Until they become photoautotrophic juvenile plants, seedlings depend upon the reserves stored in seed tissues. These reserves must be mobilized and metabolized, and their breakdown products must be distributed to the different organs of the growing seedling. Here, we investigated the mobilization of soybean (Glycine max) seed reserves during seedling growth by initially constructing a genome-scale stoichiometric model for this important crop plant and then adapting the model to reflect metabolism in the cotyledons and hypocotyl/root axis (HRA). A detailed analysis of seedling growth and alterations in biomass composition was performed over 4 d of postgerminative growth and used to constrain the stoichiometric model. Flux balance analysis revealed marked differences in metabolism between the two organs, together with shifts in primary metabolism occurring during different periods postgermination. In particular, from 48 h onward, cotyledons were characterized by the oxidation of fatty acids to supply carbon for the tricarboxylic acid cycle as well as production of sucrose and glutamate for export to the HRA, while the HRA was characterized by the use of a range of imported amino acids in protein synthesis and catabolic processes. Overall, the use of flux balance modeling provided new insight into well-characterized metabolic processes in an important crop plant due to their analysis within the context of a metabolic network and reinforces the relevance of the application of this technique to the analysis of complex plant metabolic systems.

The confused taxonomy of the east Palaearctic pear psyllids, serious pests on cultivated pear, is reviewed. Fifty-six nominal species have been reported from Pyrus, 25 of which we consider valid and ten as not being associated with Pyrus. Our taxonomic revision suggests that, in Korea, four Cacopsylla species develop on pear: the univoltine C. burckhardti Luo et al. previously misidentified as C. pyrisuga (Foerster), the polyvoltine, seasonally dimorphic C. jukyungi (Kwon) (winter form 'cinereosignata' Luo et al., summer form 'jukyungi'), commonly found in Korean pear orchards, and C. maculatili Li (winter form 'maculatili', summer form 'qiuzili' Li) previously misidentified as C. pyricola (Foerster) by some authors, as well as the probably polyvoltine but not dimorphic C. sandolbaea (Park & Lee). The former three species (C. burckhardti, C. jukyungi, misidentified as C. chinensis (Yang & Li), and C. maculatili) occur also in Japan. Keys to the adult and fifth instar immatures as well as short biological notes are provided, and C. jukyungi and C. sandolbaea are redescribed. Following nomenclatorial changes are proposed: Cacopsylla betulaefoliae (Yang & Li, 1981) = Psylla heterobetulaefoliae Yang & Li, 1981, syn. nov.; Cacopsylla bidens (Šulc, 1907) = Psylla jiangli Yang & Li, 1981, syn. nov.; Cacopsylla jukyungi (Kwon) = C. cinereosignata Luo et al., syn. nov.; Cacopsylla maculatili Li = C. qiuzili Li, syn. nov.; Cacopsylla nigella (Konovalova), comb. nov. from Psylla. The synonymy of P. obongsana Kwon with C. sandolbaea is confirmed.

Polymer complexes of a basic polymer, poly(N-methyl-4-piperidinyl methacrylate) (PMPMA), with a weak acidic polymer poly(p-vinylphenol) (PVPh), and strong acidic polymers such as poly(acrylic acid) (PAA), poly(methacrylic acid) (PMAA), poly(styrenesulfonic acid) (PSSA), and poly(vinylphosphonic acid) (PVPA), have been prepared by mixing ethanol/H2O (1:1) solutions of the respective components. The complexes were examined by Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and differential scanning calorimetry. Both the FTIR and XPS studies showed the existence of piperidinium ions in the complexes of PMPMA with PAA, PMAA, PVPA, and PSSA, indicating that the interactions in these complexes are ionic in nature. However, the N-methyl groups prevent the piperidine nitrogen atoms from interaction with PVPh and hence the carbonyl groups of PMPMA interact with the hydroxyl groups of PVPh by hydrogen bonding. From the XPS studies, the number of protonated piperidine atoms was found to correlate with the acid strength of the polyacid.

Triggered or induced earthquakes have been widely reported as resulting from various human activities, yet seismicity triggered by small-scale infrastructure construction is rare. Here, we report on an investigation of an extremely shallow M w 4.1 earthquake which occurred on 11 August 2016 in the Sichuan Basin (China), a region with historically low seismicity. Our seismic waveform analyses indicate an almost pure thrust focal mechanism at a centroid depth of~1 km. Furthermore, 18 Sentinel-1 synthetic aperture radar interferograms, stacked to obtain subcentimeter accuracy, reveal up to 3 cm line-of-sight deformation which overlaps with an automotive testing site constructed in 2014. Removal of 10 m of a surface rock layer during the construction may have produced an unloading effect and resulted in up to 0.11 MPa Coulomb stress changes on a blind fault, larger than the 0.01 MPa threshold typically invoked in studies of tectonic earthquakes. However, the delayed triggering still requires further investigation. Plain Language SummaryWhile induced earthquakes in the shallow part of the crust have been observed globally, a remaining knowledge gap is whether small-scale infrastructure construction can trigger earthquakes or not. We investigate these questions on an extremely shallow M w 4.1 earthquake in the eastern Sichuan Basin (China). To determine earthquake source parameters, we combine seismological data with satellite imaging. We find this thrust event ruptured at the depth of~1 km, located just beneath an automotive testing site constructed in 2014. Crucially, we note the testing site construction involved removal of a large volume of surface rock. We further analyze the stress changes produced by the unloading of the surface rock. We find a possible triggering relationship between the infrastructure construction and the occurrence of this shallow earthquake. Our results thus shed new light on the causes of shallow earthquakes associated with small-scale infrastructure construction.

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