543 research outputs found
Contribución a la palinología de Liliaceae en Andalucía Occidental (excepto subfamilias Scilloideae y Allioideae)
Se estudia la morfol ogía del polen de 23 especies de Liliaceae en Andal ucía Occidental, pertenecientes a los géneros Asphodelus, Anthericum, Simethis, Aphyllanthes, Colchicum, Merendera, Gag ea , Tulipa, Fri tillaría, Po!ygonatum, Asparagus, Ruscus y Smilax. Por l os caracteres polinices analizados se reconocen 14 tipos diferentes . Palinológicamente está justificada la separación de Smilacoideae como familia independiente , pero no se justifica la separación de Liliaceae y AmaryllidaceaeThe pollen morphol ogy of 23 species of Liliaceae from W. Andalucía belonging to the genera Asphodelus, Anthericum, Simethis, Aphyllanthes, Colchicum , Merendera, Gagea, Tulipa , Fritillaria, Polygonatum, Asparagus, Ruscus and Smilax have been studied. Fourteen types of pollen grains have been found, which are more or l ess in accordance wi t h the accepted genera . The palynol ogical data agree wi th the separation o f Smila9oideae as a different family. The tradi ti anal separation of Liliaceae a nd Amaryllidaceae is not justificd palynologicall
Density-Matrix functional theory of strongly-correlated lattice fermions
A density functional theory (DFT) of lattice fermion models is presented,
which uses the single-particle density matrix gamma_{ij} as basic variable. A
simple, explicit approximation to the interaction-energy functional W[gamma] of
the Hubbard model is derived from exact dimer results, scaling properties of
W[gamma] and known limits. Systematic tests on the one-dimensional chain show a
remarkable agreement with theBethe-Ansatz exact solution for all interaction
regimes and band fillings. New results are obtained for the ground-state
energyand charge-excitation gap in two dimensions. A successful description of
strong electron correlations within DFT is achieved.Comment: 15 pages, 6 figures Submitted to PR
The supplementation with Resveratrol and α-Tocopherol could reduce the risk of sarcopenia in dogs by counteracting the oxidative stress
Several scienti\ufb01c evidences show that oxidative stress is associated with the origin, progression and severity of chronic noncommunicable diseases. Due to the longer duration of life, sarcopenia, osteopenia, osteoporosis and cachexia are considered emerging syndromes for dogs and cats. The objective was to investigate the impact of a supplementation with resveratrol and -tocopherol (JUVENIA \uae ) on the harmful effects of oxidative stress in adult dogs. The study was able to demonstrate this supplementation was able to positively modulate creatine phosphokinase and alkaline phosphatase, which are considered useful biomarkers for sarcopenia, bone formation and speed in bone remodeling. As a result of the longer life of domestic animals and, in particular dogs, the use of food supplements with antioxidant activity could play a critical role in reducing/delaying the onset of chronic-degenerative diseases. On the basis of the present study, the use of products containing resveratrol and -tocopherol acetate seems to be a promising approach for improving the health of dogs
Interaction energy functional for lattice density functional theory: Applications to one-, two- and three-dimensional Hubbard models
The Hubbard model is investigated in the framework of lattice density
functional theory (LDFT). The single-particle density matrix with
respect the lattice sites is considered as the basic variable of the many-body
problem. A new approximation to the interaction-energy functional
is proposed which is based on its scaling properties and which recovers exactly
the limit of strong electron correlations at half-band filling. In this way, a
more accurate description of is obtained throughout the domain of
representability of , including the crossover from weak to strong
correlations. As examples of applications results are given for the
ground-state energy, charge-excitation gap, and charge susceptibility of the
Hubbard model in one-, two-, and three-dimensional lattices. The performance of
the method is demonstrated by comparison with available exact solutions, with
numerical calculations, and with LDFT using a simpler dimer ansatz for .
Goals and limitations of the different approximations are discussed.Comment: 25 pages and 8 figures, submitted to Phys. Rev.
