289 research outputs found

    Comparison of Niskin vs. in situ approaches for analysis of gene expression in deep Mediterranean Sea water samples

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    Author Posting. © The Author(s), 2014. This is the author's version of the work. It is posted here by permission of Elsevier for personal use, not for redistribution. The definitive version was published in Deep Sea Research Part II: Topical Studies in Oceanography 129 (2016): 213-222, doi:10.1016/j.dsr2.2014.10.020.Obtaining an accurate picture of microbial processes occurring in situ is essential for our understanding of marine biogeochemical cycles of global importance. Water samples are typically collected at depth and returned to the sea surface for processing and downstream experiments. Metatranscriptome analysis is one powerful approach for investigating metabolic activities of microorganisms in their habitat and which can be informative for determining responses of microbiota to disturbances such as the Deepwater Horizon oil spill. For studies of microbial processes occurring in the deep sea, however, sample handling, pressure, and other changes during sample recovery can subject microorganisms to physiological changes that alter the expression profile of labile messenger RNA. Here we report a comparison of gene expression profiles for whole microbial communities in a bathypelagic water column sample collected in the Eastern Mediterranean Sea using Niskin bottle sample collection and a new water column sampler for studies of marine microbial ecology, the Microbial Sampler – In Situ Incubation Device (MS-SID). For some taxa, gene expression profiles from samples collected and preserved 33 in situ were significantly different from potentially more stressful Niskin sampling and 34 preservation on deck. Some categories of transcribed genes also appear to be affected by sample 35 handling more than others. This suggests that for future studies of marine microbial ecology, 36 particularly targeting deep sea samples, an in situ sample collection and preservation approach 37 should be considered.This research was funded by NSF OCE-1061774 to VE and CT, NSF DBI-0424599 to CT and NSF OCE-0849578 to VE and colleague J. Bernhard. Cruise participation was partially supported by Deutsche Forschungsgemeinschaft (DFG) grant STO414/10-1 to T. Stoeck

    Celebrity abuse on Twitter: the impact of tweet valence, volume of abuse, and dark triad personality factors on victim blaming and perceptions of severity

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    Celebrities are increasingly utilizing social media platforms to establish their brand and interact with their fan base, but in doing so they often become the targets of online abuse. While such abusive acts are known to cause severe consequences in the general population little is known about how celebrity abuse is perceived by observers. This study investigated observers' impressions of the severity of online abuse on Twitter, the blame attributed to celebrities for the abuse they received, and the role of the dark triad of observers' personality factors (Machiavellianism, narcissism, and psychopathy) in these decisions. We manipulated celebrity tweet content (negative, neutral, positive) and the volume of abusive comments (high, low) the tweets received. Celebrities received more blame the more negative their initial tweet was, and incidents were perceived as least severe following a negative tweet with a high volume of abuse. Observer impressions were influenced by their dark triad personality factors. Following negative tweets, as observer narcissism increased, victim blame increased and perceived severity decreased. Following positive tweets, as observer psychopathy increased, perceived severity decreased. Results are discussed in the context of the Warranting Theory of online impression formation and the ramifications for celebrity social media use are explored

    Identification of Cytokinin-Responsive Genes Using Microarray Meta-Analysis and RNA-Seq in Arabidopsis

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    Cytokinins are N6-substituted adenine derivatives that play diverse roles in plant growth and development. We sought to define a robust set of genes regulated by cytokinin as well as to query the response of genes not represented on microarrays. To this end, we performed a meta-analysis of microarray data from a variety of cytokinin-treated samples and used RNA-seq to examine cytokinin-regulated gene expression in Arabidopsis (Arabidopsis thaliana). Microarray meta-analysis using 13 microarray experiments combined with empirically defined filtering criteria identified a set of 226 genes differentially regulated by cytokinin, a subset of which has previously been validated by other methods. RNA-seq validated about 73% of the up-regulated genes identified by this meta-analysis. In silico promoter analysis indicated an overrepresentation of type-B Arabidopsis response regulator binding elements, consistent with the role of type-B Arabidopsis response regulators as primary mediators of cytokinin-responsive gene expression. RNA-seq analysis identified 73 cytokinin-regulated genes that were not represented on the ATH1 microarray. Representative genes were verified using quantitative reverse transcription-polymerase chain reaction and NanoString analysis. Analysis of the genes identified reveals a substantial effect of cytokinin on genes encoding proteins involved in secondary metabolism, particularly those acting in flavonoid and phenylpropanoid biosynthesis, as well as in the regulation of redox state of the cell, particularly a set of glutaredoxin genes. Novel splicing events were found in members of some gene families that are known to play a role in cytokinin signaling or metabolism. The genes identified in this analysis represent a robust set of cytokinin-responsive genes that are useful in the analysis of cytokinin function in plants

