Incentives for public investment under fiscal rules

The authors explore the relationship between fiscal rules and capital budgeting. The current budgetary approach to limit deficits to a fixed portion of GDP or to balance budgets could undermine incentives to invest in public capital with long-run returns since politicians concerned about electoral prospects would favor expenditures providing immediate benefits to their voters. An alternative budgetary approach is to separate capital from current revenues and expenditures and relax fiscal constraints by allowing governments to finance capital expenditures with debt, as suggested by the golden rule approach to capital funding. But the effect of capital budgeting would be to provide opportunities to politicians to escape the fiscal rule constraints by shifting current expenditures into capital accounts that are difficult to measure properly, thereby leading to increased borrowing. As an alternative, the authors propose a modified golden rule limiting debt finance to a proportion of the government's investment in self-liquidating assets.Public Sector Economics&Finance,Investment and Investment Climate,Economic Theory&Research,Public&Municipal Finance,Urban Economics

Term Limits and Electoral Accountability

Periodic elections are the main instrument through which voters can hold politicians accountable. From this perspective term limits, which restrict voters' ability to reward politicians with re-election, appear counterproductive. We show that despite the disciplining effect of elections, term limits can be ex ante welfare improving from the perspective of voters. By reducing the value of holding office term limits can induce politicians to implement policies that are closer to their private preferences. Such "truthful" behavior by incumbents in turn results in better screening of incumbents. We show that the combination of these two effects can strictly increase the utility of voters.Political Agency, Accountability, Term Limits

An update on the correlation between the cosmic radiation intensity and the geomagnetic AA index

A statistical study between the cosmic ray intensity, as observed by a neutron monitor, and of the geomagnetic aa index, as representative of perturbations in the plasma and interplanetary magnetic field in the heliosphere, has been updated to specifically exclude time periods around the reversal of the solar magnetic field. The results of this study show a strong negative correlation for the period 1960 through 1968 with a correlation coefficient of approximately -0.86. However, there is essentially no correlation between the cosmic ray intensity and the aa index for the period 1972-1979 (i.e. correlation coefficient less than 0.16). These results would appear to support the theory of preferential particle propagation into the heliosphere vis the ecliptic during the period 1960-1968 and via the solar polar regions during 1972-1979

Epitaxial-strain-induced multiferroicity in SrMnO3_{3} from first principles

First-principles density-functional calculations reveal a large spin-phonon coupling in cubic SrMnO$_{3}$, with ferromagnetic ordering producing a polar instability. Through combination of this coupling with the strain-polarization coupling characteristic of perovskites, the bulk antiferromagnetic paraelectric ground state of SrMnO$_3$ is shown to be driven to a previously unreported multiferroic ferroelectric-ferromagnetic state by increasing epitaxial strain, both tensile and compressive. This state has a computed polarization and estimated Curie temperature above 54 $\mu$C/cm$^2$ and 92 K. Large mixed magnetic-electric-elastic responses are predicted in the vicinity of the phase boundaries.Comment: 5 pages, 2 figures, 1 tabl

Team Cognitive Ability as a Predictor of Team Performance

This manuscript presents two studies of the relationship between team cognitive ability (average Scholastic Aptitude Test score of team members) and team performance (a subjective coach\u27s evaluation and an objective measure using Sagarin\u27s Power Rankings) among NCAA Division 1 Men\u27s Basketball teams. Study 1 was conducted following the 1991-92 season whereas Study 2 was conducted during the 1993-94 season. Both studies indicated that team cognitive ability was significantly related to the coach\u27s evaluation but not to the power ranking measure, and that team strategy moderated the relationship between cognitive ability and the coach\u27s evaluation of performance. Cognitive ability moderated the relationship between team strategy and power ranking, but the nature of the interaction was different across the two studies

Nanoscale-targeted patch-clamp recordings of functional presynaptic ion channels

Important modulatory roles have been attributed to presynaptic NMDA receptors (NMDARs) located on cerebellar interneuron terminals. Evidence supporting a presynaptic location includes an increase in the frequency of mini events following the application of NMDA and gold particle-labelled NMDA receptor antibody localisation. However, more recent work, using calcium indicators, casts doubt on the idea of presynaptic NMDARs because basket cell varicosities did not show the expected calcium rise following either the local iontophoresis of L-aspartate or the two-photon uncaging of glutamate. (In theory such calcium imaging is sensitive enough to detect the calcium rise from even a single activated receptor.) It has therefore been suggested that the effects of NMDA are mediated via the activation of somatodendritic channels, which subsequently cause a subthreshold depolarization of the axon. Here we report results from a vibrodissociated preparation of cerebellar Purkinje cells, in which the interneuron cell bodies are no longer connected but many of their terminal varicosities remain attached and functional. This preparation can retain both inhibitory and excitatory inputs. We find that the application of NMDA increases the frequency of both types of synaptic event. The characteristics of these events suggest they can originate from interneuron, parallel fiber and even climbing fiber terminals. Interestingly, retrograde signalling seems to activate only the inhibitory terminals. Finally, antibody staining of these cells shows NMDAR-like immunoreactivity co-localised with synaptic markers. Since the Purkinje cells show no evidence of postsynaptic NMDAR-mediated currents, we conclude that functional NMDA receptors are located on presynaptic terminals

