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Vanos J.K.,Environmental Health Science and Research Bureau | Cakmak S.,Environmental Health Science and Research Bureau | Bristow C.,Statistics Canada | Brion V.,Environmental Health Science and Research Bureau | And 3 more authors.
Environmental Research | Year: 2013

Background: Synoptic circulation patterns (large-scale weather systems) affect ambient levels of air pollution, as well as the relationship between air pollution and human health. Objective: To investigate the air pollution-mortality relationship within weather types and seasons, and to determine which combination of atmospheric conditions may pose increased health threats in the elderly age categories. Methods: The relative risk of mortality (RR) due to air pollution was examined using Poisson generalized linear models (GLMs) within specific weather types. Analysis was completed by weather type and age group (all ages, ≤64, 65-74, 75-84, ≥85 years) in ten Canadian cities from 1981 to 1999. Results: There was significant modification of RR by weather type and age. When examining the entire population, weather type was shown to have the greatest modifying effect on the risk of dying due to ozone (O3). This effect was highest on average for the dry tropical (DT) weather type, with the all-age RR of mortality at a population weighted mean (PWM) found to be 1.055 (95% CI 1.026-1.085). All-weather type risk estimates increased with age due to exposure to carbon monoxide (CO), nitrogen dioxide (NO2), and sulphur dioxide (SO2). On average, RR increased by 2.6, 3.8 and 1.5% for the respective pollutants between the ≤64 and ≥85 age categories. Conversely, mean ozone estimates remained relatively consistent with age. Elevated levels of air pollution were found to be detrimental to the health of elderly individuals for all weather types. However, the entire population was negatively effected by air pollution on the hot dry (DT) and hot humid (MT) days. Conclusions: We identified a significant modification of RR for mortality due to air pollution by age, which is enhanced under specific weather types. Efforts should be targeted at minimizing pollutant exposure to the elderly and/or all age groups with respect to weather type in question. © 2013. Source

Helgason B.L.,Agriculture and Agri Food Canada | Konschuh H.J.,Agriculture and Agri Food Canada | Konschuh H.J.,University of Saskatchewan | Bedard-Haughn A.,University of Saskatchewan | VandenBygaart A.J.,Eastern Cereal and Oilseed Research Center
Agriculture, Ecosystems and Environment | Year: 2014

Hummocky landscapes are naturally susceptible to erosion by water and tillage. Downslope movement of material results in the accumulation of soil in depositional positions and exposed sub-soils at the surface of eroded positions, affecting landscape-scale C cycling and productivity. Prolonged or extreme erosion can create inverted soil profiles with deeply buried C-rich surface material. The susceptibility of this C to decomposition is largely controlled by the potential of microorganisms to degrade it with long-term implications for C dynamics in agroecosystems. Our objective in this study was to evaluate whether the redistribution of soil along eroded hill slopes creates differences in the structure of the soil microbial community, both laterally across the landscape and vertically through the soil profile. Using phospholipid fatty acid analysis (PLFA) and high-throughput DNA sequencing, we investigated the abundance, diversity and community structure of microbial communities along an eroded landscape. Microbial abundance and community structure were found to be strongly influenced by a depth gradient at the near-surface (0-20cm). In a depositional backslope position, viable microbial biomass was detected to the depth of the A horizon (85cm), with a C-rich buried layer that contained substantial viable biomass (10.1 -18.8μg PLFAg-1 soil). Soil organic carbon (SOC) concentration was significantly correlated (r=0.40; p<0.001) with PLFA concentration at all positions, indicating microbial abundance is determined by C availability. In contrast, community structure was related to the origin of the soil in the landscape, and may be regulated more strongly by SOC composition. Pyrosequencing of bacterial and fungal DNA showed that genetic diversity was largely maintained in former surface soils. Our work demonstrates that abundant microbial biomass is supported in C-rich buried soils while SOC is largely preserved for decades. The presence of an abundant and diverse community suggests that there is potential for enhanced C loss under changing conditions such as climate change or modified land-use. © 2014. Source

Rousseau M.,Laval University | LeSage L.,Eastern Cereal and Oilseed Research Center
Canadian Entomologist | Year: 2015

A pair of elytra of the striped flea beetle Phyllotreta striolata (Fabricius) (Coleoptera: Chrysomelidae) was recovered from a sample of sediment dating before 1668 collected in Ville de Québec, Québec, Canada, making it the earliest recorded introduction of the species in North America. It is proposed that its transatlantic voyage took place on crucifers either voluntarily transported as foodstock and animal fodder or involuntarily as weeds. © Entomological Society of Canada 2015 Source

Schroers H.-J.,Agricultural Institute of Slovenia | Grafenhan T.,Eastern Cereal and Oilseed Research Center | Grafenhan T.,Canadian Grain Commission | Nirenberg H.I.,Julius Kuhn Institute | Seifert K.A.,Eastern Cereal and Oilseed Research Center
Studies in Mycology | Year: 2011