    Characterization of the cytokinin-responsive transcriptome in rice

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    Abstract Background Cytokinin activates transcriptional cascades important for development and the responses to biotic and abiotic stresses. Most of what is known regarding cytokinin-regulated gene expression comes from studies of the dicotyledonous plant Arabidopsis thaliana. To expand the understanding of the cytokinin-regulated transcriptome, we employed RNA-Seq to analyze gene expression in response to cytokinin in roots and shoots of the monocotyledonous plant rice. Results We identified over 4,600 and approximately 2,400 genes differentially expressed in response to cytokinin in roots and shoots respectively. There were some similarities in the sets of cytokinin-regulated genes identified in rice and Arabidopsis, including an up-regulation of genes that act to reduce cytokinin function. Consistent with this, we found that the preferred DNA-binding motif of a rice type-B response regulator is similar to those from Arabidopsis. Analysis of the genes regulated by cytokinin in rice revealed a large number of transcription factors, receptor-like kinases, and genes involved in protein degradation, as well as genes involved in development and the response to biotic stress. Consistent with the over-representation of genes involved in biotic stress, there is a substantial overlap in the genes regulated by cytokinin and those differentially expressed in response to pathogen infection, suggesting that cytokinin plays an integral role in the transcriptional response to pathogens in rice, including the induction of a large number of WRKY transcription factors. Conclusions These results begin to unravel the complex gene regulation after cytokinin perception in a crop of agricultural importance and provide insight into the processes and responses modulated by cytokinin in monocots

    Concealed identity information detection with pupillometry in rapid serial visual presentation

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    The concealed information test (CIT) relies on bodily reactions to stimuli that are hidden in mind. However, people can use countermeasures, such as purposely focusing on irrelevant things, to confound the CIT. A new method designed to prevent countermeasures uses rapid serial visual presentation (RSVP) to present stimuli on the fringe of awareness. Previous studies that used RSVP in combination with electroencephalography (EEG) showed that participants exhibit a clear reaction to their real first name, even when they try to prevent such a reaction (i.e., when their name is concealed information). Because EEG is not easily applicable outside the laboratory, we investigated here whether pupil size, which is easier to measure, can also be used to detect concealed identity information. In our first study, participants adopted a fake name, and searched for this name in an RSVP task, while their pupil sizes were recorded. Apart from this fake name, their real name and a control name also appeared in the task. We found pupil dilation in response to the task-irrelevant real name, as compared to control names. However, while most participants showed this effect qualitatively, it was not statistically significant for most participants individually. In a second study, we preregistered the proof-of-concept methodology and replicated the original findings. Taken together, our results show that the current RSVP task with pupillometry can detect concealed identity information at a group level. Further development of the method is needed to create a valid and reliable concealed identity information detector at the individual level

    Could strength of exposure to the residential neighbourhood modify associations between walkability and physical activity?

