928 resultados para GROWTH POTENTIAL


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The growth potential of turbot Scophthalmus maximus larvae and juveniles was studied using nucleic acid-based indices and protein variables. The experiment was carried out from 4 to 60 days post hatching (dph). A significant increase in instantaneous growth rate during metamorphosis and retarded growth rate during post-metamorphic phase were observed. Ontogenetic patterns of DNA, RNA and protein all showed developmental stage-specific traits. The RNA:DNA ratio decreased up to 12 dph, then increased rapidly till 19 dph and fluctuated until 35 dph followed by a decline to the end. The RNA:DNA ratio was positively correlated with growth rate of juveniles during the post-metamorphic phase, whereas this ratio was not a sensitive indicator of growth during the pre-metamorphic phase and metamorphosis. The protein:DNA ratio showed a similar tendency to the RNA:DNA ratio. Changes of DNA content and protein:DNA ratio revealed that growth of S. maximus performed mainly by hyperplasia from 4 to 12 dph and hypertrophy until 21 dph during the pre-metamorphic larval phase. Growth was dominantly hypertrophical from the early- to mid-metamorphosing phase and hyperplastic thereafter. The results show that the DNA content and protein:DNA ratio can evaluate growth rates of larval and juvenile S. maximus on a cellular level.

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Nursery areas for juvenile fishes are often important for determining recruitment in marine populations by providing habitats that can maximize growth and thereby minimize mortality. Pacific ocean perch (POP, Sebastes alutus) have an extended juvenile period where they inhabit rocky nursery habitats. We examined POP nursery areas to link growth potential to recruitment. Juvenile POP were captured from nursery areas in 2004 and 2008, and estimated growth rates ranged from −0.19 to 0.60 g day−1 based on differences in size between June and August. Predicted growth rates from a bioenergetics model ranged from 0.05 to 0.49 g day−1 and were not significantly different than observed. Substrate preferences and the distribution of their preferred habitats were utilized to predict the extent of juvenile POP nursery habitat in the Gulf of Alaska. Based on densities of fish observed on underwater video transects and the spatial extent of nursery areas, we predicted 278 and 290 million juvenile POP were produced in 2004 and 2008. Growth potential for juvenile POP was reconstructed using the bioenergetics model, spring zooplankton bloom timing and duration and bottom water temperature for 1982–2008. When a single outlying recruitment year in 1986 was removed, growth potential experienced by juvenile POP in nursery areas was significantly correlated to the recruitment time-series from the stock assessment, explaining ∼30% of the variability. This research highlights the potential to predict recruitment using habitat-based methods and provides a potential mechanism for explaining some of the POP recruitment variability observed for this population.

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This paper is devoted to an examination of the main issues identified with Brazil’s barriers to growth in the long term. It begins with a decomposition of per capita and total GDP long term growth to identify the main proximate sources of Brazil’s growth deceleration. Most of the analysis in this part concentrates on factors affecting aggregate supply. The reason for this approach is that, within certain limits past experience reveals that it is easy to stimulate aggregate demand via fiscal and monetary stimuli in Brazil. The risk is on bumping into production capacity barriers, i.e., supply constraints. Five substantially diversified but interconnected issues have been raised in the literature as supply constraints, many of which associated to a rate of savings lower than deemed necessary for sustaining faster growth: the tax burden, institutional factors, infrastructure, finance and education. Accordingly, the paper also deals with the issues of a high an increasing tax burden, institutional shortcomings and policy settings, insufficient investment in infrastructure, insufficient long term financing, and educational shortcomings, as growth impediments. A survey of policies aimed at removing the barriers to growth thus identified is presented next. The paper concludes by bringing again to the fore the need to increase savings and investment for growth resumption and by speculating on the growth potential of Brazil, conditional on productivity and investment growth.