Studies on exploiting semiochemicals for pest management in organic farming systems OF0188

This study addresses the extent to which pest management systems can exploit semiochemicals (defined below) in ways acceptable to organic farming, and determines where the science base needs to be expanded to accommodate specific problems arising in an increasing organic farming sector. It considers whether current knowledge of semiochemical release from particular crop plants, herbs and wild plant species could be investigated further in relation to organic farming practice and identifies how strategies of multiple cropping, that exploit known semiochemical interactions, could be applied to key pest problems in organic production. Where such exploitation is not feasible, other strategies using semiochemicals including traps, extracts of natural products and nature-identical synthetic products are considered. Finally, general and specific directions in which research and development could facilitate greater penetration of the use of semiochemicals in crop protection for organic farming are identified. Semiochemicals are natural products that, by acting as signals, regulate interactions between organisms e.g. plants and insects. Once the semiochemical interactions between a pest and its host plant have been elucidated they can be exploited to regulate the pest population, providing an alternative control strategy to conventional toxicants. The choice of approach by which the semiochemicals are deployed relates to three options, i.e. from a natural plant source, from an extract or as a nature identical synthetic product. However, even where the most natural situations of mixed cropping are used, the scientific basis of the interaction must be established for robustness and sustainability of the approach. A complete understanding of the process allows a risk assessment to be made of any problems that might ensue when exploiting natural systems in different configurations from those encountered naturally. A major approach to using semiochemical based pest control is to exploit ways of repelling pests from crop plants and attracting them towards trap plantations. Deploying semiochemicals generated naturally by plants is consistent with organic farming practice, where a range of mixed cropping techniques are employed already, which ‘unconsciously’ utilise semiochemical effects. Thus, the acceptance and use of systems exploiting aspects of semiochemical deployment demonstrate an emerging role in organic farming practices. However, as emphasised before, a comprehensive knowledge of the semiochemical interactions that underpin these techniques is vital if they are to be exploited fully. Other pest control approaches compatible with organic farming, such as encouragement of beneficial species and the use of reflective surfaces in mulches, may not involve semiochemical effects, but could be exploited more beneficially by integration with semiochemical practices. Semiochemicals generated naturally by plants can be used to influence beneficial organisms as well as invertebrate pests. For example, plant defence chemicals, induced by pest or pathogen infestation, can affect the behaviour of pests and their natural enemies. Semiochemicals can be employed to maximise the impact of parasitic organisms that attack pest populations, for example in the management of refugia for maintaining and increasing populations of these beneficial organisms. In addition, the approach can be applied against other organisms antagonistic to agriculture besides invertebrate pests, for example in weed control, where signals interfering with weed germination can be exploited. Extracts of natural products provide semiochemicals in a form that is familiar and acceptable to organic farming practice, where plant extracts are already used as toxicants or as semiochemical antifeedants and repellents. However, often the scientific basis for use of these materials is limited, and therefore, exploitation is also limited and can be unreliable. By understanding the composition and the mechanism of activity of semiochemicals, natural product extracts can be improved by selection of the best sources of natural materials and appropriate processes of extraction and formulation. Many natural products, particularly pheromones (semiochemicals acting between members of the same species), can be synthesised as nature-identical and the synthetic forms are often indistinguishable from the natural form. Synthesis can be expensive, but where possible, starting materials should be obtained from natural renewable resources. Nature-identical synthetic pheromones are used widely in parts of the world, either deployed in traps for monitoring, mass trapping and lure and kill strategies or for direct pest control approaches such as mating disruption. In addition, manipulation of beneficial species with pheromones is being investigated and synthetic food-related attractants and oviposition attractants have also been developed for pests where pheromones are not available. Already some nature-identical synthetic semiochemicals have been accepted as compatible with organic farming practice. The registration of many sex and aggregation pheromones has been possible because they are nature-identical and are deployed away from the crop or on crop areas that are not consumed. In most cases, semiochemicals, deployed alone, are not sufficiently robust to control pest populations directly. They are most effective when incorporated into strategies, such as the ‘push-pull’ strategy, that are integrated with other forms of pest control, e.g. pathogens, parasitoids and predators, mechanical barriers and resistant plant varieties. The integration of semiochemical approaches with other methods of pest population reduction will help prevent the development of pest resistance to the overall strategy. Since the integrated strategy comprises a number of components that affect different aspects of pest behaviour and development each component can be relatively ineffective when compared to conventional pesticides. However, this has the advantage of not selecting efficiently for resistance to any component of the strategy and thus contributes to the sustainability of the approach. Recommendations 1) Develop a priority list of specific and general problems in organic production to be targeted by semiochemical methodologies in addition to known problems such as in carrot and lettuce production, aphids on a range of vegetable crops and for fruit pests. 2) Develop semiochemical based control methods suitable for 1) and for the targets already known. 3) Provide scientific input, where lacking, for 1 and 2. 4) Encourage greater diversification in organic cropping systems, including agroforestry, so as to exploit current knowledge of semiochemical based control and to pave the way for new interventions as the science develops. 5) Consider semiochemical attributes of non-crop plant inputs including mulches, weeds and multifunctional beneficial plants and the roles that they might play in organic systems. 6) Initiate organic plant breeding programmes, specifically to exploit natural semiochemical release where understood, for crop and companion plants