Growth curves for ostriches (Struthio camelus) in a Brazilian population

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The economics of demand-led growth: theory and evidence for Brazil

Includes bibliography

Growth curves of Nile tilapia (Oreochromis niloticus) strains cultivated at different temperatures

Growth of Red, GIFT and Supreme Nile tilapia strains were evaluated. Fish were cultivated in indoor recirculation systems in 0.5 m³ tanks with controlled temperatures of 22, 28 and 30°C. Random samples of 20 fish from each strain (10 fish tank-1) were weighed at day 7, 30, 60, 90 and 120. Exponential model (y=AeKx) and Gompertz model (y = Aexp(-Be-Kx)) were fitted and the estimates parameters were obtained by Weighted Least Squares. At 22°C, Red, GIFT and Supreme strain presented similar growth and fit of exponential model. GIFT and Supreme strain presented higher growth rate at 30°C of cultivation when compared to Red strain. Temperature influences weight and age at the inflection point. The temperature of cultivation influences the growth description of Red, GIFT and Supreme tilapia strains. It changes the age and weight at inflection point and the qualities of growth model fits, changing the variation of the batch.

Population structure, sex ratio and growth of the seabob shrimp Xiphopenaeus kroyeri (Decapoda, Penaeidae) from coastal waters of southern Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Exact field-driven interface dynamics in the two-dimensional stochastic Ising model with helicoidal boundary conditions

We investigate the interface dynamics of the two-dimensional stochastic Ising model in an external field under helicoidal boundary conditions. At sufficiently low temperatures and fields, the dynamics of the interface is described by an exactly solvable high-spin asymmetric quantum Hamiltonian that is the infinitesimal generator of the zero range process. Generally, the critical dynamics of the interface fluctuations is in the Kardar-Parisi-Zhang universality class of critical behavior. We remark that a whole family of RSOS interface models similar to the Ising interface model investigated here can be described by exactly solvable restricted high-spin quantum XXZ-type Hamiltonians. (C) 2012 Elsevier B.V. All rights reserved.

Validation of age determination methods and growth studies of the sand sole Pegusa lascaris (Soleidae) from the eastern-central Atlantic

[EN]The age and growth of the sand sole Pegusa lascaris from the Canarian Archipelago were studied from 2107 fish collected between January 2005 and December 2007. To find an appropriate method for age determination, sagittal otoliths were observed by surface-reading and frontal section and the results were compared. The two methods did not differ significantly in estimated age but the surface-reading method is superior in terms of cost and time efficiency. The sand sole has a moderate life span, with ages up to 10 years recorded. Individuals grow quickly in their first two years, attaining approximately 48% of their maximum standard length; after the second year, their growth rate drops rapidly as energy is diverted to reproduction. Males and females show dimorphism in growth, with females reaching a slightly greater length and age than males. Von Bertalanffy, seasonalized von Bertalanfy, Gompertz, and Schnute growth models were fitted to length-at-age data. Akaike weights for the seasonalized von Bertalanffy growth model indicated that the probability of choosing the correct model from the group of models used was >0.999 for males and females. The seasonalized von Bertalanffy growth parameters estimated were: L? = 309 mm standard length, k = 0.166 yr?1, t0 = ?1.88 yr, C = 0.347, and ts = 0.578 for males; and L? = 318 mm standard length, k = 0.164 yr?1, t0 = ?1.653 yr, C = 0.820, and ts = 0.691 for females. Fish standard length and otolith radius are closely correlated (R2 = 0.902). The relation between standard length and otolith radius is described by a power function (a = 85.11, v = 0.906)

Condensational growth of atmospheric aerosol particles in an expanding water saturated air flow

Aerosol particles and water vapour are two important constituents of the atmosphere. Their interaction, i.e. thecondensation of water vapour on particles, brings about the formation of cloud, fog, and raindrops, causing the water cycle on the earth, and being responsible for climate changes. Understanding the roles of water vapour and aerosol particles in this interaction has become an essential part of understanding the atmosphere. In this work, the heterogeneous nucleation on pre-existing aerosol particles by the condensation of water vapour in theflow of a capillary nozzle was investigated. Theoretical and numerical modelling as well as experiments on thiscondensation process were included. Based on reasonable results from the theoretical and numerical modelling, an idea of designing a new nozzle condensation nucleus counter (Nozzle-CNC), that is to utilise the capillary nozzle to create an expanding water saturated air flow, was then put forward and various experiments were carried out with this Nozzle-CNC under different experimental conditions. Firstly, the air stream in the long capillary nozzle with inner diameter of 1.0~mm was modelled as a steady, compressible and heat-conducting turbulence flow by CFX-FLOW3D computational program. An adiabatic and isentropic cooling in the nozzle was found. A supersaturation in the nozzle can be created if the inlet flow is water saturated, and its value depends principally on flow velocity or flow rate through the nozzle. Secondly, a particle condensational growth model in air stream was developed. An extended Mason's diffusion growthequation with size correction for particles beyond the continuum regime and with the correction for a certain particle Reynolds number in an accelerating state was given. The modelling results show the rapid condensational growth of aerosol particles, especially for fine size particles, in the nozzle stream, which, on the one hand, may induce evident `over-sizing' and `over-numbering' effects in aerosol measurements as nozzle designs are widely employed for producing accelerating and focused aerosol beams in aerosol instruments like optical particle counter (OPC) and aerodynamical particle sizer (APS). It can, on the other hand, be applied in constructing the Nozzle-CNC. Thirdly, based on the optimisation of theoretical and numerical results, the new Nozzle-CNC was built. Under various experimental conditions such as flow rate, ambient temperature, and the fraction of aerosol in the total flow, experiments with this instrument were carried out. An interesting exponential relation between the saturation in the nozzle and the number concentration of atmospheric nuclei, including hygroscopic nuclei (HN), cloud condensation nuclei (CCN), and traditionally measured atmospheric condensation nuclei (CN), was found. This relation differs from the relation for the number concentration of CCN obtained by other researchers. The minimum detectable size of this Nozzle-CNC is 0.04?m. Although further improvements are still needed, this Nozzle-CNC, in comparison with other CNCs, has severaladvantages such as no condensation delay as particles larger than the critical size grow simultaneously, low diffusion losses of particles, little water condensation at the inner wall of the instrument, and adjustable saturation --- therefore the wide counting region, as well as no calibration compared to non-water condensation substances.

