Review of Solar and Reactor Neutrinos

Over the last several years, experiments have conclusively demonstrated that neutrinos are massive and that they mix. There is now direct evidence for $\nu_e$s from the Sun transforming into other active flavors while en route to the Earth. The disappearance of reactor $\bar{\nu}_e$s, predicted under the assumption of neutrino oscillation, has also been observed. In this paper, recent results from solar and reactor neutrino experiments and their implications are reviewed. In addition, some of the future experimental endeavors in solar and reactor neutrinos are presented.Comment: Proceedings of the XXII International Symposium on Lepton and Photon Interactions at High Energy (Lepton-Photon 2005, June 30 to July 5, 2005, Uppsala, Sweden). 11 figures, 5 table

Trading Posts along the Yukon River: Noochuloghoyet Trading Post in Historical Context

Between 1868 and 1900, American companies established a series of trading posts along a 32 km stretch of the Yukon River immediately west of Noochuloghoyet Point, a peninsula formed by the confluence of the Yukon and Tanana rivers. This study makes use of written historical accounts, historical maps, and archaeological evidence to trace the founding and locational movements of these posts. Findings indicate that in the early interior of Alaska rivers were the major transportation routes, and the English and the Russians established trading posts at major river confluences, which became centers for trade. Later, the Americans pursued patterns inherited earlier from the English and the Russians. Political considerations provided the original reason for discovery and some constraints; nevertheless economic and environmental factors appear to have been the more important considerations in the exploration and development of the Yukon River valley. Cultural considerations were only important in that they bracketed the manner in which the Euro-Americans operated.Key words: fur traders, trading posts, Yukon River, historical maps, historical sitesRÉSUMÉ. Entre 1868 et 1900, des compagnies américaines établirent des postes de traite répartis sur vingt milles le long du cours du Yukon, immédiatement à l’ouest de Noochuloghoyet Point, la péninsule formée par la confluence du Yukon et de la rivière Tanana. La présente étude se sert derécits historiques écrits, de cartes historiques et de preuves archéologiques pour retracer la fondation et les déplacements de ces postes. Les résultats indiquent que, dans l’intérieur de l’Alaska, les cours d’eau étaient les principales voies de transport et que les Anglais et les Russes établirent, aux grands confluents de ces voies d’eau, des postes de traite qui devinrent des centres commerciaux. Les Américains reprirent le modèle des Anglais et des Russes. Ce sont des considérations politiques qui furent a l’origine de la découverte - et qui y attachèrent certaines restrictions- , mais les facteurs économiques et écologiques semblent avoir été des considérations encore plus importantes dans l’exploration et l’exploitation de la vallée du Yukon. Les considérations culturelles n’ont été importantes que dans la mesure où elles ont imposé aux Euraméricains des limites sur leur façon d’opérerMots clés: trappeurs, postes de traite, Yukon, cartes historiques, sites historique

Instability strips of SPB and beta Cephei stars: the effect of the updated OP opacities and of the metal mixture

The discovery of $\beta$ Cephei stars in low metallicity environments, as well as the difficulty in theoretically explaining the excitation of the pulsation modes observed in some $\beta$ Cephei and hybrid SPB-$\beta$ Cephei pulsators, suggest that the ``iron opacity bump'' provided by stellar models could be underestimated. We analyze the effect of uncertainties in the opacity computations and in the solar metal mixture, on the excitation of pulsation modes in B-type stars. We carry out a pulsational stability analysis for four grids of main-sequence models with masses between 2.5 and 12 $\rm M_\odot$ computed with OPAL and OP opacity tables and two different metal mixtures. We find that in a typical $\beta$ Cephei model the OP opacity is 25% larger than OPAL in the region where the driving of pulsation modes occurs. Furthermore, the difference in the Fe mass fraction between the two metal mixtures considered is of the order of 20%. The implication on the excitation of pulsation modes is non-negligible: the blue border of the SPB instability strip is displaced at higher effective temperatures, leading to a larger number of models being hybrid SPB-$\beta$ Cephei pulsators. Moreover, higher overtone p-modes are excited in $\beta$ Cephei models and unstable modes are found in a larger number of models for lower metallicities, in particular $\beta$ Cephei pulsations are also found in models with Z=0.01.Comment: Accepted for publication in MNRAS Letter

A functional central limit theorem for a Markov-modulated infinite-server queue

The production of molecules in a chemical reaction network is modelled as a Poisson process with a Markov-modulated arrival rate and an exponential decay rate. We analyze the distributional properties of $M$, the number of molecules, under specific time-scaling; the background process is sped up by $N^{\alpha}$, the arrival rates are scaled by $N$, for $N$ large. A functional central limit theorem is derived for $M$, which after centering and scaling, converges to an Ornstein-Uhlenbeck process. A dichotomy depending on $\alpha$ is observed. For $\alpha\leq1$ the parameters of the limiting process contain the deviation matrix associated with the background process.Comment: 4 figure