A revision of Fusarium-like species associated with the plant genus Buxus led to a reconsideration of generic concepts in the Fusarium clade of the Nectriaceae. Phylogenetic analyses of the partial second largest subunit of the RNA polymerase II (rpb2) and the larger subunit of the ATP citrate lyase (acl1) gene exons confirm the existence of a clade, here called the terminal Fusarium clade, that includes genera such as Fusarium sensu stricto (including its Gibberella teleomorphs), Albonectria, Cyanonectria, "Haematonectria", the newly described genus Geejayessia, and "Nectria" albida. Geejayessia accommodates five species. Four were previously classified in Nectria sensu lato, namely the black perithecial, KOH- species G. atrofusca and the orange or reddish, KOH+ G. cicatricum, G. desmazieri and G. zealandica. Geejayessia celtidicola is newly described. Following our phylogenetic analyses showing its close relationship with Cyanonectria cyanostoma, the former Gibbera buxi is recombined as the second species of Cyanonectria. A three gene phylogenetic analysis of multiple strains of each morphological species using translation elongation factor 1 α (tef-1), rpb2 and acl1 gene exons and introns confirms their status as distinct phylogenetic species. Internal transcribed spacer of the ribosomal RNA gene cluster and nuclear large ribosomal subunit sequences were generated as additional DNA barcodes for selected strains. The connection of Fusarium buxicola, often erroneously reported as the anamorph of G. desmazieri, with the bluish black and KOH+ perithecial species C. buxi is reinstated. Most Cyanonectria and Geejayessia species exhibit restricted host ranges on branches or twigs of Buxus species, Celtis occidentalis, or Staphylea trifolia. Their perithecia form caespitose clusters on well-developed, mostly erumpent stromata on the bark or outer cortex of the host and are relatively thin-walled, mostly smooth, and therefore reminiscent of the more or less astromatous, singly occurring perithecia of Cosmospora, Dialonectria, and Microcera. The cell walls in outer- and inner layers of the perithecial walls of Cyanonectria and Geejayessia have inconspicuous pore-like structures, as do representative species of Albonectria, Fusarium sensu stricto, "Haematonectria", and "Nectria" albida. The taxonomic significance of these structures, which we call Samuels' pores, is discussed. © 2011 by the CBS Fungal Biodiversity Centre. Source

Grafenhan T.,Eastern Cereal and Oilseed Research Center | Grafenhan T.,Canadian Grain Commission | Schroers H.-J.,Agricultural Institute of Slovenia | Nirenberg H.I.,Julius Kuhn Institute | Seifert K.A.,Eastern Cereal and Oilseed Research Center
Studies in Mycology | Year: 2011

A comprehensive phylogenetic reassessment of the ascomycete genus Cosmospora (Hypocreales, Nectriaceae) is undertaken using fresh isolates and historical strains, sequences of two protein encoding genes, the second largest subunit of RNA polymerase II (rpb2), and a new phylogenetic marker, the larger subunit of ATP citrate lyase (acl1). The result is an extensive revision of taxonomic concepts, typification, and nomenclatural details of many anamorph- and teleomorph-typified genera of the Nectriaceae, most notably Cosmospora and Fusarium. The combined phylogenetic analysis shows that the present concept of Fusarium is not monophyletic and that the genus divides into two large groups, one basal in the family, the other terminal, separated by a large group of species classified in genera such as Calonectria, Neonectria, and Volutella. All accepted genera received high statistical support in the phylogenetic analyses. Preliminary polythetic morphological descriptions are presented for each genus, providing details of perithecia, micro- and/or macro-conidial synanamorphs, cultural characters, and ecological traits. Eight species are included in our restricted concept of Cosmospora, two of which have previously documented teleomorphs and all of which have Acremonium-like microconidial anamorphs. A key is provided to the three anamorphic species recognised in Atractium, which is removed from synonymy with Fusarium and epitypified for two macroconidial synnematous species and one sporodochial species associated with waterlogged wood. Dialonectria is recognised as distinct from Cosmospora and two species with teleomorph, macroconidia and microconidia are accepted, including the new species D. ullevolea. Seven species, one with a known teleomorph, are classified in Fusicolla, formerly considered a synonym of Fusarium including members of the F. aquaeductuum and F. merismoides species complex, with several former varieties raised to species rank. Originally a section of Nectria, Macroconia is raised to generic rank for five species, all producing a teleomorph and macroconidial anamorph. A new species of the Verticillium-like anamorphic genus Mariannaea is described as M. samuelsii. Microcera is recognised as distinct from Fusarium and a key is included for four macroconidial species, that are usually parasites of scale insects, two of them with teleomorphs. The four accepted species of Stylonectria each produce a teleomorph and micro- and macroconidial synanamorphs. The Volutella species sampled fall into three clades. Pseudonectria is accepted for a perithecial and sporodochial species that occurs on Buxus. Volutella s. str. also includes perithecial and/or sporodochial species and is revised to include a synnematous species formerly included in Stilbella. The third Volutella-like clade remains unnamed. All fungi in this paper are named using a single name system that gives priority to the oldest generic names and species epithets, irrespective of whether they are originally based on anamorph or teleomorph structures. The rationale behind this is discussed. © 2011 CBS-KNAW Fungal Biodiversity Centre. Source

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