40 research outputs found
Fine tuning of MLCT states in new mononuclear complexes of ruthenium(II) containing tris(1-pyrazolyl)methane, 2,2âČ-bipyridine and aromatic nitrogen heterocycles
The syntheses of new mononuclear ruthenium(II) complexes of the type: [Ru(bpy)(L)(tpm)](PF6)2 {tpm = tris(1-pyrazolyl)-methane; bpy = 2,2âČ-bipyridine; L = pz (pyrazine; 1), 4,4âČ-bpy (4,4âČ-bipyridine; 2), and bpe [trans-1,2-bis(4-pyridyl)ethylene; 3]} are described, together with their spectroscopic, electrochemical, and photophysical properties. A complete assignment of the NMR resonances of the three species could be made in CD3CN by bidimensional techniques. A fine tuning of the energies of MLCT (metal-to-ligand charge transfer) states in these complexes is disclosed when comparing, in CH3CN, the values of their maximum absorption wave-lengths for the most intense visible bands (λ max) and their redox potentials for the RuIII/Ru II couples; this effect, relevant to the design of efficient photocatalysts, can be attributed to a decreasing order of dÏ(Ru) â*(2,2âČ-bpy) backbonding when decreasing the distance between both N atoms in the aromatic nitrogen heterocycle L that acts in a monodentate manner. Only the species with L = bpe emits at room temperature, pointing to the conclusion that MLCT excited states in this series become higher in energy than dd excited states when the value of λmax is lower than 400 nm. These species are also useful building blocks for new dinuclear mixed-valent complexes. © Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005.Fil: Katz, NĂ©stor Eduardo. Universidad Nacional de TucumĂĄn. Facultad de BioquĂmica, QuĂmica y Farmacia. Instituto de QuĂmica FĂsica; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - TucumĂĄn. Instituto de QuĂmica del Noroeste. Universidad Nacional de TucumĂĄn. Facultad de BioquĂmica, QuĂmica y Farmacia. Instituto de QuĂmica del Noroeste; ArgentinaFil: Romero, Isabel. Universidad de Girona; EspañaFil: Llobet, Antoni. Universidad de Girona; EspañaFil: Parella, Teodor. Universitat AutĂČnoma de Barcelona; EspañaFil: Benet Buchholz, Jordi. Bayer Industry Services; Alemani
Identification, characterization, and gene expression analysis of nucleotide binding site (NB)-type resistance gene homologues in switchgrass
Abstract
Background
Switchgrass (Panicum virgatum L.) is a warm-season perennial grass that can be used as a second generation bioenergy crop. However, foliar fungal pathogens, like switchgrass rust, have the potential to significantly reduce switchgrass biomass yield. Despite its importance as a prominent bioenergy crop, a genome-wide comprehensive analysis of NB-LRR disease resistance genes has yet to be performed in switchgrass.
Results
In this study, we used a homology-based computational approach to identify 1011 potential NB-LRR resistance gene homologs (RGHs) in the switchgrass genome (v 1.1). In addition, we identified 40 RGHs that potentially contain unique domains including major sperm protein domain, jacalin-like binding domain, calmodulin-like binding, and thioredoxin. RNA-sequencing analysis of leaf tissue from ĂąâŹËAlamoĂąâŹâą, a rust-resistant switchgrass cultivar, and ĂąâŹËDacotahĂąâŹâą, a rust-susceptible switchgrass cultivar, identified 2634 high quality variants in the RGHs between the two cultivars. RNA-sequencing data from field-grown cultivar ĂąâŹËSummerĂąâŹâą plants indicated that the expression of some of these RGHs was developmentally regulated.
