Generalized Binomial Probability Distributions attached to Landau levels on the Riemann sphere

A family of generalized binomial probability distributions attached to Landau levels on the Riemann sphere is introduced by constructing a kind of generalized coherent states. Their main statistical parameters are obtained explicitly. As application, photon number statistics related to coherent states under consideration are discussed.Comment: 12 pages, 1 figure. This is a revised and improved exposition. Typos corrected and references adde

Generalized second Bargmann transforms associated with the hyperbolic Landau levels on the Poincar\'e disk

We deal with a family of generalized coherent states associated to the hyperbolic Landau levels of the Schr\"odinger operator with uniform magnetic field on the Poincar\'e disk. Their associated coherent state transforms constitute a class of generalized second Bargmann transforms.Comment: 7 page

Study of IDF curves established by the property of scale invariance in Tunis

This work focuses on the study of intensity-duration-frequency (IDF) curves of Tunis-Manoubia station located in Tunis (Tunisia). The assumption of simple scale invariance combined with the Gumbel distribution was used to develop the formulas of IDF curves. Indeed, firstly, the scale exponent was derived using all analyzed reference periods (5, 10, 15, 20, 30, 40, 50, 60, 90, 120, 180 minutes and 24 hours). It should be noted that the daily rainfall intensities are corrected using the coefficient of Weiss to obtain those of 24 hours. However, the study of probability weighted moments unveiled a scale break at 30 minutes. Hence, there are two intervals each one characterized by a simple scale invariance and a scale exponent namely [5 minutes - 30 minutes] and [30 minutes - 24 hours]. IDF curves obtained by simple scaling were compared with those experimental one determined by DGRE (Directorate General of Water Resources of Tunisia). It proved that the maximum intensities estimated by DGRE for different return times (2, 5, 10, 20, 58, 100 years) are overestimated for durations of references less than 30 minutes which is oversize hydraulic works, whose design is based on these curves such as dams and sewage works. Since the rainfall data at high resolution (minutes to hours) are not available because most stations are equipped with non-recording gauges. Only totals are available, hence the interest of this method is the estimation of maximum intensity for periods less than one day using only daily data

Regionalization of IDF curves using the property of scale invariance

Networks of daily rainfall raingauges are often much dense than tippet bucket raingages networks. Consequently, it would be of high interest to make use of daily rainfall information assessing IDF curves for unobserved locations. The present work proposes achieving this goal by using the assumption of simple scale invariance. The simple scaling property is identified using the fitting of regression of log transforms of rainfall statistical moments of order q versus log transforms of rainfall durations (scale). In case where the relation of slopes versus moment orders is linear, "simple scaling invariance" is assumed (Gupta et Waymire, 1990). Yu et al. (2004), Bara et al. (2009) as well as Ceresetti et al., (2010) adopted the assumptions of simple scaling to maximum annual rainfall for durations in the interval 30 mn to 24 h. Thus, using 24h-rainfall totals, they suggested estimating quantiles of rainfall intensities of short durations using quantiles of 24 h rainfall. In the present work, series constituted by the N most important maximum annual intensities observed during N years in 15 stations are studied. Observed intensities for various time resolutions extending from 5 minutes to 24 h are available. The period of observation is 1950 to 2001. Two simple scale invariance behaviors are identified namely a scale regime in the interval [5 minutes - 30 minutes] and another in the interval [30 minutes - 24 hours] for all stations. The study focuses on durations in the interval [30 minutes - 24 hours]. The resulting scale exponents vary from k=0.55 to k=0.89 for the resolutions [30 minutes - 24 hours] and vary from k=0.40 to k=0.65 for [5 minutes - 30 minutes] resolutions. Furthermore, for regionalization purposes, a power low regression is fitted and cross-validated between the estimated scale exponents and 90th percentile of sample maximum annual daily rainfall

Effects of metal ions on cyprinid fish immune response: In vitro effects of Zn2+ and Mn2+ on the mitogenic response of carp pronephros lymphocytes

International audienceLymphocytes from the pronephros of carp (Cyprinus carpio L) have been subjected to transformation by mitogens, concanavalin A (Con A), phytohemagglutinin (PHA), and lipopolysaccharides (LPS), with Zn or Mn at varying concentrations. Addition of Zn2+ (10−7 to 10−3 M) to mitogen-stimulated T and B cells enhanced [3H]thymidine incorporation. Addition of 10−5 M Zn2+ inhibited the response to Con A, PHA, and LPS. At this concentration, Zn was toxic. Addition of Mn2+ (10−7 to 10−3 M) to mitogen-stimulated lymphocytes enhanced [3H]thymidine incorporation. This effect was observed with Con A- and PHA-stimulated lymphocytes, but not with LPS-stimulated lymphocytes. In contrast, addition of 10−1 M Mn2+ to lymphocyte cultures exerted an inhibitor effect on the response to Con A or to PHA, while the response to LPS was unaffected. Addition of 10−1 M Mn2+ to Con A- or PHA-stimulated cultures at different times after initiation of stimulation indicated that Mn2+ was inhibitory only when it was added before the first 16 hr of cultures. The inhibition induced by 10−1 M Mn2+ could be reversed by adding 2 mM CaCl2 to the culture