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The acronym BRICS was a fad among the media and global investors. Now, the acronym sounds passé. However, the group of countries remains important, from both political and economic reasons. They have a large aggregate size, 28% of the global GDP and 42% of the world’s population, high growth potential due to the current significant misallocation of resources and relatively low stock of human capital, structural transformation is in progress and one of them, China, is taking steps to become a global power and a challenger to the US dominance. This paper provides a brief overview of the five economies, Brazil, Russia, India, China and South Africa. We focus on some aspects of their history, the Chinese initiatives in international finance and geopolitical strategic moves, their growth experience and structural transformation over the last 35 years, trade and investment integration into the global economy and among themselves, the growth challenges faced by their economies and the potential gains to the Brazilian economy from a stronger integration with the other BRICS. In association with its efforts to be a global power, China aims to become a major player in global finance and to achieve the status of global currency for the renminbi, which would be the first currency of an emerging economy to attain such position. Despite the similarities, the BRICS encompass very diverse economies. In the recent decades, China and India showed stellar growth rates. On the other hand, Brazil, Russia and South Africa have expanded just in line with global output growth with the Russian economy exhibiting high volatility. China is by far the largest economy, and South Africa the smallest, the only BRICS economy with a GDP lower than US$ 1 trillion. Russia abandoned communism almost 25 years ago, but reversed many of the privatizations of 90’s. China is still ruled by communism, but has a vibrant private sector and recently has officially declared market forces to play a dominant role in its economy. Brazil, Russia and South Africa are global natural resources powerhouses and commodity exporters while China and India are large commodity importers. Brazil is relatively closed to international trade of goods and services, in marked contrast to the other four economies. Brazil, India and South Africa are dependent on external capital flows whereas China and Russia are capital exporters. India and South Africa have younger populations and a large portion living below the poverty line. Despite its extraordinary growth experience that lifted many millions from poverty, China still has 28% of its population classified as poor. Russia and China have much older populations and one of their challenges is to deal with the effects of a declining labor force in the near future. India, China and South Africa face a long way to urbanization, while Brazil and Russia are already urbanized countries. China is an industrial economy but its primary sector still absorbs a large pool of workers. India is not, but the primary sector employs also a large share of the labor force. China’s aggregate demand structure is biased towards investment that has been driving its expansion. Brazil and South Africa have an aggregate demand structure similar to the developed economies, with private consumption accounting for approximately 70%. The same similarity applies to the supply side, as in both economies the share of services nears 70%. The development problem is a productivity problem, so microeconomic reforms are badly needed to foster long-term growth of the BRICS economies since they have lost steam due a variety of factors, but fundamentally due to slower total factor productivity growth. China and India are implementing ambitious reform programs, while Brazil is dealing with macroeconomic disequilibria. Russia and South Africa remain mute about structural reforms. There are some potential benefits to Brazil to be extracted from a greater economic integration with the BRICS, particularly in natural resources intensive industries and services. Necessary conditions to the materialization of those gains are the removal of the several sources of resource misallocation and strong investment in human capital.

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Vegetated riparian buffer strips have been established in Southern Quebec (Canada) in order to intercept nutrients such as nitrate (NO(3)(-)) and protect water quality near agricultural fields. Buffer strips may also favour denitrification through a combination of high soil moisture, NO(3)(-) and carbon supply, which could lead to the production of nitrous oxide (N(2)O), a greenhouse gas. Denitrification could be further amplified by the presence of earthworms, or by plant species that promote earthworm and bacterial activity in soils. Soils from four farms, comprising maize fields and adjacent buffer strips, were sampled in the fall of 2008. A total of six earthworm species were found, but average earthworm biomass did not differ between buffer strips and maize agroecoecosystems. Nitrate concentrations and net nitrification rates were higher in the maize fields than in the buffer strips: there was no difference in N(2)O production in soils collected from the two sampling locations. Potential denitrification, measured by acetylene inhibition, varied by two orders of magnitude, depending on experimental conditions: when amended with H(2)O or with H(2)O + NO3-, potential denitrification was higher (P < 0.05) in soils from buffer strips than from maize fields. Potential denitrification was highest in soils amended with H(2)O+glucose, or with H(2)O+ NO(3)(-) + glucose. Using microcosms, we tested the effect of litter-soil mixtures on earthworm growth, and the effect of earthworm-litter-soil mixtures on potential denitrification. Based on four categories of chemical assays, litters of woody species (oak, apple, Rhododendron) were generally of lower nutritional quality than litter from agronomic species (alfalfa, switchgrass, corn stover). Alfalfa litter had the most positive effect, whereas apple litter had the most negative effect, on earthworm growth. Potential denitrification was 2-4 times higher in earthworm-litter-soil mixtures than in plain soil. Litter treatments that included corn stover had lower potential denitrification than those that included alfalfa or switchgrass, whereas litter treatments that included oak had lower potential denitrification than those that included apple or Rhododendron. Results suggest that potential N(2)O emissions may be higher in riparian buffer strips than in adjacent maize fields, that N(2)O emissions in buffer strips may be amplified by comminuting earthworms, and that plant litters that reduce earthworm growth may not be best at mitigating N(2)O emissions. (c) 2010 Elsevier B.V. All rights reserved.

