It has been hypothesised that intense metabolism of nectar-inhabiting yeasts (NIY) may change nectar chemistry, including volatile profile, which may affect pollinator foraging behaviours and consequently plant fitness. However, empirical evidence for the plant-microbe-pollinator interactions remains little known.• To test this hypothesis, we use a bumblebee-pollinated vine Clematis akebioides endemic to southwest China as an experimental model plant. To quantify the incidence and density of Metschnikowia reukaufii, a cosmopolitan NIY in floral nectar, a combination of yeast cultivation and microscopic cell-counting method was used. To examine the effects of NIY on plant-pollinator interactions, we used real flowers filled with artificial nectar with or without yeast cells. Then the volatile metabolites produced in the yeast-inoculated nectar were analysed with coupled gas chromatography and mass spectrometry (GC-MS).• On average 79.3% of the C. akebioides flowers harboured M. reukaufii, and cell density of NIY was high to 7.4 9 10 4 cells mm À3 . In the field population, the presence of NIY in flowers of C. akebioides increased bumblebee (Bombus friseanus) pollinator visitation rate and consequently seed set per flower. A variety of fatty acid derivatives produced by M. reukaufii may be responsible for the above beneficial interactions.• The volatiles produced by the metabolism of M. reukaufii may serve as an honest signal to attract bumblebee pollinators and indirectly promote the female reproductive fitness of C. akebioides, forming a potentially tripartite plant-microbe-pollinator mutualism.Plant Biology 21 (2019) 732-737

Changes in the strength of trophic cascades over time have been associated with dramatic shifts in community structure and function. However, the pattern, process, and potential underlying mechanism of temporal variation in trophic cascades remains relatively unexplored. A top–down trophic cascade has been documented for the effects of predacious weaver ants Oecophylla smaragdina on the success of fig tree Ficus racemosa seed production. Ants cause high mortality of non‐pollinating fig wasps Sycophaga mayri that parasitize fruits, leading to greater success for the pollinating fig wasp–fig tree mutualists. Here, using a design in which pairs of branches were selected on a tree, and ants were excluded from one of each pair, we quantified the magnitude of the trophic cascade in the cool–dry, hot–dry and rainy (hot–wet) seasons in Xishuangbanna, southwest China. We also recorded the daily behavioral dynamics of ants and fig wasps in different seasons and analyzed the correlation between behavioral, activity and trophic cascade strength. We found that the strength of the trophic cascade was strong in the hot–dry season, diminished in the rainy season and disappeared in the cool–dry season in this system. The strength of species interactions between ants and non‐pollinating fig wasps, is positively correlated with trophic cascade strength, indicating that trophic cascade strength is determined by a top–down process when the community is well established. Moreover, because pollinating fig wasps, Ceratosolen fusciceps, play a central role in the establishment of fig wasp communities, when C. fusciceps wasps are absent, the community quickly disassembles as is the case in the cool–dry season. In summary, the strength of the trophic cascade is triggered by top–down processes, however, the occurrence of the trophic cascade is determined by a keystone species that plays a central role in assembly of the community.

In recent years, the SC FFT architecture has become popular for processing serial data. It requires a small number of components and achieves full utilization of the butterflies, which improves previous serial FFT architectures. By contrast, the MSC FFT architecture, which is the parallel version of the SC FFT, has not been studied in depth in the literature and it has not been analyzed if this new type of FFT architecture improves previous parallel FFTs. The aim of this paper is to provide a rigorous study of MSC architectures that expands the field of FFT architectures by incorporating fundamental knowledge about this promising FFT. With this goal, this paper proposes new MSC FFT architectures for any FFT size, radix, and parallelization. In order to derive these architectures, efficient modules have been developed. These modules are connected by permutation circuits to create the architectures. The optimization of the modules results in a reduction in the number of rotators and their complexity compared to previous designs. As a result, the proposed architectures not only achieve high throughput due to their parallel nature but also the lowest hardware complexity among parallel pipelined FFT architectures so far. To verify the architectures and compare the proposed approach to previous works, a 1024-point MSC FFT architecture has been implemented. Experimental results show that the architecture achieves a throughput of 1.32 gigasamples per second, and reduces the area and power consumption significantly with respect to previous designs.INDEX TERMS Fast Fourier transform (FFT), multi-path serial-commutator (MSC), pipelined architecture, radix-2 k .

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