295 research outputs found
One New Species And One New Subspecies Of Cissus (vitaceae) From Colombia
Cissus colombiensis and C. verticillata subsp. colombiana, new taxa of Vitaceae, are described from Colombia. In addition to descriptions and illustrations, comments on their probable relationships and distributions are presented. Cissus L. has approximately 55 species in South America and is the largest genus in the Vitaceae. Many of the species described by Baker (1871; placed in the genus Vitis), and Planchon (1887) were considered synonyms in a recent taxonomic survey by the author (Lombard!, 1995), while one new species and one new subspecies were found in Colombia: Cissus colombiensis and C. verticillata subsp. colombiana.62191194Baker, J.G., Ampelideae (1871) Pp. 197-220 in C. F. P. Martius (Editor), Flora Brasiliensis, Vol. 14. Frid. Fleischer, Leipzig.Lombard, J.A., Typification of names of South American Casus (Vitaceae) (1995) Taxon, 44, pp. 193-206Planchon, J.E., Monographie des Ampélidées vraies (1887) Pp. 305-654 M A. & C. DeCandolle (Editors), Monographiae Phanerogamarum, Vol. 5. G. Masson, Paris
FlorĂstica Vascular NĂŁo ArbĂłrea Em Uma Reserva Particular Do PatrimĂ´nio Natural (rppn) Na Floresta Atlântica De SĂŁo Paulo, Brasil
The private owned conservation area of RPPN Paiol Maria includes 76 ha of montane forest located at the municipality of São Lourenço da Serra, São Paulo State, belongs to the biodiversity corridor of the Serra do Mar, and is located at the northern part of Ribeira valley. This study was carried out during the period of June 2010 to September 2011 and our aim was to elaborate a checklist of the non-arboreal species occurring in the RPPN. A total of 330 species, distributed in 84 families and 223 genera were collected. Four species recorded for this work appears in the red list for the state of São Paulo. A similarity analysis between the epiphytes found in the RPPN and other four areas of montane forest reassert the important role of secondary forest fragments to the knowledge and conservation of the Atlantic Forest biodiversity.67111
HP2 survey: III. the California Molecular Cloud : A sleeping giant revisited
We present new high resolution and dynamic range dust column density and temperature maps of the California Molecular Cloud derived from a combination of Planck and Herschel dust-emission maps, and 2MASS NIR dust-extinction maps. We used these data to determine the ratio of the 2.2 \uce\ubcm extinction coefficient to the 850 \uce\ubcm opacity and found the value to be close to that found in similar studies of the Orion B and Perseus clouds but higher than that characterizing the Orion A cloud, indicating that variations in the fundamental optical properties of dust may exist between local clouds. We show that over a wide range of extinction, the column density probability distribution function (pdf) of the cloud can be well described by a simple power law (i.e., PDFNAK-n) with an index (n = 4.0 \uc2\ub1 0.1) that represents a steeper decline with AKthan found (n 3) in similar studies of the Orion and Perseus clouds. Using only the protostellar population of the cloud and our extinction maps we investigate the Schmidt relation, that is, the relation between the protostellar surface density, \uce\ua3-, and extinction, AK, within the cloud. We show that \uce\ua3-is directly proportional to the ratio of the protostellar and cloud pdfs, i.e., PDF-(AK)/PDFN(AK). We use the cumulative distribution of protostars to infer the functional forms for both \uce\ua3-and PDF-. We find that \uce\ua3-is best described by two power-law functions. At extinctions AK2.5 mag, \uce\ua3-AK\uce\ub2with \uce\ub2 = 3.3 while at higher extinctions \uce\ub2 = 2.5, both values steeper than those (2) found in other local giant molecular clouds (GMCs). We find that PDF-is a declining function of extinction also best described by two power-laws whose behavior mirrors that of \uce\ua3-. Our observations suggest that variations both in the slope of the Schmidt relation and in the sizes of the protostellar populations between GMCs are largely driven by variations in the slope, n, of PDFN(AK). This confirms earlier studies suggesting that cloud structure plays a major role in setting the global star formation rates in GMCs
Anti-inflammatory activity of Lychnophora passerina, Asteraceae (Brazilian “Arnica”)
AbstractEthnopharmacological relevanceLychnophora passerina (Asteraceae), popularly known as “arnica,” is used to treat inflammation, pain, rheumatism, contusions, bruises and insect bites in Brazilian traditional medicine.Materials and methodsThe anti-inflammatory activity of crude ethanolic extract of aerial parts of L. passerina and its ethyl acetate and methanolic fractions had their abilities to modulate the production of NO, TNF-α and IL-10 inflammatory mediators in LPS/IFN-γ-stimulated J774.A1 macrophages evaluated. Moreover, the crude ethanolic extract and derived fractions were also in vivo assayed by carrageenan-induced paw oedema in mice.ResultsIn vitro assays showed remarkable anti-inflammatory activity of L. passerina crude ethanolic extract (EE) and its ethyl acetate (A) and methanolic (M) fractions, through the inhibition of production of NO and TNF-α inflammatory mediators and induction of production of IL-10 anti-inflammatory cytokine. In vivo assays showed anti-inflammatory activity for EE 10% ointment, similar to the standard drug diclofenac gel. The A and M fraction ointments 20% presented anti-inflammatory activity.ConclusionThe results obtained showed that possible anti-inflammatory effects of EE and its A and M fractions may be attributed to inhibition pro-inflammatory cytokines production, TNF-α and NO and to increased IL-10 production. EE, A and M ointments showed topical in vivo anti-inflammatory activity. The in vivo anti-inflammatory activity of EE of L. passerina may be related to synergistic effects of different substances in the crude extract. Therefore, traditional use of aerial parts of L. passerina in the inflammatory conditions could be beneficial to treat topical inflammatory conditions, as evidenced by the present study
Adiabatic evolution of a coupled-qubit Hamiltonian
We present a general method for studying coupled qubits driven by
adiabatically changing external parameters. Extended calculations are provided
for a two-bit Hamiltonian whose eigenstates can be used as logical states for a
quantum CNOT gate. From a numerical analysis of the stationary Schroedinger
equation we find a set of parameters suitable for representing CNOT, while from
a time-dependent study the conditions for adiabatic evolution are determined.
