De-Mystifying Inventive Thinking: A Survey With Pedagogic Implications

Students on an enterprise course running in a number of colleges in the UK in which invention and innovation formed part of the curriculum were asked to complete a questionnaire immediately upon having an inventive thought in an attempt to establish the thinking processes involved. Results from those who had ideas that subsequently proved to be genuinely inventive are presented in this paper. The results show that such thinking is most frequently categorised by the thinker in terms that suggest it is similar to other everyday modes of thought, rather than anything more mysterious. The implication of this research is that accessing the kind of creativity required to begin students inventing is not as problematic as has previously been assumed, although it can be made so by approaches that fail to take account of the need for problem construction and the need to overcome the inertia created by the extent to which invention has been mythologized in the minds of both students and teachers

High-resolution QTL mapping in Tetranychus urticae reveals acaricide-specific responses and common target-site resistance after selection by different METI-I acaricides

Arthropod herbivores cause dramatic crop losses, and frequent pesticide use has led to widespread resistance in numerous species. One such species, the two-spotted spider mite, Tetranychus urticae, is an extreme generalist herbivore and a major worldwide crop pest with a history of rapidly developing resistance to acaricides. Mitochondrial Electron Transport Inhibitors of complex I (METI-Is) have been used extensively in the last 25 years to control T. urticae around the globe, and widespread resistance to each has been documented. METI-I resistance mechanisms in T. urticae are likely complex, as increased metabolism by cytochrome P450 monooxygenases as well as a target-site mutation have been linked with resistance. To identify loci underlying resistance to the METI-I acaricides fenpyroximate, pyridaben and tebufenpyrad without prior hypotheses, we crossed a highly METI-I-resistant strain of T. urticae to a susceptible one, propagated many replicated populations over multiple generations with and without selection by each compound, and performed bulked segregant analysis genetic mapping. Our results showed that while the known H92R target-site mutation was associated with resistance to each compound, a genomic region that included cytochrome P450-reductase (CPR) was associated with resistance to pyridaben and tebufenpyrad. Within CPR, a single nonsynonymous variant distinguished the resistant strain from the sensitive one. Furthermore, a genomic region linked with tebufenpyrad resistance harbored a non-canonical member of the nuclear hormone receptor 96 (NHR96) gene family. This NHR96 gene does not encode a DNA-binding domain (DBD), an uncommon feature in arthropods, and belongs to an expanded family of 47 NHR96 proteins lacking DBDs in T. urticae. Our findings suggest that although cross-resistance to METI-Is involves known detoxification pathways, structural differences in METI-I acaricides have also resulted in resistance mechanisms that are compound-specific

Trait mapping in diverse arthropods by bulked segregant analysis

Bulked segregant analysis (BSA) is a cross-based method for genetic mapping in sexually reproducing organisms. The method's use of bulked (pooled) samples markedly reduces the genotyping effort associated with traditional linkage mapping studies. Further, it can be applied to species with life histories or physical attributes (as for micro-insects) that render genetic mapping with other methods impractical. Recent studies in both insects and mites have revealed that advanced BSA experimental designs can resolve causal loci to narrow genomic intervals, facilitating follow-up investigations. As high-quality genomes become more widely available, BSA methods are poised to become an increasingly important tool for the rapid mapping of both monogenic and polygenic traits in diverse arthropod species

Viscous-like forces control the impact response of shear-thickening dense suspensions

We experimentally and theoretically study impacts into dense cornstarch and water suspensions. We vary impact speed as well as intruder size, shape, and mass, and we characterize the resulting dynamics using high-speed video and an onboard accelerometer. We numerically solve previously proposed models, most notably the added-mass model as well as a class of viscous-like models. In the viscous-like models, the intruder dynamics are dominated by large, viscous-like forces at the boundary of the jammed front where large shear rates and accompanying large viscosities are present. We find that our experimental data are consistent with this class of models and inconsistent with the added mass model. Our results strongly suggest that the added-mass model, which is the dominant model for understanding the dynamics of impact into shear-thickening dense suspensions, should be updated to include these viscous-like forces.Office of Naval ResearchOffice of Naval Research Global Visiting Scientist ProgramNo. N0001419WX01519VSP 19-7-00