Search

Reported data for Lu, Hf mass fractions and 176Hf/177Hf isotopic ratios of mafic‐ultramafic rock reference materials (RMs) are rare at present, hampering the comparison of data quality between difference laboratories. Herein, we measured the Lu and Hf mass fractions and the 176Hf/177Hf isotopic ratios of ten mafic‐ultramafic rock RMs, including OKUM (komatiite), WPR‐1 (serpentinised peridotite), NIM‐N (norite), NIM‐P (pyroxenite), UB‐N (serpentinised peridotite), JP‐1 (peridotite), NIM‐D (dunite), MUH‐1 (serpentinised harzburgite), HARZ01 (harzburgite), DTS‐2b (dunite), which contain extremely low amounts of Lu and Hf (Lu, 2–150 ng g−1; Hf, 5–500 ng g−1). All measurements were conducted on a Neptune Plus multi‐collector inductively coupled plasma‐mass spectrometer employing an Aridus II desolvator inlet system and Jet sample/X skimmer cone configuration. The following RMs, OKUM, WPR‐1, UB‐N, JP‐1, NIM‐D, HARZ01 and DTS‐2b, have 176Hf/177Hf precision of less than 60 ppm (2s) at test portions of 0.06 to 0.3 g, and are good ultramafic RMs for Lu‐Hf systems. In contrast, significant Hf mass fraction and isotopic variability were observed in NIM‐N, NIM‐P and MUH‐1 at test portion masses of 0.1 to 0.3 g. Collectively, our study provides a new database that can be used by the geochemical community for evaluating the Lu‐Hf system of mafic‐ultramafic rocks. [ABSTRACT FROM AUTHOR]

In order to understand the differences in the structural characteristics of natural, semi-natural and artificial plant communities, three typical plant communities in Dapeng New District of Shenzhen were selected to comparatively study the structure and diversity of plant communities by using the random combined with typical community investigation method. The results showed that the evenness and richness of natural plant community were higher than those of semi-natural and artificial plant communities, and the α-diversity index character was natural community > semi-natural community > artificial community. There was a significant positive correlation between plant height and coverage of tree layer in the natural and semi-natural plant communities (P<0.01). The ecological dominance of the artificial plant community was high, and the dominant species were prominent. The plant evenness of the natural plant community was high, the important value gap between plants was narrowed, and the status of the dominant species was decreased. The species in the vertical structure (aboveground part) of natural plant community were abundant and evenly distributed, and the vertical space was fully utilized for plant growth. In the natural plant community, Aquilaria sinensis, Tainia hongkongensis, Poly podium barometz, and Pholidota chinensis were recorded as the national secondary protected plants, while in the artificial plant community, the invasive plant Wedelia trilobata was recorded. Through the comparative study, it could be seen that the structure of natural plant community was stable and the diversity was high. The investigation and study of natural plant community could provide reference for promoting the ecological stability and the vegetation restoration. [ABSTRACT FROM AUTHOR]

Vitellogenin receptor (VgR) is crucial for vitellogenin (Vg) uptake by oocytes. VgR is less known in Arachnida, especially in spiders. Different from only one VgR in an arthropod species, two VgRs, VgR‐1 and VgR‐2, were found in the pond wolf spider, Pardosa pseudoannulata. Both VgRs had the typical domains of the low‐density lipoprotein receptor family except for the absence of the ligand‐binding domain 1 in VgR‐2. Spatiotemporal expression profiles showed that two VgR genes were consistently highly expressed in females and their ovaries, but VgR‐1 was 48‐fold that of VgR‐2 in ovaries. The transcriptional level of VgR‐1 was significantly downregulated by RNAi, but it did not work for VgR‐2 although several trials were performed. Vg‐1 and Vg‐2 might be the ligands of VgR‐1 because their expressions were also decreased in the dsVgR‐1‐treated females. Silencing VgR‐1 prolonged the pre‐oviposition period by 56 h. The expression of VgRs and Vgs were upregulated by juvenile hormones (JHs), which suggested that JHs were the essential factors to vitellogenesis in the spider. The present study revealed the importance of VgR‐1 in the spider oviposition, which will improve the understanding on VgR physiological functions in spiders. [ABSTRACT FROM AUTHOR]