324 research outputs found
W-superalgebras as truncation of super-Yangians
We show that some finite W-superalgebras based on gl(M|N) are truncation of
the super-Yangian Y(gl(M|N)). In the same way, we prove that finite
W-superalgebras based on osp(M|2n) are truncation of the twisted super-Yangians
Y(gl(M|2n))^{+}.
Using this homomorphism, we present these W-superalgebras in an R-matrix
formalism, and we classify their finite-dimensional irreducible
representations.Comment: Latex, 32 page
Near-UV to near-IR disk-averaged Earth's reflectance spectra
We report 320 to 1020nm disk-averaged Earth reflectance spectra obtained from
Moon's Earthshine observations with the EMMI spectrograph on the NTT at ESO La
Silla (Chile). The spectral signatures of Earth atmosphere and ground
vegetation are observed. A vegetation red-edge of up to 9% is observed on
Europe and Africa and ~2% upon Pacific Ocean. The spectra also show that Earth
is a blue planet when Rayleigh scattering dominates, or totally white when the
cloud cover is large.Comment: Proceeding of an oral prensentation at the UAI No200 Colloquiu
INTERIM REPORT drawn up on behalf of the Committee on Agriculture on the common organization of the market in ethyl alcohol of agricultural origin. EP Working Document, Document 1972-1973 266/72, 17 January 1973
Soliton surfaces associated with symmetries of ODEs written in Lax representation
The main aim of this paper is to discuss recent results on the adaptation of
the Fokas-Gel'fand procedure for constructing soliton surfaces in Lie algebras,
which was originally derived for PDEs [Grundland, Post 2011], to the case of
integrable ODEs admitting Lax representations. We give explicit forms of the
\g-valued immersion functions based on conformal symmetries involving the
spectral parameter, a gauge transformation of the wave function and generalized
symmetries of the linear spectral problem. The procedure is applied to a
symmetry reduction of the static -field equations leading to the
Jacobian elliptic equation. As examples, we obtain diverse types of surfaces
for different choices of Jacobian elliptic functions for a range of values of
parameters.Comment: 14 Pages, 2 figures Conference Proceedings for QST7 Pragu
Properties and nature of Be stars 30. Reliable physical properties of a semi-detached B9.5e+G8III binary BR CMi = HD 61273 compared to those of other well studied semi-detached emission-line binaries
Reliable determination of the basic physical properties of hot emission-line
binaries with Roche-lobe filling secondaries is important for developing the
theory of mass exchange in binaries. It is a very hard task, however, which is
complicated by the presence of circumstellar matter in these systems. So far,
only a small number of systems with accurate values of component masses, radii,
and other properties are known. Here, we report the first detailed study of a
new representative of this class of binaries, BR CMi, based on the analysis of
radial velocities and multichannel photometry from several observatories, and
compare its physical properties with those for other well-studied systems. BR
CMi is an ellipsoidal variable seen under an intermediate orbital inclination
of ~51 degrees, and it has an orbital period of 12.919059(15) d and a circular
orbit. We used the disentangled component spectra to estimate the effective
temperatures 9500(200) K and 4655(50) K by comparing them with model spectra.
They correspond to spectral types B9.5e and G8III. We also used the
disentangled spectra of both binary components as templates for the 2-D
cross-correlation to obtain accurate RVs and a reliable orbital solution. Some
evidence of a secular period increase at a rate of 1.1+/-0.5 s per year was
found. This, together with a very low mass ratio of 0.06 and a normal mass and
radius of the mass gaining component, indicates that BR CMi is in a slow phase
of the mass exchange after the mass-ratio reversal. It thus belongs to a still
poorly populated subgroup of Be stars for which the origin of Balmer emission
lines is safely explained as a consequence of mass transfer between the binary
components.Comment: 17 pages, 5 figures, accepted for publication in Astronomy and
Astrophysics. appears in Astronomy and Astrophysics 201
Near-UV to near-IR disk-averaged Earth's spectra from Moon's Earthshine observations
We discuss a series of Earthshine spectra obtained with the NTT/EMMI
instrument between 320nm and 1020nm with a resolution of R~450 in the blue and
R~250 in the red. These ascending and descending Moon's Earthshine spectra
taken from Chile give disk-averaged spectra for two different Earth's phases.
