A model for the vertical flux of nitrogen in the upper ocean: Simulating the alteration of isotopic ratios

An idealized, one-dimensional, constant diffusivity mathematical model for the study of the vertical flux of nitrogen in the upper-ocean is presented. We attempt to simulate observed patterns in vertical profiles for the natural abundance of 15N in particulate organic nitrogen (PON) and the concentrations of PON and NO3−. The concentration of phytoplankton nitrogen (II) increased as a result of either increasing the upward flux of NO3−(N) or by increasing the residence time of II. A minimum in the δ15N of phytoplankton nitrogen (δ2) appeared near a maximum in II at the inflection point of the N profile. Increasing the residence time or the vertical eddy diffusivity, reduced the amplitude of the δ2 profile. The model was able to produce reasonably good simulations of observed profiles from two warm-core rings, Rings 82-E and 82-H, using the most appropriate values for the light extinction coefficient and the residence time of PON. These results lend general support to current views regarding the nature and significance of the vertical fluxes of nitrogen in the upper-ocean and hypotheses presented previously concerning the factors which affect the δ15N of PON

Statistical Mechanical Theory of a Closed Oscillating Universe

Based on Newton's laws reformulated in the Hamiltonian dynamics combined with statistical mechanics, we formulate a statistical mechanical theory supporting the hypothesis of a closed oscillating universe. We find that the behaviour of the universe as a whole can be represented by a free entropic oscillator whose lifespan is nonhomogeneous, thus implying that time is shorter or longer according to the state of the universe itself given through its entropy. We conclude that time reduces to the entropy production of the universe and that a nonzero entropy production means that local fluctuations could exist giving rise to the appearance of masses and to the curvature of the space

Epidermoid cyst of the floor of the mouth: two case reports

This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

Hydrographic data from the OPTOMA Program: OPTOMA11, 5-June-5 August, 1984

The six cruises and one aircraft flight comprising OPTOMA11 were undertaken in June, July and August 1984 to sample two subdomains of the California Current. This report presents the hydrographic data, acquired by XBT, AXBT and CTD casts, from the cruises and the flight.Research project "Ocean Prediction Through Observations, Modeling and Analysis" sponsored by the Physical Oceanography Program of the Office of Naval Research under Program Element 61153N.http://archive.org/details/hydrographicdata011wittN000148WR24051NAApproved for public release; distribution is unlimited