The Challenges E-Commerce Poses to the Determination of a Taxable Presence: the “Permanent Establishment†Concept Analyzed From a South African Perspective

It is a principle of International tax law that a country may not tax the business profits of a non-resident enterprise unless those profits are attributed to a “permanent establishmentâ€located in the source country. A “permanent establishment†is defined as a fixed place of businessthrough which the enterprise is wholly or partly carried on. The “business establishment†concept ishowever based on the world where there had to be a physical presence of the business in order for itsprofits to be taxed. The requirement of a fixed place of business faces challenges when trade isconducted electronically as e-commerce makes it difficult to identifying a taxable presence in thesource country. This article analyses the challenges that e-commerce poses to the “permanentestablishment†concept

Nonlinear models of the bump cepheid HV 905 and the distance modulus to the large magellanic cloud

Nonlinear pulsation models have been used to simulate the light curve of the LMC bump Cepheid HV 905. In order to reproduce the light curve accurately, tight constraints on the input parameters M, L, and T-eff are required. The results, combined with accurate existing V and I photometry, yield an LMC distance modulus of 18.51 +/- 0.05, and they show that the luminosity of HV 905 is much higher than expected from the mass-luminosity relation of stellar evolution theory. If we assume that the pulsation models are accurate, this suggests that there is a larger amount of convective core overshoot during the main-sequence evolution of stars with M similar to 5 M. than is usually assumed

Impacts Environnementaux De La Gestion Des Déchets Solides Ménagers Dans La Cite Lacustre De Ladji Au Sud Du Benin

La recherche de meilleures conditions d’hygiène et d’assainissement, doit s’inscrire au premier rang des préoccupations de nos municipalités, car l’insalubrité à laquelle nous assistons dans nos villes, continue de dégrader l’environnement et la santé des populations, freinant ainsi le développement urbain.L’évaluation de la gestion des déchets solides ménagers dans la cité lacustre de Ladji a révélé l’inexistence d’un mode de gestion adéquat. Les DSM sont en grande partie rejetés directement dans le lac causant une pollution aussi bien organique, chimique que microbienne. Ainsi, le Lac, ressource vitale, se trouve transformer à la fois en un réservoir sans aucun traitement pour les fèces et en même temps comme poubelle pour les DSM. "Qui sème les déchets récolte la pollution" dit-on, ainsi, les maladies liées à un défaut d’assainissement, surtout, celles d’origine  hydro-fécales, sont au rendez-vous, signe de risque pour la santé publique. Les principales maladies sont : le paludisme, le choléra, la dysenterie et la fièvre typhoïde. De façon générale l’environnement de Ladji n’est pas sain, la pollution y est visible. D’importants efforts sont à faire sur le plan information, éducation et communication avec la population.Pour lutter contre la pollution du lac et améliorer les conditions de vie de la population de Ladji, les suggestions suivantes sont formulées à l’endroit des autorités et institutions compétentes qui interviennent dans la gestion des déchets solides ménagers et excrétas. Il s’agit de :-          Mettre en place des latrines publiques et privées ECOSAN afin de lutter contre la pollution par la défécation du lac ;-          Mettre en place une structure de gestion des déchets, afin de lutter contre la pollution du lac par le rejet des DSM ;-          Faire de vastes campagnes de sensibilisation de la population sur les règles d’hygiène et les bonnes pratiques ;-          Informer, Eduquer et Communiquer avec la population sur la gestion des déchets solides ménagers

A Database of Cepheid Distance Moduli and TRGB, GCLF, PNLF and SBF Data Useful for Distance Determinations