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Two experiments were conducted to develop and evaluate a model to estimate ME requirements and determine Gompertz growth parameters for broilers. The first experiment was conducted to determine maintenance energy requirements and the efficiencies of energy utilization for fat and protein deposition. Maintenance ME (ME m) requirements were estimated to be 157.8, 112.1, and 127.2 kcal of ME/kg 0.75 per day for broilers at 13, 23, and 32°C, respectively. Environmental temperature (T) had a quadratic effect on maintenance requirements (ME m = 307.87 - 15.63T + 0.3105T 2; r 2= 0.93). Energy requirements for fat and protein deposition were estimated to be 13.52 and 12.59 kcal of ME/g, respectively. Based on these coefficients, a model was developed to calculate daily ME requirements: ME = BW 0.75 (307.87 - 15.63T + 0.3105 T 2) + 13.52 G f + 12.59 G p. This model considers live BW, the effects of environmental temperature, and fractional fat (G f) and protein (G p) deposition. The second experiment was carried out to estimate the growth parameters of Ross broilers and to collect data to evaluate the ME requirement model proposed. Live BW, empty feather-free carcass, weight of the feathers, and carcass chemical compositions were analyzed until 16 wk of age. Parameters of Gompertz curves for each component were estimated. Males had higher growth potential and higher capacity to deposit nutrients than females, except for fat deposition. Data of BW and body composition collected in this experiment were fitted into the energy model proposed herein and the equations described by Emmans (1989) and Chwalibog (1991). The daily ME requirements estimated by the model determined in this study were closer to the ME intake observed in this trial compared with other models. ©2005 Poultry Science Association, Inc.

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Includes bibliography

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Includes bibliography

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The objective of this study was to estimate growth parameters of carcass components (wing, thighs and drumsticks, back and breast) and organs (heart, liver, gizzard and gut) in males and females of one meat-type quail strain (Coturnix coturnix coturnix) and two laying strains (Coturnix coturnix japonica) designated either yellow or red.A total of 1350 quail from 1 to 42d old were distributed in a completely randomised design, with 5 replicates of each strain. The carcass component weights and body organs were analysed weekly and evaluated using the Gompertz function; growth rates were evaluated through derivative equations.The meat-type strain presented the highest growth rates in carcass components and organs. Across strains, females showed the highest weight of internal organs at maturity compared to males.Females had greater growth potential in breast, wings and back than males for both yellow and red laying quail.

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Intrauterine growth restriction (IUGR) is defined as a condition in which the fetus does not reach its genetically given growth potential, resulting in low birth weight. IUGR is an important cause of perinatal morbidity and mortality, thus contributing substantially to medically indicated preterm birth in order to prevent fetal death. We subjected umbilical cord blood serum samples either belonging to the IUGR group (n = 15) or to the control group (n = 15) to fractionation by affinity chromatography using a bead system with hydrophobic interaction capabilities. So prepared protein mixtures were analyzed by MALDI-TOF mass spectrometric profiling. The six best differentiating ion signals at m/z 8205, m/z 8766, m/z 13 945, m/z 15 129, m/z 15 308, and m/z 16 001 were collectively assigned as IUGR proteome signature. Separation confidence of our IUGR proteome signature reached a sensitivity of 0.87 and a specificity of 0.93. Assignment of ion signals in the mass spectra to specific proteins was substantiated by SDS-PAGE in conjunction with peptide mass fingerprint analysis of cord blood serum proteins. One constituent of this proteome signature, apolipoprotein C-III(0) , a derivative lacking glycosylation, has been found more abundant in the IUGR cord blood serum samples, irrespective of gestational age. Hence, we suggest apolipoprotein C-III(0) as potential key-marker of the here proposed IUGR proteome signature, as it is a very low-density lipoprotein (VLDL) and high-density lipoprotein (HDL) member and as such involved in triglyceride metabolism that itself is discussed as being of importance in IUGR pathogenesis. Our results indicate that subtle alterations in protein glycosylation need to be considered for improving our understanding of the pathomechanisms in IUGR.

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Heart and lung transplantation has been performed in cases of end-stage cardiopulmonary disease in infants. Nevertheless, it still remains unclear whether lung allografts adjust to a growing organism. In 6 young domestic pigs unilateral left lung allotransplantation was performed. Immunosuppression consisted of a triple drug therapy including cyclosporine, azathioprine, and corticosteroids. Lung growth was studied by using bronchography, pulmonary angiography, and lung histology. After 11 weeks the transplanted animals had doubled their body weight from 24 kg to 48 kg. Non-transplanted animals in contrast doubled their weight within only 6 weeks. The growth retardation was attributed to the immunosuppressive therapy. The bronchial tree and pulmonary vasculature of lung allografts showed a similar growth potential to non-transplanted lungs in animals of equivalent body weight. In one case of recurrent severe rejection of the lung no growth was observed. Therefore it was concluded that lung allografts grow adequately according to the development of the recipient organism. Lung transplantation in children does not seem to be restricted by a limited growth potential of the graft.

