37 research outputs found
Space VLBI 2020: Science and Technology Futures Conference Summary
The "Space VLBI 2020: Science and Technology Futures" meeting was the second in The Future of High-Resolution Radio Interferometry in Space series. The first meeting (2018 September 5--6; Noordwijk, the Netherlands) focused on the full range of science applications possible for very long baseline interferometry (VLBI) with space-based antennas. Accordingly, the observing frequencies (wavelengths) considered ranged from below 1~MHz (> 300 m) to above 300~GHz (< 1 mm). For this second meeting, the focus was narrowed to mission concepts and the supporting technologies to enable the highest angular resolution observations at frequencies of 30~GHz and higher (< 1 cm).
This narrowing of focus was driven by both scientific and technical considerations. First, results from the RadioAstron mission and the Event Horizon Telescope (EHT) have generated considerable excitement for studying the inner portions of black hole (BH) accretion disks and jets and testing elements of the General Theory of Relativity (GR). Second, the technologies and requirements involved in space-based VLBI differ considerably between 100~MHz and 100~GHz; a related consideration is that there are a number of existing instruments or mission concepts for frequencies of approximately 100~MHz and below, while it has been some time since attention has been devoted to space VLBI at frequencies above 10~GHz.
This conference summary attempts to capture elements of presentations and discussions that occurred
Space VLBI 2020: Science and Technology Futures Conference Summary
The "Space VLBI 2020: Science and Technology Futures" meeting was the second
in The Future of High-Resolution Radio Interferometry in Space series. The
first meeting (2018 September 5--6; Noordwijk, the Netherlands) focused on the
full range of science applications possible for very long baseline
interferometry (VLBI) with space-based antennas. Accordingly, the observing
frequencies (wavelengths) considered ranged from below 1~MHz (> 300 m) to above
300~GHz (< 1 mm). For this second meeting, the focus was narrowed to mission
concepts and the supporting technologies to enable the highest angular
resolution observations at frequencies of 30~GHz and higher (< 1 cm).
This narrowing of focus was driven by both scientific and technical
considerations. First, results from the RadioAstron mission and the Event
Horizon Telescope (EHT) have generated considerable excitement for studying the
inner portions of black hole (BH) accretion disks and jets and testing elements
of the General Theory of Relativity (GR). Second, the technologies and
requirements involved in space-based VLBI differ considerably between 100~MHz
and 100~GHz; a related consideration is that there are a number of existing
instruments or mission concepts for frequencies of approximately 100~MHz and
below, while it has been some time since attention has been devoted to space
VLBI at frequencies above 10~GHz.
This conference summary attempts to capture elements of presentations and
discussions that occurred.Comment: Nine pages + references and conference schedule appendix; conference
Web site
http://www.cvent.com/events/space-vlbi-2020/event-summary-c7b30de0068e454591a66e5639f86668.asp
キコウ ヘンドウ モンダイ ニ オケル チキュウ カンキョウ ガバナンス COP17 デノ ギロン ノ キケツ ト テンボウ
本稿は2011年12月に南アフリカのダーバンで開催された第17回国連気候変動枠組条約締約国会議(COP17)における会議プロセスに注目する。京都議定書によって義務づけられている削減目標の期間は2012年で終了するため、COP17では2013年以降の国際的な温暖化対策への一刻も早い合意が期待されていたという意味で重要な会議であった。このような背景に対し、本稿では締約国が自主的にボトムアップ式で目標や対策を決めるという流れと、締約国が法的拘束力のもとに一定のトップダウンで目標や対策を定めていくという、二つの流れに着目しながらCOP17における交渉プロセスを詳細に分析する。この結果、COP17では法的拘束力を持たず、あくまで自主的にボトムアップ方式で温暖化対策を目指したコペンハーゲン合意から、法的拘束力のある次期枠組みへの交渉に向けて舵を切った会議であったことが分かった。つまり、COP17ではすべての国が法的拘束力のある枠組みの中で科学的知見に沿った削減目標を掲げるという機会を提供したといえる。このような結果を踏まえ、今後においてはトップダウンとボトムアップの両者のバランスを考慮した「衡平性」の議論が交渉の中で重要な論点になることを提起する