Conclusions
Our results provide useful insight into the molecular structure, distribution, and expression patterns of members of the NB-LRR gene family in switchgrass. These results also provide a foundation for future work aimed at elucidating the molecular mechanisms underlying disease resistance in this important bioenergy crop
European consensus conference on unruptured brain AVMs treatment (Supported by EANS, ESMINT, EGKS, and SINCH)
In December of 2016, a Consensus Conference on unruptured AVM treatment, involving 24 members of the three European societies dealing with the treatment of cerebral AVMs (EANS, ESMINT, and EGKS) was held in Milan, Italy. The panel made the following statements and general recommendations: (1) Brain arteriovenous malformation (AVM) is a complex disease associated with potentially severe natural history; (2) The results of a randomized trial (ARUBA) cannot be applied equally for all unruptured brain arteriovenous malformation (uBAVM) and for all treatment modalities; (3) Considering the multiple treatment modalities available, patients with uBAVMs should be evaluated by an interdisciplinary neurovascular team consisting of neurosurgeons, neurointerventionalists, radiosurgeons, and neurologists experienced in the diagnosis and treatment of brain AVM; (4) Balancing the risk of hemorrhage and the associated restrictions of everyday activities related to untreated unruptured AVMs against the risk of treatment, there are sufficient indications to treat unruptured AVMs grade 1 and 2 (Spetzler-Martin); (5) There may be indications for treating patients with higher grades, based on a case-to-case consensus decision of the experienced team; (6) If treatment is indicated, the primary strategy should be defined by the multidisciplinary team prior to the beginning of the treatment and should aim at complete eradication of the uBAVM; (7) After having considered the pros and cons of a randomized trial vs. a registry, the panel proposed a prospective European Multidisciplinary Registry.Peer reviewe
Supplement: "Localization and broadband follow-up of the gravitational-wave transient GW150914" (2016, ApJL, 826, L13)
This Supplement provides supporting material for Abbott et al. (2016a). We briefly summarize past electromagnetic (EM) follow-up efforts as well as the organization and policy of the current EM follow-up program. We compare the four probability sky maps produced for the gravitational-wave transient GW150914, and provide additional details of the EM follow-up observations that were performed in the different bands
Multi-messenger observations of a binary neutron star merger
On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transientâs position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta
Localization and Broadband Follow-up of the Gravitational-wave Transient GW150914
A gravitational-wave (GW) transient was identified in data recorded by
the Advanced Laser Interferometer Gravitational-wave Observatory (LIGO)
detectors on 2015 September 14. The event, initially designated G184098
and later given the name GW150914, is described in detail elsewhere. By
prior arrangement, preliminary estimates of the time, significance, and
sky location of the event were shared with 63 teams of observers
covering radio, optical, near-infrared, X-ray, and gamma-ray wavelengths
with ground- and space-based facilities. In this Letter we describe the
low-latency analysis of the GW data and present the sky localization of
the first observed compact binary merger. We summarize the follow-up
observations reported by 25 teams via private Gamma-ray Coordinates
Network circulars, giving an overview of the participating facilities,
the GW sky localization coverage, the timeline, and depth of the
observations. As this event turned out to be a binary black hole merger,
there is little expectation of a detectable electromagnetic (EM)
signature. Nevertheless, this first broadband campaign to search for a
counterpart of an Advanced LIGO source represents a milestone and
highlights the broad capabilities of the transient astronomy community
and the observing strategies that have been developed to pursue neutron
star binary merger events. Detailed investigations of the EM data and
results of the EM follow-up campaign are being disseminated in papers by
the individual teams.
</p
Multi-messenger Observations of a Binary Neutron Star Merger
On 2017 August 17 a binary neutron star coalescence candidate (later
designated GW170817) with merger time 12:41:04 UTC was observed through
gravitational waves by the Advanced LIGO and Advanced Virgo detectors.
The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray
burst (GRB 170817A) with a time delay of ⌠1.7 {{s}} with respect to
the merger time. From the gravitational-wave signal, the source was
initially localized to a sky region of 31 deg2 at a
luminosity distance of {40}-8+8 Mpc and with
component masses consistent with neutron stars. The component masses
were later measured to be in the range 0.86 to 2.26 {M}ÈŻ
. An extensive observing campaign was launched across the
electromagnetic spectrum leading to the discovery of a bright optical
transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC
4993 (at ⌠40 {{Mpc}}) less than 11 hours after the merger by the
One-Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The
optical transient was independently detected by multiple teams within an
hour. Subsequent observations targeted the object and its environment.
