Arctic Marine Phototrophic Systems: Functions of Sea Ice Stabilization

A forgotten nineteenth-century report provides evidence that there are two floras, not one, on the bottom of arctic sea ice, distinguishable in time, species composition, and, perhaps, nutrient condition. A halocline flora is also noted from recent studies that is analogous in habitat to the ice floras. Thus at least three separate autotrophic systems augment phytoplankton production in arctic seas. These augmenting systems seem to be a function of stability provided by sea ice.Key words: sea ice, ice algae, phytoplankton, halocline flora, ecosystem stabilityMots clés: glace marine, algue marine, phytoplancton, flore halocline, stabilité de l'écosystèm

Chlorophyll in Arctic Sea Ice

Reviews investigations 1961-1963 into chlorophyll concentrations in sea ice in both arctic and antarctic regions. Results are compared with own researches off Devon Island, Canada, which are reported in detail. Chlorophyll a and c concentrations were obtained from underside of ice by a 7.5 cm diam ice corer and light penetration was measured by freezing a photometer into the ice; readings of both are tabulated. Chlorophyll values exceed concentrations in open sea water. The values were found to fall with increased light, and the high ratio of c to a is interpreted as a adaptation for maximum absorption of blue light through ice and snow. The algae are associated mainly with young ice peripheral to the Arctic Ocean. As a primary production resource, an estimated volume of 25 X 10*6 kg of chlorophyll a for a two-month for the arctic region is considered conservative

Estimate of CP Violation for the LBNE Project and $\delta_{CP}

Measurements of CP violation (CPV) and the basic $\delta_{CP}$ parameter are the goals of the LBNE Project, which is being planned. Using the expected energy and baseline parameters for the LBNE Project, CPV and the dependence of CPV on $\delta_{CP}$ are estimated, to help in the planning of this project.Comment: 7 pages, 1 figur

Viewing Lepton Mixing through the Cabibbo Haze

We explore the hypothesis that the Cabibbo angle is an expansion parameter for lepton as well as quark mixing. Cabibbo effects are deviations from zero mixing for the quarks but are deviations from unknown mixings for the leptons, such that lepton mixing is veiled by a Cabibbo haze. We present a systematic classification of parametrizations and catalog the leading order Cabibbo effects. We find that the size of the CHOOZ angle is not always correlated with the observability of CP violation. This phenomenological approach has practical merit both as a method for organizing top-down flavor models and as a guideline for planning future experiments.Comment: References added, minor typos fixe

Mass Hierarchy Determination Using Neutrinos from Multiple Reactors

We report the results of Monte Carlo simulations of a medium baseline reactor neutrino experiment. The difference in baselines resulting from the 1 km separations of Daya Bay and Ling Ao reactors reduces the amplitudes of 1-3 oscillations at low energies, decreasing the sensitivity to the neutrino mass hierarchy. A perpendicular detector location eliminates this effect. We simulate experiments under several mountains perpendicular to the Daya Bay/Ling Ao reactors, considering in particular the background from the TaiShan and YangJiang reactor complexes. In general the hierarchy can be determined most reliably underneath the 1000 meter mountain BaiYunZhang, which is 44.5 km from Daya Bay. If some planned reactors are not built then nearby 700 meter mountains at 47-51 km baselines gain a small advantage. Neglecting their low overhead burdens, hills near DongKeng would be the optimal locations. We use a weighted Fourier transform to avoid a spurious dependence on the high energy neutrino spectrum and find that a neural network can extract quantities which determine the hierarchy marginally better than the traditional RL + PV.Comment: 22 pages, added details on the neural network (journal version

