Non-thermal radio emission from Saturn

Direct, strong evidence for non-thermal radio emission from Saturn exists in the hectometric data observed by Imp 6. The planet has been tentatively identified as a decametric source, but the most sensitive and most recent data fail to confirm this. At metric or decimetric wavelengths Saturn has no non-thermal emission like Jupiter's synchrotron sources. Finally, a comparative study of Earth and Jupiter radio emissions suggests lightning discharges

Greenhouse abatement policy: insights from the G-cubed multi-country model

The third meeting of the Conference of the Parties of the Framework Convention on Climate Change held in Japan last December was a lost opportunity to set a realistic policy framework for addressing climate change in the coming decades. A number of countries proposed targets for greenhouse emissions, to be reached by a target date. The outcome was a range of different targets for each country. Analysis with the G‐cubed multi‐country model suggests that fixed targets are a costly way to address climate change. The extent of potential cost suggests the agreement will eventually fail. A better way to address climate change is to focus on uniformity in policy instruments that deliver differentiated outcomes rather than focus on differentiated policy settings.Resource /Energy Economics and Policy,

The effects of fiscal consolidation in the OECD

Despite the current recession in many parts of the OECD, fiscal consolidation is likely in many OECD economies in the 1990s. The author asks: is fiscal consolidation in the OECD in a period of low growth a recipe for global stagnation? In particular, what effects are likely in developing countries? The author starts with an overview of cuts in the U.S. fiscal deficit proposed by the Clinton administration and the extent to which European governments must cut fiscal deficits between now and 1997 to satisfy deficit targets in the Maastricht Treaty. How changes in fiscal policy are transmitted within an economy and between that economy and the rest of the world depends on whether those changes lead to permanent or temporary changes in government saving; whether they are implemented through government spending or taxes; and whether the taxes fall on households or firms. The main channels of transmission are through changes in: agents'expectations about future taxes, interest rates, exchange rates, and economic activity. The author uses the MSG2 multicountry models to quantify the ramifications of those changes. He concludes, among other things, that fiscal contraction in the OECD will probably lead to slower growth over the next several years. But the current and likely paths of fiscal policy are such that deficit reduction programs may have stimulating effect in the short run, as long as future fiscal contraction is credible. And fiscal deficit reduction will probably increase long-run output in the OECD through its effects on savings and investment. Finally, growth in the developing countries (at least total growth) may not be impaired at all by fiscal consolidationin the OECD. The negative effects of fiscal contraction will occur through lower net exports of non-OECD economies. For developing countries with open capital markets, the initial reduction in demand through lower exports can be offset by the reduction in interest rates following an inflow of capital from the countries with contracting fiscal policy. A significant decline in real global interest rates is likely to increase growth in developing countries that are debt-constrained, either directly (through private capital inflows) or indirectly (by relaxing the balance of payments constraint, allowing more resources to be channeled to domestic investment needs).Economic Theory&Research,Economic Stabilization,Environmental Economics&Policies,Banks&Banking Reform,Macroeconomic Management

Teaching mathematical modelling: demonstrating enrichment and elaboration

This paper uses a series of models to illustrate one of the fundamental processes of model building – that of enrichment and elaboration. The paper describes how a problem context is given which allows a series of models to be developed from a simple initial model using a queuing theory framework. The process encourages students to think about the assumptions being made within their models and how these assumptions may be relaxed to produce an enriched model

Acetylene reduction associated with zostera novazelandica Setch. and Spartina alterniflora Loisel., in Whangateau harbour, North Island, New Zealand

Nitrogen fixation (acetylene reduction) was investigated in Zostera novazelandica Setch. and Spartina alterniflora Loisel., in the North Island of New Zealand. Moderate rates of acetylene reduction were found in sediments in which plants were growing (means ± 95% confidence limit: 15.2 ± 2.8 |jmol C2H4 nrr2 h~l for Zostera and 24.7 ± 4.6 |amol C2H4 m~2 h"1 for Spartina). Activity was closely correlated with the dry weight of root; (r2 = 0.65, N = 15 for Zostera, and r2 = 0.85, A' =10 for Spartina). Sediment close to the plant beds, but without plants, exhibited only low rates of acetylene reduction (2.9 ± 2.2 and 4.5 ± l.OjLtmol C2H4 m~2 h"1, respectively). Sediments associated with Z. novazelandica and S. alterniflora in New Zealand exhibit moderate rates of nitrogenase activity compared to rates found in other countries. N fixation may contribute significantly to the nutrition of these plants in New Zealand estuaries

An application of dynamic programming to pattern recognition

technique which has found only limited usage in the Industrial and Business Management fields which are home to many other of the OR techniques. Its main application has been in problems o