The spectra show the ozone (Huggins and Chappuis bands), oxygen and water
vapour absorption bands, and also the stronger Rayleigh scattering in the blue.
Removing the known telluric absorptions reveals a spectral feature around 700nm
which is attributed to the vegetation stronger reflectivity in the near-IR,
so-called vegetation red-edge.Comment: 2 pages, 1 figure, proceedings from a poster at 'Semaine de
l'Astrophysique Francaise', 27th june-1st july 2005, Strasbour
Surfaces immersed in Lie algebras associated with elliptic integrals
The main aim of this paper is to study soliton surfaces immersed in Lie
algebras associated with ordinary differential equations (ODE's) for elliptic
functions. That is, given a linear spectral problem for such an ODE in matrix
Lax representation, we search for the most general solution of the wave
function which satisfies the linear spectral problem. These solutions allow for
the explicit construction of soliton surfaces by the Fokas-Gel'fand formula for
immersion, as formulated in (Grundland and Post 2011) which is based on the
formalism of generalized vector fields and their prolongation structures. The
problem has been reduced to examining three types of symmetries, namely, a
conformal symmetry in the spectral parameter (known as the Sym-Tafel formula),
gauge transformations of the wave function and generalized symmetries of the
associated integrable ODE. The paper contains a detailed explanation of the
immersion theory of surfaces in Lie algebras in connection with ODE's as well
as an exposition of the main tools used to study their geometric
characteristics. Several examples of the Jacobian and P-Weierstrass elliptic
functions are included as illustrations of the theoretical results.Comment: 22 pages, 3 sets of figures. Keywords: Generalized symmetries,
integrable models, surfaces immersed in Lie algebra
Meromorphic traveling wave solutions of the complex cubic-quintic Ginzburg-Landau equation
We look for singlevalued solutions of the squared modulus M of the traveling
wave reduction of the complex cubic-quintic Ginzburg-Landau equation. Using
Clunie's lemma, we first prove that any meromorphic solution M is necessarily
elliptic or degenerate elliptic. We then give the two canonical decompositions
of the new elliptic solution recently obtained by the subequation method.Comment: 14 pages, no figure, to appear, Acta Applicandae Mathematica
Stability of Reconstituted and Diluted Mitomycin C Solutions in Polypropylene Syringes and Glass VialsAbstract
Purpose: Mitomycin C (MMC) is widely used in treatment of non-muscle invasive bladder cancer at a 1 mg/mL concentration, by intravesical instillation. MMC is also used as an ophthalmic procedure in glaucoma care mostly with 0.2 mg/mL concentration. To accelerate syringes provision, it could be interesting to demonstrate the stability of the drug, in order to be able to prepare the chemotherapeutic drug several hours before the chemotherapy administration.
Methods: A stability indicating HPLC-UV method was developed and validated according to the ICH guidelines. Concentrations of the MMC stored at 25 °C and 60 % of relative humidity and protected from light in polypropylene syringes (1 mg/mL and 0.2 mg/mL) or glass vials (1 mg/mL) were evaluated for 96 h and compared to the initial observed concentrations.
Results: MMC stability was demonstrated in syringes and glass vials at 1 mg/mL only for 8 h in water for injections and for 10 h at 0.2 mg/mL in 0.9 % sodium chloride solutions, because relative concentrations (95 % confidence interval of the mean of 3 samples) were systematically over 90 % of the initial concentrations. After 96 h the relative concentrations were found below 80 % as compared to initial concentrations, thus indicating instability of these solutions. Degradation products were observed and remained below 3 %.
Conclusion: This study confirms that MMC solutions for ophthalmic application at 0.2 mg/mL or vesical instillation at 1 mg/mL have to be formulated extemporaneously to maintain the desired concentration
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