22 research outputs found
Distinct Expression Profiles and Different Functions of Odorant Binding Proteins in Nilaparvata lugens StĂĄl
Background: Odorant binding proteins (OBPs) play important roles in insect olfaction. The brown planthopper (BPH), Nilaparvata lugens StaËšl (Delphacidae, Auchenorrhyncha, Hemiptera) is one of the most important rice pests. Its monophagy (only feeding on rice), wing form (long and short wing) variation, and annual long distance migration (seeking for rice plants of high nutrition) imply that the olfaction would play a central role in BPH behavior. However, the olfaction related proteins have not been characterized in this insect. Methodology/Principal Findings: Full length cDNA of three OBPs were obtained and distinct expression profiles were revealed regarding to tissue, developmental stage, wing form and gender for the first time for the species. The results provide important clues in functional differentiation of these genes. Binding assays with 41 compounds demonstrated that NlugOBP3 had markedly higher binding ability and wider binding spectrum than the other two OBPs. Terpenes and Ketones displayed higher binding while Alkanes showed no binding to the three OBPs. Focused on NlugOBP3, RNA interference experiments showed that NlugOBP3 not only involved in nymph olfaction on rice seedlings, but also had non-olfactory functions, as it was closely related to nymph survival. Conclusions: NlugOBP3 plays important roles in both olfaction and survival of BPH. It may serve as a potential target fo
A rhetorical balancing act: Popular punitivism in the Netherlands
The level of influence public discourse has on policy can vary widely. Research has noted that while it is largely dependent on the topic, frequency, and severity of the message, political rhetoric has the potential to sway public opinion and support. Particularly true for crime policy, rhetoric has historically been a strong factor for many countries such as the United States and England often understood as popular punitivism. However, popular punitivism has not been empirically characterized with specific focus given to political discourse, especially in international context. This paper attempts to capture the scope and relationship between rhetoric, political gain, crime policy, and public response in the Netherlands. Using the context of popular punitivism, we analyze rhetoric from three different political outlets (party platforms, coalition agreements, and statements of the throne) and triangulate the codes with passed policies, voter support, and systemic action. Findings suggest that recent rhetoric often exaggerates observed crime in society, consistent with expectations of popular punitivism perspectives. However, such exaggeration does not necessarily correlate with public support and system response patterns. Implications for discourse theory and popular punitivism are discussed
Responses of recurrent nets of asymmetric ON and OFF cells
A neural field model of ON and OFF cells with all-to-all inhibitory feedback is investigated. External spatiotemporal stimuli drive the ON and OFF cells with, respectively, direct and inverted polarity. The dynamic differences between networks built of ON and OFF cells (“ON/OFF”) and those having only ON cells (“ON/ON”) are described for the general case where ON and OFF cells can have different spontaneous firing rates; this asymmetric case is generic. Neural responses to nonhomogeneous static and time-periodic inputs are analyzed in regimes close to and away from self-oscillation. Static stimuli can cause oscillatory behavior for certain asymmetry levels. Time-periodic stimuli expose dynamical differences between ON/OFF and ON/ON nets. Outside the stimulated region, we show that ON/OFF nets exhibit frequency doubling, while ON/ON nets cannot. On the other hand, ON/ON networks show antiphase responses between stimulated and unstimulated regions, an effect that does not rely on specific receptive field circuitry. An analysis of the resonance properties of both net types reveals that ON/OFF nets exhibit larger response amplitude. Numerical simulations of the neural field models agree with theoretical predictions for localized static and time-periodic forcing. This is also the case for simulations of a network of noisy integrate-and-fire neurons. We finally discuss the application of the model to the electrosensory system and to frequency-doubling effects in retina