1,034 research outputs found
Autonomic Road Transport Support Systems
The work on Autonomic Road Transport Support (ARTS) presented here aims at
meeting the challenge of engineering autonomic behavior in Intelligent Transportation
Systems (ITS) by fusing research from the disciplines of traffic engineering
and autonomic computing. Ideas and techniques from leading edge artificial intelligence
research have been adapted for ITS over the last years. Examples include
adaptive control embedded in real time traffic control systems, heuristic algorithms
(e.g. in SAT-NAV systems), image processing and computer vision (e.g. in automated
surveillance interpretation). Autonomic computing which is inspired from the
biological example of the body’s autonomic nervous system is a more recent development.
It allows for a more efficient management of heterogeneous distributed
computing systems. In the area of computing, autonomic systems are endowed
with a number of properties that are generally referred to as self-X properties,
including self-configuration, self-healing, self-optimization, self-protection and more
generally self-management. Some isolated examples of autonomic properties such
as self-adaptation have found their way into ITS technology and have already proved
beneficial. This edited volume provides a comprehensive introduction to Autonomic
Road Transport Support (ARTS) and describes the development of ARTS systems. It
starts out with the visions, opportunities and challenges, then presents the foundations
of ARTS and the platforms and methods used and it closes with experiences
from real-world applications and prototypes of emerging applications. This makes
it suitable for researchers and practitioners in the fields of autonomic computing,
traffic and transport management and engineering, AI, and software engineering.
Graduate students will benefit from state-of-the-art description, the study of novel
methods and the case studies provided
Nicotiana small RNA sequences support a host genome origin of Cucumber mosaic virus satellite RNA
Satellite RNAs (satRNAs) are small noncoding subviral RNA pathogens in plants that depend on helper viruses for replication and spread. Despite many decades of research, the origin of satRNAs remains unknown. In this study we show that a β-glucuronidase (GUS) transgene fused with a Cucumber mosaic virus (CMV) Y satellite RNA (Y-Sat) sequence (35S-GUS:Sat) was transcriptionally repressed in N. tabacum in comparison to a 35S-GUS transgene that did not contain the Y-Sat sequence. This repression was not due to DNA methylation at the 35S promoter, but was associated with specific DNA methylation at the Y-Sat sequence. Both northern blot hybridization and small RNA deep sequencing detected 24-nt siRNAs in wild-type Nicotiana plants with sequence homology to Y-Sat, suggesting that the N. tabacum genome contains Y-Sat-like sequences that give rise to 24-nt sRNAs capable of guiding RNA-directed DNA methylation (RdDM) to the Y-Sat sequence in the 35S-GUS:Sat transgene. Consistent with this, Southern blot hybridization detected multiple DNA bands in Nicotiana plants that had sequence homology to Y-Sat, suggesting that Y-Sat-like sequences exist in the Nicotiana genome as repetitive DNA, a DNA feature associated with 24-nt sRNAs. Our results point to a host genome origin for CMV satRNAs, and suggest novel approach of using small RNA sequences for finding the origin of other satRNAs
Nicotiana Small RNA Sequences Support a Host Genome Origin of Cucumber Mosaic Virus Satellite RNA
Satellite RNAs (satRNAs) are small noncoding subviral RNA pathogens in plants that depend on helper viruses for replication and spread. Despite many decades of research, the origin of satRNAs remains unknown. In this study we show that a β-glucuronidase (GUS) transgene fused with a Cucumber mosaic virus (CMV) Y satellite RNA (Y-Sat) sequence (35S-GUS:Sat) was transcriptionally repressed in N. tabacum in comparison to a 35S-GUS transgene that did not contain the Y-Sat sequence. This repression was not due to DNA methylation at the 35S promoter, but was associated with specific DNA methylation at the Y-Sat sequence. Both northern blot hybridization and small RNA deep sequencing detected 24-nt siRNAs in