Separation of the Asian summer monsoon and local precipitation from stalagmite oxygen isotope records in Eastern China during the last millennium

The Asian summer monsoon (ASM) regulates water vapor and heat transport across the East Asian continent and has a significant impact on patterns of regional precipitation. However, assessment of the long-term association between the monsoon and precipitation in different regions remains difficult due to spatial chronological differences and uncertainties in interpretation of climate proxies. This study provides a novel insight into the interpretation of stalagmite oxygen isotopes (δ18O) records and obtained synchronous ASM index series and precipitation variations in Northern China (NC), Central China (CC), and Southwestern China (SWC) over the last 1134 years (850–1983CE). The results show that the ASM index sequence is consistent with the trend evident in the monsoon intensity records from the region upstream of the water vapor source, which represents the response to the inter-hemispheric temperature dominated by effective solar radiation (ESR). Reconstruction precipitation data were in general agreement with the existing paleo-hydrological records of the regions, confirming the reliability and chronological accuracy of the reconstruction. Correlation analysis highlighted the significant regional heterogeneity in the destabilizing relationship between precipitation and the monsoon over the past millennium in Eastern China at sub-centennial scales. Specifically, the precipitation-monsoon relationships in three regions, NC, CC, and SWC, might be related to the North Atlantic Oscillation (NAO), the position of the intertropical convergence zone (ITCZ), and solar activity, respectively. Moreover, at the millennial scale, a certain positive correlation between precipitation and ASM in NC and SWC was identified, whereas there was a weaker correlation between precipitation and ASM in CC. This study represents an attempt to further interpret the stalagmite δ18O record, which can be generalized to larger and longer time scales

A role for Innexin2 and Innexin3 proteins from Spodoptera litura in apoptosis.

Gap junctions formed by two hemichannels from two neighboring cells are cell-to-cell communication channels; hemichannels are communication channels between intracellular and extracellular environments. Hemichannels are hexameric proteins formed by connexins, pannexins, innexins and vinnexins. Innexin-hemichannels (innexons) exist in the lepidopteran cell surface, but their component innexins and functions have not been reported. Recent studies by others have demonstrated that hemichannels, connexons and pannexons from vertebrates serve as regulators of apoptosis via inactivating the PI3K/Akt signaling pathway. Here, the apoptogenic properties of innexons are demonstrated using two innexin cDNAs, Spli-inx2 and Spli-inx3, which were isolated from hemocytes of lepidopteran Spodoptera litura. Alignment analysis revealed that these two genes belong to a conserved innexin family, as they contain the insect signature YYQWV motif at the beginning of the second transmembrane domain. Immunofluorescence showed that two fusion proteins, Inx2-V5 and Inx3-V5, were localized predominantly in the cell membrane, cytoplasm and also nuclei. Ectopic expression in Sf9 cells and over-expression of Inx2 and Inx3 in Spli221 cells promoted apoptosis. In the Spli221 cells, apoptotic cells presented remarkable membrane blebbing. This study also showed that Sf9 and Spli221 cells undergo low level apoptosis under normal culture conditions, but not Hi5 cells. In Hi5 stable cell lines, biotinylation was used to isolate surface proteins and confirm Inx2 and Inx3 localization in the cell membrane and also further data showed that Hi5 cells may activate the PI3K signaling pathway via phosphorylating molecular Akt downstream. This result suggests that innexon-promoted apoptosis may be involving the PI3K/Akt signaling pathway. These findings will facilitate further examinations of the apoptotic regulation by the PI3K/Akt signaling pathway and comparative studies of innexons, connexons, pannexons, and vinnexons

The transient expression by transfection of plasmids of Inx2 and Inx3 in cells from three types of Lepidopteran species.

<p>The construct of transfective plasmids (A), GFP was used to monitor transfection efficiency (B), and anti-V5 was used to visualize expression of the fusion proteins in cells (C). Empty plasmid vector (pIZT) was used as a negative control and tubulin was used as a loading control. Bar = 20 µm. (Hi5 derives from <i>T. ni</i>; Sf9 derives from <i>S. frugiperda</i>; Spli221 derives <i>S. litura</i>). Assays were repeated at least three times.</p

Over-expression of Inx2 and Inx3 contributed to membrane blebbing in Spli221 cells.

<p>A. Membrane blebbing was observed (white arrows) in Spli221 cells 72 and 96 hrs after transfection. B. Apoptotic bodies were observed by immunofluorescence in cells expressing Inx2 and Inx3. C. Activated caspase 3 localized to the nucleus of apoptotic cells, as determined by immunofluorescence. D. Levels of cleaved caspase 3 were detected by western blot. Bar = 20 µm. Assays were repeated at least three times.</p

INX2 and INX3 from lepidopteran insects belong to a conserved innexin family, which contains a YYQWV motif at the beginning of the second TM domain.

<p>Alignment of the deduced amino acid sequence of SpliINX2 (A) with 3 other members of the Lepidoptera species, <i>S. frugiperda</i>, <i>B. mori</i> and <i>T. ni</i>, and SpliINX3 (B) with other 2 Lepidoptera species, <i>S. frugiperda</i>, <i>B. mori</i>. The predicted four transmembrane domains (TMs) are highlighted with frames, and the conserved motif YYQWV is highlighted in bold italic font. SpliINX2 (KC018471), Hi5INX2 (KC018473), BmINX2 (AAR97567), SfINX2 (AAP40732), BmINX3 (ACK38254), SpliINX3 (KC018472), and SfINX3_Partial (Sf1M11836-5-1, Sf2L00880-5-1 and Sf2L01032-5-1 from <a href="http://bioweb.ensam.inra.fr/spodobase/" target="_blank">http://bioweb.ensam.inra.fr/spodobase/</a>).</p

Study of Electron Beam-Initiated Structure Damage and Recovery of Perovskite Thin Films

Perovskite light-emitting diodes (PeLEDs) are rising techniques that have attracted worldwide attention, and the community is increasingly considering vapor-phase deposition (VPD) as a promising route to realize reliable perovskite displays. Transmission electron microscopy (TEM) has been extensively applied to characterize the structural details of perovskites and related devices. However, under conventional imaging conditions, the high-energy electron beam is sufficient to cause collapse of the original crystal structure and the electron radiation effect on perovskites prepared by VPD has not been systematically studied. In this study, the damage and recovery processes of vacuum-deposited perovskite nanocrystalline structures are systematically studied by comprehensive transmission electron microscopy (TEM) techniques. It is observed that with prolonged electron beam irradiation, the CsPbBr3 nanocrystals surrounding the irradiation zone are gradually damaged, generating Pb nanoparticles, whereas the crystal structure within the irradiated region is not damaged. Further theoretical analysis reveals that a high-energy electric field is formed at the edge of the irradiation zone due to electron beam irradiation, which would lead to Br ion migration to the irradiation center and the breakdown of the CsPbBr3 nanocrystalline structure at the periphery regions. When the electron beam is shifted to the periphery region, the Pb nanoparticles gradually disappear with the regrowth of CsPbBr3 nanocrystals, which indicates that Br ions migrate back to the newly positively charged irradiation zone. The mechanism of the reversible transformation process is highly related to the electron beam-induced electric field, which would facilitate a deeper understanding of the electron beam irradiation effect on perovskite materials and help understand and enhance the stability of perovskites in devices

Transcription of <i>M. bicoloratus</i> bracovirus genes during development of parasitoid <i>M. bicoloratus</i> in host hemocytes.

<p>Transcription of <i>M. bicoloratus</i> bracovirus genes during development of parasitoid <i>M. bicoloratus</i> in host hemocytes.</p