Externalities and interdependent growth: Theory and evidence

I formulate and estimate a model of externalities within countriesand technological interdependence across countries. I find that externalreturns to scale to physical capital within countries are 8 percent; thata 10 percent increase of total factor productivity of a country's neighborsraises its total factor productivity by 6 percent; and that a 2 percentannual growth rate of labor productivity can be explained as an endogenousresponse to an exogenous 0.2 percent annual growth rate of total factorproductivity in the steady--state.

Age and growth of leaping grey mullet (Liza saliens (Risso, 1810)) in Minorca (Balearic Islands)

A population of leaping grey mullet (Liza saliens (Risso, 1810) was studied in order to measure seasonal and annual growth rates. The annual growth rates were similar to those reported for other populations from the central Western Mediterranean and intermediate between those living in northern and southern areas. As usual, the growth rate of adult males was slower than that of females. Males reached adulthood in their third summer. Females of the same age showed a moderate gonadal development, but did not ripen until the next summer. Mullets of all ages gained weight only when the water temperature was higher than 20°C. However adults and immature fish showed reduced growth in mid-summer, when that of the juveniles peaked. This difference is not a consequence of the reproductive cost, because the growth rate of immatures was greatly reduced although they did not spawn.

Cost-Based Models of Economic Growth

In this paper we highlight the importance of the operational costs in explaining economic growth and analyze how the industrial structure affects the growth rate of the economy. If there is monopolistic competition only in an intermediate goods sector, then production growth coincides with consumption growth. Moreover, the pattern of growth depends on the particular form of the operational cost. If the monopolistically competitive sector is the final goods sector, then per capita production is constant but per capita effective consumption or welfare grows. Finally, we modify again the industrial structure of the economy and show an economy with two different growth speeds, one for production and another for effective consumption. Thus, both the operational cost and the particular structure of the sector that produces the final goods determines ultimately the pattern of growth.

Side-branch growth in two-dimensional dendrits. Part II: Phase-field model

The development of side-branching in solidifying dendrites in a regime of large values of the Peclet number is studied by means of a phase-field model. We have compared our numerical results with experiments of the preceding paper and we obtain good qualitative agreement. The growth rate of each side branch shows a power-law behavior from the early stages of its life. From their birth, branches which finally succeed in the competition process of side-branching development have a greater growth exponent than branches which are stopped. Coarsening of branches is entirely defined by their geometrical position relative to their dominant neighbors. The winner branches escape from the diffusive field of the main dendrite and become independent dendrites.

Cost-Based Models of Economic Growth

In this paper we highlight the importance of the operational costs in explaining economic growth and analyze how the industrial structure affects the growth rate of the economy. If there is monopolistic competition only in an intermediate goods sector, then production growth coincides with consumption growth. Moreover, the pattern of growth depends on the particular form of the operational cost. If the monopolistically competitive sector is the final goods sector, then per capita production is constant but per capita effective consumption or welfare grows. Finally, we modify again the industrial structure of the economy and show an economy with two different growth speeds, one for production and another for effective consumption. Thus, both the operational cost and the particular structure of the sector that produces the final goods determines ultimately the pattern of growth.

A general approach to the in situ energy butget of Eudendrium racemosum (Cnidaria, Hydrozoa) in the Western Mediterranean

An in situ energy budget of the hydropolyp Eudendrium racemosum (Cavolini, 1785) is presented. Ingestion and respiration rates and ammonium excretion were studied over two 24 h cycles, with two-hour sample intervals. The species ingested as much as 25.9% of its own biomass per day (minimum rate). Respiration was 1.62 ml O2 g-1 d w h-1 while excretion was 13.6 mM NH4 g-1dw h-1. We estimated that the species increased its biomass at a rate of 9.6% per day (Growth + Reproduction). This value is higher than those previously reported for other cnidarians. We can assume that the capacity of E. racemosum to survive - albeit for a limited period of the year - in the highly-competitive shallow-water communities is based on its high growth rate.

