The MAXI Mission on the ISS: Science and Instruments for Monitoring All Sky X-Ray Images

The MAXI (Monitor of All-sky X-ray Image) mission is the first astronomical payload to be installed on the Japanese Experiment Module-Exposed Facility (JEM-EF) on the ISS. It is scheduled for launch in the middle of 2009 to monitor all-sky X-ray objects on every ISS orbit. MAXI will be more powerful than any previous X-ray All Sky Monitor (ASM) payloads, being able to monitor hundreds of AGN. MAXI will provide all sky images of X-ray sources of about 20 mCrab in the energy band of 2-30 keV from observation on one ISS orbit (90 min), about 4.5 mCrab for one day, and about 1 mCrab for one month. A final detectability of MAXI could be 0.2 mCrab for 2 year observations.Comment: 12 pages, 11 figures, accepted for publication in Publications of the Astronomical Society of Japa

Identification of target genes of the bZIP transcription factor OsTGAP1, whose overexpression causes elicitor-induced hyperaccumulation of diterpenoid phytoalexins in rice cells.

Phytoalexins are specialised antimicrobial metabolites that are produced by plants in response to pathogen attack. Momilactones and phytocassanes are the major diterpenoid phytoalexins in rice and are synthesised from geranylgeranyl diphosphate, which is derived from the methylerythritol phosphate (MEP) pathway. The hyperaccumulation of momilactones and phytocassanes due to the hyperinductive expression of the relevant biosynthetic genes and the MEP pathway gene OsDXS3 in OsTGAP1-overexpressing (OsTGAP1ox) rice cells has previously been shown to be stimulated by the chitin oligosaccharide elicitor. In this study, to clarify the mechanisms of the elicitor-stimulated coordinated hyperinduction of these phytoalexin biosynthetic genes in OsTGAP1ox cells, transcriptome analysis and chromatin immunoprecipitation with next-generation sequencing were performed, resulting in the identification of 122 OsTGAP1 target genes. Transcriptome analysis revealed that nearly all of the momilactone and phytocassane biosynthetic genes, which are clustered on chromosomes 4 and 2, respectively, and the MEP pathway genes were hyperinductively expressed in the elicitor-stimulated OsTGAP1ox cells. Unexpectedly, none of the clustered genes was included among the OsTGAP1 target genes, suggesting that OsTGAP1 did not directly regulate the expression of these biosynthetic genes through binding to each promoter region. Interestingly, however, several OsTGAP1-binding regions were found in the intergenic regions among and near the cluster regions. Concerning the MEP pathway genes, only OsDXS3, which encodes a key enzyme of the MEP pathway, possessed an OsTGAP1-binding region in its upstream region. A subsequent transactivation assay further confirmed the direct regulation of OsDXS3 expression by OsTGAP1, but other MEP pathway genes were not included among the OsTGAP1 target genes. Collectively, these results suggest that OsTGAP1 participates in the enhanced accumulation of diterpenoid phytoalexins, primarily through mechanisms other than the direct transcriptional regulation of the genes involved in the biosynthetic pathway of these phytoalexins

Spiral Eu(iii) coordination polymers with circularly polarized luminescence

A spiral-type chiral Eu(iii) coordination polymer showed strong luminescence (emission quantum yield phi(f-f) = 57% and photosensitized energy transfer efficiency (sens) = 53%) and effective CD and CPL properties (g(CPL) = 0.17) when compared with a mono-nuclear chiral Eu(iii) complex in the solid state (phi(f-f) = 36%, (sens) = 14%, and g(CPL) = 0.09)

Overview of the results of ChIP-seq.

<p>(A) Distribution of OsTGAP1-binding regions in the rice genome. The upstream region includes the binding regions within 2 kbp of the transcription start site. The gene region includes the binding regions that are located between the transcription start site and the transcription termination site. The downstream region includes the binding regions within 2 kbp of the transcription termination site. The remaining binding regions were assigned to intergenic regions. (B) Distribution of OsTGAP1-binding regions in the upstream and downstream regions. Red lines indicate the average of number of OsTGAP1-binding regions. Statistical analysis was performed for each 100-bp region, and significantly enriched regions were indicated by asterisks (<i>P</i><0.01 the binomial test and the Bonferroni correction). (C) Overrepresented motifs in the OsTGAP1-binding regions analysed in the untreated and elicitor-treated conditions using Partek Genomics Suite based on Gibbs motif sampler <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0105823#pone.0105823-Neuwald1" target="_blank">[37]</a>. (D) Distribution of TGACGT sequences around the OsTGAP1-binding regions.</p

Gel mobility shift assay using the <i>OsDXS3</i> upstream region.

<p>(A) DNA probes used in GMSA. Closed triangles indicate TGACGT sequences. (B) GMSA was performed using purified recombinant GST-fused OsTGAP1 (GST-OsTGAP1) protein and ³²P-labelled DNA probes containing the TGACGT sequences in the <i>OsDXS3</i> promoter. WT: wild-type probe, m1–m3: mutated probes.</p