14,981 research outputs found
Overcoming child malnutrition in developing countries
In 1995, 167 million children under five years old—almost one-third of developing-country children—were malnourished. Malnutrition causes a great deal of human suffering, and it is a violation of a child's human rights. It is associated with more than half of all deaths of children worldwide. People who survive a malnourished childhood are less physically and intellectually productive and suffer from more chronic illness and disability. The costs to society are enormous. Eradicating malnutrition remains a tremendous public policy challenge. Which types of interventions will have the greatest impact in reducing child malnutrition? The study on which this brief is based uses national data for 63 countries over 1970–96 to explore this question. Smith and Hadded examine the determinants of child nutritional status and discuss reductions in child malnutrition during 1970–95. they forecast the status of child malnutrition to the year 2020 and sugest priorities for the future.Malnutrition in children Developing countries History. ,Malnutrition in children Developing countries Forecasting. ,
Explaining child malnutrition in developing countries: a cross-country analysis
"One in three pre-school children in the developing world is undernourished. As a consequence, their human rights are violated. In addition, they are more likely to have impaired immune systems, poorer cognitive development, lower productivity as adults, and greater susceptibility to diet-related chronic diseases such as hypertension and coronary heart disease later in life. Undernourished female preschoolers are likely to grow into undernourished young women who are more likely to give birth to babies who are undernourished even before they are born, thus perpetuating the inter-generational transmission of deprivation. Reducing these unacceptably high numbers remains a tremendous challenge to public policy. As a guide to the direction of future efforts, this research report examines the success of the efforts of the past 25 years to reduce preschooler undernutrition. The report uses an econometric model to identify the factors associated with the reduction in undernutrition. The formulation of the econometric model is guided by the widely accepted food-care-health conceptual model of child growth. The contributions of both underlying and basic determinants to reductions in undernutrition are assessed using the model. The potential of these factors to further reduce undernutrition is evaluated in a region-by-region priority-setting exercise. In addition, projections of child nutrition are made under various scenarios to the year 2020. What will it take to dramatically reduce undernutrition in the next 20 years? The report attempts some broad answers to these questions..." (Forward by Per Pinstrup-Andersen)Malnutrition in children Developing countries., Malnutrition in children Developing countries Prevention., Developing countries., Econometric models., Gender, Health and nutrition,
Explaining child malnutrition in developing countries
"One in three pre school children in the developing world is undernourished. As a consequence, their human rights are violated. In addition, they are more likely to have impaired immune systems, poorer cognitive development, lower productivity as adults, and greater susceptibility to diet-related chronic diseases such as hypertension and coronary heart disease later in life. Undernourished female preschoolers are likely to grow into undernourished young women who are more likely to give birth to babies who are undernourished even before they are born, thus perpetuating the inter-generational transmission of deprivation. Reducing these unacceptably high numbers remains a tremendous challenge to public policy. As a guide to the direction of future efforts, this research report examines the success of the efforts of the past 25 years to reduce preschooler undernutrition. The report uses an econometric model to identify the factors associated with the reduction in undernutrition. The formulation of the econometric model is guided by the widely accepted food-care-health conceptual model of child growth. The contributions of both underlying and basic determinants to reductions in undernutrition are assessed using the model. The potential of these factors to further reduce undernutrition is evaluated in a region-by-region priority-setting exercise. In addition, projections of child nutrition are made under various scenarios to the year 2020. What will it take to dramatically reduce undernutrition in the next 20 years? The report attempts some broad answers to these questions..." (Forward by Per Pinstrup-Andersen)Gender ,Malnutrition in children Developing countries Prevention ,Nutrition ,
Overcoming child malnutrition in developing countries: past achievements and future choices
"About 167 million children under five years of age —almost one-third of the developing world's children —are malnourished. If they survive childhood, many of these children will suffer from poorer cognitive development and lower productivity. As adults, their ability to assure good nutrition for their children could be compromised, perpetuating a vicious cycle. What will it take to eradicate child malnutrition in developing countries? As Lisa Smith and Lawrence Haddad point out in this 2020 Vision discussion paper, Overcoming Child Malnutrition in Developing Countries: Past Achievements and Future Choices, we must first understand the causes of malnutrition and delineate which are the most important before we can identify and act upon those areas of intervention that will be most successful in reducing malnutrition. Toward that end, their path-breaking research identifies and assesses the contribution of each key determinant to reductions in child