 4 isolates including standard pathotype III isolate Ae109 were pathotype III, and USA isolate Ae16-01 was a pathotype II isolate. An alfalfa isolate from Quebec was avirulent on all pea genotypes. These findings indicate that pathotype type I is predominant on the Canadian prairies

Management Implications of the Biodiversity and Socio-Economic Impacts of Shrimp Trawler By-Catch in Bahía de Kino, Sonora, México

The shrimp fishery is the most economically important fishery in Mexico. The trawler-based portion of this fishery results in high rates of by-catch. This study quantifies and describes the biodiversity of by-catch associated with trawling in the Bahía de Kino region of Sonora, Mexico. Data were collected from 55 trawls, on six boats, over 14 nights, during November of 2003, 2004, 2006–2009. By-catch rates within trawl samples averaged 85.9% measured by weight. A total of 183 by-catch species were identified during the course of this study, including 97 species of bony fish from 43 families, 19 species of elasmobranchs from 12 families, 66 species of invertebrates from eight phyla, and one species of marine turtle; seven of the documented by-catch species are listed on the IUCN Red List, CITES, or the Mexican NOM-059-ECOL-2010; 35 species documented in the by-catch are also targeted by local artisanal fishers. Some of the species frequently captured as juveniles in the by-catch are economically important to small-scale fishers in the region, and are particularly sensitive to overexploitation due to their life histories. This study highlights the need for further research quantifying the impacts of high levels of by-catch upon small-scale fishing economies in the region and presents strong ecological and economic rationale for by-catch management within the shrimp fishery of the Gulf of California. Site-specific by-catch management plans should be piloted in the Bahía de Kino region to address the growing momentum in national and international fisheries policy regimes toward the reduction of by-catch in shrimp fisheries

Measurement of the collision rate coefficients between atmospheric ions and multiply charged aerosol particles in the CERN CLOUD chamber

Aerosol particles have an important role in Earth's radiation balance and climate, both directly and indirectly through aerosol–cloud interactions. Most aerosol particles in the atmosphere are weakly charged, affecting both their collision rates with ions and neutral molecules, as well as the rates by which they are scavenged by other aerosol particles and cloud droplets. The rate coefficients between ions and aerosol particles are important since they determine the growth rates and lifetimes of ions and charged aerosol particles, and so they may influence cloud microphysics, dynamics, and aerosol processing. However, despite their importance, very few experimental measurements exist of charged aerosol collision rates under atmospheric conditions, where galactic cosmic rays in the lower troposphere give rise to ion pair concentrations of around 1000 cm−3. Here we present measurements in the CERN CLOUD chamber of the rate coefficients between ions and small (&lt;10 nm) aerosol particles containing up to 9 elementary charges, e. We find the rate coefficient of a singly charged ion with an oppositely charged particle increases from 2.0 (0.4–4.4) × 10−6 cm3 s−1 to 30.6 (24.9–45.1) × 10−6 cm3 s−1 for particles with charges of 1 to 9 e, respectively, where the parentheses indicate the ±1σ uncertainty interval. Our measurements are compatible with theoretical predictions and show excellent agreement with the model of Gatti and Kortshagen (2008).</p

Evaluation and Validation of Thorax Model Responses: A Hierarchical Approach to Achieve High Biofidelity for Thoracic Musculoskeletal System

As one of the most frequently occurring injuries, thoracic trauma is a significant public health burden occurring in road traffic crashes, sports accidents, and military events. The biomechanics of the human thorax under impact loading can be investigated by computational finite element (FE) models, which are capable of predicting complex thoracic responses and injury outcomes quantitatively. One of the key challenges for developing a biofidelic FE model involves model evaluation and validation. In this work, the biofidelity of a mid-sized male thorax model has been evaluated and enhanced by a multi-level, hierarchical strategy of validation, focusing on injury characteristics, and model improvement of the thoracic musculoskeletal system. At the component level, the biomechanical responses of several major thoracic load-bearing structures were validated against different relevant experimental cases in the literature, including the thoracic intervertebral joints, costovertebral joints, clavicle, sternum, and costal cartilages. As an example, the thoracic spine was improved by accurate representation of the components, material properties, and ligament failure features at tissue level then validated based on the quasi-static response at the segment level, flexion bending response at the functional spinal unit level, and extension angle of the whole thoracic spine. At ribcage and full thorax levels, the thorax model with validated bony components was evaluated by a series of experimental testing cases. The validation responses were rated above 0.76, as assessed by the CORA evaluation system, indicating the model exhibited overall good biofidelity. At both component and full thorax levels, the model showed good computational stability, and reasonable agreement with the experimental data both qualitatively and quantitatively. It is expected that our validated thorax model can predict thorax behavior with high biofidelity to assess injury risk and investigate injury mechanisms of the thoracic musculoskeletal system in various impact scenarios. The relevant validation cases established in this study shall be directly used for future evaluation of other thorax models, and the validation approach and process presented here may provide an insightful framework toward multi-level validating of human body models.</jats:p