Observations of Radiation Belt Losses Due to Cyclotron Wave-Particle Interactions

Electron loss to the atmosphere plays a critical role in driving dynamics of the Earths Van Allen radiation belts and slot region. This is a review of atmospheric loss of radiation belt electrons caused by plasma wave scattering via Doppler-shifted cyclotron resonance. In particular, the focus is on observational signatures of electron loss, which include direct measurements of precipitating electrons, measured properties of waves that drive precipitation, and variations in the trapped population resulting from loss. We discuss wave and precipitation measurements from recent missions, including simultaneous multi-payload observations, which have provided new insight into the dynamic nature of the radiation belts

New constraints on the Cretaceous geodynamics of paleo-Pacific plate subduction: Insights from the Xiaojiang–Beizhang granitoids, Zhejiang Province, southeast China

The relationship between the evolution of Cretaceous magmatism along the southeastern margin of Eurasia and subduction of the paleo-Pacific plate remains controversial. Here we investigate the petrogenesis of the Xiaojiang–Beizhang ferroan and magnesian granitoids, melanocratic microgranular enclaves (MME) that are found within the granitoids, and an associated mafic dyke exposed in southeast China to provide new constraints on the geodynamics of paleo-Pacific plate subduction. Zircon U–Pb ages indicate that the ferroan and magnesian granitoids were emplaced in the Cretaceous (ca. 120 and 110 Ma, respectively), and that the MME and mafic dyke are coeval with their host granitoids. Geochemical characteristics imply that the granitoids were produced by partial melting of crustal rocks and mixed with mantle-derived magmas. The MME are derivatives of the mafic magmas that intruded the silicic magmas. Two phases of mafic magmatism are evident. Stage 1 mafic rocks (the ca. 120 Ma MME) were derived mainly from the subcontinental lithospheric mantle (SCLM) with some contribution from asthenospheric mantle. The parental mafic magmas for Stage 2 (the ca. 110 Ma MME and mafic dykes) were derived from interaction and metasomatism of the SCLM and asthenosphere with slab-derived fluids. Iron enrichment or depletion in the granitoids was controlled mainly by oxygen fugacity and pressure. Our new data, combined with previously published data from Cretaceous igneous rocks in southeastern China, reveal major geochemical changes at 136 and 118 Ma, respectively. The 132–119 Ma igneous rocks record the minimal addition of slab-derived components to their source, and provide strong evidence for an abrupt change in the direction of motion of the paleo-Pacific plate from southwest to northwest at ca. 125–122 Ma

Colour categories are reflected in sensory stages of colour perception when stimulus issues are resolved

Debate exists about the time course of the effect of colour categories on visual processing. We investigated the effect of colour categories for two groups who differed in whether they categorised a blue-green boundary colour as the same- or different-category to a reliably-named blue colour and a reliably-named green colour. Colour differences were equated in just-noticeable differences to be equally discriminable. We analysed event-related potentials for these colours elicited on a passive visual oddball task and investigated the time course of categorical effects on colour processing. Support for category effects was found 100 ms after stimulus onset, and over frontal sites around 250 ms, suggesting that colour naming affects both early sensory and later stages of chromatic processing

How biological attention mechanisms improve task performance in a large-scale visual system model

How does attentional modulation of neural activity enhance performance? Here we use a deep convolutional neural network as a large-scale model of the visual system to address this question. We model the feature similarity gain model of attention, in which attentional modulation is applied according to neural stimulus tuning. Using a variety of visual tasks, we show that neural modulations of the kind and magnitude observed experimentally lead to performance changes of the kind and magnitude observed experimentally. We find that, at earlier layers, attention applied according to tuning does not successfully propagate through the network, and has a weaker impact on performance than attention applied according to values computed for optimally modulating higher areas. This raises the question of whether biological attention might be applied at least in part to optimize function rather than strictly according to tuning. We suggest a simple experiment to distinguish these alternatives

Identifying relevant studies in software engineering

Context Systematic literature review (SLR) has become an important research methodology in software engineering since the introduction of evidence-based software engineering (EBSE) in 2004. One critical step in applying this methodology is to design and execute appropriate and effective search strategy. This is a time-consuming and error-prone step, which needs to be carefully planned and implemented. There is an apparent need for a systematic approach to designing, executing, and evaluating a suitable search strategy for optimally retrieving the target literature from digital libraries. Objective The main objective of the research reported in this paper is to improve the search step of undertaking SLRs in software engineering (SE) by devising and evaluating systematic and practical approaches to identifying relevant studies in SE. Method We have systematically selected and analytically studied a large number of papers (SLRs) to understand the state-of-the-practice of search strategies in EBSE. Having identified the limitations of the current ad-hoc nature of search strategies used by SE researchers for SLRs, we have devised a systematic and evidence-based approach to developing and executing optimal search strategies in SLRs. The proposed approach incorporates the concept of ‘quasi-gold standard’ (QGS), which consists of collection of known studies, and corresponding ‘quasi-sensitivity’ into the search process for evaluating search performance. Results We conducted two participant–observer case studies to demonstrate and evaluate the adoption of the proposed QGS-based systematic search approach in support of SLRs in SE research. Conclusion We report their findings based on the case studies that the approach is able to improve the rigor of search process in an SLR, as well as it can serve as a supplement to the guidelines for SLRs in EBSE. We plan to further evaluate the proposed approach using a series of case studies on varying research topics in SE