Small Molecules Targeted to a Non-Catalytic “RVxF” Binding Site of Protein Phosphatase-1 Inhibit HIV-1
HIV-1 Tat protein recruits host cell factors including CDK9/cyclin T1 to HIV-1 TAR RNA and thereby induces HIV-1 transcription. An interaction with host Ser/Thr protein phosphatase-1 (PP1) is critical for this function of Tat. PP1 binds to a Tat sequence, Q35VCF38, which resembles the PP1-binding “RVxF” motif present on PP1-binding regulatory subunits. We showed that expression of PP1 binding peptide, a central domain of Nuclear Inhibitor of PP1, disrupted the interaction of HIV-1 Tat with PP1 and inhibited HIV-1 transcription and replication. Here, we report small molecule compounds that target the “RVxF”-binding cavity of PP1 to disrupt the interaction of PP1 with Tat and inhibit HIV-1 replication. Using the crystal structure of PP1, we virtually screened 300,000 compounds and identified 262 small molecules that were predicted to bind the “RVxF”-accommodating cavity of PP1. These compounds were then assayed for inhibition of HIV-1 transcription in CEM T cells. One of the compounds, 1H4, inhibited HIV-1 transcription and replication at non-cytotoxic concentrations. 1H4 prevented PP1-mediated dephosphorylation of a substrate peptide containing an RVxF sequence in vitro. 1H4 also disrupted the association of PP1 with Tat in cultured cells without having an effect on the interaction of PP1 with the cellular regulators, NIPP1 and PNUTS, or on the cellular proteome. Finally, 1H4 prevented the translocation of PP1 to the nucleus. Taken together, our study shows that HIV- inhibition can be achieved through using small molecules to target a non-catalytic site of PP1. This proof-of-principle study can serve as a starting point for the development of novel antiviral drugs that target the interface of HIV-1 viral proteins with their host partners
Analytical strategies for characterization of oxysterol lipidomes: Liver X receptor ligands in plasma
Bile acids, bile alcohols, and hormonal steroids represent the ultimate biologically active products of cholesterol metabolism in vertebrates. However, intermediates in their formation, including oxysterols and cholestenoic acids, also possess known, e.g., as ligands to nuclear and G-protein-coupled receptors, and unknown regulatory activities. The potential diversity of molecules originating from the cholesterol structure is very broad and their abundance in biological materials ranges over several orders of magnitude. Here we describe the application of enzyme-assisted derivatization for sterol analysis (EADSA) in combination with liquid chromatography–electrospray ionization–mass spectrometry to define the oxysterol and cholestenoic acid metabolomes of human plasma. Quantitative profiling of adult plasma using EADSA leads to the detection of over 30 metabolites derived from cholesterol, some of which are ligands to the nuclear receptors LXR, FXR, and pregnane X receptor or the G-protein-coupled receptor Epstein–Barr virus-induced gene 2. The potential of the EADSA technique in screening for inborn errors of cholesterol metabolism and biosynthesis is demonstrated by the unique plasma profile of patients suffering from cerebrotendinous xanthomatosis. The analytical methods described are easily adapted to the analysis of other biological fluids, including cerebrospinal fluid, and also tissues, e.g., brain, in which nuclear and G-protein-coupled receptors may have important regulatory roles
Draft genomes of gammaproteobacterial methanotrophs isolated from terrestrial ecosystems
Genome sequences of Methylobacter luteus, Methylobacter whittenburyi, Methylosarcina fibrata, Methylomicrobium agile, and Methylovulum miyakonense were generated. The strains represent aerobic methanotrophs typically isolated from various terrestrial ecosystems
Considerações gerais sobre a aplicação de esterco no processo de compostagem dos resíduos de poda e capina