wild-type Nicotiana plants with sequence homology to Y-Sat, suggesting that the N. tabacum genome contains Y-Sat-like sequences that give rise to 24-nt sRNAs capable of guiding RNA-directed DNA methylation (RdDM) to the Y-Sat sequence in the 35S-GUS:Sat transgene. Consistent with this, Southern blot hybridization detected multiple DNA bands in Nicotiana plants that had sequence homology to Y-Sat, suggesting that Y-Sat-like sequences exist in the Nicotiana genome as repetitive DNA, a DNA feature associated with 24-nt sRNAs. Our results point to a host genome origin for CMV satRNAs, and suggest novel approach of using small RNA sequences for finding the origin of other satRN
DNA demethylases target promoter transposable elements to positively regulate stress responsive genes in Arabidopsis
Background: DNA demethylases regulate DNA methylation levels in eukaryotes. Arabidopsis encodes four DNA demethylases, DEMETER (DME), REPRESSOR OF SILENCING 1 (ROS1), DEMETER-LIKE 2 (DML2), and DML3. While DME is involved in maternal specific gene expression during seed development, the biological function of the remaining DNA demethylases remains unclear. Results: We show that ROS1, DML2, and DML3 play a role in fungal disease resistance in Arabidopsis. A triple DNA demethylase mutant, rdd (ros1 dml2 dml3), shows increased susceptibility to the fungal pathogen Fusarium oxysporum. We identify 348 genes differentially expressed in rdd relative to wild type, and a significant proportion of these genes are downregulated in rdd and have functions in stress response, suggesting that DNA demethylases maintain or positively regulate the expression of stress response genes required for F. oxysporum resistance. The rdd-downregulated stress response genes are enriched for short transposable element sequences in their promoters. Many of these transposable elements and their surrounding sequences show localized DNA methylation changes in rdd, and a general reduction in CHH methylation, suggesting that RNA-directed DNA methylation (RdDM), responsible for CHH methylation, may participate in DNA demethylase-mediated regulation of stress response genes. Many of the rdd-downregulated stress response genes are downregulated in the RdDM mutants nrpd1 and nrpe1, and the RdDM mutants nrpe1 and ago4 show enhanced susceptibility to F. oxysporum infection. Conclusions: Our results suggest that a primary function of DNA demethylases in plants is to regulate the expression of stress response genes by targeting promoter transposable element sequence
Selective and catalytic carbon dioxide and heteroallene activation mediated by cerium N-heterocyclic carbene complexes
We thank the EPSRC for funding through the Centre for Doctoral Training in Critical Resource Catalysis (CRITICAT, EP/L016419/1, R. W. F. K.), EP/J018139/1 and the UK Catalysis Hub (EP/K014714/1, P. L. A., C. W.), EP/M010554/1 (P. L. A.). This project has received funding from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme (grant agreement No. 740311, P. L. A.). K. W. thanks the China Scholarship Council (CSC) for a postgraduate fellowship. P. L. A., M. W. M., J. R. and F. E. K. thank the Technische Universität München – Institute for Advanced Study, funded by the German Excellence Initiative. A. D. S. thanks the Royal Society for a Wolfson Research Merit Award. C. J. thanks the DAAD for a scholarship, and C. J. and J. R. thank the TUM Graduate School for financial support.A series of rare earth complexes of the form Ln(LR)3 supported by bidentate ortho-aryloxide–NHC ligands are reported (LR = 2-O-3,5-tBu2-C6H2(1-C{N(CH)2N(R)})); R = iPr, tBu, Mes; Ln = Ce, Sm, Eu). The cerium complexes cleanly and quantitatively insert carbon dioxide exclusively into all three cerium carbene bonds, forming Ce(LR·CO2)3. The insertion is reversible only for the mesityl-substituted complex Ce(LMes)3. Analysis of the capacity of Ce(LR)3 to insert a range of heteroallenes that are isoelectronic with CO2 reveals the solvent and ligand size dependence of the selectivity. This is important because only the complexes capable of reversible CO2-insertion are competent catalysts for catalytic conversions of CO2. Preliminary studies show that only Ce(LMes·CO2)3 catalyses the formation of propylene