7,894 research outputs found

    Extended early childhood intervention and school achievement: Age 13 findings from the Chicago longitudinal study

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    We evaluated the effects of participation in an extended program of compensatory education for a large sample of inner-city black children up to the seventh grade. The intervention is the Chicago Child-Parent Center and Expansion Program. Groups included 426 children who participated in the program from preschool to grades 2 or 3 and 133 school-stable children whose participation ceased in kindergarten. After taking into account initial differences in both the level and the growth rate of achievement, frequency of school mobility after the program, and sample selection bias, program participation for two or three years after preschool and kindergarten is positively associated with reading and math achievement in grade 7 and negatively associated with cumulative grade retention four years after the end of the program. Study findings provide rare longitudinal evidence from an established program concerning the effects of extending compensatory education into the primary grades.

    Statistical classification techniques for engineering and climatic data samples

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    Fisher's sample linear discriminant function is modified through an appropriate alteration of the common sample variance-covariance matrix. The alteration consists of adding nonnegative values to the eigenvalues of the sample variance covariance matrix. The desired results of this modification is to increase the number of correct classifications by the new linear discriminant function over Fisher's function. This study is limited to the two-group discriminant problem

    Diffraction coefficients for flat-bottomed holes from 3-D finite difference calculations

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    Conventional pulse-echo ultrasonic inspection uses the ratio of the signal from a crack-like defect to the signal from a reference reflector as one factor which determines whether the flaw merits reporting, further sizing, and, possibly, removal. Two reference reflectors are in common use: a side-drilled hole and a flat-bottomed hole

    Dependence of the SWR Linewidth on the Wavevector in Amorphous Thin Films

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    Work supported in part by the Central Research Project 01.08.B.Zadanie pt. „Digitalizacja i udostępnienie w Cyfrowym Repozytorium Uniwersytetu Łódzkiego kolekcji czasopism naukowych wydawanych przez Uniwersytet Łódzki” nr 885/P-DUN/2014 zostało dofinansowane ze środków MNiSW w ramach działalności upowszechniającej naukę

    Fruit, vegetables, and cancer prevention trials

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    Antioxidants and disease: more questions than answers

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    Reactive oxygen species are widely believed to be involved in the etiology of many diseases as indicated by the signs of oxidative stress seen in those diseases. Conversely, antioxidants are believed to be protective. An important part of the supporting evidence is the consistently-seen inverse association between, on the one hand, intake of B-carotene and vitamin C and of fruit and vegetables, and, on the other hand, risk of cancer and coronary heart disease (CHD). However, the failure of supplemental p-carotene to prevent these diseases in intervention trials suggests that the associations for that nutrient reflect confounding rather than cause and effect. With respect to other antioxidants there is inconsistent evidence that supplements of vitamin E may have some ability to prevent cancer and CHD while selenium may prevent cancer. Overall, the role of oxidative stress in disease, especially cancer and CHD, has probably been overstated; other components of the diet (other nutrients, phytochemicals and dietary fiber) likely play a significantly greater role The possible benefits of supplements are discussed

    Food Adverts on Children's Programs on TV in South Africa

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    I attended the conference from April 5 to 9. This conference was very valuable for my work for several reasons: I presented my poster, which was viewed by many people, I had a meeting with the series editor of Humana (one of my publishers) and several authors, I had valuable meetings with many people.Research in the U.S.A. since the early 1990s has shown that adverts that appear on children’s programs on TV are the antithesis of the recommended diet. They are mainly for fast foods and for foods rich in sugar and fat. There is almost no promotion of healthy food choices. Essentially all such previous research has been conducted in developed countries. In this study we examined food advertising on children’s TV in South Africa. We recorded 2 sets of children’s programs during weekdays: (1) 12 hours of programs (SABC2; 9 am-11 am); these are for children below school age, are mainly in English and Africaan, plus a small amount in Xhosa. Out of 47 ads none were for food. (2) 37.5 hours of programs were recorded on YoTV (SABC1; 3 pm-530 pm). This program is for children aged over approximately 7 years. It is mainly in English plus a small amount in Zulu. Out of 408 ads 69 (16.9%) were for food. Virtually all (97%) of the food ads fall into 2 groups: (1) 38 ads (55%) were for foods of generally poor nutritional value (fast food restaurants, highly refined breakfast cereals, candies, potato chips, and sugar-rich cold drinks); (2) 29 ads (42%) were for foods of generally good nutritional value (yoghurt and peanut butter). These findings suggest that food ads on children’s TV in South Africa is more evenly balance towards healthier foods than is the case in the U.S.A. Further investigation is required to form a clearer picture.Academic & Professional Development Fund (A&PDF

    International Survey Data

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    Dietary fats and coronary heart disease.

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    The prevention and treatment of coronary heart disease (CHD) necessitates vigorous dietary intervention so as 10 lower the serum cho1eslero11evel by at least 6%. Greater decreases in serum cholesterol can bring about reversal of atherosclerosis. The critical dietary change is the reduction in intake of saturated fat and cholesterol. Some of this fat may be replaced by unsaturated fats, especial1y monounsaturated fat (olive or canola oil). Fish and the omega-3 fats they contain may also be useful for the prevention of CHD. The benefits of omega-3 fats occur within a few months and probably involve an anti-thrombotic effect. There is evidence that the intake of rrans-fatty acids formed by the hydrogenation of oils should be reduced as they are associated with CHD. Hypolipidaemic drugs may be useful for persons at very high risk of CHD but should general1y be avoided for primary prevention
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