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PURPOSE: To retrospectively evaluate the influence of hyoid bone resection according to Sistrunk in early age due to a thyroglossal duct cyst on craniofacial growth. MATERIALS AND METHODS: We retrospectively examined 10 patients (2 females and 8 males) having had hyoid bone resection according to Sistrunk due to thyroglossal duct cysts by lateral cephalograms taken before orthodontic treatment (mean, 17.1 years; range, 8.6-31.9 years). Surgery was carried out at a mean age of 4.4 years (range, 0.37-9.8 years). All lateral cephalograms were evaluated and traced by hand. Descriptive statistics were calculated, and data from each patient were compared individually with corresponding standard values (age and gender) from Bathia and Leighton. RESULTS: With regard to sagittal parameters, the SNB angles were by trend too small and the ANB angles were too large. However, the ratio of mandibular to maxillary length showed that the patients had a mandible that was too large or maxilla that was too small. With regard to vertical parameters, large deviations from normal values in both directions (hyperdivergent to hypodivergent pattern) could be detected when we analyzed NSL/ML', NL/ML', and NSL/NL. With regard to dental parameters, the majority of the patients had retroclined upper (IsL/NL, IsL/N-A) and lower (IiL/ML, IiL/N-B) incisors. CONCLUSIONS: Several vertical and horizontal skeletal and dental cephalometric parameters were shown to be different by trend when compared with control values. A possible negative impact on craniofacial growth potential and direction as a result of hyoid resection in early age according to Sistrunk cannot be excluded.

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INTRODUCTION Intrauterine Growth Restriction (IUGR) is a multifactorial disease defined by an inability of the fetus to reach its growth potential. IUGR not only increases the risk of neonatal mortality/morbidity, but also the risk of metabolic syndrome during adulthood. Certain placental proteins have been shown to be implicated in IUGR development, such as proteins from the GH/IGF axis and angiogenesis/apoptosis processes. METHODS Twelve patients with term IUGR pregnancy (birth weight < 10th percentile) and 12 CTRLs were included. mRNA was extracted from the fetal part of the placenta and submitted to a subtraction method (Clontech PCR-Select cDNA Subtraction). RESULTS One candidate gene identified was the long non-coding RNA NEAT1 (nuclear paraspeckle assembly transcript 1). NEAT1 is the core component of a subnuclear structure called paraspeckle. This structure is responsible for the retention of hyperedited mRNAs in the nucleus. Overall, NEAT1 mRNA expression was 4.14 (±1.16)-fold increased in IUGR vs. CTRL placentas (P = 0.009). NEAT1 was exclusively localized in the nuclei of the villous trophoblasts and was expressed in more nuclei and with greater intensity in IUGR placentas than in CTRLs. PSPC1, one of the three main proteins of the paraspeckle, co-localized with NEAT1 in the villous trophoblasts. The expression of NEAT1_2 mRNA, the long isoform of NEAT1, was only modestly increased in IUGR vs. CTRL placentas. DISCUSSION/CONCLUSION The increase in NEAT1 and its co-localization with PSPC1 suggests an increase in paraspeckles in IUGR villous trophoblasts. This could lead to an increased retention of important mRNAs in villous trophoblasts nuclei. Given that the villous trophoblasts are crucial for the barrier function of the placenta, this could in part explain placental dysfunction in idiopathic IUGR fetuses.

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Secondary sexual traits in males of polygynous species are important determinants of reproductive success. It is, however, unknown if and how the development of continuously growing traits at different life-stages is related to reproduction in long-lived male mammals. In this study, we evaluated the relationship of early and late horn growth on social status and reproduction in long-lived male Alpine ibex (Capra ibex). For this, we analysed individual horn growth and assessed its effect on dominance and reproduction. No evidence was detected for compensatory horn growth, as late-life horn growth positively depended on early-life horn growth in males. Still, individuals with longer horn segments grown during early adulthood experienced a stronger age-dependent length decline in annual horn growth during the late development. Accordingly, a divergence between individual growth potential and realized horn growth late in life has to be assumed. Residual age-specific horn length and length of early grown horn segments both positively affected dominance and reproductive success, whereas, contrary to our expectation, no significant effect of the length of horn segments grown during the late development was detected. Suspected higher somatic costs incurred by high-quality males during their late development might at least partly be responsible for this finding. Overall, our study suggests that the total length of horns and their early development in long-lived male Alpine ibex is a reliable indicator of reproductive success and that individuals may be unable to compensate for poor early-life growth performance at a later point in life.

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The failure of fetuses to achieve the ir full growth potential is known as intrauterine growth restriction (IUGR). Silde nafil citrate (SC) is a phosphodiesterase 5 (PDE 5) inhibitor, which enhances nitric oxide (NO) dependent vasodilatation, adn it may have a potential therapeutic role in the treatment of IUGR.