Microstructural evolution of primary crystallization in diffusion-controlled grain growth

A model has been developed for evaluating grain size distributions in primary crystallizations where the grain growth is diffusion controlled. The body of the model is grounded in a recently presented mean-field integration of the nucleation and growth kinetic equations, modified conveniently in order to take into account a radius-dependent growth rate, as occurs in diffusion-controlled growth. The classical diffusion theory is considered, and a modification of this is proposed to take into account interference of the diffusion profiles between neighbor grains. The potentiality of the mean-field model to give detailed information on the grain size distribution and transformed volume fraction for transformations driven by nucleation and either interface- or diffusion-controlled growth processes is demonstrated. The model is evaluated for the primary crystallization of an amorphous alloy, giving an excellent agreement with experimental data. Grain size distributions are computed, and their properties are discussed.

Endogenous growth with capital in R&D production functions

[eng] In this paper we claim that capital is as important in the production of ideas as in the production of final goods. Hence, we introduce capital in the production of knowledge and discuss the associated problems arising from the public good nature of knowledge. We show that although population growth can affect economic growth, it is not necessary for growth to arise. We derive both the social planner and the decentralized economy growth rates and show the optimal subsidy that decentralizes it. We also show numerically that the effects of population growth on the market growth rate, the optimal growth rate and the optimal subsidy are small. Besides, we find that physical capital is more important for the production of knowledge than for the production of goods.

Endogenous growth with capital in R&D production functions

[eng] In this paper we claim that capital is as important in the production of ideas as in the production of final goods. Hence, we introduce capital in the production of knowledge and discuss the associated problems arising from the public good nature of knowledge. We show that although population growth can affect economic growth, it is not necessary for growth to arise. We derive both the social planner and the decentralized economy growth rates and show the optimal subsidy that decentralizes it. We also show numerically that the effects of population growth on the market growth rate, the optimal growth rate and the optimal subsidy are small. Besides, we find that physical capital is more important for the production of knowledge than for the production of goods.

Nitrogen metabolism in Zucker rats is affected by moderate reduction, but not by moderate incerase in dietary protein

Marked changes in the content of protein in the diet affects the rat"s pattern of growth, but there is not any data on the effects to moderate changes. Here we used a genetically obese rat strain (Zucker) to examine the metabolic modifications induced to moderate changes in the content of protein of diets, doubling (high-protein (HP): 30%) or halving (low-protein (LP): 8%) the content of protein of reference diet (RD: 16%). Nitrogen, energy balances, and amino acid levels were determined in lean (L) and obese (O) animals after 30 days on each diet. Lean HP (LHP) animals showed higher energy efficiency and amino acid catabolism but maintained similar amino acid accrual rates to the lean RD (LRD) group. Conversely, the lean LP (LLP) group showed a lower growth rate, which was compensated by a relative increase in fat mass. Furthermore, these animals showed greater efficiency accruing amino acids. Obesity increased amino acid catabolism as a result of massive amino acid intake; however, obese rats maintained protein accretion rates, which, in the OHP group, implied a normalization of energy efficiency. Nonetheless, the obese OLP group showed the same protein accretion pattern as in lean animals (LLP). In the base of our data, concluded that the Zucker rats accommodate their metabolism to support moderates increases in the content of protein in the diet, but do not adjust in the same way to a 50% decrease in content of protein, as shown by an index of growth reduced, both in lean and obese rats.

Short communication. SNP analyses of the 5HT1R and STAT genes in Pacific white shrimp, Litopenaeus vannamei

La industria de la producción de camarón es una de las industrias acuícolas que se encuentra en más crecimiento en la actualidad. Los estudios para encontrar marcadores genéticos son muy efectivos para la mejora de sus propiedades y de gran interés para los productores de camarón. En este trabajo se utilizaron seis individuos de una población de Litopenaeus vannamei, donde se encontraron cuatro polimorfismos de nucleótido único (SNPs) en el gen 5HT1R (5-hidroxitriptamina receptor1) y un SNP en el gen STAT (transductor de señal y activador de la transcripción). Sin embargo, el polimorfismo en el gen STAT resultó ser homocigoto en una población diferente utilizada para análisis de asociación. Los presentes análisis revelaron que el alelo C, en dos polimorfismos SNP (C109T y C395G) del gen 5HT1R, tiende a estar asociado con el aumento del peso corporal. Consideramos que hay necesidad de hacer nuevos estudios utilizando una muestra más amplia y diversa de la población en cuestión.