In the category of the solid waste, are included the yard solid waste, this kind of solid waste are noble raw material and uncontaminated being recycled through the composting processing. Inside this context, it was studied the influence of horse manure in yard solid waste composting process, analyze the viability to compost the yard solid waste in UNESP Bela Vista. It was made four piles of composting, two of them are composed only by yard solid waste and the others are composed by horse manure and yard solid waste. The experiments were operated during 45 days. The evaluation of the process was made through temperature measurements of the piles daily during the test period. On the contrary of the piles with horse manure, the piles with no horse manure didn’t undergo complete maturation in the end of the experiment. Through the results obtained concluded that it was important to use manure horse in yard solid waste composting process to accelerate this process, because the piles without horse manure didn’t reach temperatures that characterize the composting process.Inclui-se na categoria dos resíduos sólidos urbanos, os resíduos de poda e capina que são considerados matéria-prima nobre desprovida de contaminantes, podendo ser reaproveitados por meio do processo de compostagem. Dentro deste contexto, estudou-se a influência da utilização do inoculo esterco de cavalo no processo de compostagem dos resíduos de poda e capina (grama, capim e folha). Foram montadas quatro leiras de compostagem, sendo duas compostas por apenas resíduos de poda e capina e, as outras duas por resíduos de poda e capina e inoculo. O canteiro de compostagem foi operado por 45 dias com medição diária da temperatura da leira. Ao contrário das leiras com inoculo, as leiras sem inoculo não sofreram completa maturação ao final do experimento. Com base nos resultados obtidos, concluiu-se que para a compostagem dos resíduos de poda e capina é fundamental o uso de inoculo para aceleração do processo, pois as leiras sem inoculo não atingiram temperaturas que caracterizassem o desenvolvimento do processo de compostagem
Characterization of cooperative bicarbonate uptake into chloroplast stroma in the green alga Chlamydomonas reinhardtii.
藻類の光合成を支える二酸化炭素濃縮システムを解明. 京都大学プレスリリース. 2015-05-27.The supply of inorganic carbon (Ci; CO2 and HCO3 (-)) is an environmental rate-limiting factor in aquatic photosynthetic organisms. To overcome the difficulty in acquiring Ci in limiting-CO2 conditions, an active Ci uptake system called the CO2-concentrating mechanism (CCM) is induced to increase CO2 concentrations in the chloroplast stroma. An ATP-binding cassette transporter, HLA3, and a formate/nitrite transporter homolog, LCIA, are reported to be associated with HCO3 (-) uptake [Wang and Spalding (2014) Plant Physiol 166(4):2040-2050]. However, direct evidence of the route of HCO3 (-) uptake from the outside of cells to the chloroplast stroma remains elusive owing to a lack of information on HLA3 localization and comparative analyses of the contribution of HLA3 and LCIA to the CCM. In this study, we revealed that HLA3 and LCIA are localized to the plasma membrane and chloroplast envelope, respectively. Insertion mutants of HLA3 and/or LCIA showed decreased Ci affinities/accumulation, especially in alkaline conditions where HCO3 (-) is the predominant form of Ci. HLA3 and LCIA formed protein complexes independently, and the absence of LCIA decreased HLA3 mRNA accumulation, suggesting the presence of unidentified retrograde signals from the chloroplast to the nucleus to maintain HLA3 mRNA expression. Furthermore, although single overexpression of HLA3 or LCIA in high CO2 conditions did not affect Ci affinity, simultaneous overexpression of HLA3 with LCIA significantly increased Ci affinity/accumulation. These results highlight the HLA3/LCIA-driven cooperative uptake of HCO3 (-) and a key role of LCIA in the maintenance of HLA3 stability as well as Ci affinity/accumulation in the CCM