Variation in frequency of avirulence genes in Leptosphaeria maculans in western Canada

Non-Peer Reviewe

Temperature-dependent structure and dynamics of highly-branched poly(N-isopropylacrylamide) in aqueous solution

Small-angle neutron scattering (SANS) and neutron spin-echo (NSE) have been used to investigate the temperature-dependent solution behaviour of highly-branched poly(N-isopropylacrylamide) (HB-PNIPAM). SANS experiments have shown that water is a good solvent for both HB-PNIPAM and a linear PNIPAM control at low temperatures where the small angle scattering is described by a single correlation length model. Increasing the temperature leads to a gradual collapse of HB-PNIPAM until above the lower critical solution temperature (LCST), at which point aggregation occurs, forming disperse spherical particles of up to 60 nm in diameter, independent of the degree of branching. However, SANS from linear PNIPAM above the LCST is described by a model that combines particulate structure and a contribution from solvated chains. NSE was used to study the internal and translational solution dynamics of HB-PNIPAM chains below the LCST. Internal HB-PNIPAM dynamics is described well by the Rouse model for non-entangled chains

Rapid and highly variable warming of lake surface waters around the globe

In this first worldwide synthesis of in situ and satellite-derived lake data, we find that lake summer surface water temperatures rose rapidly (global mean = 0.34°C decade−1) between 1985 and 2009. Our analyses show that surface water warming rates are dependent on combinations of climate and local characteristics, rather than just lake location, leading to the counterintuitive result that regional consistency in lake warming is the exception, rather than the rule. The most rapidly warming lakes are widely geographically distributed, and their warming is associated with interactions among different climatic factors—from seasonally ice-covered lakes in areas where temperature and solar radiation are increasing while cloud cover is diminishing (0.72°C decade−1) to ice-free lakes experiencing increases in air temperature and solar radiation (0.53°C decade−1). The pervasive and rapid warming observed here signals the urgent need to incorporate climate impacts into vulnerability assessments and adaptation efforts for lakes.Peer reviewe

A global database of lake surface temperatures collected by in situ and satellite methods from 1985–2009

Peer reviewe

Integrating sequence and array data to create an improved 1000 Genomes Project haplotype reference panel

A major use of the 1000 Genomes Project (1000GP) data is genotype imputation in genome-wide association studies (GWAS). Here we develop a method to estimate haplotypes from low-coverage sequencing data that can take advantage of single-nucleotide polymorphism (SNP) microarray genotypes on the same samples. First the SNP array data are phased to build a backbone (or 'scaffold') of haplotypes across each chromosome. We then phase the sequence data 'onto' this haplotype scaffold. This approach can take advantage of relatedness between sequenced and non-sequenced samples to improve accuracy. We use this method to create a new 1000GP haplotype reference set for use by the human genetic community. Using a set of validation genotypes at SNP and bi-allelic indels we show that these haplotypes have lower genotype discordance and improved imputation performance into downstream GWAS samples, especially at low-frequency variants. © 2014 Macmillan Publishers Limited. All rights reserved

Rapid and highly variable warming of lake surface waters around the globe

peer reviewedIn this first worldwide synthesis of in situ and satellite-derived lake data, we find that lake summer surface water temperatures rose rapidly (global mean = 0.34°C decade-1) between 1985 and 2009. Our analyses show that surface water warming rates are dependent on combinations of climate and local characteristics, rather than just lake location, leading to the counterintuitive result that regional consistency in lake warming is the exception, rather than the rule. The most rapidly warming lakes are widely geographically distributed, and their warming is associated with interactions among different climatic factors - from seasonally ice-covered lakes in areas where temperature and solar radiation are increasing while cloud cover is diminishing (0.72°C decade-1) to ice-free lakes experiencing increases in air temperature and solar radiation (0.53°C decade-1). The pervasive and rapid warming observed here signals the urgent need to incorporate climate impacts into vulnerability assessments and adaptation efforts for lakes. © 2015. American Geophysical Union. All Rights Reserved

Rapid and highly variable warming of lake surface waters around the globe

Peer reviewed. ©2015. The Authors.This is an open access article under theterms of the Creative CommonsAttribution-NonCommercial-N oDerivsLicense, which permits use and distri-bution in any medium, provided theoriginal work is properly cited, the use isnon-commerc ial and no modificationsor adaptations are made.In this first worldwide synthesis of in situ and satellite-derived lake data, we find that lake summer surface water temperatures rose rapidly (global mean = 0.34°C decade 1) between 1985 and 2009. Our analyses show that surface water warming rates are dependent on combinations of climate and local characteristics, rather than just lake location, leading to the counterintuitive result that regional consistency in lake warming is the exception, rather than the rule. The most rapidly warming lakes are widely geographically distributed, and their warming is associated with interactions among different climatic factors —from seasonally ice-covered lakes in areas where temperature and solar radiation are increasing while cloud cover is diminishing (0.72°C decade 1) to ice-free lakes experiencing increases in air temperature and solar radiation (0.53°C decade 1). The pervasive and rapid warming observed here signals the urgent need to incorporate climate impacts into vulnerability assessments and adaptation efforts for lakes

Frequency of avirulence genes in Leptosphaeria maculans in western Canada

International audienceChanges in pathogenicity of populations of Leptosphaeria maculans, the cause of blackleg disease of canola and other Brassica spp., have been observed in western Canada. These changes in the population are believed to have resulted from the use of specific resistance (Rlm) genes in Brassica spp., many of which have only recently been identified. We determined the frequency of 10 avirulence alleles for 96 isolates of L. maculans collected between 1997 and 2005 from Alberta, Saskatchewan and Manitoba, Canada from infested canola stubble in field plots or farmers’ fields. Cotyledon interaction phenotypes were scored after inoculation of each isolate on a differential set of Brassica varieties or lines carrying the known resistance genes LepR3 and Rlm1 to Rlm10, except for Rlm8. The avirulence (AvrLm) alleles present in each isolate were inferred from the data. Due to the presence of confounding resistance genes in the host differentials, AvrLm1 and AvrLm2 could not be determined in nine of the isolates, AvrLm6 in two isolates and AvrLepR3 in 49. Based on the number of isolates in which the avirulence genes were confirmed, AvrLm1 was detected in 46.0% and AvrLm9 in 60.4% of the isolates in this collection. A high proportion of isolates carried AvrLm2 (96.6%) and AvrLepR3 (97.9%), and all isolates carried AvrLm6 and AvrLm10. The proportion of L. maculans isolates carrying AvrLm3, AvrLm4, AvrLm5 and AvrLm7 was much lower and varied between 10.4 and 29.2%. In total, 16 races of L. maculans were identified based on 10 avirulence alleles, with seven races accounting for 89.7% of the isolates. Information on the avirulence frequency in the pathogen population will be useful for development of resistance management strategies to control blackleg disease in B. napus oilseed rape in western Canada

Major gene and polygenic resistance to Leptosphaeria maculans in oilseed rape (Brassica napus)

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