Specializing to a concrete physical system involving SQUIDs, we determine
reasonable parameters for experimental purposes. The dissipation for SQUIDs is
discussed by fitting experimental data. The low dissipation obtained supports
the idea that adiabatic operations could be performed on a time scale shorter
than the decoherence time.Comment: 10 pages, 4 figures, to be pub.in Phys Rev
Various features of quasiequilibrium sequences of binary neutron stars in general relativity
Quasiequilibrium sequences of binary neutron stars are numerically calculated
in the framework of the Isenberg-Wilson-Mathews (IWM) approximation of general
relativity. The results are presented for both rotation states of synchronized
spins and irrotational motion, the latter being considered as the realistic one
for binary neutron stars just prior to the merger. We assume a polytropic
equation of state and compute several evolutionary sequences of binary systems
composed of different-mass stars as well as identical-mass stars with adiabatic
indices gamma=2.5, 2.25, 2, and 1.8. From our results, we propose as a
conjecture that if the turning point of binding energy (and total angular
momentum) locating the innermost stable circular orbit (ISCO) is found in
Newtonian gravity for some value of the adiabatic index gamma_0, that of the
ADM mass (and total angular momentum) should exist in the IWM approximation of
general relativity for the same value of the adiabatic index.Comment: Text improved, some figures changed or deleted, new table, 38 pages,
31 figures, accepted for publication in Phys. Rev.
Post-Newtonian SPH calculations of binary neutron star coalescence. II. Binary mass ratio, equation of state, and spin dependence
Using our new Post-Newtonian SPH (smoothed particle hydrodynamics) code, we
study the final coalescence and merging of neutron star (NS) binaries. We vary
the stiffness of the equation of state (EOS) as well as the initial binary mass
ratio and stellar spins. Results are compared to those of Newtonian
calculations, with and without the inclusion of the gravitational radiation
reaction. We find a much steeper decrease in the gravity wave peak strain and
luminosity with decreasing mass ratio than would be predicted by simple
point-mass formulae. For NS with softer EOS (which we model as simple
polytropes) we find a stronger gravity wave emission, with a
different morphology than for stiffer EOS (modeled as polytropes as
in our previous work). We also calculate the coalescence of NS binaries with an
irrotational initial condition, and find that the gravity wave signal is
relatively suppressed compared to the synchronized case, but shows a very
significant second peak of emission. Mass shedding is also greatly reduced, and
occurs via a different mechanism than in the synchronized case. We discuss the
implications of our results for gravity wave astronomy with laser
interferometers such as LIGO, and for theoretical models of gamma-ray bursts
(GRBs) based on NS mergers.Comment: RevTeX, 38 pages, 24 figures, Minor Corrections, to appear in Phys.
Rev.
The Planetary Nebula Luminosity Function at the Dawn of Gaia
The [O III] 5007 Planetary Nebula Luminosity Function (PNLF) is an excellent
extragalactic standard candle. In theory, the PNLF method should not work at
all, since the luminosities of the brightest planetary nebulae (PNe) should be
highly sensitive to the age of their host stellar population. Yet the method
appears robust, as it consistently produces < 10% distances to galaxies of all
Hubble types, from the earliest ellipticals to the latest-type spirals and
irregulars. It is therefore uniquely suited for cross-checking the results of
other techniques and finding small offsets between the Population I and
Population II distance ladders. We review the calibration of the method and
show that the zero points provided by Cepheids and the Tip of the Red Giant
Branch are in excellent agreement. We then compare the results of the PNLF with
those from Surface Brightness Fluctuation measurements, and show that, although
both techniques agree in a relative sense, the latter method yields distances
that are ~15% larger than those from the PNLF. We trace this discrepancy back
to the calibration galaxies and argue that, due to a small systematic error
associated with internal reddening, the true distance scale likely falls
between the extremes of the two methods. We also demonstrate how PNLF
measurements in the early-type galaxies that have hosted Type Ia supernovae can
help calibrate the SN Ia maximum magnitude-rate of decline relation. Finally,
we discuss how the results from space missions such as Kepler and Gaia can help
our understanding of the PNLF phenomenon and improve our knowledge of the
physics of local planetary nebulae.Comment: 12 pages, invited review at the conference "The Fundamental Cosmic
Distance Scale: State of the Art and Gaia Perspective", to appear in
Astrophysics and Space Scienc
Unfolding of differential energy spectra in the MAGIC experiment
The paper describes the different methods, used in the MAGIC experiment, to
unfold experimental energy distributions of cosmic ray particles (gamma-rays).
Questions and problems related to the unfolding are discussed. Various
procedures are proposed which can help to make the unfolding robust and
reliable. The different methods and procedures are implemented in the MAGIC
software and are used in most of the analyses.Comment: Submitted to NIM
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