Monitoring Hypoxia Conditions in Corpus Christi Bay – 2005

Hypoxia occurs predominantly in the southeastern region of Corpus Christi Bay in summer. During the summer of 2005, a moderate number of hypoxia events were found in spatial surveys in comparison to previous years. Disturbance by hypoxia did not significantly change over the nine year period sampled. Additional long-term sampling is needed to determine if disturbance caused by hypoxia is significantly changing over time in Corpus Christi Bay or if anthropogenic changes, such as the dredging of Packery Channel and brine discharge into Oso Bay will have an effect on the occurrence of hypoxic events.Coastal Bend Bay and Estuaries Program contract number 0528Marine Scienc

Matagorda Bay and Nearby Coastal Waters Dissolved Oxygen and pH TMDL Assessment Report

This project provides technical support to the Texas Commission on Environmental Quality (TCEQ) for the development of a Total Maximum Daily Load (TMDL). The TCEQ will lead an effort to assess the causes and sources of the following water quality problems identified in the 2002 Texas Water Quality Inventory and 303(d) List for Matagorda Bay/Powderhorn Lake (Segment 2451), which only partially supports the aquatic life use due to exceedence of the dissolved oxygen (DO) standard on the east half of the main bay; Tres Palacios/Turtle Bay (Segment 2452),which only partially supports the aquatic life use due to exceedance of the dissolved oxygen standard in the Palacios area assessment unit and Carancahua Bay (Segment 2456); which only partially supports the general use due to high pH in 9.2 square miles at the north end of the bay; and Carancahua Creek and Conn Brown Harbor (Segment 2483A), which does not support the aquatic life use in the entire harbor due to depressed dissolved oxygen. The goals of the current project were to develop a Quality Assurance Project Plan, to develop and implement a monitoring program to assess the DO conditions in Matagorda Bay, Tres Palacios Bay, and Conn Brown Harbor and the pH conditions in Carancahua Bay, and to assess the data collected from the monitoring plan and determine the cause of impairments that result in exceedence of the water quality criteria.Project Title: Total Maximum Daily Load (TMDL) AssessmentFinal Report Submitted To: Texas Commission On Environmental QualityUmbrella Contract No. 582-1-30479 (UTMSI) Total Maximum Daily Load Research Support Work Order No. 582-1-30479-07Marine Scienc

Five minutes with Anne Applebaum: “Putin cannot let Ukraine become a democratic, pro-European state”

Tensions have continued to rise in Crimea ahead of a planned referendum on the region seceding from Ukraine and joining Russia. In an interview with EUROPP’s Managing Editor Stuart Brown, Anne Applebaum discusses the importance of Vladimir Putin’s domestic situation to his handling of the crisis, the role of the Russian media in shaping public opinion, and why a key priority for the EU should be to enforce its own anti-corruption standards with regard to Russian investors

First exit times of solutions of stochastic differential equations driven by multiplicative Levy noise with heavy tails

In this paper we study first exit times from a bounded domain of a gradient dynamical system $\dot Y_t=-\nabla U(Y_t)$ perturbed by a small multiplicative L\'evy noise with heavy tails. A special attention is paid to the way the multiplicative noise is introduced. In particular we determine the asymptotics of the first exit time of solutions of It\^o, Stratonovich and Marcus canonical SDEs.Comment: 19 pages, 2 figure

The role of the nature of the noise in the thermal conductance of mechanical systems

Focussing on a paradigmatic small system consisting of two coupled damped oscillators, we survey the role of the L\'evy-It\^o nature of the noise in the thermal conductance. For white noises, we prove that the L\'evy-It\^o composition (Lebesgue measure) of the noise is irrelevant for the thermal conductance of a non-equilibrium linearly coupled chain, which signals the independence between mechanical and thermodynamical properties. On the other hand, for the non-linearly coupled case, the two types of properties mix and the explicit definition of the noise plays a central role.Comment: 9 pages, 2 figures. To be published in Physical Review

Fractional Fokker-Planck Equations for Subdiffusion with Space-and-Time-Dependent Forces

We have derived a fractional Fokker-Planck equation for subdiffusion in a general space-and- time-dependent force field from power law waiting time continuous time random walks biased by Boltzmann weights. The governing equation is derived from a generalized master equation and is shown to be equivalent to a subordinated stochastic Langevin equation.Comment: 5 page

Stationary Random Fields on the Unitary Dual of a Compact Group

We generalise the notion of wide-sense stationarity from sequences of complex-valued random variables indexed by the integers, to fields of random variables that are labelled by elements of the unitary dual of a compact group. The covariance is positive definite, and so it is the Fourier transform of a finite central measure (the spectral measure of the field) on the group. Analogues of the Cramer and Kolmogorov theorems are extended to this framework. White noise makes sense in this context and so, for some classes of group, we can construct time series and investigate their stationarity. Finally we indicate how these ideas fit into the general theory of stationary random fields on hypergroups

Transition Densities and Traces for Invariant Feller Processes on Compact Symmetric Spaces

We find necessary and sufficient conditions for a finite K–bi–invariant measure on a compact Gelfand pair (G, K) to have a square–integrable density. For convolution semigroups, this is equivalent to having a continuous density in positive time. When (G, K) is a compact Riemannian symmetric pair, we study the induced transition density for G–invariant Feller processes on the symmetric space X = G/K. These are obtained as projections of K–bi–invariant L´evy processes on G, whose laws form a convolution semigroup. We obtain a Fourier series expansion for the density, in terms of spherical functions, where the spectrum is described by Gangolli’s L´evy–Khintchine formula. The density of returns to any given point on X is given by the trace of the transition semigroup, and for subordinated Brownian motion, we can calculate the short time asymptotics of this quantity using recent work of Ba˜nuelos and Baudoin. In the case of the sphere, there is an interesting connection with the Funk–Hecke theorem

A Generalised Gangolli-Levy-Khintchine Formula for Infinitely Divisible Measures and Levy Processes on Semi-Simple Lie Groups and Symmetric Spaces

In 1964 R.Gangolli published a Levy-Khintchine type formula which characterised K bi-invariant infinitely divisible probability measures on a symmetric space G=K. His main tool was Harish-Chandra's spherical functions which he used to construct a generalisation of the Fourier transform of a measure. In this paper we use generalised spherical functions (or Eisenstein integrals) and extensions of these which we construct using representation theory to obtain such a characterisation for arbitrary infinitely divisible probability measures on a non-compact symmetric space. We consider the example of hyperbolic space in some detail