282 research outputs found

    The geographic mosaic of herbicide resistance evolution in the common morning glory, Ipomoea purpurea: Evidence for resistance hotspots and low genetic differentiation across the landscape

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    Strong human‐mediated selection via herbicide application in agroecosystems has repeatedly led to the evolution of resistance in weedy plants. Although resistance can occur among separate populations of a species across the landscape, the spatial scale of resistance in many weeds is often left unexamined. We assessed the potential that resistance to the herbicide glyphosate in the agricultural weed Ipomoea purpurea has evolved independently multiple times across its North American range. We examined both adaptive and neutral genetic variations in 44 populations of I. purpurea by pairing a replicated dose–response greenhouse experiment with SSR genotyping of experimental individuals. We uncovered a mosaic pattern of resistance across the landscape, with some populations exhibiting high‐survival postherbicide and other populations showing high death. SSR genotyping revealed little evidence of isolation by distance and very little neutral genetic structure associated with geography. An approximate Bayesian computation (ABC) analysis uncovered evidence for migration and admixture among populations before the widespread use of glyphosate rather than the very recent contemporary gene flow. The pattern of adaptive and neutral genetic variations indicates that resistance in this mixed‐mating weed species appears to have evolved in independent hotspots rather than through transmission of resistance alleles across the landscape.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/113156/1/eva12290_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/113156/2/eva12290.pd

    Assessment of cognitive self-statements during marital problem solving: A comparison of two methods

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    Twenty maritally distressed couples (DC) and 20 nondistressed couples (NDC) were recruited and asked to undertake 10 minutes of problem-solving discussions, which were videotaped. Each individual partner’s cognitive self-statements during the interaction were assessed using two methods: video-assisted recall (VR) and thought listing (TL). Reported cognitions from each method were content- analysed and classified into five categories: partner- referent positive, partner- referent negative, self-referent positive, self- referent negative, and other. Proportions of reported cognitions falling into each category were analysed in two separate two-way MANOVAs (marital distress/ nondistress x sex) for the VR and TL measures. Results of each MANOVA indicated a highly significant effect of marital distress on cognitions, and a significant effect of sex on the VR but not the TL measure. Discriminant analyses showed that the VR and TL methods both discriminated between DC and NDC groups. Post hoc univariate ANOVAs indicated that DC had significantly higher proportions of negative partner- referent cognitions, and lower proportions of positive partner- referent cognitions, than NDC while problem solving. The relative merits of each cognitive assessment method, and their potential use in increasing marital therapy effectiveness, are discussed

    Couple Communication in Cancer: Protocol for a Multi-Method Examination

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    Cancer and its treatment pose challenges that affect not only patients but also their significant others, including intimate partners. Accumulating evidence suggests that couples’ ability to communicate effectively plays a major role in the psychological adjustment of both individuals and the quality of their relationship. Two key conceptual models have been proposed to account for how couple communication impacts psychological and relationship adjustment: the social-cognitive processing (SCP) model and the relationship intimacy (RI) model. These models posit different mechanisms and outcomes, and thus have different implications for intervention. The purpose of this project is to test and compare the utility of these models using comprehensive and methodologically rigorous methods. Aims are: (1) to examine the overall fit of the SCP and RI models in explaining patient and partner psychological and relationship adjustment as they occur on a day-to-day basis and over the course of 1 year; (2) to examine the fit of the models for different subgroups (males vs. females, and patients vs. partners); and (3) to examine the utility of various methods of assessing communication by examining the degree to which baseline indices from different measurement strategies predict self-reported adjustment at 1-year follow up. The study employs a longitudinal, multi-method approach to examining communication processes including: standard self-report questionnaires assessing process and outcome variables collected quarterly over the course of 1 year; smartphone-based ecological momentary assessments to sample participant reports in real time; and laboratory-based couple conversations from which we derive observational measures of communicative behavior and affective expression, as well as vocal indices of emotional arousal. Participants are patients with stage II-IV breast, colon, rectal, or lung cancer and their spouses/partners, recruited from two NCI-designated comprehensive cancer centers. Results will be published in scientific journals, presented at scientific conferences, and conveyed to a larger audience through infographics and social media outlets. Findings will inform theory, measurement, and the design and implementation of efficacious interventions aimed at optimizing both patient and partner well-being

    LTR retrotransposon dynamics in the evolution of the olive (Olea europaea) genome.