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    Item does not contain fulltextThe importance of neighbourhoods for health and wellbeing may vary according to an individual's reliance on their local resources, but this assertion is rarely tested. We investigate whether greater neighbourhood 'exposure' through reliance on or engagement with the residential setting magnifies neighbourhood-health associations. METHODS: Three built environment characteristics (destination density, streetscape (attractiveness of built environment) and street connectivity) and two physical activity components (weekday and weekend accelerometer counts) were measured for 2033 residents living in 48 neighbourhoods within four New Zealand cities in 2009-2010, giving six different built environment-physical activity associations. Interactions for each built environment-physical activity association with four individual-level characteristics (acting as proxies for exposure: gender, working status, car access, and income) were assessed with multi-level regression models; a total of 24 'tests'. RESULTS: Of the 12 weekday built environment-physical activity tests, 5 interaction terms were significant (p < 0.05) in the expected direction (e.g. stronger streetscape-physical activity among those with restricted car access). For weekend tests, one association was statistically significant. No significant tests were contradictory. Pooled across the 12 weekday physical activity 'tests', a 1 standard deviation increase in the walkability of the built environment was associated with an overall 3.8% (95% CI: 3.6%-4.1%) greater increase in weekday physical activity across all the types of people we hypothesised to spend more time in their residential neighbourhood, and for weekend physical activity it was 4.2% (95% CI 3.9%-4.5%). CONCLUSIONS: Using multiple evaluation methods, interactions were in line with our hypothesis, with a stronger association seen for proxy exposure indicators (for example, restricted car access). Added to the wider evidence base, our study strengthens causal evidence of an effect of the built environment on physical activity, and highlights that health gains from improvements of the residential neighbourhood may be greater for some people

    Models and metaphors: complexity theory and through-life management in the built environment

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    Complexity thinking may have both modelling and metaphorical applications in the through-life management of the built environment. These two distinct approaches are examined and compared. In the first instance, some of the sources of complexity in the design, construction and maintenance of the built environment are identified. The metaphorical use of complexity in management thinking and its application in the built environment are briefly examined. This is followed by an exploration of modelling techniques relevant to built environment concerns. Non-linear and complex mathematical techniques such as fuzzy logic, cellular automata and attractors, may be applicable to their analysis. Existing software tools are identified and examples of successful built environment applications of complexity modelling are given. Some issues that arise include the definition of phenomena in a mathematically usable way, the functionality of available software and the possibility of going beyond representational modelling. Further questions arising from the application of complexity thinking are discussed, including the possibilities for confusion that arise from the use of metaphor. The metaphor of a 'commentary machine' is suggested as a possible way forward and it is suggested that an appropriate linguistic analysis can in certain situations reduce perceived complexity

    Cytokinin induces genome-wide binding of the type-B response regulator ARR10 to regulate growth and development in Arabidopsis

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    Cytokinins, like other plant hormones, affect a diverse array of plant growth and development processes and responses to the environment. How a signaling molecule mediates such a diverse array of outputs and how these response pathways are integrated with other inputs remain fundamental questions in plant biology. An integrated set of approaches was used to define the targets of the type-B response regulators, a key set of transcription factors that control cytokinin-dependent gene expression. Results shed light on the physiological role of the type-B ARRs in regulating the cytokinin response, mechanism of type-B ARR activation, and basis by which cytokinin regulates diverse aspects of growth and development as well as responses to biotic and abiotic factors

    Attributing minds to vampires in Richard Matheson’s I Am Legend

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    For Palmer (2004, 2010), and other proponents of a cognitive narratology, research into real-world minds in the cognitive sciences provides insights into readers’ experiences of fictional minds. In this article, I explore the application of such research to the minds constructed for the vampire characters in Richard Matheson’s (1954) science fiction/horror novel I Am Legend. I draw upon empirical research into ‘mind attribution’ in social psychology, and apply Cognitive Grammar (Langacker, 2008), and its notion of ‘construal’, as a framework for the application of such findings to narrative. In my analysis, I suggest that readers’ attribution of mental-states to the vampires in Matheson’s novel is strategically limited through a number of choices in their linguistic construal. Drawing on online reader responses to the novel, I argue that readers’ understanding of these other minds plays an important role in their empathetic experience and their ethical judgement of the novel’s main character and focaliser, Robert Neville. Finally, I suggest that the limited mind attribution for the vampires invited through their construal contributes to the presentation of a ‘mind style’ (Fowler, 1977) for this character
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