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In contrast to most hormonal biomarkers of the follicular status, anti-Müllerian hormone (AMH) is exclusively produced by the granulosa cells of a wide range of follicles (primary to the early antral stages), presumably FSH-independently and with little susceptibility to disorders of antral follicle growth during the luteal-follicular transition. This paper summarizes the authors' clinical research on the role of AMH as a marker of ovarian functioning. It shows that the relationship between antral follicle counts and serum AMH concentrations is stronger than that observed with FSH, inhibin B and oestradiol on day 3, and that intercycle reproducibility of AMH measurements is better than the latter parameters. In addition, peripheral AMH concentrations decline during ovarian stimulation, thus confirming that maturing follicles loose progressively their ability to produce AMH. Indeed, follicular fluid (FF) AMH concentrations in small antral follicles are 3 fold as high as AMH in pre-ovulatory follicles. Further, human chorionic gonadotrophin-driven luteinization additionally curtails follicular AMH production. Finally, AMH production measured in FF from individual follicles is increased in women having normal follicular counts and responsiveness to ovarian stimulation. Together, these data reinforce the soundness of AMH measurements as a quantitative and possibly qualitative marker of granulosa cell activity and health. [ABSTRACT FROM AUTHOR]

High levels of penetration of distributed generation (DG) are a new challenge for traditional electric power systems. Power injections from DGs change network power flows modifying energy losses. Although it is considered that DG reduce losses, this paper shows that this is not always true. This paper presents an approach to compute annual energy losses variations when different penetration and concentration levels of DG are connected to a distribution network. In addition, the impact on losses of different DG technologies, such as combined heat and power, wind power, photovoltaic, and fuel-cells, is analyzed. Results show that energy losses variation, as a function of the DG penetration level, presents a characteristic U-shape trajectory. Moreover, when DG units are more dispersed along network feeders, higher losses reduction can be expected. Regarding DG technologies, it should be noted that wind power is the one that shows the worst behavior in losses reduction. Finally, DG units with reactive power control provide a better network voltage profile and lower losses. [ABSTRACT FROM AUTHOR]

We describe a revised procedure for the numerical simulation of planetary nebulae luminosity functions (PNLFs), improving on previous work. The procedure is now based on new H-burning post-asymptotic giant branch (AGB) evolutionary tracks. For a given stellar mass, the new central stars are more luminous and evolve faster. We have slightly changed the distribution of the [O iii] 5007 intensities relative to those of and the generation of absorbing factors, while still basing their numerical modeling on empirical information extracted from studies of galactic planetary nebulae (PNs) and their central stars. We argue that the assumption of PNs being completely optically thick to H-ionizing photons leads to conflicts with observations and show that to account for optically thin PNs is necessary. We then use the new simulations to estimate a maximum final mass, clarifying its meaning, and discuss the effect of internal dust extinction as a possible way of explaining the persistent discrepancy between PNLFs and surface brightness fluctuation distances. By adjusting the range of minimum to maximum final mass, it is also possible to explain the observed variety of PNLF shapes at intermediate magnitudes. The new PN formation rates are calculated to be slightly lower than suggested by previous simulations based on older post-AGB evolutionary tracks. [ABSTRACT FROM AUTHOR]

The central star of the planetary nebula NGC 1514 is among the visually brightest central stars in the sky (V = 9.5). It has long been known to show a composite spectrum, consisting of an A-type star and a much hotter star responsible for the ionization of the surrounding nebula. These two stars have always been assumed to form a binary system. High-resolution spectrograms obtained with Espadons at the Canada–France–Hawaii Telescope on Maunakea have allowed us to measure good radial velocities for both stars: they differ by 13 ± 2 km s−1. The stellar velocities were unchanged after 500 days. We have also estimated the metallicity of the cooler star. Combining these data with other information available in the literature, we conclude that, unless all the published nebular radial velocities are systematically wrong, the cooler star is just a chance alignment, and the two stars are not orbiting each other. The cooler star cannot have played any role in the formation of NGC 1514. [ABSTRACT FROM AUTHOR]

In this paper, a probabilistic methodology for estimating the energy costs in the market for wind generators associated with wind prediction errors is proposed. Generators must buy or sell energy production deviations due to prediction errors when they bid in day-ahead or hour-ahead energy markets. The prediction error is modeled through a probability density function that represents the accuracy of the prediction model. Production hourly energy deviations and their associated trading costs are then calculated. Three study cases based on real wind power installations in Spain are analyzed. The three study cases show that the error prediction costs can reach as much as 10% of the total generator energy incomes. [ABSTRACT FROM AUTHOR]