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    Improved knowledge of genome composition, especially of its repetitive component, generates important information for both theoretical and applied research. The olive repetitive component is made up of two main classes of sequences: tandem repeats and retrotransposons (REs). In this study, we provide characterization of a sample of 254 unique full-length long terminal repeat (LTR) REs. In the sample, Ty1-Copia elements were more numerous than Ty3-Gypsy elements. Mapping a large set of Illumina whole-genome shotgun reads onto the identified retroelement set revealed that Gypsy elements are more redundant than Copia elements. The insertion time of intact retroelements was estimated based on sister LTR's divergence. Although some elements inserted relatively recently, the mean insertion age of the isolated retroelements is around 18 million yrs. Gypsy and Copia retroelements showed different waves of transposition, with Gypsy elements especially active between 10 and 25 million yrs ago and nearly inactive in the last 7 million yrs. The occurrence of numerous solo-LTRs related to isolated full-length retroelements was ascertained for two Gypsy elements and one Copia element. Overall, the results reported in this study show that RE activity (both retrotransposition and DNA loss) has impacted the olive genome structure in more ancient times than in other angiosperms

    Reviewing research priorities in weed ecology, evolution and management: A horizon scan

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    Weedy plants pose a major threat to food security, biodiversity, ecosystem services and consequently to human health and wellbeing. However, many currently used weed management approaches are increasingly unsustainable. To address this knowledge and practice gap, in June 2014, 35 weed and invasion ecologists, weed scientists, evolutionary biologists and social scientists convened a workshop to explore current and future perspectives and approaches in weed ecology and management. A horizon scanning exercise ranked a list of 124 pre-submitted questions to identify a priority list of 30 questions. These questions are discussed under seven themed headings that represent areas for renewed and emerging focus for the disciplines of weed research and practice. The themed areas considered the need for transdisciplinarity, increased adoption of integrated weed management and agroecological approaches, better understanding of weed evolution, climate change, weed invasiveness and finally, disciplinary challenges for weed science. Almost all the challenges identified rested on the need for continued efforts to diversify and integrate agroecological, socio-economic and technological approaches in weed management. These challenges are not newly conceived, though their continued prominence as research priorities highlights an ongoing intransigence that must be addressed through a more system-oriented and transdisciplinary research agenda that seeks an embedded integration of public and private research approaches. This horizon scanning exercise thus set out the building blocks needed for future weed management research and practice; however, the challenge ahead is to identify effective ways in which sufficient research and implementation efforts can be directed towards these needs

    Geospatial data analysis in Russia’s geoweb

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    The chapter examines the role of geospatial data in Russia’s online ecosystem. Facilitated by the rise of geographic information systems and user-generated content, the distribution of geospatial data has blurred the line between physical spaces and their virtual representations. The chapter discusses different sources of these data available for Digital Russian Studies (e.g., social data and crowdsourced databases) together with the novel techniques for extracting geolocation from various data formats (e.g., textual documents and images). It also scrutinizes different ways of using these data, varying from mapping the spatial distribution of social and political phenomena to investigating the use of geotag data for cultural practices’ digitization to exploring the use of geoweb for narrating individual and collective identities online

    Is food addiction a predictor of treatment outcome among patients with eating disorder?

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    ObjectivesThe study aimed to examine whether food addiction (FA) was associated with greater severity in both binge eating disorders (BED) and bulimia nervosa and, therefore, to determine if FA was predictive of treatment outcome.MethodSeventy-one adult patients with bulimia nervosa and BED (42 and 29, respectively) participated in the study. FA was assessed by means of the Yale Food Addiction Scale.ResultsThe results confirmed a high prevalence of FA in patients with binge disorders (around 87%) and also its association with a greater severity of the disorder (i.e., related to an increased eating psychopathology and greater frequency of binge eating episodes). Although FA did not appear as a predictor of treatment outcome in general terms, when the diagnostic subtypes were considered separately, FA was associated with poor prognosis in the BED group. In this vein, FA appeared as a mediator in the relationship between ED severity and treatment outcome.DiscussionsOur findings suggest that FA may act as an indicator of ED severity, and it would be a predictor of treatment outcome in BED but not in BN.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152018/1/erv2705.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/152018/2/erv2705_am.pd

    Phylotranscriptomic analysis of the origin and early diversification of land plants

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    Reconstructing the origin and evolution of land plants and their algal relatives is a fundamental problem in plant phylogenetics, and is essential for understanding how critical adaptations arose, including the embryo, vascular tissue, seeds, and flowers. Despite advances inmolecular systematics, some hypotheses of relationships remain weakly resolved. Inferring deep phylogenies with bouts of rapid diversification can be problematic; however, genome-scale data should significantly increase the number of informative characters for analyses. Recent phylogenomic reconstructions focused on the major divergences of plants have resulted in promising but inconsistent results. One limitation is sparse taxon sampling, likely resulting from the difficulty and cost of data generation. To address this limitation, transcriptome data for 92 streptophyte taxa were generated and analyzed along with 11 published plant genome sequences. Phylogenetic reconstructions were conducted using up to 852 nuclear genes and 1,701,170 aligned sites. Sixty-nine analyses were performed to test the robustness of phylogenetic inferences to permutations of the datamatrix or to phylogeneticmethod, including supermatrix, supertree, and coalescent-based approaches, maximumlikelihood and Bayesian methods, partitioned and unpartitioned analyses, and amino acid versus DNA alignments. Among other results, we find robust support for a sister-group relationship between land plants and one group of streptophyte green algae, the Zygnematophyceae. Strong and robust support for a clade comprising liverworts and mosses is inconsistent with a widely accepted view of early land plant evolution, and suggests that phylogenetic hypotheses used to understand the evolution of fundamental plant traits should be reevaluated
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