Effects of Different Salinities on Juvenile Growth of Gammarus aequicauda (Malacostraca: Amphipoda)

Gammarus aequicauda is a euryhaline amphipod that is a common inhabitant of brackish environments of theMediterranean Sea. In the Ebro delta, the population density of G. aequicauda is highly variable throughout the year. The main objective of this study is to investigate the effect of salinity on the growth of G. aequicauda juveniles. G. aequicauda embryos and juveniles can survive and grow in the laboratory between 2 psu and 40 psu salinity, depending on the previous acclimation period for the reproductive individuals. Adults acclimated at 34 psu produced embryos and juveniles that survived and developed at salinities between 9 psu and 40 psu; adults acclimated at 9 psu produced embryos and juveniles that could develop in oligohaline conditions. The lower growth rate values were 10.9 μmd−1 and 13.5 μmd−1 at 40 psu and 2 psu, respectively, with the higher values of 18.0 μmd−1 and 18.5 μmd−1 at 19 and 34 psu, respectively.

Effect of feed fat by-products with trans fatty acids and heated oil on cholesterol and oxycholesterols in chicken

Chicken is the most widely consumed meat all over the world due to chickens being easy to rear, their fast growth rate and the meat having good nutritional characteristics. The main objective of this paper was to study the effects of dietary fatty by-products in low, medium and high levels of oxidized lipids and trans fatty acids (TFAs) on the contents of cholesterol and oxycholesterols in meat, liver, and plasma of chickens. A palm fatty acid distillate, before and after hydrogenation, and a sunflower-olive oil blend (70/30, v/v) before and after use in a commercial frying process were used in feeding trials after adding 6% of the fats to the feeds. Highly oxidized lipid and TFA feeds significantly increased the contents of cholesterol and oxycholesterols in all tissues of chicken (0.01 < p <= 0.05). The contents of oxycholesterols in chicken meat, liver and plasma obtained from TFA feeding trials varied between 17 and 48 μg/100 g in meat, 19-42 μg/100 g in liver and 105-126 μg/dL in plasma. In contrast, in the oxidized lipid feeding trials, oxycholesterols varied between 13 and 75 μg/100 g in meat, 30-58 μg/100 g in liver and 66-209 μg/dL in plasma. Meat from chickens fed with feeds containing high levels of TFAs or oxidized lipids may contribute to higher ingestion of cholesterol and oxycholesterols by humans.

Life-time growth patterns of pumpkinseed Lepomis gibbosus introduced to Europe, relative to North American populations

The pumpkinseed Lepomis gibbosus, an omnivorous, nest guarding North American sunfish, was introduced into European waters about 100 years ago. To assess growth performance following introduction, we reviewed the available data for North American and European populations of pumpkinseed and compared the back-calculated age-specific growth for juveniles (standard length, SL, at age two) and adults (age two to five increment) as well as adult body size (SL at age five), von Bertalanffy growth model parameters and the index of growth (in length) performance (φ′). For continental comparisons of growth trajectory, mean growth curves for North American and Europe were calculated with the von Bertalanffy model using pooled data sets for each continent. Juvenile growth rate did not differ between European and North American pumpkinseed, but mean adult body size and adult growth rate were both significantly greater in North American than European populations. Adult body size decreased with increasing latitude (ANOVA) in North American populations, but this was not observed with adult growth rate. In contrast, adult body size tended to increase with latitude in European populations. Adult body size correlated significantly with φ′. The von Bertalanffy model described the overall growth patterns of North American and European populations reasonably well, but on the individual population level, length asymptotes were unrealistic (estimates that were > 20 % of the mean back-calculated size for the oldest age class) for a third of European populations and 80% of the North American populations. In contrast to North American pumpkinseed populations, somatic growth in European populations appears to be compromised by limited, but adequate, food resources, probably due to strong intraspecific interactions. This appears to be especially acute in adults, having potential ramifications for life span and reproductive allocation

The Effects of Corruption and Seigniorage on Growth and Inflation

In the last two decades, cases of corruption have been unveiled in different countries, raising public awareness and reinforcing a trend in which society expects more from their leaders. Our objective in this paper is to examine the effects of corruption and seigniorage on inflation and growth rates. The model used in this article is an extension of the model used by Huang and Wei (2006). We find interesting results and one of them is that, under some conditions, corruption has a positive impact on the growth rate. JEL classification : D73, E52, E58, E62. Keywords : Corruption; Fiscal Policy; Growth; Monetary Policy; Seigniorage.