904 resultados para Cost of reproduction
Resumo:
Includes bibliography
Resumo:
Objective: To determine the nervous activation, muscle strength, and biomechanical parameters that influence the cost of walking in older fallers and non-fallers. Methods: Maximal voluntary isokinetic torque was measured for the hip, knee and ankle of older women. Oxygen consumption was measured at rest and during 8 min of walking at self-selected speed. An additional minute of walking was performed to collect kinematic variables and the electromyographic signal of trunk, hip, knee, and ankle muscles, which was analyzed by the linear envelope. Cost of walking was calculated by subtracting resting body mass-normalized oxygen consumption from walking body mass-normalized oxygen consumption. Stride time and length, and ankle and hip range of motion were calculated from kinematic data. Findings: Older adult fallers had 28% lower knee extensor strength (p = 0.02), 47% lower internal oblique activation at heel contact (p = 0.03), and higher coactivation between tibialis anterior and gastrocnemius lateralis in each of the gait phases (p < 0.05). For fallers, a higher activation of gluteus maximus was associated with a higher cost of walking (r = 0.55, p < 0.05 and r = 0.71, p < 0.01, before and after heel contact, respectively). For non-fallers, an association between cost of walking and age (r = 0.60, p = 0.01) and cost of walking and thigh muscle coactivation (r = 0.53, p = 0.01) existed. Interpretation: This study demonstrated that there may be links between lower-extremity muscle weakness, muscle activation patterns, altered gait, and increased cost of walking in older fallers. © 2013 Elsevier Ltd. All rights reserved.
Resumo:
Includes bibliography
Resumo:
Includes bibliography
Resumo:
Phenotypic data from female Canchim beef cattle were used to obtain estimates of genetic parameters for reproduction and growth traits using a linear animal mixed model. In addition, relationships among animal estimated breeding values (EBVs) for these traits were explored using principal component analysis. The traits studied in female Canchim cattle were age at first calving (AFC), age at second calving (ASC), calving interval (CI), and bodyweight at 420 days of age (BW420). The heritability estimates for AFC, ASC, CI and BW420 were 0.03±0.01, 0.07±0.01, 0.06±0.02, and 0.24±0.02, respectively. The genetic correlations for AFC with ASC, AFC with CI, AFC with BW420, ASC with CI, ASC with BW420, and CI with BW420 were 0.87±0.07, 0.23±0.02, -0.15±0.01, 0.67±0.13, -0.07±0.13, and 0.02±0.14, respectively. Standardised EBVs for AFC, ASC and CI exhibited a high association with the first principal component, whereas the standardised EBV for BW420 was closely associated with the second principal component. The heritability estimates for AFC, ASC and CI suggest that these traits would respond slowly to selection. However, selection response could be enhanced by constructing selection indices based on the principal components. © CSIRO 2013.
Resumo:
Incluye Bibliografía
Resumo:
1) International Trade and Transport Profiles of Latin American Countries, by Jan Hoffmann, Gabriel Pérez, and Gordon Wilmsmeier, ECLAC, Serie 19 Manuales www.eclac.cl/transporte/perfil/bti.asp;2) Globalization - the Maritime Nexus, by Jan Hoffmann and Shashi Kumar, in Handbook of Maritime Economics, London, LLP, due to be published in October 2002; and3) Port Efficiency and International Trade, by Ricardo J. Sánchez, Jan Hoffmann, Alejandro Micco, Georgina Pizzolitto, Martín Sgut, and Gordon Wilmsmeier, to be submitted at the "IAME Panama 2002" Conference, November 2002.
Resumo:
This issue of the FAL Bulletin examines the implications of road safety for the health-care system. It focuses on the economic cost of treating and rehabilitating road traffic injury victims and, for the sake of better public policy, proposes policy changes aimed at improving data collection as well as coordination among government agencies.
Resumo:
The Economic Commission for Latin America and the Caribbean (ECLAC) jointly with the World Program of Food (WFP) and recognized experts of the region developed a methodology that, using secondary information, estimate the opportunity cost derived from undernutrition. This methodology has been successfully applied in Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, Panama and the Dominican Republic, where the cost of undernutrition was estimated at 6.7 billion dollars in 2004. The present study covers four countries in South America: Bolivia, Ecuador, Paraguay and Peru. The results indicate that the cost of the malnutrition in these countries reached 4.3 billion dollars in 2005, which is equivalent to 3.3 per cent of the GDP of these countries. The results strongly point out that child undernutrition is not only a problem of health or an unacceptable situation ethically, but it is a national problem, given the enormous social costs and the loss of opportunities that it imposes on the national economy.
Resumo:
This document presents the results derived from the analyses of the cost of undernutrition in Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, Panama and the Dominican Republic. The study shows that not only are the effects reported valid for the countries of Central America and the Dominican Republic, but the resultant economic impact is also significant, representing between 1.7% and 11.4% of GDP. In this regard, productivity losses as a consequence of the higher death rate and the lower level of education account for 90% of the costs. Thus, in addition to the ethical imperative, eradicating undernutrition would yield benefits as well. Therefore, any programme that is effective in reducing the prevalence of this problem will have an impact on people's quality of life, and will also represent major savings for society. The greater the problem, the greater the challenge, but the greater the benefits as well, especially in terms of countries' production capacity.
Resumo:
Energetic cost of digging behavior in workers of the leaf-cutting ant Atta sexdens (Fabricius). During nest excavation, leaf-cutting ant workers undergo reduction in their body reserve, particularly carbohydrates. In order to estimate the energetic cost of digging, groups of 30 workers of the leaf-cutting ant Atta sexdens were sealed in a hermetic chamber for 24, 48 and 72 hours, with and without soil for digging, and had the CO2 concentration measured using respirometric chambers as well as volume of soil excavated (g). As expected, the worker groups that carried out soil excavation expelled more carbon dioxide than the groups that did not excavate. Therefore, a worker with body mass of 9.65 ± 1.50 mg dug in average 0.85 ± 0.27 g of soil for 24 hours, consuming ca. 0.58 ± 0.23 J. In this study, we calculate that the energetic cost of excavation per worker per day in the experimental set-up was ca. 0.58 J.