368 research outputs found

    Special issue highlighting research presented at the 25th IWGO Conference, Chicago 2014

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    The two most destructive insect pests of maize in Europe and the USA are the western corn rootworm, Diabrotica virgifera virgifera, and the European corn borer Ostrinia nubilalis. In Asia, these are represented by similar species, the two-spotted leaf beetle, Monolepta hieroglyphica, and the Asian corn borer, Ostrinia furnacalis, and there is great concern that D. v. virgifera could be introduced there as well. South America has recently undergone an invasion by the Old World corn earworm, Helicoverpa armigera, adding to a devastating complex of lepidopteran pests of maize such as fall armyworm, Spodoptera frugiperda, that are increasingly difficult for farmers to manage

    Uniform bounds for higher-order semilinear problems in conformal dimension

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    We establish uniform a-priori estimates for solutions of the semilinear Dirichlet problem \begin{equation} \begin{cases} (-\Delta)^m u=h(x,u)\quad&\mbox{in }\Omega,\\ u=\partial_nu=\cdots=\partial_n^{m-1}u=0\quad&\mbox{on }\partial\Omega, \end{cases} \end{equation} where hh is a positive superlinear and subcritical nonlinearity in the sense of the Trudinger-Moser-Adams inequality, either when Ω\Omega is a ball or, provided an energy control on solutions is prescribed, when Ω\Omega is a smooth bounded domain. The analogue problem with Navier boundary conditions is also studied. Finally, as a consequence of our results, existence of a positive solution is shown by degree theory.Comment: Minor correction

    Spreading Law of Evaporative Droplets

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    Droplet spreading is ubiquitous and plays a significant role in applications such as spray cooling, inkjet printing, and micro-flow devices. While the spreading of non-volatile droplets can be described by the competition between capillary and viscous dissipation, namely the Tanner's law, R(t)~t1/10, the spreading and flow transition in volatile droplets remains elusive due to the complexity added by interfacial phase change. Here we show, using both theoretical modeling and experiments, that the wetting dynamics of volatile droplets can be scaled by the spatial temporal interplay between capillary, evaporation, and thermal Marangoni effects. We quantify these complex interactions using phase diagrams based on detailed theoretical and experimental analyses. We further illustrate the spreading law of droplets by generalizing the Tanner's law to a full range of liquids with saturation vapor pressure spanning from 101 to 104 Pa and on substrates with thermal conductivity spanning from 10-1 to 103W/m/K. Our conclusions enable a unifying explanation to a series of individual works including the criterion of flow reversal and the state of dynamic wetting, making it possible to control liquid transport in diverse application scenarios

    Transpositional reactivation of the Dart transposon family in rice lines derived from introgressive hybridization with Zizania latifolia

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    <p>Abstract</p> <p>Background</p> <p>It is widely recognized that interspecific hybridization may induce "genome shock", and lead to genetic and epigenetic instabilities in the resultant hybrids and/or backcrossed introgressants. A prominent component involved in the genome shock is reactivation of cryptic transposable elements (TEs) in the hybrid genome, which is often associated with alteration in the elements' epigenetic modifications like cytosine DNA methylation. We have previously reported that introgressants derived from hybridization between <it>Oryza sativa </it>(rice) and <it>Zizania latifolia </it>manifested substantial methylation re-patterning and rampant mobilization of two TEs, a <it>copia </it>retrotransposon <it>Tos17 </it>and a MITE <it>mPing</it>. It was not known however whether other types of TEs had also been transpositionally reactivated in these introgressants, their relevance to alteration in cytosine methylation, and their impact on expression of adjacent cellular genes.</p> <p>Results</p> <p>We document in this study that the <it>Dart </it>TE family was transpositionally reactivated followed by stabilization in all three studied introgressants (RZ1, RZ2 and RZ35) derived from introgressive hybridization between rice (cv. Matsumae) and <it>Z. latifolia</it>, while the TEs remained quiescent in the recipient rice genome. Transposon-display (TD) and sequencing verified the element's mobility and mapped the excisions and re-insertions to the rice chromosomes. Methylation-sensitive Southern blotting showed that the <it>Dart </it>TEs were heavily methylated along their entire length, and moderate alteration in cytosine methylation patterns occurred in the introgressants relative to their rice parental line. Real-time qRT-PCR quantification on the relative transcript abundance of six single-copy genes flanking the newly excised or inserted <it>Dart</it>-related TE copies indicated that whereas marked difference in the expression of all four genes in both tissues (leaf and root) were detected between the introgressants and their rice parental line under both normal and various stress conditions, the difference showed little association with the presence or absence of the newly mobilized <it>Dart-</it>related TEs.</p> <p>Conclusion</p> <p>Introgressive hybridization has induced transpositional reactivation of the otherwise immobile <it>Dart</it>-related TEs in the parental rice line (cv. Matsumae), which was accompanied with a moderate alteration in the element's cytosine methylation. Significant difference in expression of the <it>Dart</it>-adjacent genes occurred between the introgressants and their rice parental line under both normal and various abiotic stress conditions, but the alteration in gene expression was not coupled with the TEs.</p

    The Influence of Social Comparison and Peer Group Size on Risky Decision-Making

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    This study explores the influence of different social reference points and different comparison group sizes on risky decision-making. Participants were presented with a scenario describing an exam, and presented with the opportunity of making a risky decision in the context of different information provided about the performance of their peers. We found that behavior was influenced, not only by comparison with peers, but also by the size of the comparison group. Specifically, the larger the reference group, the more polarized the behavior it prompted. In situations describing social loss, participants were led to make riskier decisions after comparing themselves against larger groups, while in situations describing social gain, they become more risk averse. These results indicate that decision making is influenced both by social comparison and the number of people making up the social reference group
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