1,417 research outputs found

    Differential breeding targets in wheat influence non-target traits related to grain quality, but not crop nitrogen requirement

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    Wheat is considered an established crop with a long breeding history. Its varieties are being developed with differential breeding targets, e.g. high grain yield or high grain protein content. The different breeding targets strongly influence performance in the targeted traits, but may also influence non-target traits related to grain quality, biofortification potential, and nutrient accumulation. This influence of non-targeted traits may, in turn, affect the environmental performance and ecological sustainability of the crop. The aim of this study was to evaluate the relationships between breeding target traits such as grain yield and grain quality, and non-target traits for three groups of spring wheat varieties differing in breeding targets, i.e. high yield (I), organic high protein (II), and intermediate (III) wheat types. Data from a field trial with nine spring wheat varieties grown under two soil compaction treatments over two years with contrasting weather were used. We found that wheat type affected most target and non-target traits with partly large effect sizes (0.874≤η  2p≤0.173) , but not nitrogen (N) uptake efficiency ( η  2p =0.006), which reflects the potential N resource requirement of the crop. Associations shown between target and non-target traits will be advantageous for wheat breeding programs. Wheat type and environment had similarly sized effects on grain yield and quality traits. Grain concentrations of various macro- and micro-nutrients were frequently, but not always, correlated, indicating that the biofortification potential varied between wheat types and was affected by environmental conditions. The grain and starch yields per accumulated plant N were higher in the wheat varieties bred for high grain yields than those bred for high grain protein content; whilst the protein yield per accumulated whole-plant N was similar across all wheat types despite much higher grain N concentrations in the high-protein varieties. Additionally, most of the evaluated traits tended to preserve their static stability across environments. The results link grain yield and grain quality traits to crop nutrient accumulation aspects relevant for the environmental performance and ecological sustainability of the crop. Future breeding strategies should consider the non-target effects in traits that influence the environmental performance of the crop

    Four thesis for Critical Library and Information Studies: a manifesto

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    This essay proposes four theses for a Critical Library and Information Studies (CLIS) research agenda. The author argues that a normative commitment to libraries as social institutions should guide any future CLIS research agenda, that the natural sciences are a poor model for CLIS research, that value neutrality should be abandoned, and that any CLIS project should propose alternative

    Four thesis for Critical Library and Information Studies: a manifesto

    Get PDF
    This essay proposes four theses for a Critical Library and Information Studies (CLIS) research agenda. The author argues that a normative commitment to libraries as social institutions should guide any future CLIS research agenda, that the natural sciences are a poor model for CLIS research, that value neutrality should be abandoned, and that any CLIS project should propose alternative

    CALIPSO Satellite Lidar Identification Of Elevated Dust Over Australia Compared With Air Quality Model PM60 Forecasts

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    Global measurements of the vertical distribution of clouds and aerosols have been recorded by the lidar on board the CALIPSO (Cloud Aerosol Lidar Infrared Pathfinder Satellite Observations) satellite since June 2006. Such extensive, height-resolved measurements provide a rare and valuable opportunity for developing, testing and validating various atmospheric models, including global climate, numerical weather prediction, chemical transport and air quality models. Here we report on the initial results of an investigation into the performance of the Australian Air Quality Forecast System (AAQFS) model in forecasting the distribution of elevated dust over the Australian region. The model forecasts of PM60 dust distribution are compared with the CALIPSO lidar Vertical Feature Mask (VFM) data product. The VFM classifies contiguous atmospheric regions of enhanced backscatter as either cloud or aerosols. Aerosols are further classified into six subtypes. By comparing forecast PM60 concentration profiles to the spatial distribution of dust reported in the CALIPSO VFM, we can assess the model s ability to predict the occurrence and the vertical and horizontal extents of dust events within the study area

    The evolution of harm: effect of sexual conflicts and population size

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    Conflicts of interest between mates can lead to the evolution of male traits reducing female fitness and to coevolution between the sexes. The rate of adaptation and counter-adaptation is constrained by the intensity of selection and its efficiency, which depends on drift and genetic variability. This leads to the largely untested prediction that coevolutionary adaptations such as those driven by sexual conflict should evolve faster in large populations where the response to selection is stronger and sexual selection is more intense. We test this using the bruchid beetle Callosobruchus maculatus, a species with well documented male harm. Whilst most experimental evolution studies remove sexual conflicts, we reintroduce sexual conflict in populations where it has been experimentally removed. Both population size and standing genetic variability were manipulated in a factorial experimental design. After 90 generations of relaxed conflict (monogamy), the reintroduction of sexual conflicts for 30 generations favoured males that harmed females and females more resistant to the genital damage inflicted by males. Large population size rather than high initial genetic variation allowed males to evolve faster and become more harmful. Sexual selection thus creates conditions where males benefit from harming females and this selection is more effective in larger populations

    "2A-like" signal sequences mediating translational recoding : a novel form of dual protein targeting

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    The authors gratefully acknowledge the support of the UK Biotechnology and Biological Sciences Research Council (BBSRC) who funded this research. The authors also gratefully acknowledge the support of the Wellcome Trust for the provision of mass spectrometry facilities at St Andrews.We report the initial characterisation of an N-terminal oligopeptide ‘2A-like’ sequence that is able to function both as a signal sequence and as a translational recoding element. Due to this translational recoding activity, two forms of nascent polypeptide are synthesised: (i) when 2A-mediated translational recoding has not occurred: the nascent polypeptide is fused to the 2A-like N-terminal signal sequence and the fusion translation product is targeted to the exocytic pathway, and, (ii) a translation product where 2A-mediated translational recoding has occurred: the 2A-like signal sequence is synthesised as a separate translation product and, therefore, the nascent (downstream) polypeptide lacks the 2A-like signal sequence and is localised to the cytoplasm. This type of dual-functional signal sequence results, therefore, in the partitioning of the translation products between the two sub-cellular sites and represents a newly described form of dual protein targeting.Publisher PDFPeer reviewe

    The Pesticide Risk Beliefs Inventory: A Quantitative Instrument for the Assessment of Beliefs about Pesticide Risks

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    Recent media attention has focused on the risks that agricultural pesticides pose to the environment and human health; thus, these topics provide focal areas for scientists and science educators to enhance public understanding of basic toxicology concepts. This study details the development of a quantitative inventory to gauge pesticide risk beliefs. The goal of the inventory was to characterize misconceptions and knowledge gaps, as well as expert-like beliefs, concerning pesticide risk. This study describes the development and field testing of the Pesticide Risk Beliefs Inventory with an important target audience: pesticide educators in a southeastern U.S. state. The 19-item, Likert-type inventory was found to be psychometrically sound with a Cronbach’s alpha of 0.780 and to be a valuable tool in capturing pesticide educators’ beliefs about pesticide risk, assessing beliefs in four key categories. The Pesticide Risk Beliefs Inventory could be useful in exploring beliefs about pesticide risks and in guiding efforts to address misconceptions held by a variety of formal and informal science learners, educators, practitioners, the agricultural labor force, and the general public
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