malnutrition over the past quarter century. The most startling and important finding is that improvements in women's education have contributed by far the most, accounting for 43 percent of the reduction in child malnutrition between 1970 and 1995, while improvements in per capita food availability con tributed about 26 percent. In a signal service to policymakers, Smith and Haddad also evaluate the potential of these factors to further reduce malnutrition durng the next two decades to 2020 and lay out the key policy priorities for each major developing region. By shedding light on which areas of intervention will be most successful in overcoming child malnutrition in developing countries, this research will contribute to realizing the 2020 Vision of a world where hunger and malnutrition are absent." (Forward by Per Pinstrup-Andersen)Malnutrition in children Developing countries History., Malnutrition in children Developing countries Forecasting., Gender, Health and nutrition,
Transit-time devices as local oscillators for frequencies above 100 GHz
Very promising preliminary experimental results have been obtained from GaAs IMPATT diodes at F-band frequencies (75 mW, 3.5 percent at 111.1 GHz and 20 mW, 1.4 percent at 120.6 GHz) and from GaAs TUNNETT diodes at W-band frequencies (26 mW, 1.6 percent at 87.2 GHz and 32 mW, 2.6 percent at 93.5 GHz). These results indicate that IMPATT, MITATT and TUNNETT diodes have the highest potential of delivering significant amounts of power at Terahertz frequencies. As shown recently, the noise performance of GaAs W-band IMPATT diodes can compete with that of Gunn devices. Since TUNNETT diodes take advantage of the quieter tunnel injection, they are expected to be especially suited for low-noise local oscillators. This paper will focus on the two different design principles for IMPATT and TUNNETT diodes, the material parameters involved in the design and some aspects of the present device technology. Single-drift flat-profile GaAs D-band IMPATT diodes had oscillations up to 129 GHz with 9 mW, 0.9 percent at 128.4 GHz. Single-drift GaAs TUNNETT diodes had oscillations up to 112.5 GHz with 16 mW and output power levels up to 33 mW and efficiencies up to 3.4 percent around 102 GHz. These results are the best reported so far from GaAs IMPATT and TUNNETT diodes
Flow field over the wing of a delta-wing fighter model with vortex control devices at Mach 0.6 to 1.2
As part of a cooperative research program between NASA, McDonnell Douglas Corporation, and Wright Research and Development Center, a flow field investigation was conducted on a 7.52 percent scale windtunnel model of an advanced fighter aircraft design. The investigation was conducted in the Langley 16 ft Transonic Tunnel at Mach numbers of 0.6, 0.9, and 1.2. Angle of attack was varied from -4 degrees to 30 degrees and the model was tested at angles of sideslip of 0, 5, and -5 degrees. Data for the over the wing flow field were obtained at four axial survey stations by the use of six 5 hole conical probes mounted on a survey mechanism. The wing leading edge primary vortex exerted the greatest influence in terms of total pressure loss on the over the wing flow field in the area surveyed. A number of vortex control devices were also investigated. They included two different apex flaps, wing leading edge vortex flaps, and small large wing fences. The vortex flap and both apex flaps were beneficial in controlling the wing leading edge primary vortex
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Development of a Virtual Laparoscopic Trainer using Accelerometer Augmented Tools to Assess Performance in Surgical training
Previous research suggests that virtual reality (VR) may supplement conventional training in laparoscopy. It may prove useful in the selection of surgical trainees in terms of their dexterity and spatial awareness skills in the near future. Current VR training solutions provide levels of realism and in some instances, haptic feedback, but they are cumbersome by being tethered and not ergonomically close to the actual surgical instruments for weight and freedom of use factors. In addition, they are expensive hence making them less accessible to departments than conventional box trainers. The box trainers in comparison, although more economical, lack tangible feedback and realism for handling delicate tissue structures. We have previously reported on the development of a modified digitally enhanced surgical instrument for laparoscopic training, named the Parkar Tool. This tool contains wireless accelerometer and gyroscopic sensors integrated into actual laparoscopic instruments. By design, it alleviates the need for both tethered and physically different shaped tools thereby enhancing the realism when performing surgical procedures. Additionally the software (Valhalla) has the ability to digitally record surgical motions, thereby enabling it to remotely capture surgical training data to analyse and objectively evaluate performance. We have adapted and further developed our initial single training tool method as used with a laparoscopic pyloromyotomy scenario, to an enhanced method using multiple Parkar wireless tools simultaneously, for use in several different case scenarios. This allows the use and measurement of right and left handed dexterity with the benefit of using several tasks of differing complexity. The development of a 3D tissue-surface deformations solution written in OpenGL gives us several different virtual surgical training scenario approximations to use with the instruments. The trainee can start with learning simple tasks e.g. incising tissue, grasping, squeezing and stretching tissue, to more complex procedures such as suturing, herniotomies, bowel anastomoses, as well as the original pyloromyotomy as used in the first model
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