Search results for "ECD"
showing 10 items of 195 documents
Cuticle: Formation, Moulting and Control
1984
The relative rigidity of the arthropod exoskeleton makes it impossible for body size to increase continuously during the postembryonic development of these animals. Once they have hatched from the egg, they grow in steps, passing through a variable number of (larval) stages (Fig. 1 a). Apart from a few exceptions, there are between 3 and 10 such stages in the arachnids, 3–20 in the crustaceans, and 3–10 in the insects. In many cases a metamorphosis stage intervenes (some crustaceans; holometabolous insects) (Fig. 9b, c).
The precocious commitment of wing Anlagen in Tenebrio molitor revealed by the addition of 20-hydroxyecdysone.
1992
Abstract An injection of 20-hydroxyecdysone (10 μg per animal) 6–13 days after the moult of the last larval instar of Tenebrio molitor induces the development of prothetelic larvae and larval-pupal intermediates. The state of larval-pupal switchover, or commitment, is only disclosed at the time of injection of the moulting hormone. Prothetelic A and B larvae, with small and medium sized wing Anlagen, undergo another larval or pupal instar. Prothetelic C larvae with bigger Anlagen are unable to moult, but the adult programme is expressed. Ecdysed larval-pupal intermediates give more or less perfect adults, while unecdysed mealworms, imprisoned in their larval cuticle, also expressed the adul…
A functional analysis of ACP-20, an adult-specific cuticular protein gene from the beetle Tenebrio. Role of an intronic sequence in transcriptional a…
2004
0962-1075 (Print) Comparative Study Journal Article Research Support, Non-U.S. Gov't; A gene encoding the adult cuticular protein ACP-20 was isolated in Tenebrio. It consists of three exons interspersed by two introns, intron 1 interrupting the signal peptide. To understand the regulatory mechanisms of ACP-20 expression, ACP-20 promoter-luciferase reporter gene constructs were transfected into cultured pharate adult wing epidermis. Transfection assays needed the presence of 20-hydroxyecdysone, confirming that ACP-20 is up-regulated by ecdysteroids. Analysis of 5' deletion constructs revealed that three regions are necessary for high levels of transcription. Interaction experiments between i…
The factor content of regional bilateral trade: The role of technology and demand
2011
Abstract The Heckscher–Ohlin–Vanek (HOV) model in its strict form has been strongly rejected by the data. Relaxing some assumptions of the standard HOV model is key to find improvements in its performance. We apply the Davis and Weinstein (2001) methodology to analyse the validity of the HOV model using regions rather than countries. Surprisingly, our results using data for 17 Spanish regions are similar to theirs with international data for OECD countries. Accounting for technological differences improves the predictive capacity of the factor proportions model and including trade costs and geography reduces significantly the missing trade problem. However, relaxing the assumption of factor…
Technology spillover effects within Spanish communities
2017
ABSTRACTThe article uses panel data for the period 1990–2010 to estimate technology spillover effects on 17 Spanish communities. Accounting for nonstationarity and cointegration, we use the dynamic OLS estimator to estimate the impact of domestic and non-domestic R&D capital stock on labour productivity of Spanish communities, taking into account trade-, migration- and foreign direct investment (FDI)-related technology diffusion channels. We find significant trade-related spillover effects within Spanish communities and from EU countries. On average, an increase in the non-domestic R&D stock of 1% increases their labour productivity between 0.02% and 0.12% if related to bilateral trade patt…
Is the ‘euro effect’ on trade so small after all? New evidence using gravity equations with panel cointegration techniques
2014
In this paper we present new evidence on the aggregate effect of the euro on trade using data for 26 OECD countries for the period 1967–2008. We strive to fill the gaps present in the previous literature through a second-generation panel cointegration tests and estimators that account for both cross-section dependence in the data and discontinuities in the deterministic and the cointegrating vector in the time dimension. This approach allows us to put the adoption of the euro by EMU members in historical perspective. We argue that the creation of the EMU is best interpreted as a progression of policy changes. Once we control for all of them the euro effect decreases considerably but is stil…
The macroeconomic effects of public investment: Evidence from advanced economies
2015
This paper provides new evidence of the macroeconomic effects of public investment in advanced economies. Using public investment forecast errors to identify the causal effect of government investment in a sample of 17 OECD economies since 1985 and model simulations, the paper finds that increased public investment raises output, both in the short term and in the long term, crowds in private investment, and reduces unemployment. Several factors shape the macroeconomic effects of public investment. When there is economic slack and monetary accommodation, demand effects are stronger, and the public-debt-to-GDP ratio may actually decline. Public investment is also more effective in boosting ou…
Macroeconomic performance and convergence in OECD countries
1996
Abstract This paper investigates the robustness of the correlation between growth and a set of variables which comprises accumulation rates in human and physical capital and medium term macroeconomic indicators in OECD countries. We include these variables as additional regressors in the standard growth equation that comes from the human capital-augmented Solow model. Our results show that variables related to medium term macroeconomic performance affect both growth and convergence. In some periods these variables even outperform the explanatory power of the conventional growth variables such as the accumulation rates. Our results also suggest that it is difficult to analyse the contributio…
The Effects of Social Spending on Economic Activity: Empirical Evidence from a Panel of OECD countries
2012
The aim of this paper is to assess the short term effects of social spending on economic activity. Using a panel of OECD countries from 1980 to 2005, the results show that social spending has expansionary effects on GDP. In particular, we find that an increase of 1% of social spending increases GDP by about 0.1 percentage point, which, given the share of social spending to GDP, corresponds to a multiplier of about 0.6. The effect is similar to the one of total government spending, and it is larger in periods of severe downturns. Among spending subcategories, social spending in Health and Unemployment benefits have the greatest effects. Social spending also positively affects private consump…
Stabilization effects of social spending: Empirical evidence from a panel of OECD countries
2010
Abstract The aim of this paper is to assess the ability of social spending to smooth output shocks and to provide stabilization. The results show that overall social spending is able to smooth about 15 percent of a shock to GDP. Among its sub-categories, social spending devoted to Old Age, Health and Unemployment are those that contribute more to provide smoothing. Moreover, the stabilization effects of social spending are significantly larger in those countries where the size of social spending is higher, and in countries in which social spending is less volatile. The empirical results are economically and statistically significant, and robust.