Mixed effects model in negative exponential curve

Despite many researches on development in education and psychology, not often is the methodology tested with real data. A major barrier to test the growth model is that the design of study includes repeated observations and the nature of the growth is nonlinear. The repeat measurements on a nonlinear model require sophisticated statistical methods. In this study, we present mixed effects model in a negative exponential curve to describe the development of children's reading skills. This model can describe the nature of the growth on children's reading skills and account for intra-individual and inter-individual variation. We also apply simple techniques including cross-validation, regression, and graphical methods to determine the most appropriate curve for data, to find efficient initial values of parameters, and to select potential covariates. We illustrate with an example that motivated this research: a longitudinal study of academic skills from grade 1 to grade 12 in Connecticut public schools. ^

A Generic Model of Financial Repression

The paper develops a growth model in an overlapping generations framework of a financially repressed small open economy, and analyzes the effects of financial liberalization. The following observations are made: An increase (decrease) of interest rate (reserve requirements) reduces (increases) the steady-state stock of capital and the trade balance, but improves (deteriorates) the level of foreign exchange reserves. However, financial liberalization, in any form, is always welfare-improving. The paper, thus, advocates financial liberalization policies to be oriented towards reduction of reserve requirements rather than interest rate deregulation, if foreign reserve holding is not in a critical position.

Economic Growth, Longevity, and the Epidemiological Transition

This paper integrates investments in health to a standard growth model where physical and human capital investments are the combined engines of growth. It shows the existence of two distinct health regimes separated by an 'Epidemiological Transition'. The various patterns of the transition identified in the epidemiological literature can be mapped into the model. The model also leads to the important hypothesis that the epidemiological transition may induce an economy to switch to a modern growth regime.

Population structure, growth and production of the surf clam Donax hanleyanus (Bivalvia: Donacidae) from northern Argentinean beaches

The surf clams Mesodesma mactroides Reeve, 1854 and Donax hanleyanus Philippi, 1847 are the two dominating species in macrobenthic communities of sandy beaches off northern Argentina, with the latter now surpassing M. mactroides populations in abundance and biomass. Before stock decimation caused by exploitation (during the 1940s and 1950s) and mass mortality events (1995, 1999 and 2007) M. mactroides was the prominent primary consumer in the intertidal ecosystem and an important economic resource in Argentina. Since D. hanleyanus was not commercially fished and not affected by mass mortality events, it took over as the dominant species, but did never reach the former abundance of M. mactroides. Currently abundance and biomass of both surf clams are a multiple smaller than those of forty years ago, indicating the conservation status of D. hanleyanus and M. mactroides as endangered. Therefore the aim of this study is to analyse the population dynamics (population structure, growth and reproductive biology) of D. hanleyanus and M. mactroides, and to compare the results with historical data in order to detect possible differences within surf clam populations forty years ago and at present.

Reform momentum and its impact on Greek growth. Bruegel Policy Contribution 2015/12, July 2015

Greece has an imperfect track-record of structural reform implementation. However, the poor growth outcome of the Greek programmes is also a consequence of the timing and composition of reforms, which were not optimally geared towards a speedy transition to a new growth model based on the private sector. While the main responsibility for this lies with the Greek authorities, international institutions share the responsibility for the poor growth-enhancing effect of reforms. In the current context, further structural reform efforts should be mainly targeted at supporting Greece's speedy return to solid growth rates. This is not only because poverty and unemployment have reached very high levels, but also for political economy reasons: reforms must quickly be seen to be working in order to buttress the consensus in favour of reform. Further efforts should be made to improve Greece’s business environment and to liberalise product markets, in addition to shifting taxation away from labour and towards consumption. Reforms to improve the quality of institutions should continue and are very much needed in the Greek setting, while taking into account that their demanding implementation might use up administrative capacity and their impact on growth will only be seen over long time horizons.