Revealing spectrum features of stochastic neuron spike trains

Power spectra of spike trains reveal important properties of neuronal behavior. They exhibit several peaks, whose shape and position depend on applied stimuli and intrinsic biophysical properties, such as input current density and channel noise. The position of the spectral peaks in the frequency domain is not straightforwardly predictable from statistical averages of the interspike intervals, especially when stochastic behavior prevails. In this work, we provide a model for the neuronal power spectrum, obtained from Discrete Fourier Transform and expressed as a series of expected value of sinusoidal terms. The first term of the series allows us to estimate the frequencies of the spectral peaks to a maximum error of a few Hz, and to interpret why they are not harmonics of the first peak frequency. Thus, the simple expression of the proposed power spectral density (PSD) model makes it a powerful interpretative tool of PSD shape, and also useful for neurophysiological studies aimed at extracting information on neuronal behavior from spike train spectra

Construction, Management and Visualization of 3D Models of Large Archeological and Architectural Sites for E-Heritage GIS Systems

In this paper we present an integrated system developed in order to record, construct, pre-process, manage, visualize and visually navigate 3D models reality based of large archeological and architectural sites for eHeritage GIS systems. The framework integrates structured geometrical and documentary information resulting from multiple sources with the aim to enhance the knowledge of those sites within the frame of its historical evolution and its institutional management in a 3D GIS/DB. The developed applications were designed for different types of users, with a largely scalable interface, able to support different output devices and to work at different levels of iconicity. The system allows a full comprehension of the buildings in their own context, permitting to discover unknown relationships, to evaluate their architectural occupancy and to quickly access a complex system of information. The framework has been tested in two different systems - designed and developed to satisfy both internal (cataloguing, documentation, preservation, management of archaeological heritage) and external (communication through the web portal) purposes: the first, in Pompeii, developed in order to have a web-based system that uses Open Source software and complies with national and international standards; the second one, a prototype designed to make available on the Google Earth platform the complete Palladian corpus documentation implemented by the CISAAP

Protected areas as refuges for pest species? The case of wild boar

Abstract Protected areas are often blamed for offering refuge to pest species populations, giving rise to the so-called "reserve effect". Nevertheless, this major conservation side effect has seldom been investigated or verified on a local scale. Along the borders of two protected areas of different size, we modelled wild boar individual likelihood of being either inside or outside the protected areas throughout the year, considering their activity rhythms and resource availability. No evidence of reserve effect was found in the small protected area, yet the percentage of wild boar moving across the border was smaller in the large one. Moreover, although wild boar use of the large protected area resulted to increase in autumn, we showed that this was not the consequence of hunting avoidance. Our results clearly highlighted the importance to verify reserve effect on a local scale with studies based on detailed information on animal spatial behaviour and environmental variables

Degeneracies at a beta-Beam and a Super-Beam Facility

The presence of degeneracies can considerably worsen the measure of the neutrino oscillation parameters $\theta_{13}$ and $\delta$. We study the physics reach of a specific ``CERN'' setup, using a standard $\beta$-Beam and Super-Beam facility. These facilities have a similar sensitivity in both parameters. Their combination does not provide any dramatic improvement as expected due to their almost identical L/E ratio. We analyse if adding the correspondent disappearance channels can help in reducing the effect of degeneracies in the $(\theta_{13},\delta)$ measure.Comment: 5 pages, 7 eps figure

Observation of Neutrons with a Gadolinium Doped Water Cerenkov Detector

Spontaneous and induced fission in Special Nuclear Material (SNM) such as 235U and 239Pu results in the emission of neutrons and high energy gamma-rays. The multiplicities of and time correlations between these particles are both powerful indicators of the presence of fissile material. Detectors sensitive to these signatures are consequently useful for nuclear material monitoring, search, and characterization. In this article, we demonstrate sensitivity to both high energy gamma-rays and neutrons with a water Cerenkov based detector. Electrons in the detector medium, scattered by gamma-ray interactions, are detected by their Cerenkov light emission. Sensitivity to neutrons is enhanced by the addition of a gadolinium compound to the water in low concentrations. Cerenkov light is similarly produced by an 8 MeV gamma-ray cascade following neutron capture on the gadolinium. The large solid angle coverage and high intrinsic efficiency of this detection approach can provide robust and low cost neutron and gamma-ray detection with a single device.Comment: 7 pages, 4 figures. Submitted to Nuclear Instruments and Methods,