Measurement of the analyzing power Ay0 for the reaction H(p⃗,d)π+ between 1000 and 1300 MeV
The analyzing power Ay0 of the reaction H(p⃗,d)π+ has been measured at a fixed value of the Mandelstam variable ud=-0.17GeV2 for nine proton energies between 1000 and 1300 MeV. The experiment was performed at SATURNE with the SPES1 spectrometer. The data exhibit structure around √s≃2.37GeV. The origin of this structure could be related to a resonancelike behavior of the 1S0P or 1G4F partial amplitudes
A bright, high rotation-measure FRB that skewers the M33 halo
We report the detection of a bright fast radio burst, FRB\,191108, with
Apertif on the Westerbork Synthesis Radio Telescope (WSRT). The interferometer
allows us to localise the FRB to a narrow 5\arcsec\times7\arcmin ellipse by
employing both multibeam information within the Apertif phased-array feed (PAF)
beam pattern, and across different tied-array beams. The resulting sight line
passes close to Local Group galaxy M33, with an impact parameter of only
18\,kpc with respect to the core. It also traverses the much larger
circumgalactic medium of M31, the Andromeda Galaxy. We find that the shared
plasma of the Local Group galaxies could contribute 10\% of its
dispersion measure of 588\,pc\,cm. FRB\,191108 has a Faraday rotation
measure of +474\,\,rad\,m, which is too large to be explained by
either the Milky Way or the intergalactic medium. Based on the more moderate
RMs of other extragalactic sources that traverse the halo of M33, we conclude
that the dense magnetised plasma resides in the host galaxy. The FRB exhibits
frequency structure on two scales, one that is consistent with quenched
Galactic scintillation and broader spectral structure with
\,MHz. If the latter is due to scattering in the shared
M33/M31 CGM, our results constrain the Local Group plasma environment. We found
no accompanying persistent radio sources in the Apertif imaging survey data
Distinct branches of the N-end rule pathway modulate the plant immune response
The N-end rule pathway is a highly conserved constituent of the ubiquitin proteasome system, yet little is known about its biological roles. Here we explored the role of the N-end rule pathway in the plant immune response. We investigated the genetic influences of components of the pathway and known protein substrates on physiological, biochemical and metabolic responses to pathogen infection. We show that the glutamine (Gln) deamidation and cysteine (Cys) oxidation branches are both components of the plant immune system, through the E3 ligase PROTEOLYSIS (PRT)6. In Arabidopsis thaliana Gln-specific amino-terminal (Nt)-amidase (NTAQ1) controls the expression of specific defence-response genes, activates the synthesis pathway for the phytoalexin camalexin and influences basal resistance to the hemibiotroph pathogen Pseudomonas syringae pv tomato (Pst). The Nt-Cys ETHYLENE RESPONSE FACTOR VII transcription factor substrates enhance pathogen-induced stomatal closure. Transgenic barley with reduced HvPRT6 expression showed enhanced resistance to Ps. japonica and Blumeria graminis f. sp. hordei, indicating a conserved role of the pathway. We propose that that separate branches of the N-end rule pathway act as distinct components of the plant immune response in flowering plants
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector
A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
Jet size dependence of single jet suppression in lead-lead collisions at sqrt(s(NN)) = 2.76 TeV with the ATLAS detector at the LHC
Measurements of inclusive jet suppression in heavy ion collisions at the LHC
provide direct sensitivity to the physics of jet quenching. In a sample of
lead-lead collisions at sqrt(s) = 2.76 TeV corresponding to an integrated
luminosity of approximately 7 inverse microbarns, ATLAS has measured jets with
a calorimeter over the pseudorapidity interval |eta| < 2.1 and over the
transverse momentum range 38 < pT < 210 GeV. Jets were reconstructed using the
anti-kt algorithm with values for the distance parameter that determines the
nominal jet radius of R = 0.2, 0.3, 0.4 and 0.5. The centrality dependence of
the jet yield is characterized by the jet "central-to-peripheral ratio," Rcp.
Jet production is found to be suppressed by approximately a factor of two in
the 10% most central collisions relative to peripheral collisions. Rcp varies
smoothly with centrality as characterized by the number of participating
nucleons. The observed suppression is only weakly dependent on jet radius and
transverse momentum. These results provide the first direct measurement of
inclusive jet suppression in heavy ion collisions and complement previous
measurements of dijet transverse energy imbalance at the LHC.Comment: 15 pages plus author list (30 pages total), 8 figures, 2 tables,
submitted to Physics Letters B. All figures including auxiliary figures are
available at
http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2011-02
Observation of a new chi_b state in radiative transitions to Upsilon(1S) and Upsilon(2S) at ATLAS
The chi_b(nP) quarkonium states are produced in proton-proton collisions at
the Large Hadron Collider (LHC) at sqrt(s) = 7 TeV and recorded by the ATLAS
detector. Using a data sample corresponding to an integrated luminosity of 4.4
fb^-1, these states are reconstructed through their radiative decays to
Upsilon(1S,2S) with Upsilon->mu+mu-. In addition to the mass peaks
corresponding to the decay modes chi_b(1P,2P)->Upsilon(1S)gamma, a new
structure centered at a mass of 10.530+/-0.005 (stat.)+/-0.009 (syst.) GeV is
also observed, in both the Upsilon(1S)gamma and Upsilon(2S)gamma decay modes.
This is interpreted as the chi_b(3P) system.Comment: 5 pages plus author list (18 pages total), 2 figures, 1 table,
corrected author list, matches final version in Physical Review Letter
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