carbonate from propylene oxide under 1 atm of CO2 pressure. The mono-ligand complexes can be isolated from reactions using LiCe(NiPr2)4 as a starting material; LiBr adducts [Ce(LR)(NiPr2)Br·LiBr(THF)]2 (R = Me, iPr) are reported, along with a hexanuclear N-heterocyclic dicarbene [Li2Ce3(OArCMe–H)3(NiPr2)5(THF)2]2 by-product. The analogous para-aryloxide–NHC proligand (p-LMes = 4-O-2,6-tBu2-C6H2(1-C{N(CH)2NMes}))) has been made for comparison, but the rare earth tris-ligand complexes Ln(p-LMes)3(THF)2 (Ln = Y, Ce) are too reactive for straightforward Lewis pair separated chemistry to be usefully carried out.Publisher PDFPeer reviewe
Largeâ eddy simulation of biogenic VOC chemistry during the DISCOVERâ AQ 2011 campaign
Biogenic volatile organic compounds (BVOCs) are oxidized quickly in the atmosphere to form oxygenated VOC (OVOC) and play crucial roles in the formation of ozone and secondary organic aerosols. We use the National Center for Atmospheric Research’s largeâ eddy simulation model and Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality 2011 flight data to understand the role of boundary layer turbulence on the atmospheric chemistry of key BVOC species and their oxidation products. We simulate three distinct convective environments during the campaign, representing fair weather conditions (case 1: 1 July), a convective event dominated by southwesterly flow (case 2: 11 July), and a polluted event with high temperature and convection (case 3: 29 July). Isoprene segregation is greatest in the lower boundary layer under warm and convective conditions, reaching up to a 10% reduction in the isopreneâ OH reaction rate. Under warm and convective conditions, the BVOC lifetimes lengthen due to increased isoprene emission, elevated initial chemical concentrations, and OH competition. Although turbulenceâ driven segregation has less influence on the OVOC species, convection mixes more OVOC into the upper atmospheric boundary layer (ABL) and increases the total OH reactivity. Production and loss rates of ozone above 2â km in all the three cases indicate in situ ozone formation in addition to vertical convective transport of ozone from the surface and aloft, consistent with the increased contribution of OH reactivity from OVOC. Together, these results show that total OH reactivity in the ABL increases under warmer and stronger convective conditions due to enhanced isoprene emission and the OVOC contribution to ozone formation.Key PointsLES and DISCOVERâ AQ flight data are compared to understand the role of turbulence on BVOC chemistryTurbulenceâ induced segregation is less important for OVOC than isoprene, but OVOC compensates for isoprene rate reductionsConvection mixes more OVOC into the upper ABL and increases total OH reactivityPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/133566/1/jgrd53113_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/133566/2/jgrd53113-sup-0001-SI-S01.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/133566/3/jgrd53113.pd
Search for C-parity violation in and
Using events recorded in
collisions at 3.686 GeV with the BESIII at the BEPCII collider, we
present searches for C-parity violation in and decays via . No significant
signals are observed in either channel. Upper limits on the branching fractions
are set to be and
at the 90\%
confidence level. The former is one order of magnitude more stringent than the
previous upper limit, and the latter represents the first limit on this decay
channel.Comment: 7 pages, 2 figure
Observation of the state in at BESIII
We report the observation of the in the process with a statistical
significance of , in data samples at center-of-mass energies
4.230, 4.260, 4.360, 4.420 and 4.600~GeV collected with the BESIII
detector at the BEPCII electron positron collider. The measured mass of the
is ~MeV/, where the first error is
statistical and the second systematic, and the width is less than ~MeV at
the 90\% confidence level. The products of the Born cross sections for
and the branching ratio are also measured. These measurements are in good
agreement with the assignment of the as the charmonium
state.Comment: 7 pages, 3 figures, version to appear in Phys. Rev. Let
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