The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Balbina Moli - One of the best experts on this subject based on the ideXlab platform.
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age and Growth of the sparids diplodus vulgaris d sargus and d annularis in adult populations and the differences in their juvenile Growth patterns in the north western mediterranean sea
Fisheries Research, 1997Co-Authors: Ana Gordoa, Balbina MoliAbstract:Abstract Age and Growth patterns of adults of three common species of sparids, Diplodus vulgaris, D. sargus and D. annularis from the north-western Mediterranean Sea are analyzed. Length-at-age values are estimated from otoliths and Growth patterns are well described by the von Bertalanffy Growth Equation. The sampled length interval ranged from 8–40, 28 and 20 cm for D. sargus, D. vulgaris and D. annularis, respectively. The estimates of t0 for D. vulgaris and D. sargus, −0.67 and −0.74 respectively, indicate that the Growth of these species during the first months of life do not adhere to the von Bertalanffy model. In contrast, for D. annularis the estimation of the origin of the von Bertalanffy model is close to zero (t0 = −0.03), suggesting that this species is faithful to this Growth model from the beginning of settlement. The variations from juveniles to adults in the Growth pattern are explained by the permanence or the variations of the habitat of each of the species throughout their life.
Leonard Waverman - One of the best experts on this subject based on the ideXlab platform.
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telecommunications infrastructure and economic development a simultaneous approach
The American Economic Review, 2001Co-Authors: Larshendrik Roller, Leonard WavermanAbstract:This paper investigates how telecommunications infrastructure affects economic Growth. This issue is important and has received considerable attention in the popular press concerning the creation of the 'information superhighway' and its potential impacts on the economy. We use evidence from 21 OECD countries over a twenty-year period to examine the impacts that telecommunications developments may have had. We estimate a structural model, which endogenizes telecommunication investment by specifying a micro-model of supply and demand for telecommunication investments. The micro-model is then jointly estimated with the macro-Growth Equation. After controlling for country-specific fixed effects, we find evidence of a significant positive causal link, especially when a critical mass of telecommunications infrastructure is present. Interestingly, the critical mass appears to be at a level of telecommunications infrastructure that is near universal service.
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telecommunications infrastructure economic development a simultaneous approach
1997Co-Authors: Leonard Waverman, Larshendrik RollerAbstract:This paper investigates how telecommunications infrastructure affects economic Growth. This issue is important and has received considerable attention in the popular press concerning the creation of the 'information superhighway' and its potential impacts on the economy. We use evidence from 21 OECD countries over a twenty-year period to examine the impacts that telecommunications developments may have had. We estimate a structural model, which endogenizes telecommunication investment by specifying a micro-model of supply and demand for telecommunication investments. The micro-model is then jointly estimated with the macro-Growth Equation. After controlling for country-specific fixed effects, we find evidence of a significant positive causal link, especially when a critical mass of telecommunications infrastructure is present. Interestingly, the critical mass appears to be at a level of telecommunications infrastructure that is near universal service.
Larshendrik Roller - One of the best experts on this subject based on the ideXlab platform.
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telecommunications infrastructure and economic development a simultaneous approach
The American Economic Review, 2001Co-Authors: Larshendrik Roller, Leonard WavermanAbstract:This paper investigates how telecommunications infrastructure affects economic Growth. This issue is important and has received considerable attention in the popular press concerning the creation of the 'information superhighway' and its potential impacts on the economy. We use evidence from 21 OECD countries over a twenty-year period to examine the impacts that telecommunications developments may have had. We estimate a structural model, which endogenizes telecommunication investment by specifying a micro-model of supply and demand for telecommunication investments. The micro-model is then jointly estimated with the macro-Growth Equation. After controlling for country-specific fixed effects, we find evidence of a significant positive causal link, especially when a critical mass of telecommunications infrastructure is present. Interestingly, the critical mass appears to be at a level of telecommunications infrastructure that is near universal service.
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telecommunications infrastructure economic development a simultaneous approach
1997Co-Authors: Leonard Waverman, Larshendrik RollerAbstract:This paper investigates how telecommunications infrastructure affects economic Growth. This issue is important and has received considerable attention in the popular press concerning the creation of the 'information superhighway' and its potential impacts on the economy. We use evidence from 21 OECD countries over a twenty-year period to examine the impacts that telecommunications developments may have had. We estimate a structural model, which endogenizes telecommunication investment by specifying a micro-model of supply and demand for telecommunication investments. The micro-model is then jointly estimated with the macro-Growth Equation. After controlling for country-specific fixed effects, we find evidence of a significant positive causal link, especially when a critical mass of telecommunications infrastructure is present. Interestingly, the critical mass appears to be at a level of telecommunications infrastructure that is near universal service.
Karim Erzini - One of the best experts on this subject based on the ideXlab platform.
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age and Growth maturity mortality and yield per recruit for two banded bream diplodus vulgaris geoffr from the south coast of portugal
Fisheries Research, 2003Co-Authors: Jorge M S Goncalves, Rui Coelho, Luis Bentes, C Correia, Pedro G Lino, C C Monteiro, J Ribeiro, Karim ErziniAbstract:The population dynamics parameters of Diplodus vulgaris(Sparidae) from the south and south-west coast of Portugal were studied. 1086 fishes with total lengths ranging from 3.3 to 37.9 cm were obtained from previous gear selectivity studies supplemented by market sampling and beach seining for juveniles (1992–2000). The spawning season extended from September to April and total lengths at 50% maturity were 17.27 cm for males and 17.65 cm for females. These estimated sizes were greater than the minimum legal landing size (MLS = 15 cm) and smaller than length at first capture (Lc 50 = 21.68 cm) for the longline fishery. The parameters of the von Bertalanffy Growth Equation were: L∞ = 27.73 cm, K = 0.40 per year, t0 =− 0.34 year. The instantaneous rates of total mortality ( Z) and natural mortality (M) were 0.63 and 0.45 per year, respectively. Rates of fishing mortality F and exploitation E were 0.18 and 0.28 per year, respectively. Estimated parameters and the relative yield-per-recruit analysis showed that this species is not over exploited by longlines. © 2003 Elsevier Science B.V. All rights reserved.
Ana Gordoa - One of the best experts on this subject based on the ideXlab platform.
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age and Growth of the sparids diplodus vulgaris d sargus and d annularis in adult populations and the differences in their juvenile Growth patterns in the north western mediterranean sea
Fisheries Research, 1997Co-Authors: Ana Gordoa, Balbina MoliAbstract:Abstract Age and Growth patterns of adults of three common species of sparids, Diplodus vulgaris, D. sargus and D. annularis from the north-western Mediterranean Sea are analyzed. Length-at-age values are estimated from otoliths and Growth patterns are well described by the von Bertalanffy Growth Equation. The sampled length interval ranged from 8–40, 28 and 20 cm for D. sargus, D. vulgaris and D. annularis, respectively. The estimates of t0 for D. vulgaris and D. sargus, −0.67 and −0.74 respectively, indicate that the Growth of these species during the first months of life do not adhere to the von Bertalanffy model. In contrast, for D. annularis the estimation of the origin of the von Bertalanffy model is close to zero (t0 = −0.03), suggesting that this species is faithful to this Growth model from the beginning of settlement. The variations from juveniles to adults in the Growth pattern are explained by the permanence or the variations of the habitat of each of the species throughout their life.
