Advancing an Ecosystem Approach in the Gulf of Maine

<i>Abstract</i>.—Numerous studies have examined the dynamics of zooplankton in the Gulf of Maine. Here the authors reanalyze relationships found in these prior studies, using updated data, with the goal of evaluating previously identified zooplankton– environment linkages. These reanalyses support the finding that major changes occurred in the zooplankton community during the late 1980s and again in the late 1990s. Evidence for a broader change in the ecosystem during these periods and mechanisms responsible for changes in the zooplankton are discussed. In general, the results of previous studies are upheld, but it is shown that the relationship between the environmental indicators and zooplankton change through time. This result implies that all data collected in the Gulf of Maine must be considered within a historical context and that the observed environmental–zooplankton linkages are still not well understood. It is possible that changes in the seasonal cycle or shifts in the pressures systems responsible for the North Atlantic oscillation result in nonstationary environmental–zooplankton relations. These results indicate that a mechanistic understanding is required to explain the documented environment–zooplankton linkages rather than correlative explanations. Since the causes of the late-1980s and late-1990s regime shifts are still unclear, future ecosystem-based management in the Gulf of Maine must be supported by continued observation and analysis to identify ecosystem changes soon after they occur. Scenario-driven modeling also is needed to provide guidance as to how the ecosystem will respond to future changes in zooplankton abundance and community structure.

Forced Oscillation of Second-Order Half-Linear Dynamic Equations on Time Scales

We will establish a new interval oscillation criterion for second-order half-linear dynamic equation(r(t)[xΔ(t)]α)Δ+p(t)xα(σ(t))=f(t)on a time scaleTwhich is unbounded, which is a extension of the oscillation result for second order linear dynamic equation established by Erbe et al. (2008). As an application, we obtain a sufficient condition of oscillation of the second-order half-linear differential equation([x′(t)]α)′+csintxα(t)=cos⁡t, whereα=p/q,p,qare odd positive integers.

Current Status of the MiniBooNE Experiment

MiniBooNE is an experiment designed to refute or confirm the LSND [Formula: see text] oscillation result. MiniBooNE will look for oscillations of νμ → νe in a closed-box appearance analysis. MiniBooNE began collecting data in 2002, and is expected to continue data taking through 2005. Current MiniBooNE results are presented.