We present a compilation of Cepheid distance moduli and data for four secondary distance indicators that employ stars in the old stellar populations: the planetary nebula luminosity function (PNLF), the globular cluster luminosity function (GCLF), the tip of the red giant branch (TRGB), and the surface brightness fluctuation (SBF) method. The database includes all data published as of July 15, 1999. The main strength of this compilation resides in all data being on a consistent and homogeneous system: all Cepheid distances are derived using the same calibration of the period-luminosity relation, the treatment of errors is consistent for all indicators, measurements which are not considered reliable are excluded. As such, the database is ideal for inter-comparing any of the distance indicators considered, or for deriving a Cepheid calibration to any secondary distance indicator. Specifically, the database includes: 1) Cepheid distances, extinctions and metallicities; 2) apparent magnitudes of the PNLF cutoff; 3) apparent magnitudes and colors of the turnover of the GCLF (both in the V- and B-bands); 4) apparent magnitudes of the TRGB (in the I-band) and V-I colors at and 0.5 magnitudes fainter than the TRGB; 5) apparent surface brightness fluctuation magnitudes I, K', K_short, and using the F814W filter with the HST/WFPC2. In addition, for every galaxy in the database we give reddening estimates from DIRBE/IRAS as well as HI maps, J2000 coordinates, Hubble and T-type morphological classification, apparent total magnitude in B, and systemic velocity. (Abridged)Comment: Accepted for publication in the Astrophysical Journal Supplement Series. Because of space limitations, the figures included are low resolution bitmap images. Original figures can be found at http://www.astro.ucla.edu/~laura/pub.ht

The HST Key Project on the Extragalactic Distance Scale XXV. A Recalibration of Cepheid Distances to Type Ia Supernovae and the Value of the Hubble Constant

Cepheid-based distances to seven Type Ia supernovae (SNe)-host galaxies have been derived using the standard HST Key Project on the Extragalactic Distance Scale pipeline. For the first time, this allows for a transparent comparison of data accumulated as part of three different HST projects, the Key Project, the Sandage et al. Type Ia SNe program, and the Tanvir et al. Leo I Group study. Re-analyzing the Tanvir et al. galaxy and six Sandage et al. galaxies we find a mean (weighted) offset in true distance moduli of 0.12+/-0.07 mag -- i.e., 6% in linear distance -- in the sense of reducing the distance scale, or increasing H0. Adopting the reddening-corrected Hubble relations of Suntzeff et al. (1999), tied to a zero point based upon SNe~1990N, 1981B, 1998bu, 1989B, 1972E and 1960F and the photometric calibration of Hill et al. (1998), leads to a Hubble constant of H0=68+/-2(random)+/-5(systematic) km/s/Mpc. Adopting the Kennicutt et al. (1998) Cepheid period-luminosity-metallicity dependency decreases the inferred H0 by 4%. The H0 result from Type Ia SNe is now in good agreement, to within their respective uncertainties, with that from the Tully-Fisher and surface brightness fluctuation relations.Comment: Accepted for publication in The Astrophysical Journal. 62 pages, LaTeX, 9 Postscript figures. Also available at http://casa.colorado.edu/~bgibson/publications.htm

The HST Key Project on the Extragalactic Distance Scale. XXVIII. Combining the Constraints on the Hubble Constant

Since the launch of the Hubble Space Telescope nine years ago, Cepheid distances to 25 galaxies have been determined for the purpose of calibrating secondary distance indicators. A variety of these can now be calibrated, and the accompanying papers by Sakai, Kelson, Ferrarese, and Gibson employ the full set of 25 galaxies to consider the Tully-Fisher relation, the fundamental plane of elliptical galaxies, Type Ia supernovae, and surface brightness fluctuations. When calibrated with Cepheid distances, each of these methods yields a measurement of the Hubble constant and a corresponding measurement uncertainty. We combine these measurements in this paper, together with a model of the velocity field, to yield the best available estimate of the value of H_0 within the range of these secondary distance indicators and its uncertainty. The result is H_0 = 71 +/- 6 km/sec/Mpc. The largest contributor to the uncertainty of this 67% confidence level result is the distance of the Large Magellanic Cloud, which has been assumed to be 50 +/- 3 kpc

Cluster AgeS Experiment (CASE): RR Lyrae stars from the globular cluster Omega Centauri as standard candles

New photometry of RRab and RRc stars in Omega Cen is used to calibrate their absolute magnitudes M_V as a function of: a) metallicity; and b) the Fourier parameters of light curves in the V band. The zero point of both calibrations relies on the distance modulus to the cluster derived earlier by the CASE project based on observations of the detached eclipsing binary OGLE GC17. For RRab variables we obtained a relation of M_V=(0.26\pm 0.08)[Fe/H]+(0.91\pm 0.13). A dereddened distance modulus to the LMC based on that formula is $\mu_{0}=18.56\pm 0.14$ mag. The second calibration of M_V, which is based on Fourier coefficients of decomposed light curves, results in the LMC distance of $\mu_{0}=18.51\pm 0.07$ mag.Comment: accepted for publication in MNRAS, 13 pages, 8 figure