Early ultraviolet observations revealed a blue transient that faded
within 48 hours. Optical and infrared observations showed a redward
evolution over âŒ10 days. Following early non-detections, X-ray and
radio emission were discovered at the transientâs position ⌠9
and ⌠16 days, respectively, after the merger. Both the X-ray and
radio emission likely arise from a physical process that is distinct
from the one that generates the UV/optical/near-infrared emission. No
ultra-high-energy gamma-rays and no neutrino candidates consistent with
the source were found in follow-up searches. These observations support
the hypothesis that GW170817 was produced by the merger of two neutron
stars in NGC 4993 followed by a short gamma-ray burst (GRB 170817A) and
a kilonova/macronova powered by the radioactive decay of r-process
nuclei synthesized in the ejecta.</p
Structure profonde de la marge passive égyptienne au large du Nil (contribution des données de sismique multitrace et de gravimétrie)
La marge continentale égyptienne est un segment de la marge passive africaine. En 2002, 1800 km de MCS ont été acquises le long de 7 lignes régionales. Un traitement sismique standard a permis d imager les structures profondes et a montré la présence d importants bassins sédimentaires profonds. La PSDM, selon deux techniques, a permis de mieux évaluer l épaisseur sédimentaire et crustale ainsi que l architecture de ce segment de marge. L épaisseur des sédiments (mésozoïques à actuels) varie entre 10 et 15 km, recouvrant une croûte amincie (10 à 12 km). Localement, des réflecteurs profonds peuvent indiquer le Moho. Par ailleurs, à l intérieur de ces sédiments, la breack-up unconformity est datée de l Aptien, ce qui fait du rifting nilotique un événement tardif. Des données gravimétriques ont permis de mieux contraindre les structures profondes, comme la transition entre la croûte continentale égyptienne et la croûte continentale amincie.PARIS-BIUSJ-ThÚses (751052125) / SudocPARIS-BIUSJ-Sci.Terre recherche (751052114) / SudocSudocFranceF
The structural framework of the Peloponnese continental margin from Zakynthos to Pylos from seismic reflection and morpho-bathymetric data
International audienceOne of the objectives of the European project SEAHELLARC (SEismic and tsunami risk Assessment and mitigation scenarios in the western HELLenic ARC) was to identify the key elements controlling the geological structure of the Peloponnese continental margin in order to better understand the distribution of earthquakes in the area. Vintage multichannel seismic lines were reprocessed, interpreted and integrated with detailed morpho-bathymetric data and high-resolution single channel seismic data. According to the interpretation, most of the upper continental margin has been created within the former Alpine Gavrovo, Ionian and Apulian thrust units, including their Miocene to Quaternary cover and their Triassic salt-bearing formations. The Ionian thrust complex seems to have been continuously overthrusting the Apulian Ridge, itself characterised by strongly fractured acoustic basement features. Ductile and mobile Triassic evaporitic sequences are present in most of the major Ionian zone morpho-structures. The westward directed thrusts of the Ionian zone reached their final positions in Lower Pliocene and were followed by uplift of the ridges that is continuing in the present time. Previous compressional structures are being reactivated as normal faults with associated diapirism in the Triassic evaporites. NNE-SSW shear displacements related to trans-extensional motion may have activated "pull apart" basins with ENE-WSW normal faulting at their heads. This NNE-SSW dextral strikeslip motion agrees with the present anticlockwise rotation of the Peloponnese. The focal mechanism and the NNE-SSW distribution of aftershocks of a major earthquake in June 2008 along the Andravida fault define a major lineament that can be followed past the Katakolo Peninsula to the diapiric morpho-structures defining the eastern boundary of the Strophades basin